TY - JOUR TI - Gravity and light: integrating transcriptional regulation in roots. AU - Salinas-Mondragon, R. AU - Brogan, A. AU - Ward, N. AU - Perera, I. AU - Boss, W. AU - Brown, C.S. AU - Sederoff, H.W. T2 - Gravitational and space biology bulletin : publication of the American Society for Gravitational and Space Biology DA - 2005/// PY - 2005/// VL - 18 IS - 2 SP - 121-122 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-24944540197&partnerID=MN8TOARS ER - TY - JOUR TI - Co-expression and hormonal regulation of genes in response to gravity and mechanical stimulation in the Arabidopsis root apex. AU - Kimbrough, J.M. AU - Brown, C.S. AU - Sederoff, H.W. T2 - Gravitational and space biology bulletin : publication of the American Society for Gravitational and Space Biology DA - 2005/// PY - 2005/// VL - 18 IS - 2 SP - 117-118 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-26944462406&partnerID=MN8TOARS ER - TY - JOUR TI - Phytochrome-Specific Type 5 Phosphatase Controls Light Signal Flux by Enhancing Phytochrome Stability and Affinity for a Signal Transducer AU - Ryu, Jong Sang AU - Kim, Jeong-Il AU - Kunkel, Tim AU - Kim, Byung Chul AU - Cho, Dae Shik AU - Hong, Sung Hyun AU - Kim, Seong-Hee AU - Fernández, Aurora Piñas AU - Kim, Yumi AU - Alonso, Jose M. AU - Ecker, Joseph R. AU - Nagy, Ferenc AU - Lim, Pyung Ok AU - Song, Pill-Soon AU - Schäfer, Eberhard AU - Nam, Hong Gil T2 - Cell AB - Environmental light information such as quality, intensity, and duration in red (approximately 660 nm) and far-red (approximately 730 nm) wavelengths is perceived by phytochrome photoreceptors in plants, critically influencing almost all developmental strategies from germination to flowering. Phytochromes interconvert between red light-absorbing Pr and biologically functional far-red light-absorbing Pfr forms. To ensure optimal photoresponses in plants, the flux of light signal from Pfr-phytochromes should be tightly controlled. Phytochromes are phosphorylated at specific serine residues. We found that a type 5 protein phosphatase (PAPP5) specifically dephosphorylates biologically active Pfr-phytochromes and enhances phytochrome-mediated photoresponses. Depending on the specific serine residues dephosphorylated by PAPP5, phytochrome stability and affinity for a downstream signal transducer, NDPK2, were enhanced. Thus, phytochrome photoreceptors have developed an elaborate biochemical tuning mechanism for modulating the flux of light signal, employing variable phosphorylation states controlled by phosphorylation and PAPP5-mediated dephosphorylation as a mean to control phytochrome stability and affinity for downstream transducers. DA - 2005/2// PY - 2005/2// DO - 10.1016/j.cell.2004.12.019 VL - 120 IS - 3 SP - 395-406 J2 - Cell LA - en OP - SN - 0092-8674 UR - http://dx.doi.org/10.1016/j.cell.2004.12.019 DB - Crossref ER - TY - JOUR TI - Proanthocyanidin biosynthesis – still more questions than answers? AU - Xie, De-Yu AU - Dixon, Richard A. T2 - Phytochemistry AB - Proanthocyanidins, also known as condensed tannins, are oligomers or polymers of flavan-3-ol units. In spite of important breakthroughs in our understanding of the biosynthesis of the major building blocks of proanthocyanidins, (+)-catechin and (-)-epicatechin, important questions still remain to be answered as to the exact nature of the molecular species that undergo polymerization, and the mechanisms of assembly. We review the structures of proanthocyanidins reported over the past 12 years in the context of biosynthesis, and summarize the outstanding questions concerning synthesis of proanthocyanidins from the chemical, biochemical and molecular genetic perspectives. DA - 2005/9// PY - 2005/9// DO - 10.1016/j.phytochem.2005.01.008 VL - 66 IS - 18 SP - 2127-2144 J2 - Phytochemistry LA - en OP - SN - 0031-9422 UR - http://dx.doi.org/10.1016/j.phytochem.2005.01.008 DB - Crossref KW - proanthocyanidins KW - tannins KW - flavan-3-ols KW - catechin KW - epicatechin KW - anthocyanidin reductase ER - TY - JOUR TI - Ethylene signalling and response pathway: A unique signalling cascade with a multitude of inputs and outputs AU - Stepanova, A.N. AU - Alonso, J.M. T2 - Physiologia Plantarum AB - Plants as immobile organisms need to constantly monitor the changes in the environment to modify and adjust developmental and metabolic pathways accordingly. The responses to these environmental cues require an integrative mechanism where external and internal signals are detected and processed to trigger an appropriate ‘reaction’ in the plant. Hormones play a key role in mediating some of these integrative processes and in generating the response reactions. The identification and characterization of the basic hormone signalling components and their interactions represent the first step towards comprehensive understanding of plant responses to intrinsic and extrinsic cues. A relatively well‐characterized ethylene signalling and response pathway, together with numerous evidences of its interactions with other signalling/response pathways, provide an excellent example to illustrate our current knowledge and perspective on how signal integration occurs in plants. DA - 2005/// PY - 2005/// DO - 10.1111/j.1399-3054.2005.00447.x VL - 123 IS - 2 SP - 195-206 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-14644388900&partnerID=MN8TOARS ER - TY - JOUR TI - Ethylene signaling pathway. AU - Stepanova, A.N. AU - Alonso, J.M. T2 - Science's STKE : signal transduction knowledge environment DA - 2005/// PY - 2005/// VL - 2005 IS - 276 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33644877967&partnerID=MN8TOARS ER - TY - JOUR TI - Arabidopsis ethylene signaling pathway. AU - Stepanova, A.N. AU - Alonso, J.M. T2 - Science's STKE : signal transduction knowledge environment DA - 2005/// PY - 2005/// VL - 2005 IS - 276 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-33644876995&partnerID=MN8TOARS ER - TY - JOUR TI - Phytochrome-specific type 5 phosphatase controls light signal flux by enhancing phytochrome stability and affinity for a signal transducer AU - Ryu, Jong Sang AU - Kim, Jeong-Il AU - Kunkel, Tim AU - Kim, Byung Chul AU - Cho, Dae Shik AU - Hong, Sung Hyun AU - Kim, Seong-Hee AU - Fernández, Aurora Piñas AU - Kim, Yumi AU - Alonso, Jose M. T2 - Cell DA - 2005/// PY - 2005/// VL - 120 IS - 3 SP - 395-406 ER - TY - JOUR TI - NPH4/ARF7 and ARF19 promote leaf expansion and auxin‐induced lateral root formation AU - Wilmoth, Jill C. AU - Wang, Shucai AU - Tiwari, Shiv B. AU - Joshi, Atul D. AU - Hagen, Gretchen AU - Guilfoyle, Thomas J. AU - Alonso, Jose M. AU - Ecker, Joseph R. AU - Reed, Jason W. T2 - The Plant Journal DA - 2005/// PY - 2005/// VL - 43 IS - 1 SP - 118-130 ER - TY - JOUR TI - Multiple type-B response regulators mediate cytokinin signal transduction in Arabidopsis AU - Mason, Michael G. AU - Mathews, Dennis E. AU - Argyros, D. Aaron AU - Maxwell, Bridey B. AU - Kieber, Joseph J. AU - Alonso, Jose M. AU - Ecker, Joseph R. AU - Schaller, G. Eric T2 - The Plant Cell Online DA - 2005/// PY - 2005/// VL - 17 IS - 11 SP - 3007-3018 ER - TY - JOUR TI - Functional genomic analysis of the AUXIN/INDOLE-3-ACETIC ACID gene family members in Arabidopsis thaliana AU - Overvoorde, Paul J. AU - Okushima, Yoko AU - Alonso, José M. AU - Chan, April AU - Chang, Charlie AU - Ecker, Joseph R. AU - Hughes, Beth AU - Liu, Amy AU - Onodera, Courtney AU - Quach, Hong T2 - The Plant Cell Online DA - 2005/// PY - 2005/// VL - 17 IS - 12 SP - 3282-3300 ER - TY - JOUR TI - Functional genomic analysis of the AUXIN RESPONSE FACTOR gene family members in Arabidopsis thaliana: unique and overlapping functions of ARF7 and ARF19 AU - Okushima, Yoko AU - Overvoorde, Paul J. AU - Arima, Kazunari AU - Alonso, Jose M. AU - Chan, April AU - Chang, Charlie AU - Ecker, Joseph R. AU - Hughes, Beth AU - Lui, Amy AU - Nguyen, Diana T2 - The Plant Cell Online DA - 2005/// PY - 2005/// VL - 17 IS - 2 SP - 444-463 ER - TY - JOUR TI - Class III homeodomain-leucine zipper gene family members have overlapping, antagonistic, and distinct roles in Arabidopsis development AU - Prigge, Michael J. AU - Otsuga, Denichiro AU - Alonso, Jose M. AU - Ecker, Joseph R. AU - Drews, Gary N. AU - Clark, Steven E. T2 - The Plant Cell Online DA - 2005/// PY - 2005/// VL - 17 IS - 1 SP - 61-76 ER - TY - JOUR TI - Auxin response factors ARF6 and ARF8 promote jasmonic acid production and flower maturation AU - Nagpal, Punita AU - Ellis, Christine M. AU - Weber, Hans AU - Ploense, Sara E. AU - Barkawi, Lana S. AU - Guilfoyle, Thomas J. AU - Hagen, Gretchen AU - Alonso, José M. AU - Cohen, Jerry D. AU - Farmer, Edward E. T2 - Development DA - 2005/// PY - 2005/// VL - 132 IS - 18 SP - 4107-4118 ER - TY - JOUR TI - Arabidopsis ethylene signaling pathway AU - Stepanova, Anna N. AU - Alonso, Jose M. T2 - Science Signaling DA - 2005/// PY - 2005/// VL - 2005 IS - 276 SP - cm4 ER - TY - JOUR TI - " Flagellin is not a major defense elicitor in Ralstonia solanacearum cells (vol 17, pg 696, 2005) AU - Pfund, C. AU - Tans-Kersten, J. AU - Dunning, F. M. AU - Alonso, J. M. AU - Ecker, J. R. AU - Allen, C. AU - Bent, A. F. T2 - MOLECULAR PLANT-MICROBE INTERACTIONS DA - 2005/// PY - 2005/// VL - 18 IS - 9 SP - 1024 ER - TY - JOUR TI - Plant invasion alters nitrogen cycling by modifying the soil nitrifying community AU - Hawkes, Christine V. AU - Wren, Ian F. AU - Herman, Donald J. AU - Firestone, Mary K. T2 - Ecol Letters AB - Abstract Plant invasions have dramatic aboveground effects on plant community composition, but their belowground effects remain largely uncharacterized. Soil microorganisms directly interact with plants and mediate many nutrient transformations in soil. We hypothesized that belowground changes to the soil microbial community provide a mechanistic link between exotic plant invasion and changes to ecosystem nutrient cycling. To examine this possible link, monocultures and mixtures of exotic and native species were maintained for 4 years in a California grassland. Gross rates of nitrogen (N) mineralization and nitrification were quantified with 15 N pool dilution and soil microbial communities were characterized with DNA‐based methods. Exotic grasses doubled gross nitrification rates, in part by increasing the abundance and changing the composition of ammonia‐oxidizing bacteria in soil. These changes may translate into altered ecosystem N budgets after invasion. Altered soil microbial communities and their resulting effects on ecosystem processes may be an invisible legacy of exotic plant invasions. DA - 2005/9// PY - 2005/9// DO - 10.1111/j.1461-0248.2005.00802.x VL - 8 IS - 9 SP - 976-985 KW - ammonia-oxidizing bacteria KW - annual grass invasion KW - Avena barbata KW - Bromus hordeaceus KW - gross mineralization KW - gross nitrification KW - Lupinus bicolor KW - Nassella pulchra ER - TY - JOUR TI - BIOLOGY OF CHROMATIN DYNAMICS AU - Hsieh, Tzung-Fu AU - Fischer, Robert L. T2 - Annual Review of Plant Biology AB - During the development of a multicellular organism, cell differentiation involves activation and repression of transcription programs that must be stably maintained during subsequent cell divisions. Chromatin remodeling plays a crucial role in regulating chromatin states that conserve transcription programs and provide a mechanism for chromatin states to be maintained as cells proliferate, a process referred to as epigenetic inheritance. A large number of factors and protein complexes are now known to be involved in regulating the dynamic states of chromatin structure. Their biological functions and molecular mechanisms are beginning to be revealed. DA - 2005/6// PY - 2005/6// DO - 10.1146/annurev.arplant.56.032604.144118 VL - 56 IS - 1 SP - 327-351 J2 - Annu. Rev. Plant Biol. LA - en OP - SN - 1543-5008 1545-2123 UR - http://dx.doi.org/10.1146/annurev.arplant.56.032604.144118 DB - Crossref KW - chromatin remodeling KW - epigenetic inheritance KW - histone modification KW - DNA methylation KW - RNA interference ER - TY - JOUR TI - Monitoring stress-related genes during the process of biomass propagation of Saccharomyces cerevisiae strains used for wine making. AU - Pérez-Torrado, R. AU - Bruno-Bárcena, J.M. AU - Matallana, E. T2 - Applied and Environmental Microbiology AB - ABSTRACT Physiological capabilities and fermentation performance of Saccharomyces cerevisiae strains to be employed during industrial wine fermentations are critical for the quality of the final product. During the process of biomass propagation, yeast cells are dynamically exposed to a mixed and interrelated group of known stresses such as osmotic, oxidative, thermic, and/or starvation. These stressing conditions can dramatically affect the parameters of the fermentation process and the technological abilities of the yeast, e.g., the biomass yield and its fermentative capacity. Although a good knowledge exists of the behavior of S. cerevisiae under laboratory conditions, insufficient knowledge is available about yeast stress responses under the specific media and growth conditions during industrial processes. We performed growth experiments using bench-top fermentors and employed a molecular marker approach (changes in expression levels of five stress-related genes) to investigate how the cells respond to environmental changes during the process of yeast biomass production. The data show that in addition to the general stress response pathway, using the HSP12 gene as a marker, other specific stress response pathways were induced, as indicated by the changes detected in the mRNA levels of two stress-related genes, GPD1 and TRX2 . These results suggest that the cells were affected by osmotic and oxidative stresses, demonstrating that these are the major causes of the stress response throughout the process of wine yeast biomass production. DA - 2005/11// PY - 2005/11// DO - 10.1128/aem.71.11.6831-6837.2005 VL - 11 IS - 11 SP - 6831-6837 UR - http://europepmc.org/abstract/med/16269716 ER - TY - ENCYC TI - Cornales AU - Xiang, Q.-Y. T2 - Encyclopedia of Life Sciences DA - 2005/5// PY - 2005/5// DO - 10.1002/9780470015902 PB - John Wiley & Sons, Ltd. ER - TY - CHAP TI - Cornaceae, Mastixiaceae, Toricelliaceae, Helwingiacaee, Aucubaceae AU - Xiang, Q.-Y. AU - Boufford, D.E. T2 - Flora of China A2 - Wu, Z.Y. A2 - Raven, P.H. PY - 2005/// VL - 14 SP - 206-234 PB - Science Press, Beijing, and Missouri botanical Garden Press, St. Louis ER - TY - JOUR TI - High Throughput and High Content Screening Using Peptides AU - Hamilton, Paul AU - Carlson, Robert AU - Hyde-Deruyscher, Robin T2 - Phage Display In Biotechnology and Drug Discovery DA - 2005/7// PY - 2005/7// DO - 10.1201/9780849359125.ch9 SP - 347-384 ER - TY - JOUR TI - The power of chemical genomics to study the link between endomembrane system components and the gravitropic response AU - Surpin, M. AU - Rojas-Pierce, M. AU - Carter, C. AU - Hicks, G.R. AU - Vasquez, J. AU - Raikhel, N.V. T2 - Proceedings of the National Academy of Sciences of the United States of America AB - Chemical genomics is a powerful approach to dissect processes that may be intractable using conventional genetics because of gene lethality or redundancy. Recently, a link has been established between endomembrane trafficking and gravitropism. To understand this link, we screened a library of 10,000 diverse chemicals for compounds that affected the gravitropism of Arabidopsis seedlings positively or negatively. Sixty-nine of 219 compounds from the primary screen were retested, and 34 of these were confirmed to inhibit or enhance gravitropism. Four of the 34 compounds were found to cause aberrant endomembrane morphologies. The chemicals affected gravitropism and vacuole morphology in concert in a tissue-specific manner, underscoring the link between endomembranes and gravitropism. One of the chemicals (5403629) was structurally similar to the synthetic auxin 2,4-dichlorophenoxy acetate, whereas the other three chemicals were unique in their structures. An in vivo functional assay using the reporter beta-glucuronidase under the auxin-inducible DR5 promoter confirmed that the unique compounds were not auxins. Interestingly, one of the unique chemicals (5850247) appeared to decrease the responsiveness to auxin in roots, whereas another (5271050) was similar to pyocyanin, a bacterial metabolite that has been suggested to target the endomembranes of yeast. These reagents will be valuable for dissecting endomembrane trafficking and gravitropism and for cognate target identification. DA - 2005/// PY - 2005/// DO - 10.1073/pnas.0500222102 VL - 102 IS - 13 SP - 4902-4907 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-16344363588&partnerID=MN8TOARS KW - chemicals KW - GFP KW - gravitropism KW - trafficking KW - vacuoles ER - TY - JOUR TI - Taxonomy of the Gonolobus complex (Apocynaceae - Asclepiadoideae) in the southeastern US: ISSR evidence and parsimony analysis AU - Krings, A. AU - Xiang, Qiu-Yun T2 - Harvard Papers in Botany AB - In a recent morphometric analysis of the Gonolobus complex (subgenus Gonolobus) in the southeastern United States, we found former specific concepts untenable as stated, as the diagnostic characters could not consistently assign individuals to one of two groups. However, our analysis showed a strong geographical component to the distribution of individuals delimited by uniformly and multicolored corollas, which we used as a basis for suggesting that two entities do appear to exist in the Southeast that may deserve recognition at some taxonomic rank. In the present study, we performed analysis of Inter-Simple Sequence Repeats (ISSR) to assess whether the two entities are genetically differentiated and, if so, to what level. We also conducted a cladistic analysis of morphological characters of the subgenus to determine whether the entities emerge as closest relatives. Our ISSR results showed substantial genetic differentiation at 18 loci between the two entities, although no fixed differences between them were detected. At 7 loci, the frequencies of band presence are significantly higher in the multicolored corolla group (MCCG) than in the uniformly colored corolla group (UCCG). At 11 loci they are significantly higher in the UCCG. Nineteen bands are unique to the MCCG, although at various frequencies (3.5–39.0%), whereas only a single band is unique to the UCCG, suggesting that the latter possesses a subset of the MCCG gene pool and is likely a derivative of it. Analysis of 61 parsimony-informative characters using Neighbor-Joining (NJ) and Unweighted Pair-Group Method using Arithmetic means (UPGMA) did not resolve the two groups, consistent with the view of a single species. In a parsimony analysis of morphological characters of 14 species of the subgenus, the two groups consistently appear as closest relatives. This evidence indicates that the complex represents a single evolutionary lineage with two incompletely differentiated morphological subgroups. On the basis of these results, we propose to treat the MCCG and UCCG as two varieties of Gonolobus suberosus. Gonolobus granulatus Scheele is neotypified in association with the required new combination for the UCCG variety. A key to the infraspecific taxa is provided. DA - 2005/// PY - 2005/// DO - 10.3100/1043-4534(2005)10[147:totgca]2.0.co;2 VL - 10 SP - 147–159 ER - TY - JOUR TI - Ranunculus ficaria (Ranunculaceae) new to North Carolina and an updated key to Carolina congeners AU - Krings, A. AU - Weakley, A. S. AU - Neal, J. C. AU - Swab, E. C. T2 - SIDA, Contributions To Botany DA - 2005/// PY - 2005/// VL - 21 SP - 2429-2437 ER - TY - JOUR TI - New and rediscovered milkweeds from Cuba: Calotropis gigantea and Gonolobus stephanotrichus (Apocynaceae - Asclepiadoideae) AU - Krings, A. AU - Areces Berazain, F. AU - Lazcano Lara, J. C. T2 - Willdenowia AB - Krings, A., Areces Berazaín, F. & Lazcano Lara, J. C.: New and rediscovered milkweeds from Cuba: Calotropis gigantea and Gonolobus stephanotrichus (Apocynaceae: Asclepiadoideae). — Willdenowia 35: 315–318. — ISSN 0511-9618; © 2005 BGBM Berlin-Dahlem. doi:10.3372/wi.35.35213 (available via http//dx.doi.org/)Calotropis gigantea is reported new to Cuba and Gonolobus stephanotrichus is reported rediscovered after previously being known only from syntypes collected in 1860-64. Specimens are cited and keys to Cuban species of both genera are provided. DA - 2005/// PY - 2005/// DO - 10.3372/wi.35.35213 VL - 35 IS - 2 SP - 315-318 ER - TY - JOUR TI - An annotated catalogue of the Bertram Whittier Wells Big Savannah (Pender Co., North Carolina) collections in the North Carolina State University Herbarium AU - Krings, A. AU - Harris, A. J. AU - Inman, F. M. AU - Lee, E. AU - Richardson, A. R. T2 - Vulpia DA - 2005/// PY - 2005/// VL - 4 SP - 52-67 ER - TY - JOUR TI - A trichloroacetic acid-acetone method greatly reduces infrared autofluorescence of protein extracts from plant tissue AU - Shultz, RW AU - Settlage, SB AU - Hanley-Bowdoin, L AU - Thompson, WF T2 - PLANT MOLECULAR BIOLOGY REPORTER DA - 2005/12// PY - 2005/12// DO - 10.1007/BF02788888 VL - 23 IS - 4 SP - 405-409 SN - 0735-9640 KW - Arabidopsis KW - autofluorescence KW - immunoblot KW - infrared KW - Odyssey KW - plant ER - TY - JOUR TI - Typification of Ceropegia palustris Pursh and Lyonia maritima Elliott (Apocynaceae, Asclepiadoideae) AU - Krings, A. T2 - SIDA, Contributions To Botany DA - 2005/// PY - 2005/// VL - 21 SP - 1507-1513 ER - TY - JOUR TI - The flora of Nags Head Woods and the Outer Banks of North Carolina: Additions and corrections AU - Krings, A. T2 - Journal of the North Carolina Academy of Science DA - 2005/// PY - 2005/// VL - 121 SP - 111-116 ER - TY - JOUR TI - Notes on the Matelea bayatensis-correllii-tigrina complex (Apocynaceae - Asclepiadoideae - Gonolobinae) in the Greater Antilles and Bahamas AU - Krings, A. T2 - SIDA, Contributions To Botany DA - 2005/// PY - 2005/// VL - 21 SP - 1525-1533 ER - TY - JOUR TI - Lectotypification and a new combination in Matelea (Apocynaceae - Asclepiadoideae) for an endemic Hispaniolan vine AU - Krings, A. T2 - SIDA, Contributions To Botany DA - 2005/// PY - 2005/// VL - 21 SP - 2081-2085 ER - TY - JOUR TI - A new species of Matelea (Apocynaceae - Asclepiadoideae) from Hispaniola AU - Krings, A. T2 - SIDA, Contributions To Botany DA - 2005/// PY - 2005/// VL - 21 SP - 1519-1523 ER - TY - JOUR TI - A new combination in Matelea (Apocynaceae - Asclepiadoideae) for an endemic Jamaican vine AU - Krings, A. T2 - SIDA, Contributions To Botany DA - 2005/// PY - 2005/// VL - 21 SP - 1515-1517 ER - TY - JOUR TI - Specific leaf area explains differences in leaf traits between congeneric savanna and forest trees AU - Hoffmann, WA AU - Franco, AC AU - Moreira, MZ AU - Haridasan, M T2 - FUNCTIONAL ECOLOGY AB - Summary Leaf traits are commonly associated with the life history, distribution and resource requirements of a species. To improve our understanding of the ecological and physiological differences between tropical savanna and forest trees, we compared leaf traits of species native to savanna and gallery (riverine) forests in the Cerrado region of central Brazil. Congeneric species pairs from 14 different taxonomic families were studied, each with a savanna species and a forest species present at the study site. Only individuals growing in savanna conditions under full sun were studied. We measured foliar nutrients, δ 13 C, δ 15 N and specific leaf area (SLA: leaf area per unit leaf mass). We used phylogenetically independent contrasts to compare savanna and forest species and to test for correlations among species traits. Overall, leaves of forest species had 17% higher N concentration, 32% higher P concentration, and 37% higher K concentration, despite growing in similar soils. Concentrations of all three elements were strongly and positively correlated with SLA. Forest species had 52% greater SLA, on average, than savanna species, which accounts for the higher foliar nutrient concentrations of these species. Savanna species had higher δ 13 C values than forest species, indicating higher water‐use efficiency. The SLA was negatively correlated with δ 13 C, suggesting that SLA may also account for the higher water‐use efficiency of savanna species. There was no difference in foliar δ 15 N between savanna and forest species, but foliar δ 15 N was negatively correlated with soil pH. These results contribute to recent studies showing that tropical savanna and forest species represent two distinct functional types, with large differences in ecology and physiology, that have important consequences for the dynamics of savanna–forest boundaries. DA - 2005/12// PY - 2005/12// DO - 10.1111/j.1365-2435.2005.01045.x VL - 19 IS - 6 SP - 932-940 SN - 0269-8463 KW - isotopes KW - phylogenetically independent contrasts KW - specific leaf area KW - tropical forest KW - water-use efficiency ER - TY - JOUR TI - Quantitative trait loci affecting the difference in pigmentation between Drosophila yakuba and D. santomea AU - Carbone, MA AU - Llopart, A AU - DeAngelis, M AU - Coyne, JA AU - Mackay, TFC T2 - GENETICS AB - Using quantitative trait locus (QTL) mapping, we studied the genetic basis of the difference in pigmentation between two sister species of Drosophila: Drosophila yakuba, which, like other members of the D. melanogaster subgroup, shows heavy black pigmentation on the abdomen of males and females, and D. santomea, an endemic to the African island of São Tomé, which has virtually no pigmentation. Here we mapped four QTL with large effects on this interspecific difference in pigmentation: two on the X chromosome and one each on the second and third chromosomes. The same four QTL were detected in male hybrids in the backcrosses to both D. santomea and D. yakuba and in the female D. yakuba backcross hybrids. All four QTL exhibited strong epistatic interactions in male backcross hybrids, but only one pair of QTL interacted in females from the backcross to D. yabuka. All QTL from each species affected pigmentation in the same direction, consistent with adaptive evolution driven by directional natural selection. The regions delimited by the QTL included many positional candidate loci in the pigmentation pathway, including genes affecting catecholamine biosynthesis, melanization of the cuticle, and many additional pleiotropic effects. DA - 2005/9// PY - 2005/9// DO - 10.1534/genetics.105.044412 VL - 171 IS - 1 SP - 211-225 SN - 1943-2631 ER - TY - JOUR TI - Phylogeny, biogeography, and molecular dating of cornelian cherries (Cornus, Cornaceae) – tracking Tertiary plant migration AU - Xiang, Q.-Y AU - Sr, Manchester AU - Thomas, D. AU - Zhang, WH. AU - Fan, CZ T2 - Evolution AB - Data from four DNA regions (rbcL, matK, 26S rDNA, and ITS) as well as extant and fossil morphology were used to reconstruct the phylogeny and biogeographic history of an intercontinentally disjunct plant group, the cornelian cherries of Cornus (dogwoods). The study tests previous hypotheses on the relative roles of two Tertiary land bridges, the North Atlantic land bridge (NALB) and the Bering land bridge (BLB), in plant migration across continents. Three approaches, the Bayesian, nonparametric rate smoothing (NPRS), and penalized likelihood (PL) methods, were employed to estimate the times of geographic isolations of species. Dispersal and vicariance analysis (DIVA) was performed to infer the sequence and directionality of biogeographic pathways. Results of phylogenetic analyses suggest that among the six living species, C. sessilis from western North America represents the oldest lineage, followed by C. volkensii from Africa. The four Eurasian species form a clade consisting of two sister pairs, C. mas– C. officinalis and C. chinensis–C. eydeana. Results of DIVA and data from fossils and molecular dating indicate that the cornelian cherry subgroup arose in Europe as early as the Paleocene. Fossils confirm that the group was present in North America by the late Paleocene, consistent with the DIVA predictions that, by the end of the Eocene, it had diversified into several species and expanded its distribution to North America via the NALB and to Africa via the last direct connection between Eurasia and Africa prior to the Miocene, or via long-distance dispersal. The cornelian cherries in eastern Asia appear to be derived from two independent dispersal events from Europe. These events are inferred to have occurred during the Oligocene and Miocene. This study supports the hypothesis that the NALB served as an important land bridge connecting the North American and European floras, as well as connecting American and African floras via Europe during the early Tertiary. DA - 2005/// PY - 2005/// DO - 10.1554/03-763.1 VL - 59 IS - 8 SP - 139–155 ER - TY - JOUR TI - Characterization of the dinuclear metal center of Pyrococcus furiosus prolidase by analysis of targeted mutants AU - Du, XL AU - Tove, S AU - Kast-Hutcheson, K AU - Grunden, AM T2 - FEBS LETTERS AB - Prolidases are dipeptidases specific for cleavage of Xaa‐Pro dipeptides. Pyrococcus furiosus prolidase is a homodimer having one Co‐bound dinuclear metal cluster per monomer with one tightly bound Co(II) site and the other loosely bound ( K d 0.24 mM). To identify which Co site is tight‐binding and which is loose‐binding, site‐directed mutagenesis was used to modify amino acid residues that participate in binding the Co1 (E‐313 and H‐284), the Co2 site (D‐209) or the bidentate ligand (E‐327). Metal‐content, enzyme activity and CD‐spectra analyses of D209A‐, H284L‐, and E327L‐prolidase mutants show that Co1 is the tight‐binding and Co2 the loose‐binding metal center. DA - 2005/11/7/ PY - 2005/11/7/ DO - 10.1016/j.febslet.2005.09.086 VL - 579 IS - 27 SP - 6140-6146 SN - 1873-3468 KW - prolidase KW - aminopeptidase KW - dinuclear metal center KW - cobalt enzyme KW - Pyrococcus furiosus ER - TY - JOUR TI - Regulation of biosynthetic genes and antioxidant properties of vitamin B-6 vitamers during plant defense responses AU - Denslow, SA AU - Walls, AA AU - Daub, ME T2 - PHYSIOLOGICAL AND MOLECULAR PLANT PATHOLOGY AB - Vitamin B6, an essential cofactor in enzymatic reactions, has only recently been linked to cellular oxidative stress. We investigated the role of this vitamin as an antioxidant in oxidative responses linked to plant defense. B6 vitamers effectively quenched superoxide and had antioxidant activity when assayed in vitro. The de novo B6 biosynthetic genes (PDX1 and PDX2) were identified in Nicotiana tabacum cv. ‘Burley 21’ and their transcript abundance was assayed during defense responses. PDX1 and PDX2 transcript levels decreased following inoculation with the incompatible pathogen Pseudomonas syringae pv. phaseolicola and transiently increased in response to salicylic acid and methyl jasmonate. Excess vitamin B6 in tobacco leaves interfered with the development of a hypersensitive response caused by P. syringae pv. phaseolicola and increased disease severity caused by the compatible bacterium P. syringae pv. tabaci. Our findings indicate that during plant defense responses, vitamin B6 functions and its synthesis is regulated in a manner consistent with this vitamin's activity as an antioxidant and modulator of active oxygen species in vivo. DA - 2005/6// PY - 2005/6// DO - 10.1016/j.pmpp.2005.09.004 VL - 66 IS - 6 SP - 244-255 SN - 0885-5765 KW - vitamin B-6 KW - pyridoxine KW - antioxidant KW - plant defense KW - PDX1 KW - PDX2 KW - SOR1 KW - SNO KW - SNZ KW - Nicotiana tabacum cv. 'Burley 21' KW - Pseudomonas syringae pv. phaseolicola KW - Pseudomonas syringae pv. tabaci ER - TY - JOUR TI - Production of a thermostable archaeal superoxide reductase in plant cells AU - Im, YJ AU - Ji, MK AU - Lee, AM AU - Boss, WF AU - Grunden, AM T2 - FEBS LETTERS AB - Pyrococcus furiosus superoxide reductase (SOR) is a thermostable archaeal enzyme that reduces superoxide without producing oxygen. When produced as a fusion protein with the green fluorescent protein in plant cells, P. furiosus SOR is located in the cytosol and nucleus. The recombinant SOR enzyme retains its function and heat stability when assayed in vitro. Importantly, expressing SOR in plant cells enhances their survival at high temperature indicating that it functions in vivo. The archaeal SOR provides a novel mechanism to reduce superoxide and demonstrates the potential for using archaeal genes to alter eukaryotic metabolism. DA - 2005/10/24/ PY - 2005/10/24/ DO - 10.1016/j.febslet.2005.09.015 VL - 579 IS - 25 SP - 5521-5526 SN - 1873-3468 KW - archaeal KW - heat-stress KW - hyperthermophile KW - plant KW - reactive oxygen species KW - superoxide dismutase KW - superoxide reductase ER - TY - JOUR TI - A link between ethylene and auxin uncovered by the characterization of two root-specific ethylene-insensitive mutants in Arabidopsis AU - Stepanova, AN AU - Hoyt, JM AU - Hamilton, AA AU - Alonso, JM T2 - PLANT CELL AB - The plant hormone ethylene participates in the regulation of a variety of developmental processes and serves as a key mediator of plant responses to biotic and abiotic stress factors. The diversity of ethylene functions is achieved, at least in part, by combinatorial interactions with other hormonal signals. Here, we show that ethylene-triggered inhibition of root growth, one of the classical effects of ethylene in Arabidopsis thaliana seedlings, is mediated by the action of the WEAK ETHYLENE INSENSITIVE2/ANTHRANILATE SYNTHASE alpha1 (WEI2/ASA1) and WEI7/ANTHRANILATE SYNTHASE beta1 (ASB1) genes that encode alpha- and beta-subunits of a rate-limiting enzyme of Trp biosynthesis, anthranilate synthase. Upregulation of WEI2/ASA1 and WEI7/ASB1 by ethylene results in the accumulation of auxin in the tip of primary root, whereas loss-of-function mutations in these genes prevent the ethylene-mediated auxin increase. Furthermore, wei2 and wei7 suppress the high-auxin phenotypes of superroot1 (sur1) and sur2, two auxin-overproducing mutants, suggesting that the roles of WEI2 and WEI7 in the regulation of auxin biosynthesis are not restricted to the ethylene response. Together, these findings reveal that ASA1 and ASB1 are key elements in the regulation of auxin production and an unexpected node of interaction between ethylene responses and auxin biosynthesis in Arabidopsis. This study provides a mechanistic explanation for the root-specific ethylene insensitivity of wei2 and wei7, illustrating how interactions between hormones can be used to achieve response specificity. DA - 2005/8// PY - 2005/8// DO - 10.1105/tpc.105.033365 VL - 17 IS - 8 SP - 2230-2242 SN - 1532-298X UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-27744445823&partnerID=MN8TOARS ER - TY - JOUR TI - Relationships between phenolic acid concentrations, transpiration, water utilization, leaf area expansion, and uptake of phenolic acids: Nutrient culture studies AU - Blum, U AU - Gerig, TM T2 - JOURNAL OF CHEMICAL ECOLOGY DA - 2005/8// PY - 2005/8// DO - 10.1007/s10886-005-5934-5 VL - 31 IS - 8 SP - 1907-1932 SN - 0098-0331 KW - absolute and relative rates of leaf expansion KW - feedback regulation KW - inhibition KW - phenolic acids KW - phenolic acid depletion and uptake KW - recovery KW - transpiration KW - water utilization ER - TY - JOUR TI - Identification, accumulation, and functional prediction of novel tomato transcripts systemically upregulated after fire damage AU - Coker, JS AU - Vian, A AU - Davies, E T2 - PHYSIOLOGIA PLANTARUM AB - Despite the major impacts of fire on plants, responses to fire damage have not been closely studied on the level of gene expression. Here, we present analyses of novel transcripts from tomato ( Lycopersicon esculentum cv. Heinz), which are systemically upregulated in leaves after a distant leaf is wounded by flame. Nine cDNA fragments were isolated from a subtractive cDNA library of leaf tissue 1 h after flaming. Using data mining and polymerase chain reaction (PCR), full‐length open‐reading frames were predicted, amplified, and then sequenced. Real‐time (RT)‐PCR using leaf RNA after flaming confirmed the systemic accumulation of 4 and 7 transcripts within 30 and 60 min, respectively, before returning to basal levels within 3 h. During this same time course, proteinase inhibitor I levels gradually increased over 30‐fold in 6 h. Expression analyses also showed that eight of the transcripts are present in unwounded leaf, stem, and root tissues. The predicted proteins include an acyl carrier, adenylyl sulfate reductase, PS II oxygen‐evolving complex protein 3, anion : sodium symporter, chloroplast‐specific ribosomal protein, a histidine triad family protein, and an unknown wound/stress‐related protein. Homologs of several of these proteins have been associated with other types of wound and stress responses. It appears that, within an hour after being damaged by fire, plants systemically upregulate a variety of genes involved with basic cell metabolism and upkeep, in addition to classic defense genes such as proteinase inhibitors. DA - 2005/7// PY - 2005/7// DO - 10.1111/j.1399-3054.2005.00488.x VL - 124 IS - 3 SP - 311-322 SN - 0031-9317 ER - TY - JOUR TI - Identification and characterization of endoplasmic reticulum-associated degradation proteins differentially affected by endoplasmic reticulum stress AU - Kirst, ME AU - Meyer, DJ AU - Gibbon, BC AU - Jung, R AU - Boston, RS T2 - PLANT PHYSIOLOGY AB - Abstract The disposal of misfolded proteins from the lumen of the endoplasmic reticulum (ER) is one of the quality control mechanisms present in the protein secretory pathway. Through ER-associated degradation, misfolded substrates are targeted to the cytosol where they are degraded by the proteasome. We have identified four maize (Zea mays) Der1-like genes (Zm Derlins) that encode homologs of Der1p, a yeast (Saccharomyces cerevisiae) protein implicated in ER-associated degradation. Zm Derlins are capable of functionally complementing a yeast Der1 deletion mutant. Such complementation indicates that the Der1p function is conserved among species. Zm Derlin genes are expressed at low levels throughout the plant, but appear prevalent in tissues with high activity of secretory protein accumulation, including developing endosperm cells. Expression of three of the four Zm Derlin genes increases during ER stress, with Zm Derlin1-1 showing the strongest induction. Subcellular fractionation experiments localized Zm Derlin proteins to the membrane fraction of microsomes. In maize endosperm, Zm Derlin proteins were found primarily associated with ER-derived protein bodies regardless of the presence of an ER stress response. DA - 2005/5// PY - 2005/5// DO - 10.1104/pp.105.060087 VL - 138 IS - 1 SP - 218-231 SN - 1532-2548 ER - TY - JOUR TI - Geminivirus C3 protein: Replication enhancement and protein interactions AU - Settlage, SB AU - See, RG AU - Hanley-Bowdoin, L T2 - JOURNAL OF VIROLOGY AB - ABSTRACT Most dicot-infecting geminiviruses encode a replication enhancer protein (C3, AL3, or REn) that is required for optimal replication of their small, single-stranded DNA genomes. C3 interacts with C1, the essential viral replication protein that initiates rolling circle replication. C3 also homo-oligomerizes and interacts with at least two host-encoded proteins, proliferating cell nuclear antigen (PCNA) and the retinoblastoma-related protein (pRBR). It has been proposed that protein interactions contribute to C3 function. Using the C3 protein of Tomato yellow leaf curl virus , we examined the impact of mutations to amino acids that are conserved across the C3 protein family on replication enhancement and protein interactions. Surprisingly, many of the mutations did not affect replication enhancement activity of C3 in tobacco protoplasts. Other mutations either enhanced or were detrimental to C3 replication activity. Analysis of mutated proteins in yeast two-hybrid assays indicated that mutations that inactivate C3 replication enhancement activity also reduce or inactivate C3 oligomerization and interaction with C1 and PCNA. In contrast, mutated C3 proteins impaired for pRBR binding are fully functional in replication assays. Hydrophobic residues in the middle of the C3 protein were implicated in C3 interaction with itself, C1, and PCNA, while polar resides at both the N and C termini of the protein are important for C3-pRBR interaction. These experiments established the importance of C3-C3, C3-C1, and C3-PCNA interactions in geminivirus replication. While C3-pRBR interaction is not required for viral replication in cycling cells, it may play a role during infection of differentiated cells in intact plants. DA - 2005/8// PY - 2005/8// DO - 10.1128/jvi.79.15.9885-9895.2005 VL - 79 IS - 15 SP - 9885-9895 SN - 1098-5514 ER - TY - JOUR TI - The rb7 matrix attachment region increases the likelihood and magnitude of transgene expression in tobacco cells: A flow cytometric study AU - Halweg, C AU - Thompson, WF AU - Spiker, S T2 - PLANT CELL AB - Many studies in both plant and animal systems have shown that matrix attachment regions (MARs) can increase expression of transgenes in whole organisms or cells in culture. Because histochemical assays often indicate variegated transgene expression, a question arises: Do MARs increase transgene expression by increasing the percentage of cells expressing the transgene (likelihood), by increasing the level of expression in expressing cells (magnitude), or both? To address this question, we used flow cytometry to measure green fluorescent protein (GFP) expression in individual tobacco (Nicotiana tabacum) cells from lines transformed by Agrobacteriumtumefaciens. We conclude that MAR-mediated overall increases in transgene expression involve both likelihood and magnitude. On average, cell lines transformed with the Rb7 MAR-containing vector expressed GFP at levels 2.0- to 3.7-fold higher than controls. MAR lines had fewer nonexpressing cells than control lines (10% versus 45%), and the magnitude of GFP expression in expressing cells was greater in MAR lines by 1.9- to 2.9-fold. We also show that flow cytometry measurements on cells from isogenic lines are consistent with those from populations of independently transformed cell lines. By obviating the need to establish isogenic lines, this use of flow cytometry could greatly simplify the evaluation of MARs or other sequence elements that affect transgene expression. DA - 2005/2// PY - 2005/2// DO - 10.1105/tpc.104.028100 VL - 17 IS - 2 SP - 418-429 SN - 1532-298X ER - TY - JOUR TI - The CTB1 gene encoding a fungal polyketide synthase is required for cercosporin biosynthesis and fungal virulence of Cercospora nicotianae AU - Choquer, M AU - Dekkers, KL AU - Chen, HQ AU - Cao, LH AU - Ueng, PP AU - Daub, ME AU - Chung, KR T2 - MOLECULAR PLANT-MICROBE INTERACTIONS AB - Cercosporin is a light-activated, non-host-selective toxin produced by many Cercospora fungal species. In this study, a polyketide synthase gene (CTB1) was functionally identified and molecularly characterized to play a key role in cercosporin biosynthesis by Cercospora nicotianae. We also provide conclusive evidence to confirm the crucial role of cercosporin in fungal pathogenesis. CTB1 encoded a polypeptide with a deduced length of 2,196 amino acids containing a keto synthase (KS), an acyltransferase (AT), a thioesterase/claisen cyclase (TE/CYC), and two acyl carrier protein (ACP) domains, and had high levels of similarity to many fungal type I polyketide synthases. Expression of a 6.8-kb CTB1 transcript was highly regulated by light and medium composition, consistent with the conditions required for cercosporin biosynthesis in cultures. Targeted disruption of CTB1 resulted in the loss of both CTB1 transcript and cercosporin biosynthesis in C. nicotianae. The ctb1-null mutants incited fewer necrotic lesions on inoculated tobacco leaves compared with the wild type. Complementation of ctb1-null mutants with a full-length CTB1 clone restored wild-type levels of cercosporin production as well as the ability to induce lesions on tobacco. Thus, we have demonstrated conclusively that cercosporin is synthesized via a polyketide pathway, and cercosporin is an important virulence factor in C. nicotianae. The results also suggest that strategies that avoid the toxicity of cercosporin will be useful in reduction of disease incidence caused by Cercospora spp. DA - 2005/5// PY - 2005/5// DO - 10.1094/MPMI-18-0468 VL - 18 IS - 5 SP - 468-476 SN - 1943-7706 KW - gene disruption KW - pathogenicity KW - perylenequinone ER - TY - JOUR TI - Seasonal leaf dynamics across a tree density gradient in a Brazilian savanna AU - Hoffmann, WA AU - Silva, ER AU - Machado, GC AU - Bucci, SJ AU - Scholz, FG AU - Goldstein, G AU - Meinzer, FC T2 - OECOLOGIA AB - Interactions between trees and grasses that influence leaf area index (LAI) have important consequences for savanna ecosystem processes through their controls on water, carbon, and energy fluxes as well as fire regimes. We measured LAI, of the groundlayer (herbaceous and woody plants <1-m tall) and shrub and tree layer (woody plants >1-m tall), in the Brazilian cerrado over a range of tree densities from open shrub savanna to closed woodland through the annual cycle. During the dry season, soil water potential was strongly and positively correlated with grass LAI, and less strongly with tree and shrub LAI. By the end of the dry season, LAI of grasses, groundlayer dicots and trees declined to 28, 60, and 68% of mean wet-season values, respectively. We compared the data to remotely sensed vegetation indices, finding that field measurements were more strongly correlated to the enhanced vegetation index (EVI, r (2)=0.71) than to the normalized difference vegetation index (NDVI, r (2)=0.49). Although the latter has been more widely used in quantifying leaf dynamics of tropical savannas, EVI appears better suited for this purpose. Our ground-based measurements demonstrate that groundlayer LAI declines with increasing tree density across sites, with savanna grasses being excluded at a tree LAI of approximately 3.3. LAI averaged 4.2 in nearby gallery (riparian) forest, so savanna grasses were absent, thereby greatly reducing fire risk and permitting survival of fire-sensitive forest tree species. Although edaphic conditions may partly explain the larger tree LAI of forests, relative to savanna, biological differences between savanna and forest tree species play an important role. Overall, forest tree species had 48% greater LAI than congeneric savanna trees under similar growing conditions. Savanna and forest species play distinct roles in the structure and dynamics of savanna-forest boundaries, contributing to the differences in fire regimes, microclimate, and nutrient cycling between savanna and forest ecosystems. DA - 2005/9// PY - 2005/9// DO - 10.1007/s00442-005-0129-x VL - 145 IS - 2 SP - 307-316 SN - 1432-1939 KW - cerrado KW - leaf area index KW - phenology KW - tropical forest KW - water potential ER - TY - JOUR TI - Phylogenetic analyses identify 10 classes of the protein disulfide isomerase family in plants, including single-domain protein disulfide isomerase-related proteins AU - Houston, N. L. AU - Fan, C. Z. AU - Xiang, Qiu-Yun AU - Schulze, J. M. AU - Jung, R. AU - Boston, R. S. T2 - Plant Physiology AB - Abstract Protein disulfide isomerases (PDIs) are molecular chaperones that contain thioredoxin (TRX) domains and aid in the formation of proper disulfide bonds during protein folding. To identify plant PDI-like (PDIL) proteins, a genome-wide search of Arabidopsis (Arabidopsis thaliana) was carried out to produce a comprehensive list of 104 genes encoding proteins with TRX domains. Phylogenetic analysis was conducted for these sequences using Bayesian and maximum-likelihood methods. The resulting phylogenetic tree showed that evolutionary relationships of TRX domains alone were correlated with conserved enzymatic activities. From this tree, we identified a set of 22 PDIL proteins that constitute a well-supported clade containing orthologs of known PDIs. Using the Arabidopsis PDIL sequences in iterative BLAST searches of public and proprietary sequence databases, we further identified orthologous sets of 19 PDIL sequences in rice (Oryza sativa) and 22 PDIL sequences in maize (Zea mays), and resolved the PDIL phylogeny into 10 groups. Five groups (I–V) had two TRX domains and showed structural similarities to the PDIL proteins in other higher eukaryotes. The remaining five groups had a single TRX domain. Two of these (quiescin-sulfhydryl oxidase-like and adenosine 5′-phosphosulfate reductase-like) had putative nonisomerase enzymatic activities encoded by an additional domain. Two others (VI and VIII) resembled small single-domain PDIs from Giardia lamblia, a basal eukaryote, and from yeast. Mining of maize expressed sequence tag and RNA-profiling databases indicated that members of all of the single-domain PDIL groups were expressed throughout the plant. The group VI maize PDIL ZmPDIL5-1 accumulated during endoplasmic reticulum stress but was not found within the intracellular membrane fractions and may represent a new member of the molecular chaperone complement in the cell. DA - 2005/// PY - 2005/// DO - 10.1104/pp.104.056507 VL - 137 IS - 2 SP - 762–778 ER - TY - JOUR TI - Marker-free chromosomal integration of the manganese superoxide dismutase gene (sodA) from Streptococcus thermophilus into Lactobacillus gasseri AU - Bruno-Barcena, JM AU - Azcarate-Peril, MA AU - Klaenhammer, TR AU - Hassan, HM T2 - FEMS MICROBIOLOGY LETTERS AB - A strategy for functional gene replacement in the chromosome of Lactobacillus gasseri is described. The phospho-β-galactosidase II gene (lacII) was functionally replaced by the manganese superoxide dismutase (MnSOD) gene (sodA) from Streptococcus thermophilus, by adapting the insertional inactivation method described for lactobacilli [Russell, W.M. and Klaenhammer, T.R. 2001 Efficient system for directed integration into the Lactobacillus acidophilus and Lactobacillus gasseri chromosomes via homologous recombination. Appl. Environ. Microbiol. 67, 4361–4364]. L. gasseri carrying the heterologous sodA gene grew on lactose as efficiently as the wild-type parent. An active MnSOD was expressed in the transgenic strain, and the enzyme migrated on PAGE-SOD activity gels to the same position as that of MnSOD from S. thermophilus. The expression of MnSOD from a single copy of sodA integrated in the chromosome of L. gasseri provided enhanced tolerance to hydrogen peroxide, and extended the viability of carbon/energy starved cultures stored at 25 °C. This is the first report showing the successful utilization of the pORI plasmids system to generate marker-free gene integration in L. gasseri strains. DA - 2005/5/1/ PY - 2005/5/1/ DO - 10.1016/j.femsle.2005.03.044 VL - 246 IS - 1 SP - 91-101 SN - 1574-6968 UR - http://europepmc.org/abstract/med/15869967 KW - functional gene replacement KW - manganese superoxide dismutase KW - oxidative stress KW - Lactobacillus gasseri KW - lactic acid bacteria KW - probiotics ER - TY - JOUR TI - In vitro reconstitution of an NADPH-dependent superoxide reduction pathway from Pyrococcus furiosus AU - Grunden, AA AU - Jenney, FE AU - Ma, KS AU - Ji, MY AU - Weinberg, MV AU - Adams, MWW T2 - APPLIED AND ENVIRONMENTAL MICROBIOLOGY AB - ABSTRACT A scheme for the detoxification of superoxide in Pyrococcus furiosus has been previously proposed in which superoxide reductase (SOR) reduces (rather than dismutates) superoxide to hydrogen peroxide by using electrons from reduced rubredoxin (Rd). Rd is reduced with electrons from NAD(P)H by the enzyme NAD(P)H:rubredoxin oxidoreductase (NROR). The goal of the present work was to reconstitute this pathway in vitro using recombinant enzymes. While recombinant forms of SOR and Rd are available, the gene encoding P. furiosus NROR (PF1197) was found to be exceedingly toxic to Escherichia coli , and an active recombinant form (rNROR) was obtained via a fusion protein expression system, which produced an inactive form of NROR until cleavage. This allowed the complete pathway from NAD(P)H to the reduction of SOR via NROR and Rd to be reconstituted in vitro using recombinant proteins. rNROR is a 39.9-kDa protein whose sequence contains both flavin adenine dinucleotide (FAD)- and NAD(P)H-binding motifs, and it shares significant similarity with known and putative Rd-dependent oxidoreductases from several anaerobic bacteria, both mesophilic and hyperthermophilic. FAD was shown to be essential for activity in reconstitution assays and could not be replaced by flavin mononucleotide (FMN). The bound FAD has a midpoint potential of −173 mV at 23°C (−193 mV at 80°C). Like native NROR, the recombinant enzyme catalyzed the NADPH-dependent reduction of rubredoxin both at high (80°C) and low (23°C) temperatures, consistent with its proposed role in the superoxide reduction pathway. This is the first demonstration of in vitro superoxide reduction to hydrogen peroxide using NAD(P)H as the electron donor in an SOR-mediated pathway. DA - 2005/3// PY - 2005/3// DO - 10.1128/AEM.71.3.1522-1530.2005 VL - 71 IS - 3 SP - 1522-1530 SN - 1098-5336 ER - TY - JOUR TI - Ethylene signalling and response pathway: A unique signalling cascade with a multitude of inputs and outputs AU - STEPANOVA, ANNA AU - Alonso, Jose T2 - Physiologia Plantarum DA - 2005/// PY - 2005/// DO - 10.1111/j/1399-3054.2004.00447 VL - 123 IS - 2 SP - 195–206 ER - TY - JOUR TI - Connecting fine- and broad-scale species-area relationships of Southeastern US Flora AU - Fridley, JD AU - Peet, RK AU - Wentworth, TR AU - White, PS T2 - ECOLOGY AB - Although the rate that species accumulate with area has long been regarded as an important component of fine-scale community structure and several studies have examined this rate in meta-analyses, few if any studies have systematically examined fine-scale species–area relationships using a consistent survey protocol over a large region. We examined fine-scale species–area relationships using the extensive database of the Carolina Vegetation Survey (North Carolina, South Carolina, Georgia, and Tennessee, USA), including 1472 plots wherein vascular plant richness was recorded for each of six subplot sizes regularly spaced on a log10 scale, from 0.01 to 1000 m2. Contrary to prevailing theory, our data closely and consistently fit an Arrhenius (power law) species–area model, echoing broader-scale patterns. Species accumulation rate (Z) values fell within a narrow range (95% between 0.2 and 0.5) despite a 30-fold range in 1000-m2 richness. When we added regional- and global-scale richness estimates to our results, a Preston-type triphasic curve emerged. We suggest that (1) fine-scale species–area relationships are remarkably consistent and (2) full-scale species–area curves reveal scale dependencies in diversity data that are not accounted for by current species–area theory. DA - 2005/5// PY - 2005/5// DO - 10.1890/03-3187 VL - 86 IS - 5 SP - 1172-1177 SN - 1939-9170 KW - arrhenius model KW - Carolina Vegetation Survey KW - Gleason model KW - North Carolina KW - USA KW - scale KW - South Carolina KW - USA KW - species accumulation rate KW - species-area curve KW - species richness ER - TY - JOUR TI - Matrix attachment regions and regulated transcription increase and stabilize transgene expression AU - Abranches, R AU - Shultz, RW AU - Thompson, WF AU - Allen, GC T2 - PLANT BIOTECHNOLOGY JOURNAL AB - Transgene silencing has been shown to be associated with strong promoters, but it is not known whether the propensity for silencing is caused by the level of transcription, or some other property of the promoter. If transcriptional activity fosters silencing, then transgenes with inducible promoters may be less susceptible to silencing. To test this idea, a doxycycline-inducible luciferase transgene was transformed into an NT1 tobacco suspension culture cell line that constitutively expressed the tetracycline repressor. The inducible luciferase gene was flanked by tobacco Rb7 matrix attachment regions (MAR) or spacer control sequences in order to test the effects of MARs in conjunction with regulated transcription. Transformed lines were grown under continuous doxycycline (CI), or delayed doxycycline induction (DI) conditions. Delayed induction resulted in higher luciferase expression initially, but continued growth in the presence of doxycycline resulted in a reduction of expression to levels similar to those found in continuously induced lines. In both DI and CI treatments, the Rb7 MAR significantly reduced the percentage of silenced lines and increased transgene expression levels. These data demonstrate that active transcription increases silencing, especially in the absence of the Rb7 MAR. Importantly, the Rb7 MAR lines showed higher expression levels under both CI and DI conditions and avoided silencing that may occur in the absence of active transcription such as what would be expected as a result of condensed chromatin spreading. DA - 2005/9// PY - 2005/9// DO - 10.1111/j.1467-7652.2005.00144.x VL - 3 IS - 5 SP - 535-543 SN - 1467-7644 KW - PTGS KW - TGS KW - RNAi KW - MARs KW - transgene expression KW - induction ER - TY - BOOK TI - Guide to tendrillate climbers of Costa Rican mountains AU - Krings, A. CN - QK217 .K75 2005 DA - 2005/// PY - 2005/// PB - Ames, Iowa: Blackwell Pub. Professional SN - 0813807581 ER - TY - JOUR TI - Characterization and comparative analysis of Arabidopsis phosphatidylinositol phosphate 5-kinase 10 reveals differences in Arabidopsis and human phosphatidylinositol phosphate kinases AU - Perera, IY AU - Davis, AJ AU - Galanopilou, D AU - Im, YJ AU - Boss, WF T2 - FEBS LETTERS AB - Arabidopsis phosphatidylinositol phosphate (PtdInsP) kinase 10 ( At PIPK10; At4g01190) is shown to be a functional enzyme of the subfamily A, type I At PtdInsP kinases. It is biochemically distinct from At PIPK1 (At1g21980), the only other previously characterized At PtdInsP kinase which is of the B subfamily. At PIPK10 has the same K m , but a 10‐fold lower V max than At PIPK1 and it is insensitive to phosphatidic acid. At PIPK10 transcript is most abundant in inflorescence stalks and flowers, whereas At PIPK1 transcript is present in all tissues. Comparative analysis of recombinant At PIPK10 and At PIPK1 with recombinant Hs PIPKIα reveals that the Arabidopsis enzymes have roughly 200‐ and 20‐fold lower V max / K m , respectively. These data reveal one explanation for the longstanding mystery of the relatively low phosphatidylinositol‐(4,5)‐bisphosphate:phosphatidylinositol‐4‐phosphate ratio in terrestrial plants. DA - 2005/6/20/ PY - 2005/6/20/ DO - 10.1016/j.febslet.2005.05.018 VL - 579 IS - 16 SP - 3427-3432 SN - 1873-3468 KW - phosphatidylinositol phosphate kinase KW - lipid kinase KW - Arabidopsis ER - TY - JOUR TI - Visibility matters: increasing knowledge of women's contributions to ecology AU - Damschen, EI AU - Rosenfeld, KM AU - Wyer, M AU - Murphy-Medley, D AU - Wentworth, TR AU - Haddad, NM T2 - FRONTIERS IN ECOLOGY AND THE ENVIRONMENT AB - Recent scholarship about women and science is a good source of material for addressing the under-representation of women in science. This review is the result of an interdisciplinary fusion of science and women's studies to critically assess teaching tools in undergraduate ecology education. We examine: (1) the representation of women and the coverage of social and cultural context in introductory ecology textbooks, and (2) student learning about women's contributions to ecology. Discipline demographics reveal that women are presented in textbooks less often than expected, and that explicit discussions of the social and cultural context of science are rare. When course content is enriched with material about women's contributions, student's awareness of women scientists improves. Such knowledge can play a critical role in proactively challenging students' perceptions of ecology and ecologists, creating a more positive classroom climate for all students, and introducing novel avenues of questioning and discovery. DA - 2005/5// PY - 2005/5// DO - 10.2307/3868465 VL - 3 IS - 4 SP - 212-219 SN - 1540-9309 ER - TY - JOUR TI - Matrix attachment regions increase the efficiency and stability of RNA-mediated resistance to Tomato Spotted Wilt Virus in transgenic tobacco AU - Levin, JS AU - Thompson, WF AU - Csinos, AS AU - Stephenson, MG AU - Weissinger, AK T2 - TRANSGENIC RESEARCH DA - 2005/4// PY - 2005/4// DO - 10.1007/s11248-004-5413-8 VL - 14 IS - 2 SP - 193-206 SN - 1573-9368 KW - gene silencing KW - matrix attachment regions KW - RNA-mediated virus resistance KW - Tomato Spotted Wilt Virus ER - TY - JOUR TI - Long range lateral root activity by neo-tropical savanna trees AU - Sternberg, LDL AU - Bucci, S AU - Franco, A AU - Goldstein, G AU - Hoffman, WA AU - Meinzer, FC AU - Moreira, MZ AU - Scholz, F T2 - PLANT AND SOIL DA - 2005/3// PY - 2005/3// DO - 10.1007/s11104-004-1334-9 VL - 270 IS - 1-2 SP - 169-178 SN - 0032-079X ER - TY - JOUR TI - An Arabidopsis NPR1-like gene, NPR4, is required for disease resistance AU - Liu, GS AU - Holub, EB AU - Alonso, JM AU - Ecker, , JR AU - Fobert, PR T2 - PLANT JOURNAL AB - The Arabidopsis genome contains six NPR1-related genes. Given the pivotal role played by NPR1 in controlling salicylic acid (SA)-mediated gene expression and disease resistance, functional characterization of other family members appears to be justified. Reverse genetics was used to analyze the role of one NPR1-like gene, which we called NPR4. The NPR4 protein shares 36% identity with NPR1 and interacts with the same spectrum of TGA transcription factors in yeast two-hybrid assays. Plants with T-DNA insertions in NPR4 are more susceptible to the virulent bacterial pathogen Pseudomonas syringe pv. tomato DC3000. This phenotype is complemented by expression of the wild type NPR4 coding region. As determined by the parasite reproduction, the npr4-1 mutant is more susceptible to the fungal pathogen Erysiphe cichoracearum, but does not differ markedly from wild type in its interaction with virulent and avirulent strains of the oomycete Peronospora parasitica. In leaves of wild-type plants, NPR4 mRNA levels increase following pathogen challenge or SA treatment, and decrease rapidly following methyl jasmonic acid (MeJA) treatment. Transcripts of the pathogenesis-related (PR) genes PR-1, PR-2, and PR-5 are only marginally reduced in the npr4-1 mutant following pathogen challenge or SA treatment. This reduction of PR gene expression is more pronounced when leaves are challenged with the bacterial pathogen following SA treatment. Expression of the jasmonic acid-dependent pathway marker gene PDF1.2 is compromised in npr4-1 leaves following application of MeJA or a combination of SA and MeJA. These results indicate that NPR4 is required for basal defense against pathogens, and that it may be implicated in the cross-talk between the SA- and JA-dependent signaling pathways. DA - 2005/1// PY - 2005/1// DO - 10.1111/j.1365-313x.2004.02296.x VL - 41 IS - 2 SP - 304-318 SN - 1365-313X KW - reverse genetics KW - PR genes KW - cross-talk KW - signaling KW - salicylic acid KW - gene family ER - TY - JOUR TI - Accumulation and localization of aluminium in root tips of loblolly pine seedlings and the associated ectomycorrhiza Pisolithus tinctorius AU - Moyer-Henry, K AU - Silva, I AU - Macfall, J AU - Johannes, E AU - Allen, N AU - Goldfarb, B AU - Rufty, T T2 - PLANT CELL AND ENVIRONMENT AB - ABSTRACT Evidence from past studies suggests that loblolly pine may be tolerant of Al. The experiments described in this manuscript were initiated to examine Al tolerance and Al accumulation in the pine root and the degree of Al accumulation in fungal hyphae when pine roots were colonized with the ectomycorrhiza Pisolithus tinctorius . The experiments used lumogallion staining and confocal microscopy to localize Al in root and fungal structures. The results clearly showed that loblolly pine seedlings were highly resistant to Al. A decrease in primary root extension could not be detected until Al +3 activities approached 40 µ mol L −1 , and extension was suppressed only 30% at an Al +3 activity of 580 µ mol L −1 . This contrasted with the response of the Al‐sensitive ‘check’ species soybean, where primary root extension was severely restricted at Al +3 activities lower than 5 µ mol L −1 . Tissue Al measurements and lumogallion fluorescence of longitudinal sections of the pine root tip indicated that tolerance was associated with both Al exclusion from the tip region and compartmentalization of absorbed Al in peripheral cell areas outside of the meristem. In lateral roots colonized with ectomycorrhizae, lumogallion fluorescence showed that large amounts of Al accumulated at the fungal mantle and in areas with the Hartig net. At higher magnification, lumogallion indicated substantial Al accumulation inside hyphae. Little Al could be detected in lateral root cells. The results show that pine possesses multiple mechanisms that can contribute to Al tolerance in acid field soils. DA - 2005/2// PY - 2005/2// DO - 10.1111/j.1365-3040.2004.01240.x VL - 28 IS - 2 SP - 111-120 SN - 1365-3040 KW - Pisolithus tinctorius KW - confocal scanning microscopy KW - lumogallion ER - TY - JOUR TI - Root-knot nematodes and bacterial Nod factors elicit common signal transduction events in Lotus japonicus AU - Weerasinghe, RR AU - Bird, DM AU - Allen, NS T2 - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA AB - The symbiosis responsible for nitrogen fixation in legume root nodules is initiated by rhizobial signaling molecules [Nod factors (NF)]. Using transgenically tagged microtubules and actin, we dynamically profiled the spatiotemporal changes in the cytoskeleton of living Lotus japonicus root hairs, which precede root-hair deformation and reflect one of the earliest host responses to NF. Remarkably, plant-parasitic root-knot nematodes (RKN) invoke a cytoskeletal response identical to that seen in response to NF and induce root-hair waviness and branching in legume root hairs via a signal able to function at a distance. Azide-killed nematodes do not produce this signal. A similar response to RKN was seen in tomato. Aspects of the host responses to RKN were altered or abolished by mutations in the NF receptor genes nfr1 , nfr5 , and symRK , suggesting that RKN produce a molecule with functional equivalence to NF, which we name NemF. Because the ability of RKN to establish feeding sites and reproduce was markedly reduced in the mutant lines, we propose that RKN have adapted at least part of the symbiont-response pathway to enhance their parasitic ability. DA - 2005/2/22/ PY - 2005/2/22/ DO - 10.1073/pnas.0407926102 VL - 102 IS - 8 SP - 3147-3152 SN - 0027-8424 KW - cytoskeleton KW - NemF KW - rhizobia KW - actin KW - microtubule ER - TY - JOUR TI - Overexpression of the Ca2+-binding protein calreticulin in the endoplasmic reticulum improves growth of tobacco cell suspensions (Nicotiana tabacum) in high-Ca2+ medium AU - Akesson, A AU - Persson, S AU - Love, J AU - Boss, WF AU - Widell, S AU - Sommarin, M T2 - PHYSIOLOGIA PLANTARUM AB - Calreticulin (CRT) is a eukaryotic, highly conserved, Ca 2+ ‐binding protein predominantly located in the endoplasmic reticulum (ER) lumen. In addition to being involved in the regulation of cellular Ca 2+ , calreticulin is a key quality control element during protein folding in the ER lumen. Tobacco ( Nicotiana tabacum L.) suspension cells overexpressing a maize CRT (CRT1a) were used here to examine the properties of CRT in growing plant cells with respect to stress exposure. The endogenous CRT gene was induced rapidly after subculturing of the cells to new medium. In accordance, the CRT protein levels increased, peaking at days 3–4. At day 5, when the CRT transcript levels had levelled off, a further increase in endogenous CRT expression was obtained when the cells were treated with excess Ca 2+ or the N ‐linked glycosylation inhibitor tunicamycin. Whereas the response to Ca 2+ occurred within 30 min, the induction by tunicamycin took several hours to be established. Transforming tobacco cells with maize CRT1a, under a constitutive mannopine synthase promoter, resulted in a stable level of expressed CRT1a during the growth cycle compared with endogenous CRT. The CRTs showed differences in attached glycans, but both contained the high mannose‐rich‐type glycans characteristic of ER proteins. In agreement with an ER location, both tobacco CRT and the transgene product CRT1a codistributed with the ER marker NADH cytochrome c reductase after density gradient centrifugation of microsomal fractions from tobacco cells. Increased production of CRT, as was obtained in the transgenic tobacco cell lines, made cells more tolerant than wild‐type cells to high Ca 2+ during growth. These data suggest that overexpression of CRT1a in plant cells results in a more efficient calcium buffering capacity in the ER. DA - 2005/1// PY - 2005/1// DO - 10.1111/j.1399-3054.2004.00434.x VL - 123 IS - 1 SP - 92-99 SN - 1399-3054 ER - TY - JOUR TI - A Sec14p-nodulin domain phosphatidylinositol transfer protein polarizes membrane growth of Arabidopsis thaliana root hairs AU - Vincent, P AU - Chua, M AU - Nogue, F AU - Fairbrother, A AU - Mekeel, H AU - Xu, Y AU - Allen, N AU - Bibikova, TN AU - Gilroy, S AU - Bankaitis, VA T2 - JOURNAL OF CELL BIOLOGY AB - Phosphatidylinositol (PtdIns) transfer proteins (PITPs) regulate signaling interfaces between lipid metabolism and membrane trafficking. Herein, we demonstrate that AtSfh1p, a member of a large and uncharacterized Arabidopsis thaliana Sec14p-nodulin domain family, is a PITP that regulates a specific stage in root hair development. AtSfh1p localizes along the root hair plasma membrane and is enriched in discrete plasma membrane domains and in the root hair tip cytoplasm. This localization pattern recapitulates that visualized for PtdIns(4,5)P2 in developing root hairs. Gene ablation experiments show AtSfh1p nullizygosity compromises polarized root hair expansion in a manner that coincides with loss of tip-directed PtdIns(4,5)P2, dispersal of secretory vesicles from the tip cytoplasm, loss of the tip f-actin network, and manifest disorganization of the root hair microtubule cytoskeleton. Derangement of tip-directed Ca2+ gradients is also apparent and results from isotropic influx of Ca2+ from the extracellular milieu. We propose AtSfh1p regulates intracellular and plasma membrane phosphoinositide polarity landmarks that focus membrane trafficking, Ca2+ signaling, and cytoskeleton functions to the growing root hair apex. We further suggest that Sec14p-nodulin domain proteins represent a family of regulators of polarized membrane growth in plants. DA - 2005/2/28/ PY - 2005/2/28/ DO - 10.1083/jcb.200412074 VL - 168 IS - 5 SP - 801-812 SN - 1540-8140 ER - TY - JOUR TI - In vitro selection of phage RB69 RegA RNA binding sites yields UAA repeats AU - Dean, TR AU - Allen, SV AU - Miller, ES T2 - VIROLOGY AB - The SELEX method of in vitro selection was used to isolate RNAs that bind the RB69 RegA translational repressor protein immobilized on Ni-NTA agarose. After five rounds of SELEX, the pool of selected RNA displayed striking sequence uniformity: UAAUAAUAAUAAUA was clearly enriched in the 14 nucleotides that underwent selection. Individual, cloned molecules displayed a repeating (UAA) sequence, with only two RNAs having a 3' AUG. Removing the 3' AUG slightly reduced binding in gel shift assays, moving the AUG 5' proximal of the (UAA) slightly improved binding, but (UAA)4 alone still bound the purified protein. Dissociation constants showed that RNA shortened to (UAA)3 and (UAA)2 also retained binding, whereas cytosine clearly prevented binding by RB69 RegA. Scanning of RB69 gene starts and ends with an RB69 RegA SELEX information weight matrix yielded 21 sequences as potential RegA sites. One site, on the mRNA for the pentameric (4:1) phage gp44/62 DNA polymerase clamp loader complex, has the RB69 gene 44 stop codon and 3'-adjacent gene 62 initiation codon in a sequence (GAAAUAAUAUG) that is similar to in vitro selected RNA and was shown to bind RB69 RegA. Sequences between the Shine-Dalgarno and initiation codon, which frequently contain a UAA stop codon of a 5'-adjacent gene, appear to be preferred RB69 RegA binding sites. DA - 2005/5/25/ PY - 2005/5/25/ DO - 10.1016/j.virol.2005.03.002 VL - 336 IS - 1 SP - 26-36 SN - 0042-6822 KW - RNA SELEX KW - translation repressor KW - T4-type phage ER - TY - JOUR TI - Photoactivated perylenequinone toxins in fungal pathogenesis of plants AU - Daub, ME AU - Herrero, S AU - Chung, KR T2 - FEMS MICROBIOLOGY LETTERS AB - Several genera of plant pathogenic fungi produce photoactivated perylenequinone toxins involved in pathogenesis of their hosts. These toxins are photosensitizers, absorbing light energy and generating reactive oxygen species that damage the membranes of the host cells. Studies with toxin-deficient mutants and on the involvement of light in symptom development have documented the importance of these toxins in successful pathogenesis of plants. This review focuses on the well studied perylenequinone toxin, cercosporin, produced by species in the genus Cercospora. Significant progress has been made recently on the biosynthetic pathway of cercosporin, with the characterization of genes encoding a polyketide synthase and a major facilitator superfamily transporter, representing the first and last steps of the biosynthetic pathway, as well as important regulatory genes. In addition, the resistance of Cercospora fungi to cercosporin and to the singlet oxygen that it generates has led to the use of these fungi as models for understanding cellular resistance to photosensitizers and singlet oxygen. These studies have shown that resistance is complex, and have documented a role for transporters, transient reductive detoxification, and quenchers in cercosporin resistance. DA - 2005/11/15/ PY - 2005/11/15/ DO - 10.1016/j.femsle.2005.08.033 VL - 252 IS - 2 SP - 197-206 SN - 0378-1097 KW - plant disease KW - non-specific toxin KW - active oxygen KW - pyridoxine KW - zinc cluster transcription factor ER - TY - JOUR TI - Flora and soils of Wells Savannah, an example of a unique savanna type AU - Shelingoski, S AU - LeBlond, RJ AU - Stucky, JM AU - Wentworth, TR T2 - CASTANEA AB - Wells Savannah is a unique wet pine savanna located in the Lower Coastal Plain of North Carolina. It consists of two utility rights-of-way and a fire-suppressed pond pine (Pinus serotina) woodland. The objectives of this study of Wells Savannah were to characterize its soils, inventory its vascular flora, and compare its soils and flora with those of reference sites. Soil drainage, texture, and redoximorphic features were described at all locations. Wetland indices were calculated to represent the degree to which the plant communities were adapted to wet substrates. We identified 209 species in 107 genera and 48 families at Wells Savannah. Eight community associations were recognized. Wetland indices for Wells Savannah were significantly lower than those for the reference savannas. The unique combination of fine textured, very wet soil and plant species composition present at Wells Savannah has not been identified in previous studies of savannas in the region. DA - 2005/6// PY - 2005/6// DO - 10.2179/0008-7475(2005)070[0101:fasows]2.0.co;2 VL - 70 IS - 2 SP - 101-114 SN - 1938-4386 ER -