TY - JOUR TI - Isozymatic diversity in the races of maize of the Americas AU - Sanchez, J. J. AU - Stuber, C. W. AU - Goodman, M. M. T2 - Maydica DA - 2000/// PY - 2000/// VL - 45 IS - 3 SP - 185-203 ER - TY - JOUR TI - Variation among maize inbred lines and detection of quantitative trait loci for growth at low phosphorus and responsiveness to arbuscular mycorrhizal fungi AU - Kaeppler, SM AU - Parke, JL AU - Mueller, SM AU - Senior, L AU - Stuber, C AU - Tracy, WF T2 - CROP SCIENCE AB - Maize ( Zea mays L.) growth at low soil P levels is affected both by inherent physiological factors as well as interactions with soil microbes. The objectives of this study were (i) to quantify differences among maize inbred lines for growth at low P and response to mycorrhizal fungi, and (ii) to identify quantitative trait loci (QTL) controlling these traits in a B73 × Mo17 recombinant inbred population. Shoot dry weight and root volume were measured in the greenhouse after 6 wk of growth in a factorial experiment of 28 inbred maize lines using treatments of low vs. high P and mycorrhizal vs. nonmycorrhizal treatments. Shoot dry weight for the low P treatment in the absence of mycorrhizae ranged from 0.56 to 3.15 g. Mycorrhizal responsiveness based on shoot dry weight ranged from 106 to 800%. Shoot dry weight in the low P–nonmycorrhizal treatment was highly negatively correlated with mycorrhizal responsiveness. Plants grown at high P in the presence of mycorrhizae accumulated only 88% of the biomass of plants grown at high P in the absence of mycorrhizae, indicating that mycorrhizae can reduce plant growth when not contributing to the symbiosis. Percentage of root colonization was not correlated with mycorrhizal responsiveness. B73 and Mo17 were among the extremes for growth at low P and mycorrhizal responsiveness, and a B73 × Mo17 population of 197 recombinant inbred lines was used to detect QTL for growth at low P and mycorrhizal responsiveness. Three QTL were identified which controlled growth at low P in the absence of mycorrhizae based on shoot weight and one QTL which controlled mycorrhizal responsiveness. This study indicates that there is substantial variation among maize lines for growth at low P and response to mycorrhizal fungi. This variation could be harnessed to develop cultivars for regions of the world with P deficiency and for reduced‐input production systems. DA - 2000/// PY - 2000/// DO - 10.2135/cropsci2000.402358x VL - 40 IS - 2 SP - 358-364 SN - 1435-0653 ER - TY - JOUR TI - My view AU - Bell, CE AU - Fennimore, SA AU - McGiffen, ME AU - Lanini, WT AU - Monks, DW AU - Masiunas, JB AU - Bonanno, AR AU - Zandstra, BH AU - Umeda, K AU - Stall, WM AU - Bellinder, RR AU - William, RD AU - McReynolds, RB T2 - WEED SCIENCE AB - An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content. DA - 2000/// PY - 2000/// DO - 10.1614/0043-1745(2000)048[0001:MV]2.0.CO;2 VL - 48 IS - 1 SP - 1-1 SN - 1550-2759 ER - TY - JOUR TI - Substrate specificity of a maize ribosome-inactivating protein differs across diverse taxa AU - Krawetz, J. E. AU - Boston, R. S. T2 - European Journal of Biochemistry AB - The superfamily of ribosome-inactivating proteins (RIPs) consists of toxins that catalytically inactivate ribosomes at a universally conserved region of the large ribosomal RNA. RIPs carry out a single N-glycosidation event that alters the binding site of the translational elongational factor eEF1A and causes a cessation of protein synthesis that leads to subsequent cell death. Maize RIP1 is a kernel-specific RIP with the unusual property of being produced as a zymogen, proRIP1. ProRIP1 accumulates during seed development and becomes active during germination when cellular proteases remove acidic residues from a central domain and both termini. These deletions also result in RIP activation in vitro. However, the effectiveness of RIP1 activity against target ribosomes remains species-dependent. To determine the potential efficiency of maize RIP1 as a plant defense protein, we used quantitative RNA gel blots to detect products of RIP activity against intact ribosomal substrates from various species. We determined the enzyme specificity of recombinant maize proRIP1 (rproRIP1), papain-activated rproRIP1 and MOD1 (an active deletion mutant of rproRIP1) against ribosomal substrates with differing levels of RIP sensitivity. The rproRIP1 had no detectable enzymatic activity against ribosomes from any of the species assayed. The papain-activated rproRIP1 was more active than MOD1 against ribosomes from either rabbit or the corn pathogen, Aspergillus flavus, but the difference was much more marked when rabbit ribosomes were used as a substrate. The papain-activated rproRIP1 was much more active against rabbit ribosomes than homologous Zea mays ribosomes and had no detectable effect on Escherichia coli ribosomes. DA - 2000/// PY - 2000/// DO - 10.1046/j.1432-1327.2000.01200.x VL - 267 IS - 7 SP - 1966-1974 ER - TY - JOUR TI - Protein recycling from the Golgi apparatus to the endoplasmic reticulum in plants and its minor contribution to calreticulin retention AU - Pagny, S AU - Cabanes-Macheteau, M AU - Gillikin, JW AU - Leborgne-Castel, N AU - Lerouge, P AU - Boston, RS AU - Faye, L AU - Gomord, V T2 - PLANT CELL AB - Using pulse-chase experiments combined with immunoprecipitation and N-glycan structural analysis, we showed that the retrieval mechanism of proteins from post-endoplasmic reticulum (post-ER) compartments is active in plant cells at levels similar to those described previously for animal cells. For instance, recycling from the Golgi apparatus back to the ER is sufficient to block the secretion of as much as 90% of an extracellular protein such as the cell wall invertase fused with an HDEL C-terminal tetrapeptide. Likewise, recycling can sustain fast retrograde transport of Golgi enzymes into the ER in the presence of brefeldin A. However, on the basis of our data, we propose that this retrieval mechanism in plants has little impact on the ER retention of a soluble ER protein such as calreticulin. Indeed, the latter is retained in the ER without any N-glycan-related evidence for a recycling through the Golgi apparatus. Taken together, these results indicate that calreticulin and perhaps other plant reticuloplasmins are possibly largely excluded from vesicles exported from the ER. Instead, they are probably retained in the ER by mechanisms that rely primarily on signals other than H/KDEL motifs. DA - 2000/5// PY - 2000/5// DO - 10.1105/tpc.12.5.739 VL - 12 IS - 5 SP - 739-755 SN - 1531-298X ER - TY - JOUR TI - Isozymatic and morphological diversity in the races of maize of Mexico AU - Sanchez, JJ AU - Goodman, MM AU - Stuber, CW T2 - ECONOMIC BOTANY DA - 2000/// PY - 2000/// DO - 10.1007/BF02866599 VL - 54 IS - 1 SP - 43-59 SN - 1874-9364 KW - Zea mays L. KW - isozymes KW - genetic diversity KW - genetic differentiation ER - TY - JOUR TI - Herbicides for potential use in lima bean (Phaseolus lunatus) production AU - Vangessel, MJ AU - Monks, DM AU - Johnson, QR T2 - WEED TECHNOLOGY AB - Herbicides registered for lima bean (Phaseolus lunatus L.) do not consistently control many troublesome weeds. Some herbicides registered for soybean (Glycine max) will control these weeds, but tolerance to lima bean is not known. Two field and two greenhouse studies were conducted to evaluate recently registered soybean herbicides for lima bean tolerance. Field studies were conducted in Delaware from 1996 to 1998, and in North Carolina during 1997 and 1998. The first field study evaluated the preemergence (PRE) herbicides cloransulam at 0.01, 0.02, 0.03, and 0.04 kg ai/ha; flumetsulam at 0.04, 0.05, 0.06, and 0.07 plus metolachlor at 1.3, 1.6, 1.8, and 2.1 kg ai/ha; sulfentrazone at 0.1, 0.15, 0.2, and 0.25 kg ai/ha; lactofen at 0.2 and 0.25 kg ai/ha; and the commercial standard treatment of imazethapyr plus metolachlor at 0.05 and 1.7 kg ai/ha, respectively. Lima bean injury 5 to 8 wk after emergence was lowest for imazethapyr plus metolachlor (standard treatment) and all four rates of cloransulam. Crop injury with flumetsulam plus metolachlor ranged from 0 to 18% and sulfentrazone ranged from 3 to 75% depending on location and rate. Lactofen treatments caused unacceptable lima bean injury. Yield in plots treated with cloransulam were consistently greater than in the plots treated with other herbicides. The second field study examined the postemergence (POST) herbicides cloransulam (0.013 or 0.02 kg ai/ha), bentazon (1.1 kg ai/ha), imazethapyr (0.035 or 0.053 kg ai/ha), and imazamox (0.018 or 0.036 kg ai/ha), applied when the crop was at the first trifoliolate stage. Cloransulam caused 0 to 13% crop injury and imazamox caused 3 to 25% injury depending on rate and location. In greenhouse studies, no differences were observed among eight common processing lima bean cultivars in tolerance to sulfentrazone applied PRE or to cloransulam, imazamox, imazethapyr, or bentazon applied POST.Nomenclature: Bentazon, 3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide; cloransulam, 3-chloro-2-[[(5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2yl)sulfonyl]amino]benzoic acid; flumetsulam, N-(2,6-difluorophenyl)-5-methyl[1,2,4]triazolo[1,5-α]pyrimidine-2-sulfonamide; imazamox, 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-(methoxymethyl)-3-pyridinecarboxylic acid; imazethapyr, 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid; lactofen, (±)-2-ethoxy-1-methyl-2-oxoethyl-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate; metolachlor, 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide; sulfentrazone, N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide; lima bean, Phaseolus lunatus L., ‘M-15’, ‘F1072’, ‘M-408’, ‘Packers’, ‘Concentrated Fordhook’, ‘8-78’, ‘Eastland’; soybean, Glycine max (L.) Merr.Additional index words: Crop tolerance; varietal sensitivity.Abbreviations: COC, crop oil concentrate; NIS, nonionic surfactant; POST, postemergence; PRE, preemergence; WAT, weeks after treatment. DA - 2000/// PY - 2000/// DO - 10.1614/0890-037x(2000)014[0279:hfpuil]2.0.co;2 VL - 14 IS - 2 SP - 279-286 SN - 1550-2740 KW - crop tolerance KW - varietal sensitivity ER - TY - JOUR TI - Effect of herbicides on pepper (Capsicum annuum) stand establishment and yield from transplants produced using various irrigation systems AU - Galloway, BA AU - Monks, DW AU - Schultheis, , JR T2 - WEED TECHNOLOGY AB - Studies were conducted in 1996 and 1997 to determine the effect of irrigation systems used to produce transplants on subsequent tolerance of banana and bell pepper (Capsicum annuum) transplants to field-applied herbicides. The irrigation systems were overhead (OH), ebb and flood (EF), and float (F). At 2 and 4 wk, banana and bell pepper injury was greatest from clomazone (1.1 kg/ha) treatments. Banana and bell pepper yield were not influenced by herbicide treatment. Although crop injury was greater in 1997, there was no herbicide or irrigation system interaction with year. OH and EF irrigated banana pepper and OH irrigated bell pepper produced the greatest total yield over two harvests, whereas F irrigated pepper yielded the least. F irrigated bell pepper plants had reduced early total yield and fancy fruits relative to other irrigation treatments. F irrigated plants yielded 32 and 22% less than OH irrigated plants in banana and bell pepper, respectively. Stand counts at 3 wk after planting (WAP) show that, unlike OH and EF treatments, F treatments lost 240 to 330 plants/ha. Differences in stand among treatments were greater in 1997 than 1996. Based on our study, the OH irrigated system appears to be the best system for producing bell pepper transplants with the greatest total yield. With banana pepper, both OH and EF irrigated systems appear to produce banana pepper transplants with the greatest total yield. Also, pepper transplant tolerance to herbicides is not affected by the irrigation system used to produce transplants.Nomenclature: Clomazone, 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone; napropamide, N,N-diethyl-2-(1-napthalenyloxy)propanamide; trifluralin, 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine; pepper, Capsicum annuum L.Additional index words: Overhead irrigation, float irrigation, ebb and flow irrigation, bell pepper, banana pepper, herbicide tolerance.Abbreviations: DAP, days after planting; EC, emulsifiable concentrate; EF, ebb and flood; F, float; ME, microencapsulated; OH, overhead; PPI, preplant incorporated; PRE, premergence; WAP, weeks after planting. DA - 2000/// PY - 2000/// DO - 10.1614/0890-037x(2000)014[0241:eohopc]2.0.co;2 VL - 14 IS - 2 SP - 241-245 SN - 0890-037X KW - overhead irrigation KW - float irrigation KW - ebb and flow irrigation KW - bell pepper KW - banana pepper KW - herbicide tolerance ER - TY - JOUR TI - Black polyethylene tunnel covers affect plant production and quality of sweetpotato transplants AU - Bonte, La AU - Villordon, AQ AU - Schultheis, , JR AU - Monks, DW T2 - HORTSCIENCE AB - The influence of a black polyethylene tunnel cover (BTC) was evaluated for its effect on quantity and quality of sweetpotato [ Ipomoea batatas (L.) Lam.] transplants in plant beds in Louisiana and North Carolina. Use of BTC increased production of `Beauregard' transplants from 63% to 553% in comparison with the bare ground control. `Jewel' was less responsive; BTC treatments increased transplant production by at least 48% in Louisiana over the bare ground control, but no increase was observed in North Carolina. Individual transplant weight was at least 34% less in BTC treatments than in the control. The first harvest of cuttings in BTC beds was at least 14 days prior to that in control beds. Transplant quality was assessed as yield of storage roots in repeated trials that extended throughout the normal growing season. Yield of storage roots was not affected by BTC in early season plantings, but was frequently lower for BTC treatment transplants in middle and late season plantings. We therefore do not recommend this method as a means of increasing sweetpotato plant production from bedded roots. DA - 2000/4// PY - 2000/4// DO - 10.21273/hortsci.35.2.202 VL - 35 IS - 2 SP - 202-204 SN - 0018-5345 KW - Ipomoea batatas KW - transplants KW - propagation ER - TY - JOUR TI - Relationship between apple fruit epicuticular wax and growth of Peltaster fructicola and Leptodontidium elatius, two fungi that cause sooty blotch disease AU - Belding, RD AU - Sutton, TB AU - Blankenship, SM AU - Young, E T2 - PLANT DISEASE AB - Sooty blotch severity varied among apple cultivars or selections surveyed in 1989 and 1992. No mycelial growth was observed on russetted areas of the cuticle that are considered impermeable. Ursolic acid and n-alkanes were the most prominent components of the epicuticular waxes of the cultivars or selections evaluated. Although there were differences in the relative proportions of these compounds among the cultivars, the differences were not related to the severity of sooty blotch. Peltaster fructicola and Leptodontidium elatius were grown on compounds that comprise the epicuticular wax of the fruit to determine if one or more of these were needed for growth. The fungi did not grow on any of the five major components of the epicuticular wax unless dilute apple juice was included. Scanning electron microscopy studies showed that mycelia of P. fructicola grew on the surface of the wax and did not appear to degrade it. Our studies support the hypothesis that P. fructicola and L. elatius fungi are epiphytes and obtain their nutrients not from components of the cuticle, but more likely from fruit leachates. DA - 2000/7// PY - 2000/7// DO - 10.1094/PDIS.2000.84.7.767 VL - 84 IS - 7 SP - 767-772 SN - 1943-7692 ER -