@article{wu_la hovary_chen_li_eng_vallejo_qu_dewey_2020, title={An Efficient Stevia rebaudiana Transformation System and In vitro Enzyme Assays Reveal Novel Insights into UGT76G1 Function}, volume={10}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-020-60776-y}, abstractNote={Abstract Stevia rebaudiana (Bertoni) is one of a very few plant species that produce zero calorie, sweet compounds known as steviol glycosides (SG). SGs differ in their sweetness and organoleptic properties depending on the number and positioning of sugar groups on the core steviol backbone. There is great interest of modulating the SG profiles of the Stevia plant to enhance the flavor profile for a given application in the food and beverage industries. Here, we report a highly efficient Agrobacterium-mediated stable transformation system using axillary shoots as the initial explant. Using this system, we generated over 200 transgenic Stevia plants overexpressing a specific isoform of UGT76G1 . By comparing the SG profiles among independent transgenic events, we demonstrated that altering UGT76G1 expression can change the ratios of specific SG species. Furthermore, using recombinant proteins produced in E . coli , we show that two closely related UGT76G1 isoforms differ in their substrate specificities, providing new insights into mechanisms underlying the diversity of SG profiles that are observed across Stevia germplasm. Finally, we found evidence suggesting that alternative and/or aberrant splicing may serve to influence the ability of the plant to produce functional UGT76G1 transcripts, and possibly produce enzyme variants within the plant.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Wu, Qian and La Hovary, Christophe and Chen, Han-Yi and Li, Xu and Eng, Hayde and Vallejo, Veronica and Qu, Rongda and Dewey, Ralph E.}, year={2020}, month={Feb} } @article{xi_patel_dong_que_qu_2018, title={Acetosyringone treatment duration affects large T-DNA molecule transfer to rice callus}, volume={18}, ISSN={["1472-6750"]}, DOI={10.1186/s12896-018-0459-5}, abstractNote={Large T-DNA fragment transfer has long been a problem for Agrobacterium-mediated transformation. Although vector systems, such as the BIBAC series, were successfully developed for the purpose, low transformation efficiencies were consistently observed.To gain insights of this problem in monocot transformation, we investigated the T-strand accumulation of various size of T-DNA in two kinds of binary vectors (one copy vs. multi-copy) upon acetosyringone (AS) induction and explored ways to improve the efficiency of the large T-DNA fragment transfer in Agrobacterium-mediated rice transformation. By performing immuno-precipitation of VirD2-T-strands and quantitative real-time PCR assays, we monitored the accumulation of the T-strands in Agrobacterium tumeficiens after AS induction. We further demonstrated that extension of AS induction time highly significantly improved large-size T-DNA transfer to rice cells.Our data provide valuable information of the T-strand dynamics and its impact on large T-DNA transfer in monocots, and likely dicots as well.}, journal={BMC BIOTECHNOLOGY}, author={Xi, Jing and Patel, Minesh and Dong, Shujie and Que, Qiudeng and Qu, Rongda}, year={2018}, month={Aug} } @article{chen_chen_luo_qu_guo_lu_2018, title={Cholesterol accumulation by suppression of SMT1 leads to dwarfism and improved drought tolerance in herbaceous plants}, volume={41}, ISSN={["1365-3040"]}, DOI={10.1111/pce.13168}, abstractNote={Dwarfism and drought tolerance are 2 valuable traits in breeding of many crops. In this study, we report the novel physiological roles of cholesterol in regulation of plant growth and drought tolerance. Compared with the wild type, sterol-C24-methyltransferase 1 (SMT1) gene transcript was greatly reduced in a bermudagrass mutant with dwarfism and enhanced drought tolerance, accompanied with cholesterol accumulation, elevated transcript levels of a small group of genes including SAMDC, and increased concentrations of putrescine (Put), spermidine (Spd), and spermine (Spm). Knock-down of OsSMT1 expression by RNA interference resulted in similar phenotypic changes in transgenic rice. Moreover, exogenously applied cholesterol also led to elevated transcripts of a similar set of genes, higher levels of Put, Spd, and Spm, improved drought tolerance, and reduced plant height in both bermudagrass and rice. We revealed that it is Spm, but not Spd, that is responsible for the height reduction in bermudagrass and rice. In conclusion, we suggest that cholesterol induces expression of SAMDC and leads to dwarfism and elevated drought tolerance in plants as a result of the promoted Spd and Spm synthesis.}, number={6}, journal={PLANT CELL AND ENVIRONMENT}, author={Chen, Miao and Chen, Jingjing and Luo, Na and Qu, Rongda and Guo, Zhenfei and Lu, Shaoyun}, year={2018}, month={Jun}, pages={1417–1426} } @article{chen_wang_geng_arellano_chen_qu_2018, title={Effects of overexpression of jasmonic acid biosynthesis genes on nicotine accumulation in tobacco}, volume={2}, ISSN={2475-4455}, url={http://dx.doi.org/10.1002/PLD3.36}, DOI={10.1002/PLD3.36}, abstractNote={Nicotine is naturally synthesized in tobacco roots and accumulates in leaves as a defense compound against herbivory attack. Nicotine biosynthesis pathway has been extensively studied with major genes and enzymes being isolated and functionally characterized. However, the molecular regulation of nicotine synthesis has not been fully understood. The phytohormone jasmonic acid (JA) mediates many aspects of plant defense responses including nicotine biosynthesis. In this study, five key genes (AtLOX2, AtAOS, AtAOC2, AtOPR3, AtJAR1) involved in JA biosynthesis from Arabidopsis were individually overexpressed, and a JA-Ile hydrolysis-related gene, NtJIH1, was suppressed by RNAi approach, to understand their effects on nicotine accumulation in tobacco. Interestingly, while transgene expression was high, levels of JA-Ile (the biologically active form of JA) were often significantly reduced. Meanwhile, nicotine content in these transgenic plants did not increase. The research revealed a tightly controlled JA signaling pathway and a complicated regulatory network for nicotine biosynthesis by JA signaling.}, number={1}, journal={Plant Direct}, publisher={Wiley}, author={Chen, Hongxia and Wang, Bingwu and Geng, Sisi and Arellano, Consuelo and Chen, Sixue and Qu, Rongda}, year={2018}, month={Jan}, pages={e00036} } @article{hu_wu_dalal_vasani_lopez_sederoff_qu_2017, title={Accumulation of medium-chain, saturated fatty acyl moieties in seed oils of transgenic Camelina sativa}, volume={12}, ISSN={["1932-6203"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85013067776&partnerID=MN8TOARS}, DOI={10.1371/journal.pone.0172296}, abstractNote={With its high seed oil content, the mustard family plant Camelina sativa has gained attention as a potential biofuel source. As a bioenergy crop, camelina has many advantages. It grows on marginal land with low demand for water and fertilizer, has a relatively short life cycle, and is stress tolerant. As most other crop seed oils, camelina seed triacylglycerols (TAGs) consist of mostly long, unsaturated fatty acyl moieties, which is not desirable for biofuel processing. In our efforts to produce shorter, saturated chain fatty acyl moieties in camelina seed oil for conversion to jet fuel, a 12:0-acyl-carrier thioesterase gene, UcFATB1, from California bay (Umbellularia californica Nutt.) was expressed in camelina seeds. Up to 40% of short chain laurate (C12:0) and myristate (C14:0) were present in TAGs of the seed oil of the transgenics. The total oil content and germination rate of the transgenic seeds were not affected. Analysis of positions of these two fatty acyl moieties in TAGs indicated that they were present at the sn-1 and sn-3 positions, but not sn-2, on the TAGs. Suppression of the camelina KASII genes by RNAi constructs led to higher accumulation of palmitate (C16:0), from 7.5% up to 28.5%, and further reduction of longer, unsaturated fatty acids in seed TAGs. Co-transformation of camelina with both constructs resulted in enhanced accumulation of all three medium-chain, saturated fatty acids in camelina seed oils. Our results show that a California bay gene can be successfully used to modify the oil composition in camelina seed and present a new biological alternative for jet fuel production.}, number={2}, journal={PLOS ONE}, author={Hu, Zhaohui and Wu, Qian and Dalal, Jyoti and Vasani, Naresh and Lopez, Harry O. and Sederoff, Heike W. and Qu, Rongda}, year={2017}, month={Feb} } @article{lin_donohoe_ahuja_garrity_qu_tucker_himmel_wei_2017, title={Evaluation of parameters affecting switchgrass tissue culture: toward a consolidated procedure for Agrobacterium-mediated transformation of switchgrass (Panicum virgatum)}, volume={13}, ISSN={["1746-4811"]}, DOI={10.1186/s13007-017-0263-6}, abstractNote={Switchgrass (Panicum virgatum), a robust perennial C4-type grass, has been evaluated and designated as a model bioenergy crop by the U.S. DOE and USDA. Conventional breeding of switchgrass biomass is difficult because it displays self-incompatible hindrance. Therefore, direct genetic modifications of switchgrass have been considered the more effective approach to tailor switchgrass with traits of interest. Successful transformations have demonstrated increased biomass yields, reduction in the recalcitrance of cell walls and enhanced saccharification efficiency. Several tissue culture protocols have been previously described to produce transgenic switchgrass lines using different nutrient-based media, co-cultivation approaches, and antibiotic strengths for selection.After evaluating the published protocols, we consolidated these approaches and optimized the process to develop a more efficient protocol for producing transgenic switchgrass. First, seed sterilization was optimized, which led to a 20% increase in yield of induced calluses. Second, we have selected a N6 macronutrient/B5 micronutrient (NB)-based medium for callus induction from mature seeds of the Alamo cultivar, and chose a Murashige and Skoog-based medium to regenerate both Type I and Type II calluses. Third, Agrobacterium-mediated transformation was adopted that resulted in 50-100% positive regenerated transformants after three rounds (2 weeks/round) of selection with antibiotic. Genomic DNA PCR, RT-PCR, Southern blot, visualization of the red fluorescent protein and histochemical β-glucuronidase (GUS) staining were conducted to confirm the positive switchgrass transformants. The optimized methods developed here provide an improved strategy to promote the production and selection of callus and generation of transgenic switchgrass lines.The process for switchgrass transformation has been evaluated and consolidated to devise an improved approach for transgenic switchgrass production. With the optimization of seed sterilization, callus induction, and regeneration steps, a reliable and effective protocol is established to facilitate switchgrass engineering.}, journal={PLANT METHODS}, author={Lin, Chien-Yuan and Donohoe, Bryon S. and Ahuja, Neha and Garrity, Deborah M. and Qu, Rongda and Tucker, Melvin P. and Himmel, Michael E. and Wei, Hui}, year={2017}, month={Dec} } @article{zhou_bailey_niblett_qu_2016, title={Control of brown patch (Rhizoctonia solani) in tall fescue (Festuca arundinacea Schreb.) by host induced gene silencing}, volume={35}, ISSN={["1432-203X"]}, DOI={10.1007/s00299-015-1921-7}, number={4}, journal={PLANT CELL REPORTS}, author={Zhou, Binbin and Bailey, Ana and Niblett, C. L. and Qu, Rongda}, year={2016}, month={Apr}, pages={791–802} } @article{zhou_luo_qu_2016, title={Expression of the shrimp antimicrobial peptide penaeidin 4-1 confers resistance against brown patch disease in tall fescue}, volume={125}, ISSN={["1573-5044"]}, DOI={10.1007/s11240-016-0963-z}, number={3}, journal={PLANT CELL TISSUE AND ORGAN CULTURE}, author={Zhou, Binbin and Luo, Hong and Qu, Rongda}, year={2016}, month={Jun}, pages={599–603} } @article{dalal_yalamanchili_hovary_ji_rodriguez-welsh_aslett_ganapathy_grunden_sederoff_qu_et al._2015, title={A novel gateway-compatible binary vector series (PC-GW) for flexible cloning of multiple genes for genetic transformation of plants}, volume={81}, ISSN={["1095-9890"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938634755&partnerID=MN8TOARS}, DOI={10.1016/j.plasmid.2015.06.003}, abstractNote={The rapidly advancing field of plant synthetic biology requires transforming plants with multiple genes. This has sparked a growing interest in flexible plant transformation vectors, which can be used for multi-gene transformations. We have developed a novel binary vector series, named the PC-GW series (GenBank: KP826769-KP826773), for Agrobacterium-mediated plant transformation. The PC-GW vectors use the pCAMBIA vector backbone, and contain NPTII, hpt, bar, mCherry or egfp genes as selectable markers for plant transformation. In a modified multiple cloning site (MCS) of the T-DNA region, we have placed the attR1, attR2 and ccdB sequences for rapid cloning of one to four genes by Gateway™-assisted recombination. In addition, we have introduced four meganuclease sites, and other restriction sites for multi-gene vector construction. Finally, we have placed a CaMV 35S promoter and a 35S terminator on the 5' and 3' ends of the MCS. The CaMV 35S promoter is flanked by PstI restriction sites that can be used to replace it with another promoter sequence if needed. The PC-GW vectors provide choices for selectable markers, cloning methods, and can accommodate up to eight gene constructs in a single T-DNA, thereby significantly reducing the number of transformations or crosses needed to generate multi-transgene expressing plants.}, journal={PLASMID}, author={Dalal, J. and Yalamanchili, R. and Hovary, C. La and Ji, M. and Rodriguez-Welsh, M. and Aslett, D. and Ganapathy, S. and Grunden, A. and Sederoff, Heike and Qu, R. D. and et al.}, year={2015}, month={Sep}, pages={55–62} } @article{dalal_lopez_vasani_hu_swift_yalamanchili_dvora_lin_xie_qu_et al._2015, title={A photorespiratory bypass increases plant growth and seed yield in biofuel crop Camelina sativa}, volume={8}, ISSN={["1754-6834"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84945972179&partnerID=MN8TOARS}, DOI={10.1186/s13068-015-0357-1}, abstractNote={Camelina sativa is an oilseed crop with great potential for biofuel production on marginal land. The seed oil from camelina has been converted to jet fuel and improved fuel efficiency in commercial and military test flights. Hydrogenation-derived renewable diesel from camelina is environmentally superior to that from canola due to lower agricultural inputs, and the seed meal is FDA approved for animal consumption. However, relatively low yield makes its farming less profitable. Our study is aimed at increasing camelina seed yield by reducing carbon loss from photorespiration via a photorespiratory bypass. Genes encoding three enzymes of the Escherichia coli glycolate catabolic pathway were introduced: glycolate dehydrogenase (GDH), glyoxylate carboxyligase (GCL) and tartronic semialdehyde reductase (TSR). These enzymes compete for the photorespiratory substrate, glycolate, convert it to glycerate within the chloroplasts, and reduce photorespiration. As a by-product of the reaction, CO2 is released in the chloroplast, which increases photosynthesis. Camelina plants were transformed with either partial bypass (GDH), or full bypass (GDH, GCL and TSR) genes. Transgenic plants were evaluated for physiological and metabolic traits.Expressing the photorespiratory bypass genes in camelina reduced photorespiration and increased photosynthesis in both partial and full bypass expressing lines. Expression of partial bypass increased seed yield by 50-57 %, while expression of full bypass increased seed yield by 57-73 %, with no loss in seed quality. The transgenic plants also showed increased vegetative biomass and faster development; they flowered, set seed and reached seed maturity about 1 week earlier than WT. At the transcriptional level, transgenic plants showed differential expression in categories such as respiration, amino acid biosynthesis and fatty acid metabolism. The increased growth of the bypass transgenics compared to WT was only observed in ambient or low CO2 conditions, but not in elevated CO2 conditions.The photorespiratory bypass is an effective approach to increase photosynthetic productivity in camelina. By reducing photorespiratory losses and increasing photosynthetic CO2 fixation rates, transgenic plants show dramatic increases in seed yield. Because photorespiration causes losses in productivity of most C3 plants, the bypass approach may have significant impact on increasing agricultural productivity for C3 crops.}, number={1}, journal={BIOTECHNOLOGY FOR BIOFUELS}, author={Dalal, Jyoti and Lopez, Harry and Vasani, Naresh B. and Hu, Zhaohui and Swift, Jennifer E. and Yalamanchili, Roopa and Dvora, Mia and Lin, Xiuli and Xie, Deyu and Qu, Rongda and et al.}, year={2015}, month={Oct} } @article{wang_lewis_shi_song_gao_li_chen_qu_2015, title={Genetic Factors for Enhancement of Nicotine Levels in Cultivated Tobacco}, volume={5}, ISSN={["2045-2322"]}, DOI={10.1038/srep17360}, abstractNote={Nicotine has practical applications relating to smoking cessation devices and alternative nicotine products. Genetic manipulation for increasing nicotine content in cultivated tobacco (Nicotiana tabacum L.) may be of value for industrial purposes, including the possibility of enhancing the efficiency of nicotine extraction. Biotechnological approaches have been evaluated in connection with this objective, but field-based results are few. Here, we report characterization of two genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs), NtMYC2a and NtMYC2b from tobacco. Overexpression of NtMYC2a increased leaf nicotine levels in T1 transgenic lines approximately 2.3-fold in greenhouse-grown plants of tobacco cultivar 'NC 95'. Subsequent field testing of T2 and T3 generations of transgenic NtMYC2a overexpression lines showed nicotine concentrations were 76% and 58% higher than control lines, respectively. These results demonstrated that the increased nicotine trait was stably inherited to the T2 and T3 generations, indicating the important role that NtMYC2a plays in regulating nicotine accumulation in N. tabacum and the great potential of NtMYC2a overexpression in tobacco plants for industrial nicotine production. Collected data in this study also indicated a negative feedback inhibition of nicotine biosynthesis. Further enhancement of nicotine accumulation in tobacco leaf may require modification of the processes of nicotine transport and deposition.}, journal={SCIENTIFIC REPORTS}, author={Wang, Bingwu and Lewis, Ramsey S. and Shi, Junli and Song, Zhongbang and Gao, Yulong and Li, Wenzheng and Chen, Hongxia and Qu, Rongda}, year={2015}, month={Dec} } @article{patel_milla-lewis_zhang_templeton_reynolds_richardson_biswas_zuleta_dewey_qu_et al._2015, title={Overexpression of ubiquitin-like LpHUB1 gene confers drought tolerance in perennial ryegrass}, volume={13}, ISSN={["1467-7652"]}, DOI={10.1111/pbi.12291}, abstractNote={HUB1, also known as Ubl5, is a member of the subfamily of ubiquitin-like post-translational modifiers. HUB1 exerts its role by conjugating with protein targets. The function of this protein has not been studied in plants. A HUB1 gene, LpHUB1, was identified from serial analysis of gene expression data and cloned from perennial ryegrass. The expression of this gene was reported previously to be elevated in pastures during the summer and by drought stress in climate-controlled growth chambers. Here, pasture-type and turf-type transgenic perennial ryegrass plants overexpressing LpHUB1 showed improved drought tolerance, as evidenced by improved turf quality, maintenance of turgor and increased growth. Additional analyses revealed that the transgenic plants generally displayed higher relative water content, leaf water potential, and chlorophyll content and increased photosynthetic rate when subjected to drought stress. These results suggest HUB1 may play an important role in the tolerance of perennial ryegrass to abiotic stresses.}, number={5}, journal={PLANT BIOTECHNOLOGY JOURNAL}, publisher={Wiley-Blackwell}, author={Patel, Minesh and Milla-Lewis, Susana and Zhang, Wanjun and Templeton, Kerry and Reynolds, William C. and Richardson, Kim and Biswas, Margaret and Zuleta, Maria C. and Dewey, Ralph E. and Qu, Rongda and et al.}, year={2015}, month={Jun}, pages={689–699} } @article{zhao_qu_li_xu_frazier_2014, title={Tissue culture, genetic transformation, and improvement of switchgrass through genetic engineering}, journal={Compendium of bioenergy plants: switchgrass}, author={Zhao, B. Y. and Qu, R. D. and Li, R. Y. and Xu, B. and Frazier, T.}, year={2014}, pages={253–293} } @article{zhang_dewey_boss_phillippy_qu_2013, title={Enhanced Agrobacterium-mediated transformation efficiencies in monocot cells is associated with attenuated defense responses}, volume={81}, ISSN={["1573-5028"]}, DOI={10.1007/s11103-012-9997-8}, number={3}, journal={PLANT MOLECULAR BIOLOGY}, author={Zhang, Wan-Jun and Dewey, Ralph E. and Boss, Wendy and Phillippy, Brian Q. and Qu, Rongda}, year={2013}, month={Feb}, pages={273–286} } @article{patel_dewey_qu_2013, title={Enhancing Agrobacterium tumefaciens-mediated transformation efficiency of perennial ryegrass and rice using heat and high maltose treatments during bacterial infection}, volume={114}, ISSN={["1573-5044"]}, DOI={10.1007/s11240-013-0301-7}, number={1}, journal={PLANT CELL TISSUE AND ORGAN CULTURE}, author={Patel, Minesh and Dewey, Ralph E. and Qu, Rongda}, year={2013}, month={Jul}, pages={19–29} } @article{liu_feng_franks_qu_xie_xiang_2013, title={Plant regeneration and genetic transformation of C. canadensis: a non-model plant appropriate for investigation of flower development in Cornus (Cornaceae)}, volume={32}, ISSN={0721-7714, 1432-203X}, url={http://link.springer.com/10.1007/s00299-012-1341-x}, DOI={10.1007/s00299-012-1341-x}, number={1}, journal={Plant Cell Reports}, publisher={Springer Science and Business Media LLC}, author={Liu, Xiang and Feng, Chun-Miao and Franks, Robert and Qu, Rongda and Xie, De-Yu and Xiang, Qiu-Yun Jenny}, year={2013}, month={Jan}, pages={77–87} } @article{zhou_xu_wang_cheng_li_qu_2012, title={Dilute sulfuric acid pretreatment of transgenic switchgrass for sugar production}, volume={104}, ISSN={["0960-8524"]}, DOI={10.1016/j.biortech.2011.11.051}, abstractNote={Conventional Alamo switchgrass and its transgenic counterparts with reduced/modified lignin were subjected to dilute sulfuric acid pretreatment for improved sugar production. At 150 °C, the effects of acid concentration (0.75%, 1%, 1.25%) and residence time (5, 10, 20, 30 min) on sugar productions in pretreatment and enzymatic hydrolysis were investigated, with the optimal pretreatment conditions determined for each switchgrass genotype based on total sugar yield and the amounts of sugar degradation products generated during the pretreatment. The results show that genetic engineering, although did not cause an appreciable lignin reduction, resulted in a substantial increase in the ratio of acid soluble lignin:acid insoluble lignin, which led to considerably increased sugar productions in both pretreatment and enzymatic hydrolysis. At an elevated threshold concentration of combined 5-hydroxyfuranmethal and furfural (2.0 g/L), the overall carbohydrate conversions of conventional switchgrass and its transgenic counterparts, 10/9-40 and 11/5-47, reached 75.9%, 82.6%, and 82.2%, respectively.}, journal={BIORESOURCE TECHNOLOGY}, author={Zhou, Xu and Xu, Jiele and Wang, Ziyu and Cheng, Jay J. and Li, Ruyu and Qu, Rongda}, year={2012}, month={Jan}, pages={823–827} } @article{wang_xu_pandey_cheng_li_qu_2012, title={Improvement of Sugar Production from Transgenic Switchgrass with Low-Temperature Alkali Pretreatment}, volume={26}, ISSN={["1520-5029"]}, DOI={10.1021/ef3004575}, abstractNote={Genetically modified switchgrass (cv. Alamo) and its conventional plant were both pretreated using two groups of conditions: lime at 50 °C and the combination of lime and NaOH at ambient temperature. The results show that the transgenic plant (with altered lignin content and composition) was more susceptible to alkali pretreatment than the conventional plant. At the recommended conditions (0.1 g/g of raw biomass and 12 h) for lime pretreatment at 50 °C, the glucan and xylan conversions of transgenic switchgrass were 12 and 10%, respectively, higher than those of the conventional plant. These increases were reduced to 7 and 8% for glucan and xylan conversions, respectively, when the best conditions (0.025 g of lime/g of raw biomass, 0.1 g of NaOH/g of raw biomass, and 6 h) for combined alkali pretreatment at ambient temperature were employed. The advantage of transgenics over a conventional plant in sugar production could be maximized if proper pretreatment conditions were used.}, number={5}, journal={ENERGY & FUELS}, author={Wang, Ziyu and Xu, Jiele and Pandey, Pankaj and Cheng, Jay J. and Li, Ruyu and Qu, Rongda}, year={2012}, month={May}, pages={3054–3061} } @article{wang_li_xu_marita_hatfield_qu_cheng_2012, title={Sodium hydroxide pretreatment of genetically modified switchgrass for improved enzymatic release of sugars}, volume={110}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2012.01.097}, DOI={10.1016/j.biortech.2012.01.097}, abstractNote={Overcoming biomass recalcitrance to bioconversion is crucial for cellulosic biofuels commercialization. In this study, Alamo switchgrass (Panicum virgatum L.) was genetically transformed to suppress the expression of 4-coumarate-CoA ligase (4CL). The transgenic plants were determined to have lignin content reductions of up to 5.8%. The ratios of acid soluble lignin (ASL) to acid insoluble lignin (AIL) and syringyl/guaiacyl (S/G) in transgenic plants were 21.4–64.3% and 11.8–164.5%, respectively, higher than those of conventional biomass. Both conventional and transgenic plants were pretreated with 0.5%, 1%, and 2% (w/v) NaOH for 15, 30, and 60 min at 121 °C, followed by enzymatic hydrolysis with commercial cellulases and xylanases. At the optimal conditions, the glucan and xylan conversion efficiency in the best transgenic plants were 16% and 18% higher than the conventional plant, respectively. The results show that down-regulation of 4CL gene promoted enzymatic hydrolysis of plant cell walls following a mild alkali pretreatment.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Wang, Ziyu and Li, Ruyu and Xu, Jiele and Marita, Jane M. and Hatfield, Ronald D. and Qu, Rongda and Cheng, Jay J.}, year={2012}, month={Apr}, pages={364–370} } @article{li_qu_2011, title={High throughput Agrobacterium-mediated switchgrass transformation}, volume={35}, ISSN={["1873-2909"]}, DOI={10.1016/j.biombioe.2010.11.025}, abstractNote={Switchgrass is one of the most important biomass/bioenergy crops. For its improvement as a feedstock through biotechnological approach, we have developed a high throughput Agrobacterium-mediated transformation system for cv. Alamo and two new elite cultivars, Performer and Colony. Highly regenerable and transformation-competent embryogenic calli were identified and used for genetic transformation. GFP reporter gene was employed to identify transformation events at early stages and to guide modifications at various stages for improvement of transformation efficiency. The modifications included infection under vacuum, co-cultivation at desiccation conditions, resting between co-cultivation and selection, and supplement of L-proline in the callus culture and selection media. Transformation efficiency over 90% was routinely achieved for Performer, and around 50% for Alamo and Colony. The new system substantially improved switchgrass transformation efficiency and will significantly contribute to the genetic improvement of this important biofuel feedstock via biotechnological approach.}, number={3}, journal={BIOMASS & BIOENERGY}, author={Li, Ruyu and Qu, Rongda}, year={2011}, month={Mar}, pages={1046–1054} } @article{li_bruneau_qu_2010, title={Morphological mutants of St. Augustinegrass induced by gamma ray irradiation}, volume={129}, ISSN={["1439-0523"]}, DOI={10.1111/j.1439-0523.2009.01735.x}, abstractNote={With 3 figures and 3 tables St. Augustinegrass is a widely used turf and pasture grass in the southern US. ‘Raleigh’ is a cultivar known for superior cold tolerance than other St. Augustinegrass cultivars. However, its coarse-leaf texture and long internodes are undesirable when planted in home lawns. Mutagenesis by gamma ray irradiation was employed to treat node cuttings and calli for inducing semi-dwarf growth phenotype. Dosages of 48.5 and 72.6 Gy were determined as LD50 and LD20 for the cuttings, respectively. Regeneration ability of callus was greatly reduced when irradiated with higher dosages (over 100 Gy). Thirteen morphological mutants were identified among over 3000 node cuttings and 80 pieces of calli treated. Most mutants were semi-dwarf type with reduced internode length and leaf blade length. One mutant had much less and shorter stolons and displayed an upright and tufty growth pattern. The altered morphological traits were stable as shown by their growth performance in various locations and conditions.}, number={4}, journal={PLANT BREEDING}, author={Li, R. and Bruneau, A. H. and Qu, R.}, year={2010}, month={Aug}, pages={412–416} } @article{li_qu_bruneau_livingston_2010, title={Selection for freezing tolerance in St. Augustinegrass through somaclonal variation and germplasm evaluation}, volume={129}, ISSN={["1439-0523"]}, DOI={10.1111/j.1439-0523.2009.01743.x}, abstractNote={With 4 figures and 1 table St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] is the least cold-hardy turfgrass species. Development of freezing-tolerant St. Augustinegrass cultivars would greatly benefit home owners in many southern states of the US. Towards this breeding goal, 7800 plants regenerated through tissue culture and 36 germplasm accessions were screened for improved freezing tolerance. Among the conditions tested, 1 week at 13°C followed by another week at 3°C, then freezing at −3 to −5°C for 3 h, was found to be suitable to distinguish genotypes in freezing tests. The experiments revealed that germplasm accession Elm4 was significantly more freezing-tolerant under a controlled environment than ‘Raleigh’, the current commercially available, most freezing-tolerant cultivar. In addition, out of 7800 regenerated plants from tissue culture, somaclonal variant SVC3 showed significantly more freezing-tolerant than its parent ‘Raleigh’.}, number={4}, journal={PLANT BREEDING}, author={Li, R. and Qu, R. and Bruneau, A. H. and Livingston, D. P.}, year={2010}, month={Aug}, pages={417–421} } @article{li_bruneau_qu_2010, title={Tissue culture-induced morphological somaclonal variation in St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]}, volume={129}, ISSN={["1439-0523"]}, DOI={10.1111/j.1439-0523.2009.01647.x}, abstractNote={With 2 figures and 1 table Abstract Somaclonal variation has been observed in many plant species and is an alternative way to create variants and expand the germplasm pool. A large scale tissue culture experiment was conducted with St. Augustinegrass, an important turfgrass species for the southern USA, to induce somaclonal variation to enlarge the germplasm pool for breeding efforts. Using an improved protocol, approximately 7900 St. Augustinegrass plants were regenerated from cv. ‘Raleigh’, and 119 morphological variants were identified. Among the variants, 115 had a semi-dwarf growth habit with shorter and narrower leaves, and shortened internodes and stolons. However, 100 of them showed little vigour, which either grew very slowly or did not survive. The remaining 15 showed reasonable growth vigour and were further investigated in the field. Among them, 13 were semi-dwarf and 2 had longer leaves. In addition, 2 other variants, with variegated (yellow striping) leaves, or significantly thicker stems were also observed and characterized. The altered traits in the variant lines were stable during vegetative propagation and when grown in different environments.}, number={1}, journal={PLANT BREEDING}, author={Li, R. and Bruneau, A. H. and Qu, R.}, year={2010}, month={Feb}, pages={96–99} } @article{sivamani_delong_qu_2009, title={Protamine-mediated DNA coating remarkably improves bombardment transformation efficiency in plant cells}, volume={28}, ISSN={["1432-203X"]}, DOI={10.1007/s00299-008-0636-4}, number={2}, journal={PLANT CELL REPORTS}, author={Sivamani, Elumalai and DeLong, Robert K. and Qu, Rongda}, year={2009}, month={Feb}, pages={213–221} } @article{sivamani_starmer_qu_2009, title={Sequence analysis of rice rubi3 promoter gene expression cassettes for improved transgene expression}, volume={177}, ISSN={["0168-9452"]}, DOI={10.1016/j.plantsci.2009.08.006}, abstractNote={In a construct containing a GUS reporter gene driven by the 5′ regulatory elements from rubi3, expression was enhanced 4-fold when a 20-nucleotide (nt) GUS 5′ untranslated sequence was replaced with 9 nt sequences derived from rubi3′s second exon. The roles of the sequences immediately upstream from the GUS translation initiation codon, and their significance in gene expression, were investigated. Sequence analysis suggests that complementarity between sequences immediately 5′ of a translation initiation codon and the rice 17S rRNA may be responsible for the reduction in protein levels from constructs containing the GUS leader sequence. The results demonstrate an affect sequences immediately upstream from transgenic coding sequences have on expression, and when using the rubi3 5′ regulatory sequence in particular.}, number={6}, journal={PLANT SCIENCE}, author={Sivamani, Elumalai and Starmer, Joshua D. and Qu, Rongda}, year={2009}, month={Dec}, pages={549–556} } @article{feng_qu_zhou_xie_xiang_2009, title={Shoot regeneration of dwarf dogwood (Cornus canadensis L.) and morphological characterization of the regenerated plants}, volume={97}, ISSN={["1573-5044"]}, DOI={10.1007/s11240-009-9495-0}, number={1}, journal={PLANT CELL TISSUE AND ORGAN CULTURE}, author={Feng, Chun-Miao and Qu, Rongda and Zhou, Li-Li and Xie, De-Yu and Xiang, Qiu-Yun}, year={2009}, month={Apr}, pages={27–37} } @article{lu_sivamani_li_qu_2008, title={Activity of the 5 ' regulatory regions of the rice polyubiquitin rubi3 gene in transgenic rice plants as analyzed by both GUS and GFP reporter genes}, volume={27}, ISSN={["1432-203X"]}, DOI={10.1007/s00299-008-0577-y}, number={10}, journal={PLANT CELL REPORTS}, author={Lu, Jianli and Sivamani, Elumalai and Li, Xianggan and Qu, Rongda}, year={2008}, month={Oct}, pages={1587–1600} } @article{dong_shew_tredway_lu_sivamani_miller_qu_2008, title={Expression of the bacteriophage T4 lysozyme gene in tall fescue confers resistance to gray leaf spot and brown patch diseases}, volume={17}, ISSN={["1573-9368"]}, DOI={10.1007/s11248-007-9073-3}, number={1}, journal={TRANSGENIC RESEARCH}, author={Dong, Shujie and Shew, H. David and Tredway, Lane P. and Lu, Jianli and Sivamani, Elumalai and Miller, Eric S. and Qu, Rongda}, year={2008}, month={Feb}, pages={47–57} } @article{lu_sivamani_azhakanandam_samadder_li_qu_2008, title={Gene expression enhancement mediated by the 5 ' UTR intron of the rice rubi3 gene varied remarkably among tissues in transgenic rice plants}, volume={279}, ISSN={["1617-4615"]}, DOI={10.1007/s00438-008-0333-6}, number={6}, journal={MOLECULAR GENETICS AND GENOMICS}, author={Lu, Jianli and Sivamani, Elumalai and Azhakanandam, Kasi and Samadder, Partha and Li, Xianggan and Qu, Rongda}, year={2008}, month={Jun}, pages={563–572} } @article{samadder_sivamani_lu_li_qu_2008, title={Transcriptional and post-transcriptional enhancement of gene expression by the 5 ' UTR intron of rice rubi3 gene in transgenic rice cells}, volume={279}, ISSN={["1617-4623"]}, DOI={10.1007/s00438-008-0323-8}, number={4}, journal={MOLECULAR GENETICS AND GENOMICS}, author={Samadder, Partha and Sivamani, Eltunalai and Lu, Jianli and Li, Xianggan and Qu, Rongda}, year={2008}, month={Apr}, pages={429–439} } @article{azhakanandam_weissinger_nicholson_qu_weissinger_2007, title={Amplicon-plus Targeting Technology (APTT) for rapid production of a highly unstable vaccine protein in tobacco plants (vol 64, pg 619, 2007)}, volume={64}, ISSN={["0167-4412"]}, DOI={10.1007/s11103-007-9168-5}, number={5}, journal={PLANT MOLECULAR BIOLOGY}, author={Azhakanandam, Kasi and Weissinger, Sandra M. and Nicholson, Jennifer S. and Qu, Rongda and Weissinger, Arthur K.}, year={2007}, month={Jul}, pages={619–619} } @article{azhakanandam_weissinger_nicholson_qu_weissinger_2007, title={Amplicon-plus targeting technology (APTT) for rapid production of a highly unstable vaccine protein in tobacco plants}, volume={63}, DOI={10.1007/s11103-006-9096-9}, number={3}, journal={Plant Molecular Biology}, author={Azhakanandam, K. and Weissinger, S. M. and Nicholson, J. S. and Qu, R. D. and Weissinger, A. K.}, year={2007}, pages={393–404} } @article{dong_tredway_shew_wang_sivamani_qu_2007, title={Resistance of transgenic tall fescue to two major fungal diseases}, volume={173}, ISSN={["0168-9452"]}, DOI={10.1016/j.plantsci.2007.08.002}, abstractNote={Tall fescue (Festuca arundinacea Schreb.) is an open-pollinated, perennial, cool-season turf and forage grass species of great economic importance. The main problems of maintenance of tall fescue, and many other turfgrasses, are two severe fungal diseases: gray leaf spot caused by Magnaporthe grisea, and brown patch caused by Rhizoctonia solani. Three genes from various sources have been introduced into two elite cultivars, ‘Coronado’ and ‘Matador’, of tall fescue through Agrobacterium-mediated transformation, and conferred resistance to the diseases. Two genes, the alfalfa β-1,3-glucanase AGLU1 gene and a truncated frog dermaseptin SI gene, conferred resistance to both diseases. The rice Pi9 gene was specific against gray leaf spot. Of 15 T0 transgenic plants examined, 6 showed high levels of resistance to M. grisea, and 3 had enhanced resistance to R. solani. The resistance in most of these cases was highly significant.}, number={5}, journal={PLANT SCIENCE}, author={Dong, Shujie and Tredway, Lane P. and Shew, H. David and Wang, Guo-Liang and Sivamani, Elumalai and Qu, Rongda}, year={2007}, month={Nov}, pages={501–509} } @article{sivamani_qu_2006, title={Expression enhancement of a rice polyubiquitin gene promoter}, volume={60}, ISSN={["1573-5028"]}, DOI={10.1007/s11103-005-3853-z}, number={2}, journal={PLANT MOLECULAR BIOLOGY}, author={Sivamani, E and Qu, R}, year={2006}, month={Jan}, pages={225–239} } @article{li_bruneau_qu_2006, title={Improved plant regeneration and in vitro somatic embryogenesis of St Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]}, volume={125}, ISSN={["1439-0523"]}, DOI={10.1111/j.1439-0523.2006.01193.x}, abstractNote={Abstract St Augustinegrass [ Stenotaphrum secundatum (Walt.) Kuntze] is an important warm season turf and pasture grass. In vitro tissue culture of St Augustinegrass could serve as an important mean for its improvement through genetic transformation as well as induced somaclonal variation. To optimize tissue culture conditions for plant regeneration of St Augustinegrass, tissue culture responses of 11 explant tissues and four callus induction/subculture media have been examined. Embryogenic calli with regeneration potential were observed on cultures of early immature embryo [3 days after pollination (DAP)], immature embryo (7–14 DAP), and shoot base of young seedlings. The addition of benzyladenine (BA) in the callus induction/subculture medium enhances callus regeneration ability and does not harm callus induction for immature embryos. The best response came from 7 to 14 DAP immature embryo on MS medium containing 1 mg/l 2,4‐dichlorophenoxyacetic acid and 0.5 mg/l BA. The callus induction and regeneration rates were 97.7% and 47.6% respectively. However, BA supplement reduced callus formation and failed to enhance regeneration for young leaf bases. Scanning electron microscopy revealed that plant regeneration of St Augustinegrass is via somatic embryogenesis.}, number={1}, journal={PLANT BREEDING}, author={Li, R and Bruneau, AH and Qu, R}, year={2006}, month={Feb}, pages={52–56} } @article{li_li_fei_qu_2005, title={Agrobacterium-Mediated transformation of common bermudagrass (Cynodon dactylon)}, volume={83}, ISSN={["1573-5044"]}, DOI={10.1007/s11240-005-6838-3}, number={2}, journal={PLANT CELL TISSUE AND ORGAN CULTURE}, author={Li, L and Li, R and Fei, S and Qu, R}, year={2005}, month={Nov}, pages={223–229} } @article{bahieldin_eissa_mahfouz_dyer_madkour_qu_2005, title={Evidence for non-proteinaceous inhibitor(s) of beta-glucuronidase in wheat (Triticum aestivum L.) leaf and root tissues}, volume={82}, ISSN={["1573-5044"]}, DOI={10.1007/s11240-004-5890-8}, number={1}, journal={PLANT CELL TISSUE AND ORGAN CULTURE}, author={Bahieldin, A and Eissa, HF and Mahfouz, HT and Dyer, WE and Madkour, MA and Qu, RD}, year={2005}, month={Jul}, pages={11–17} } @article{dong_qu_2005, title={High efficiency transformation of tall fescue with Agrobacterium tumefaciens}, volume={168}, ISSN={["0168-9452"]}, DOI={10.1016/j.plantsci.2005.01.008}, abstractNote={An efficient genetic transformation system for tall fescue (Festuca arundinacea Schreb.), using Agrobacterium tumefaciens-mediated T-DNA delivery, is described. Seed-derived embryogenic calli were infected with Agrobacterium tumefaciens strain EHA105 harboring plasmids pTOK47 and pCAMBIA1301. Infected calli were selected at 250 mg L−1 hyg B and the regenerated plantlets at 50 mg L−1. Using the protocol developed, 34% of the calli infected were hyg B resistant, and the overall plant transformation frequency (number of independently transformed plants over number of calli infected) was 8%. Stable integration of transgene into plant genome and GUS reporter gene expression were confirmed. Low transgene copies (1 or 2 as estimated) were observed in all the transgenic plants analyzed, and the transgene was transmitted to the progenies. Further experiments suggest an elevated 2,4-D concentration (5 mg L−1) used during callus culture and co-cultivation was partially attributable to the observed high transformation efficiency, while the inclusion of plasmid pTOK47 in Agrobacterium was not. The whole process from callus induction to transplanting green plantlets to the soil takes about six months, significantly shorter than the suspension culture approach often used in tall fescue transformation.}, number={6}, journal={PLANT SCIENCE}, author={Dong, SJ and Qu, RD}, year={2005}, month={Jun}, pages={1453–1458} } @article{chen_yang_sivamani_bruneau_wang_qu_2005, title={Selective elimination of perennial ryegrass by activation of a pro-herbicide through engineering E-coli argE gene}, volume={15}, ISSN={["1572-9788"]}, DOI={10.1007/s11032-004-7243-z}, number={4}, journal={MOLECULAR BREEDING}, author={Chen, X and Yang, WQ and Sivamani, E and Bruneau, AH and Wang, BH and Qu, RD}, year={2005}, month={May}, pages={339–347} } @article{li_qu_2004, title={Development of highly regenerable callus lines and biolistic transformation of turf-type common bermudagrass [Cynodon dactylon (L.) Pers.]}, volume={22}, ISSN={["0721-7714"]}, DOI={10.1007/s00299-003-0706-6}, number={6}, journal={PLANT CELL REPORTS}, author={Li, L and Qu, R}, year={2004}, month={Jan}, pages={403–407} } @article{qu_li_du_qu_2003, title={Lead uptake by roots of four turfgrass species in hydroponic cultures}, volume={38}, DOI={10.15242/ijaaee.c1216047}, number={4}, journal={HortScience}, author={Qu, R. L. and Li, D. and Du, R. and Qu, R.}, year={2003}, pages={623–626} } @article{li_qu_2002, title={In vitro somatic embryogenesis in turf-type bermudagrass: roles of abscisic acid and gibberellic acid, and occurrence of secondary somatic embryogenesis}, volume={121}, ISSN={["0179-9541"]}, DOI={10.1046/j.1439-0523.2002.00684.x}, abstractNote={Abstract Bermudagrass is an important warm‐season turfgrass species that is recalcitrant in regeneration in tissue culture. In a previous report, we observed that somatic embryogenesis of immature inflorescence culture was substantially improved when low levels of 2,4‐dichloro‐phenoxy acetic acid (1 mg/l) and 6‐benzylaminopurine (BAP, 0.01 mg/l) were included in the callus induction medium. The object of this study was to further improve the culture conditions to enhance somatic embryo formation and plantlet regeneration. It was shown that the abscisic acid supplement (2 or 5 mg/l) to the above callus induction medium further enhanced somatic embryogenesis in hybrid bermudagrass ( Cynodon dactylon × Cynodon transvaalensis ) cv. ‘Tifgreen’. The addition of gibberellic acid (0. 2 mg/l) to the BAP (1 mg/l)‐containing regeneration medium accelerated germination/regeneration of the somatic embryos. Secondary and repetitive somatic embryogenesis, which is rarely reported in monocots, was observed in common bermudagrass ( Cynodon dactylon , cv. ‘Savannah’), and a full course of such a development was captured by a periodical microphotography. Scanning electron microscopy further confirmed the observation.}, number={2}, journal={PLANT BREEDING}, author={Li, L and Qu, R}, year={2002}, month={Apr}, pages={155–158} } @article{bradley_bruneau_qu_2001, title={Effects of cultivar, explant treatment, and medium supplements on callus induction and plantlet regeneration in perennial ryegrass}, volume={9}, number={2001}, journal={International Turfgrass Society Research Journal}, author={Bradley, D. E. and Bruneau, A. H. and Qu, R.}, year={2001}, pages={152–156} } @article{bai_qu_2001, title={Factors influencing tissue culture responses of mature seeds and immature embryos in turf-type tall fescue}, volume={120}, ISSN={["0179-9541"]}, DOI={10.1046/j.1439-0523.2001.00594.x}, abstractNote={In an effort to optimize tissue culture responses of turf-type tall fescue for genetic transformation, the effects of five culture medium supplements on tissue culture responses were investigated with immature embryos and mature seeds of an elite cultivar, ‘Coronado’, as explant tissues. For both explants, calli induced on 6-benzylaminopurine (BAP)-containing medium had significantly improved regeneration ability. The optimal concentration of BAP for the induction of regenerable callus from mature seeds was 0.1 mg/l. Thidiazuron also improved callus regeneration frequency of mature seeds. Casein hydrolysate, L-proline and myo-inositol improved callus induction of immature embryos but not mature seeds. They did not improve callus regeneration frequencies with either explant tissue. By simply slicing the mature seeds into two halves longitudinally, the callus induction frequencies, as well as the corresponding overall plant regeneration frequencies, were increased approximately three- to six-fold in all three combinations of 2,4-dichlorophenoxyacetic acid and BAP in callus induction media.}, number={3}, journal={PLANT BREEDING}, author={Bai, Y and Qu, R}, year={2001}, month={Jun}, pages={239–242} } @article{bai_qu_2001, title={Genetic transformation of elite cultivars of turf-type tall fescue (Festuca arundinacea)}, volume={9}, number={2001}, journal={International Turfgrass Society Research Journal}, author={Bai, Y. and Qu, R.}, year={2001}, pages={129–136} } @article{qu_chaudhury_2001, title={Improved young inflorescence culture and regeneration of ifway bermudagrass (Cynodon transvaalensis x C. dactylon)}, volume={9}, number={2001}, journal={International Turfgrass Society Research Journal}, author={Qu, R. and Chaudhury, A.}, year={2001}, pages={198–201} } @article{bradley_bruneau_qu_2001, title={Scanning electron microscopic study on in vitro somatic embryogenesis in perennial ryegrass and tall fescue}, volume={9}, number={2001}, journal={International Turfgrass Society Research Journal}, author={Bradley, D. E. and Bruneau, A. H. and Qu, R.}, year={2001}, pages={146–151} } @article{bai_qu_2000, title={An evaluation of callus induction and plant regeneration in twenty-five turf-type tall fescue (Festuca arundinacea Schreb.) cultivars}, volume={55}, ISSN={["0142-5242"]}, DOI={10.1046/j.1365-2494.2000.00235.x}, abstractNote={In order to investigate the genetic variation in tissue culture response and to find the cultivars with high regeneration ability for genetic transformation, twenty-five turf-type tall fescue (Festuca arundinacea Schreb.) cultivars, including many elite ones released recently, were evaluated for their callus induction and plant regeneration responses. Callus induction was initiated from mature seeds on a Murashige and Skoog (MS) medium containing 9·0 mg l–1 2,4-dichlorophenoxyacetic acid (2,4-D). Induced calli were subcultured on the same medium with 2·0 mg l–1 2,4-D and then transferred to a MS medium supplemented with 2·5 mg l–1 6-benzylaminopurine (BAP) for plant regeneration. Significant differences were observed among the twenty-five cultivars in both callus induction and plant regeneration (P < 0·001). Callus induction rate of viable seeds varied from 4·4% to 51·9%. Callus regeneration rates ranged from 16·7% to 58·8%. Overall regeneration rates (number of regenerated calli over number of cultured viable seeds) ranged from 1% to 22%. Approximately 94% of the regenerants were green plantlets.}, number={4}, journal={GRASS AND FORAGE SCIENCE}, author={Bai, Y and Qu, R}, year={2000}, month={Dec}, pages={326–330} } @article{bahieldin_dyer_qu_2000, title={Concentration effects of dicamba on shoot regeneration in wheat}, volume={119}, ISSN={["1439-0523"]}, DOI={10.1046/j.1439-0523.2000.00523.x}, abstractNote={Shoot formation and regeneration rates of calli derived from immature embryos of three spring wheat varieties were investigated to evaluate the influence on wheat regeneration of different concentrations of dicamba (0.5, 0.1 and 0.02 mg/l) in the regeneration medium. It was found that dicamba concentrations much lower (0.02 and 0.1 mg/l) than the levels reported previously (1 and 0.5 mg/l) induced significantly more shoots per callus in all three varieties, while the enhancement in regeneration rate was variety dependent. Overall, a dicamba concentration of 0.02 mg/l was more favourable for wheat regeneration.}, number={5}, journal={PLANT BREEDING}, author={Bahieldin, A and Dyer, WE and Qu, R}, year={2000}, month={Oct}, pages={437–439} } @article{sivamani_bahieldin_wraith_al-niemi_dyer_ho_qu_2000, title={Improved biomass productivity and water use efficiency under water deficit conditions in transgenic wheat constitutively expressing the barley HVA1 gene}, volume={155}, ISSN={["0168-9452"]}, DOI={10.1016/S0168-9452(99)00247-2}, abstractNote={The ABA-responsive barley gene HVA1, a member of group 3 late embryogenesis abundant (LEA) protein genes, was introduced into spring wheat (Triticum aestivum L.) cv. Hi-Line using the biolistic bombardment method. High levels of expression of the HVA1 gene, regulated by the maize ubi1 promoter, were observed in leaves and roots of independent transgenic wheat plants and were inherited by offspring generations. T(3) progenies of four selected transgenic wheat lines were tested under greenhouse conditions for tolerance of soil water deficit. Potted plants were grown under moderate water deficit and well-watered conditions, respectively. Two homozygous and one heterozygous transgenic lines expressing the HVA1 gene had significantly (P<0.01) higher water use efficiency values, 0.66-0.68 g kg(-1), as compared to 0.57 and 0.53 g kg(-1), respectively, for the non-expressing transgenic and non-transgenic controls under moderate water deficit conditions. The two homozygous transgenic plant lines also had significantly greater total dry mass, root fresh and dry weights, and shoot dry weight compared to the two controls under soil water deficit conditions. Results of this study indicate that growth characteristics were improved in transgenic wheat plants constitutively expressing the barley HVA1 gene in response to soil water deficit.}, number={1}, journal={PLANT SCIENCE}, author={Sivamani, E and Bahieldin, A and Wraith, JM and Al-Niemi, T and Dyer, WE and Ho, THD and Qu, RD}, year={2000}, month={Jun}, pages={1–9} } @article{sivamani_brey_dyer_talbert_qu_2000, title={Resistance to wheat streak mosaic virus in transgenic wheat expressing the viral replicase (NIb) gene}, volume={6}, ISSN={["1380-3743"]}, DOI={10.1023/A:1026576124482}, number={5}, journal={MOLECULAR BREEDING}, author={Sivamani, E and Brey, CW and Dyer, WE and Talbert, LE and Qu, RD}, year={2000}, month={Oct}, pages={469–477} } @article{chaudhury_qu_2000, title={Somatic embryogenesis and plant regeneration of turf-type bermudagrass: Effect of 6-benzyladenine in callus induction medium}, volume={60}, ISSN={["0167-6857"]}, DOI={10.1023/A:1006456005961}, number={2}, journal={PLANT CELL TISSUE AND ORGAN CULTURE}, author={Chaudhury, A and Qu, R}, year={2000}, pages={113–120} } @article{shan_li_qu_2000, title={Thidiazuron promotes in vitro regeneration of wheat and barley}, volume={36}, DOI={10.1007/s11627-000-0038-y}, number={3}, journal={In Vitro Cellular & Developmental Biology. Plant}, author={Shan, X. Y. and Li, D. S. and Qu, R. D.}, year={2000}, pages={207–210} } @article{arumuganathan_tallury_fraser_bruneau_qu_1999, title={Nuclear DNA content of thirteen turfgrass species by flow cytometry}, volume={39}, number={5}, journal={Crop Science}, author={Arumuganathan, K. and Tallury, S. P. and Fraser, M. L. and Bruneau, A. H. and Qu, R.}, year={1999}, pages={1518–1521} }