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Z. Y. Wang - One of the best experts on this subject based on the ideXlab platform.
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viability and longevity of pollen from transgenic and nontransgenic tall fescue festuca arundinacea poaceae plants
American Journal of Botany, 2004Co-Authors: Z. Y. Wang, M. Scott, German SpangenbergAbstract:Pollen is an important vector of gene flow in plants, particularly for outcrossing species like tall fescue. Several aspects of pollination biology were investigated using pollen from transgenic and nontransgenic plants of tall fescue ( Festuca arundinacea Schreb.), the most important forage species worldwide of the Festuca genus. To effectively assess in vitro pollen viability in tall fescue, an optimized germination medium (0.8 mol/L sucrose, 1.28 mmol/L boric acid and 1.27 mmol/L calcium nitrate) was developed. Treatment with relatively high temperatures (368 and 408C) and high doses of UV-B irradiation (900‐1500 mW/cm2) reduced pollen viability, while relative humidity did not significantly influence pollen viability. Viability of pollen from transgenic progenies (T1 and T2) was similar to that from seed-derived control plants. Pollen from primary Transgenics (T0) and primary regenerants (R0) had various levels of viability. Hand pollination using the primary regenerants and Transgenics revealed that no seed set could be obtained when pollen viability was lower than 5%. Pollen from transgenic progenies and nontransgenic control plants could survive up to 22 h under controlled conditions in growth chamber. However, under sunny atmospheric conditions, viability of transgenic and nontransgenic pollen reduced to 5% in 30 min, with a complete loss of viability in 90 min. Under cloudy atmospheric conditions, pollen remained viable up to 240 min, with about 5% viability after 150 min. This report is the first on pollen viability and longevity in transgenic forage grasses and could be useful for risk assessment of transgenic plants.
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Field performance of transgenic tall fescue (Festuca arundinacea Schreb.) plants and their progenies
Theoretical and Applied Genetics, 2003Co-Authors: Z. Y. Wang, M. Scott, J. Bell, A. Hopkins, D. LehmannAbstract:Tall fescue ( Festuca arundinacea Schreb.) is a hexaploid, outcrossing grass species widely used for forage and turf purposes. Transgenic tall fescue plants were generated by biolistic transformation of embryogenic cell suspension cultures that were derived from single genotypes of widely used cultivar Kentucky-31. Primary Transgenics from two genotypes, their corresponding regenerants from the same genotypes and control seed-derived plants were transferred to the field and evaluated for 2 years. Progenies of these three classes of plants were obtained and evaluated together with seed-derived plants in a second field experiment. The agronomic characteristics evaluated were: heading date, anthesis date, height, growth habit, number of reproductive tillers, seed yield and biomass. The agronomic performance of the primary Transgenics and regenerants was generally inferior to that of the seed-derived plants, with primary Transgenics having fewer tillers and a lower seed yield. However, no major differences between the progenies of Transgenics and the progenies of seed-derived plants were found for the agronomic traits evaluated. Primary Transgenics and regenerants from the same genotype were more uniform than plants from seeds. Progenies of Transgenics performed similarly to progenies of the regenerants. The addition of a selectable marker gene in the plant genome seems to have had little effect on the agronomic performance of the regenerated plants. No indication of weediness of the transgenic tall fescue plants was observed. Our results indicate that outcrossing grass plants generated through transgenic approaches can be incorporated into forage breeding programs.
Sergiy Lopato - One of the best experts on this subject based on the ideXlab platform.
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improvement of stress tolerance of wheat and barley by modulation of expression of dreb cbf factors
Plant Biotechnology Journal, 2011Co-Authors: Sarah Morran, Omid Eini, Tatiana Pyvovarenko, Boris Parent, Rohan Singh, Ainur Ismagul, Serik Eliby, Neil J Shirley, Peter Langridge, Sergiy LopatoAbstract:Transcription factors have been shown to control the activity of multiple stress response genes in a coordinated manner and therefore represent attractive targets for application in molecular plant breeding. We investigated the possibility of modulating the transcriptional regulation of drought and cold responses in the agriculturally important species, wheat and barley, with a view to increase drought and frost tolerance. Transgenic wheat and barley plants were generated showing constitutive (double 35S) and drought-inducible (maize Rab17) expression of the TaDREB2 and TaDREB3 transcription factors isolated from wheat grain. Transgenic populations with constitutive over-expression showed slower growth, delayed flowering and lower grain yields relative to the nontransgenic controls. However, both the TaDREB2 and TaDREB3 transgenic plants showed improved survival under severe drought conditions relative to nontransgenic controls. There were two components to the drought tolerance: real (activation of drought-stress-inducible genes) and 'seeming' (consumption of less water as a result of smaller size and/or slower growth of Transgenics compared to controls). The undesired changes in plant development associated with the 'seeming' component of tolerance could be alleviated by using a drought-inducible promoter. In addition to drought tolerance, both TaDREB2 and TaDREB3 transgenic plants with constitutive over-expression of the transgene showed a significant improvement in frost tolerance. The increased expression of TaDREB2 and TaDREB3 lead to elevated expression in the Transgenics of 10 other CBF/DREB genes and a large number of stress responsive LEA/COR/DHN genes known to be responsible for the protection of cell from damage and desiccation under stress.
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Improvement of stress tolerance of wheat and barley by modulation of expression of DREB/CBF factors
Plant Biotechnology Journal, 2011Co-Authors: Sarah Morran, Omid Eini, Tatiana Pyvovarenko, Boris Parent, Rohan Singh, Ainur Ismagul, Serik Eliby, Peter Langridge, Neil Shirley, Sergiy LopatoAbstract:P>Transcription factors have been shown to control the activity of multiple stress response genes in a coordinated manner and therefore represent attractive targets for application in molecular plant breeding. We investigated the possibility of modulating the transcriptional regulation of drought and cold responses in the agriculturally important species, wheat and barley, with a view to increase drought and frost tolerance. Transgenic wheat and barley plants were generated showing constitutive (double 35S) and drought-inducible (maize Rab17) expression of the TaDREB2 and TaDREB3 transcription factors isolated from wheat grain. Transgenic populations with constitutive over-expression showed slower growth, delayed flowering and lower grain yields relative to the nontransgenic controls. However, both the TaDREB2 and TaDREB3 transgenic plants showed improved survival under severe drought conditions relative to nontransgenic controls. There were two components to the drought tolerance: real (activation of drought-stress-inducible genes) and 'seeming' (consumption of less water as a result of smaller size and/or slower growth of Transgenics compared to controls). The undesired changes in plant development associated with the 'seeming' component of tolerance could be alleviated by using a drought-inducible promoter. In addition to drought tolerance, both TaDREB2 and TaDREB3 transgenic plants with constitutive over-expression of the transgene showed a significant improvement in frost tolerance. The increased expression of TaDREB2 and TaDREB3 lead to elevated expression in the Transgenics of 10 other CBF/DREB genes and a large number of stress responsive LEA/COR/DHN genes known to be responsible for the protection of cell from damage and desiccation under stress.
D. Lehmann - One of the best experts on this subject based on the ideXlab platform.
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Field performance of transgenic tall fescue (Festuca arundinacea Schreb.) plants and their progenies
Theoretical and Applied Genetics, 2003Co-Authors: Z. Y. Wang, M. Scott, J. Bell, A. Hopkins, D. LehmannAbstract:Tall fescue ( Festuca arundinacea Schreb.) is a hexaploid, outcrossing grass species widely used for forage and turf purposes. Transgenic tall fescue plants were generated by biolistic transformation of embryogenic cell suspension cultures that were derived from single genotypes of widely used cultivar Kentucky-31. Primary Transgenics from two genotypes, their corresponding regenerants from the same genotypes and control seed-derived plants were transferred to the field and evaluated for 2 years. Progenies of these three classes of plants were obtained and evaluated together with seed-derived plants in a second field experiment. The agronomic characteristics evaluated were: heading date, anthesis date, height, growth habit, number of reproductive tillers, seed yield and biomass. The agronomic performance of the primary Transgenics and regenerants was generally inferior to that of the seed-derived plants, with primary Transgenics having fewer tillers and a lower seed yield. However, no major differences between the progenies of Transgenics and the progenies of seed-derived plants were found for the agronomic traits evaluated. Primary Transgenics and regenerants from the same genotype were more uniform than plants from seeds. Progenies of Transgenics performed similarly to progenies of the regenerants. The addition of a selectable marker gene in the plant genome seems to have had little effect on the agronomic performance of the regenerated plants. No indication of weediness of the transgenic tall fescue plants was observed. Our results indicate that outcrossing grass plants generated through transgenic approaches can be incorporated into forage breeding programs.
M. Scott - One of the best experts on this subject based on the ideXlab platform.
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viability and longevity of pollen from transgenic and nontransgenic tall fescue festuca arundinacea poaceae plants
American Journal of Botany, 2004Co-Authors: Z. Y. Wang, M. Scott, German SpangenbergAbstract:Pollen is an important vector of gene flow in plants, particularly for outcrossing species like tall fescue. Several aspects of pollination biology were investigated using pollen from transgenic and nontransgenic plants of tall fescue ( Festuca arundinacea Schreb.), the most important forage species worldwide of the Festuca genus. To effectively assess in vitro pollen viability in tall fescue, an optimized germination medium (0.8 mol/L sucrose, 1.28 mmol/L boric acid and 1.27 mmol/L calcium nitrate) was developed. Treatment with relatively high temperatures (368 and 408C) and high doses of UV-B irradiation (900‐1500 mW/cm2) reduced pollen viability, while relative humidity did not significantly influence pollen viability. Viability of pollen from transgenic progenies (T1 and T2) was similar to that from seed-derived control plants. Pollen from primary Transgenics (T0) and primary regenerants (R0) had various levels of viability. Hand pollination using the primary regenerants and Transgenics revealed that no seed set could be obtained when pollen viability was lower than 5%. Pollen from transgenic progenies and nontransgenic control plants could survive up to 22 h under controlled conditions in growth chamber. However, under sunny atmospheric conditions, viability of transgenic and nontransgenic pollen reduced to 5% in 30 min, with a complete loss of viability in 90 min. Under cloudy atmospheric conditions, pollen remained viable up to 240 min, with about 5% viability after 150 min. This report is the first on pollen viability and longevity in transgenic forage grasses and could be useful for risk assessment of transgenic plants.
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Field performance of transgenic tall fescue (Festuca arundinacea Schreb.) plants and their progenies
Theoretical and Applied Genetics, 2003Co-Authors: Z. Y. Wang, M. Scott, J. Bell, A. Hopkins, D. LehmannAbstract:Tall fescue ( Festuca arundinacea Schreb.) is a hexaploid, outcrossing grass species widely used for forage and turf purposes. Transgenic tall fescue plants were generated by biolistic transformation of embryogenic cell suspension cultures that were derived from single genotypes of widely used cultivar Kentucky-31. Primary Transgenics from two genotypes, their corresponding regenerants from the same genotypes and control seed-derived plants were transferred to the field and evaluated for 2 years. Progenies of these three classes of plants were obtained and evaluated together with seed-derived plants in a second field experiment. The agronomic characteristics evaluated were: heading date, anthesis date, height, growth habit, number of reproductive tillers, seed yield and biomass. The agronomic performance of the primary Transgenics and regenerants was generally inferior to that of the seed-derived plants, with primary Transgenics having fewer tillers and a lower seed yield. However, no major differences between the progenies of Transgenics and the progenies of seed-derived plants were found for the agronomic traits evaluated. Primary Transgenics and regenerants from the same genotype were more uniform than plants from seeds. Progenies of Transgenics performed similarly to progenies of the regenerants. The addition of a selectable marker gene in the plant genome seems to have had little effect on the agronomic performance of the regenerated plants. No indication of weediness of the transgenic tall fescue plants was observed. Our results indicate that outcrossing grass plants generated through transgenic approaches can be incorporated into forage breeding programs.
Hui Zhang - One of the best experts on this subject based on the ideXlab platform.
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salt and paraquat stress tolerance results from co expression of the suaeda salsa glutathione s transferase and catalase in transgenic rice
Plant Cell Tissue and Organ Culture, 2006Co-Authors: Fengyun Zhao, Hui ZhangAbstract:GST (Glutathione S-transferase, EC 2.5.1.18) and CAT (Catalase, EC 1.11.1.6) play important roles in oxidative stress resistance. In this study, we transferred both GST and CAT1 of Suaeda salsa into rice (Oryza sativa cv. Zhonghua No.11) by Agrobacterium tumefaciens-mediated transformation under the control of cauliflower mosaic virus (CaMV) 35S promoter, and investigated whether co-expressing the GST and CAT1 in transgenic rice could reduce oxidative damage. Salt and paraquat stresses were applied. The data showed that co-expression of the GST and CAT1 resulted in greater increase of CAT and SOD (Superoxide Dismutase, EC 1.15.1.1) activity in the Transgenics compared to non-Transgenics following both stress imposition. Whereas the significant increase of GST activity in Transgenics only occurred in paraquat stressed plants. While the generation of H2O2, Malon dialdehyde and plasma membrane relative electrolyte leakage decreased in the Transgenics than in non-Transgenics under the same conditions. Moreover, the transgenic rice seedlings showed markedly enhanced tolerance to salt stress compared with non-Transgenics upon 200 mM NaCl treatment in greenhouse. The enhancement of the active oxygen-scavenging system that led to increased oxidative stress protection in GST + CAT1-transgenic rice plants could result not only from increased GST and CAT activity but also from the combined increase in SOD activity.
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co expression of the suaeda salsa ssnhx1 and arabidopsis avp1 confer greater salt tolerance to transgenic rice than the single ssnhx1
Molecular Breeding, 2006Co-Authors: Fengyun Zhao, Xuejie Zhang, Pinghua Li, Yanxiu Zhao, Hui ZhangAbstract:Transgenic rice plants co-expressing the Suaeda salsa SsNHX1 (vacuolar membrane Na+/H+ antiporter) and Arabidopsis AVP1 (vacuolar H+-PPase) showed enhanced salt tolerance during 3 d of 300 mM NaCl treatment under outdoor growth conditions. These transgenic rice seedlings also grew better on MS medium containing 150 mM NaCl compared to SsNHX1-transformed lines and non-transformed controls. Measurements on isolated vacuolar membrane vesicles derived from the salt stressed SsNHX1+AVP1-transgenic plants demonstrated that the vesicles had increased V-PPase hydrolytic activity in comparison with the Ss-Transgenics and non-Transgenics. Moreover the V-PPase activity was closely related to the development period of the SA-transgenic seedlings and markedly higher in 3-week-old seedlings than in 5-week-old seedlings. Statistic analysis indicated that the SA-transgenic rice plants contained relatively more ions with higher K+/Na+ ratio in their shoots compared to the SsNHX1-transformed lines upon salt treatment. Furthermore, these SA-transformants also exhibited relatively higher level of photosynthesis and root proton exportation capacity whereas reduced H2O2 generation in the same plants. In general, these results supported the hypothesis that simultaneous expression of the SsNHX1 and AVP1 conferred greater performance to the transgenic plants than that of the single SsNHX1.
