[Difference in seedlings ammonium assimilation of wheat cultivars with different drought resistance under osmotic stress].
Taking wheat cultivars drought-resistant Luohan-6 and drought-sensitive Zhoumai-18 as test objects, their seedlings ammonium assimilation enzyme activities and related parameters were determined under osmotic stress. The plant biomass had an obvious decrease under osmotic stress, with a larger decrement for Zhoumai-18 than Luohan-6. Osmotic stress increased the plant ammonium content, especially for Zhoumai-18. The glutamine synthetase (GS) activity varied with wheat cultivars. For Luohan-6, the GS activity increased significantly under low osmotic stress but decreased under high osmotic stress; while for Zhoumai-18, the GS activity decreased with increasing osmotic stress. The NADH-dependent glutamate dehydrogenase (NADH-GDH) increased with increasing osmotic stress, with a marked increment under low osmotic stress for Zhoumai-18, and under high osmotic stress for Luohan-6. The NAD(+)-dependent glutamate dehydrogenase (NAD(+)-GDH) and NADP-dependent isocitrate dehydrogenase (NADP-ICDH) activities also increased with increasing osmotic stress, with a greater increment of NAD(+)-GDH activity for Zhoumai-18, and of NADP-ICDH activity for Luohan-6. It was suggested that the increased drought resistance of wheat plants could be related to the increased ammonium assimilation resulted from the enhanced GS and NADH-GDH activities under low and high osmotic stress, respectively.
Zhang
Hui-Na
HN
Ministry of Education Key Laboratory for Crop Growth and Development Regulation, College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.
Wang
Zhi-Qiang
ZQ
Cui
Guo-Jin
GJ
Lin
Tong-Bao
TB
D000383:Agriculture / Q000379:methods; D003681:Dehydration / Q000235:genetics; D055864:Droughts; D009997:Osmotic Pressure; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013312:Stress, Physiological; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D000644:Quaternary Ammonium Compounds