The removal of nitrate reductase phosphorylation enhances tolerance to ammonium nitrogen deficiency in rice  

作　　者：HAN Rui-cai XU Zhi-rong LI Chen-yan Adnan RASHEED PAN Xiao-hua SHI Qing-hua WU Zi-ming 

机构地区：[1]Key Laboratory of Crop Physiology,Ecology and Genetic Breeding,Ministry of Education/College of Agronomy,Jiangxi Agricultural University,Nanchang 330045,P.R.China [2]Rice Research Institute,Jiangxi Academyof Agricultural Sciences/Jiangxi Provincial Key Laboratory for Physiology and Genetics of Rice,Nanchang 330200,P.R.China

出　　处：《Journal of Integrative Agriculture》2022年第3期631-643,共13页农业科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (31560350, 31760350 and 31660431);the National Key Research and Development Program of China (2018YFD0301102);the Jiangxi Natural Science Foundation, China (20202BABL205020);the Key Research and Development Program of Jiangxi Province, China (20171ACF60018 and 20192ACB60003);the Jiangxi Agriculture Research System, China (JXARS-18);the Training Program for Academic and Technical Leaders of Major Discipline in Jiangxi Province, China (20204BCJL22044)。

摘　　要：Nitrate reductase(NR) is a key enzyme for nitrogen assimilation in plants,and its activity is regulated by posttranslational phosphorylation.To investigate the effects of dephosphorylation of the NIA1 protein on the growth and the physiological and biochemical characteristics of rice under different forms of nitrogen supplies,the phenotypes,nitrogen metabolism and reactive oxygen metabolism were measured in NIA1 phosphorylation site-directed mutant lines(S532 D and S532 A),an Os Nia1 over-expression line(OE) and Kitaake(wild type,WT).Compared with WT and OE,S532 D and S532 A have stronger nitrogen assimilation capacities.When ammonium nitrate served as the nitrogen source,the plant heights,dry weights of shoots and chlorophyll(Chl) contents of S532 D and S532 A were lower than those of the WT and OE,whereas hydrogen peroxide(H_(2)O_(2)),malondialdehyde(MDA) and nitrite contents were higher.When potassium nitrate served as the nitrogen source,the plant heights,dry weights of shoots and Chl contents of S532 D and S532 A were higher than those of the WT and OE,there were no significant differences in the contents of H_(2)O_(2) and MDA in the leaves of the test materials,and the difference in nitrite contents among different lines decreased.When ammonium sulfate served as the nitrogen source,there were no significant differences in the physiological indexes of the test materials,except NR activity.Compared with ammonium nitrate and ammonium sulfate,the content of NH_(4)^(+)-N in the leaves of each plant was lower when potassium nitrate was used as the nitrogen source.The q PCR results showed that Os GS and Os NGS1 were negatively regulated by downstream metabolites,and Os Nrt2.2 was induced by nitrate.In summary,when ammonium nitrate served as the nitrogen source,the weak growth of NIA1 phosphorylation site-directed mutant lines was due to the toxicity caused by the excessive accumulation of nitrite.When potassium nitrate served as the nitrogen source,the assimilation rates of nitrate,nitrite and ammonium salt were a

关 键 词：Oryza sativa L. nitrate reductase PHOSPHORYLATION NR activity nitrogen utilization NITRITE 

分 类 号：S511[农业科学—作物学]