NO_(3)^(-)缓解小麦根部NH_(4)^(+)毒性机理  

Nitrate-dependent Alleviation of Root Ammonium Toxicity in Wheat(Triticum aestivum)

作　　者：刘笑 杜琬莹 张云秀 唐成名 李华伟[2] 夏海勇[2] 樊守金[1] 孔令安 Xiao Liu;Wanying Du;Yunxiu Zhang;Chengming Tang;Huawei Li;Haiyong Xia;Shoujin Fan;Ling’an Kong(College of Life Sciences,Shandong Normal University,Jinan 250014,China;Crop Research Institute,Shandong Academy of Agricultural Sciences,Jinan 250100,China)

机构地区：[1]山东师范大学生命科学学院,济南250014 [2]山东省农业科学院作物研究所,济南250100

出　　处：《植物学报》2024年第3期397-413,共17页Chinese Bulletin of Botany

基　　金：山东省自然科学基金(No.ZR2020MC087);国家重点研发计划(No.2022YFD2300801);山东省现代农业技术产业体系(No.SDAIT-01-07)。

摘　　要：该研究探讨了小麦(Triticum aestivum)根系NH_(4)^(+)毒性以及NO_(3)^(-)缓解其毒性机理。与7.5 mmol·L^(-1)NO_(3)^(-)处理(CK)相比,7.5 mmol·L^(-1)NH_(4)^(+)处理(SA)抑制小麦根系生长,添加1 mmol·L^(-1)NO_(3)^(-)(AN)后缓解了对根系生长的抑制。转录组分析表明,与CK相比,SA处理下,编码糖酵解途径酶、发酵关键酶、呼吸爆发性氧化酶同源物(Rbohs)、交替氧化酶(AOX)和双加氧酶相关基因显著上调表达;编码TCA循环酶、ATP合酶和水通道蛋白(AQPs)相关基因显著下调表达。与SA相比,AN处理下,糖酵解、发酵途径、Rbohs、AOX和双加氧酶相关基因的表达下调,编码TCA循环酶、ATP合酶和AQPs的基因表达上调。蛋白质组分析表明,SA处理下,糖酵解与发酵相关酶以及AOX相关基因表达上调,而AQPs相关基因表达下调。AN处理下,糖酵解与发酵相关酶以及AOX相关基因表达下调,AQPs相关基因表达上调。综上所述,单独NH_(4)^(+)处理促进糖酵解和发酵途径,抑制TCA循环,能量生成减少,最终抑制小麦根系生长,这可能与NH_(4)^(+)处理引起根系缺O_(2)胁迫有关。添加NO_(3)^(-)后抑制了糖酵解和发酵途径,促进TCA循环和能量产生,显著缓解了根系缺O_(2)胁迫以及NH_(4)^(+)对根系生长的抑制。INTRODUCTION:Nitrogen(N)is one of the most essential nutrients for the plant growth and development,and NH_(4)^(+)-N is the main form of N source.Appropriate amount of NH_(4)^(+)promotes plant growth and increase crop yield.However,when used as the only N source,NH_(4)^(+)suppresses the growth and production of crops.Wheat(Triticum aestivum)is the third largest cereal crop in China,and its production has a profound impact on the food production.As the indispensable raw material for foods,wheat is crucial to daily life,so studying NH_(4)^(+)toxicity and mitigation mechanisms are of great significance for wheat production.RATIONALE:NH_(4)^(+)toxicity is a ubiquitous issue in plants.The mechanisms of how NH_(4)^(+)causes phytotoxicity are not fully understood.To explore the mechanisms of NO_(3)^(-)-dependent alleviation of NH_(4)^(+)toxicity in the roots of wheat,both transcriptomic and proteomic approaches were used to investigate the differential expressions of genes and proteins under different nitrogen treatments.RESULTS:Compared with 7.5 mmol·L^(-1) NO_(3)^(-)(control),7.5 mmol·L^(-1) NH_(4)^(+)treatment inhibited the root growth of wheat seedlings.Transcriptome analysis showed that sole NH_(4)^(+)treatment upregulated the expressions of genes encoding glycolysis-and fermentation-related enzymes,including pyruvate decarboxylase,alcohol dehydrogenase and lactate dehydrogenase,while downregulated the expressions of genes encoding TCA cycle enzymes and the ATP synthases in the roots compared with control.Expressions of genes encoding the respiratory burst oxidase homologs(Rbohs),alternative oxidase(AOX)and dioxygenases were significantly upregulated,and expression of the PIP-type aquaporin genes were downregulated.The addition of 1 mmol·L^(-1) NO_(3)^(-)to the solution containing 7.5 mmol·L^(-1) NH_(4)^(+)downregulated the expression of genes encoding glycolysis enzymes,fermentation enzymes,Rbohs,AOX and dioxygenases,and increased the expression of genes encoding the TCA cycle enzymes,the ATP synthases and PIP

关 键 词：能量代谢 发酵 根 三羧酸循环 小麦 

分 类 号：S512.1[农业科学—作物学]