作 者：
Jiapeng Xing;Yubin Wang;Qizheng Yao;Yushi Zhang;Mingcai Zhang;Zhaohu L
单 位：
State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.;Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, China;State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, Chin;State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China; State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
关键词：
Brassinosteroids;Nitrogen uptake;Nitrate transporter gene;Root architecture;Maiz
摘 要：
Brassinosteroids (BRs) are steroid hormones that function in plant growth and development and response to environmental stresses and nutrient supplies. However, few studies have investigated the effect of BRs in modulating the physiological response to nitrogen (N) supply in maize. In the present study, BR signaling-deficient mutant zmbri1-RNAi lines and exogenous application of 2,4-epibrassinolide (eBL) were used to study the role of BRs in the regulation of physiological response in maize seedlings supplied with N. Exogenous application of eBL increased primary root length and plant biomass, but zmbril plants showed shorter primary roots and less plant biomass than wild-type plants under low N (LN) and normal N (NN) conditions. LN induced the expression of the BR signaling-associated genes ZmDWF4, ZmCPD, ZmDET2, and ZmBZR1 and the production of longer primary roots than NN. Knockdown of ZmBRI1 weakened the biological effects of LN-induced primary root elongation. eBL treatment increased N accumulation in shoots and roots of maize seedlings exposed to LN or NN treatment. Correspondingly, zmbril plants showed lower N accumulation in shoots and roots than wild-type plants. Along with reduced N accumulation, zmbril plants showed lower NO3 fluxes and (NO3)-N-15 uptake. The expression of nitrate transporter (NRT) genes (ZmNPF6.4, ZmNPF6.6, ZmNRT2.1, ZmNRT2.2) was lower in zmbril than in wild-type roots, but eBL treatments up-regulated the transcript expression of NRT genes. Thus, BRs modulated N physiological response and regulated the transcript expression of NRT genes to promote N uptake in maize. (C) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.
