转录因子HY5自地上部向根系长距离移动协调植物碳-氮平衡  

Shoot-to-Root Mobile Transcription Factor HY5 Coordinates Plant Carbon and Nitrogen Acquisition

作　　者：Xiangbin Chen Qinfang Yao Xiuhua Gao Caifu Jiang Nicholas P.Harberd 傅向东[2,3,4,5] 

机构地区：[1]不详 [2]中国科学院遗传与发育生物学研究所 [3]中国科学院大学 [4]中科院遗传发育所分子农业生物学中心 [5]中科院植物细胞与染色体工程国家重点实验室

出　　处：《科学新闻》2017年第4期115-115,共1页Science News

基　　金：国家973计划;国家自然科学基金委项目的资助

摘　　要：很早人们就发现值物根系的氮吸收要协调地上部的光合同碳以维持基本的碳氮平衡，从而保证植物能够适应多变的生存环境，但这其中地上部和根系之间远程协调的分子机制并不为人所知。Coordination of shoot photosynthetic carbon fixation with root inorganic nitrogen uptake optimizes plant performance in a fluctuating environment [1]. However, the molecular basis of this long-distance shoot-root coordination is little understood. Here we show that Arabidopsis ELONGATED HYPOCOTYL5 (HY5), a bZIP transcription factor that regulates growth in response to light [2, 3], is a shoot-to-root mobile signal that mediates light promotion of root growth and nitrate uptake. Shoot-derived HY5 auto-activates root HY5 and also promotes root nitrate uptake by activating NRT2.1, a gene encoding a high-affinity nitrate transporter [4]. In the shoot, HY5 promotes carbon assimilation and translocation, whereas in the root, HY5 activation of NRT2.1 expression and nitrate uptake is potentiated by increased carbon photoassimilate (sucrose) levels. We further show that HY5 function is fluence-rate modulated and enables homeostatic maintenance of carbon-nitrogen balance in different light environments. Thus, mobile HY5 coordinates light-responsive carbon and nitrogen metabolism, and hence shoot and root growth, in a whole-organismal response to ambient light fluctuations.

关 键 词：协调 转录因子 平衡 植物 氮 碳 距离 分子机制 

分 类 号：G633.91[文化科学—教育学]