A molecular framework underlying low-nitrogeninduced early leaf senescence in Arabidopsis thaliana  

作　　者：Hongmei Fan Shuxuan Quan Qing Ye Lei Zhang Wei Liu Ning Zhu Xiaoqi Zhang Wenyuan Ruan Keke Yi Nigel M.Crawford Yong Wang 

机构地区：[1]State Key Laboratory of Crop Biology,College of Life Sciences,Shandong Agricultural University,Tai'an,Shandong 271018,China [2]Key Laboratory of Plant Nutrition and Fertilizer,Ministry of Agriculture,Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 10081,China [3]Section of Cell and Developmental Biology,Division of Biological Science,University of California at San Diego,La Jolla,CA 92093-0116,USA

出　　处：《Molecular Plant》2023年第4期756-774,共19页分子植物（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(grant no.31970270);Y.W.,the Taishan Scholar Foundation to Y.W.,the National Research and Development Program of China(2021YFF1000401);Y.W.,and the National Natural Science Foundation of China(grant no.32200228);the Natural Science Foundation of Shandong Province(grant no.ZR2020QC028)to H.F.

摘　　要：Nitrogen(N)deficiency causes early leaf senescence,resulting in accelerated whole-plant maturation and severely reduced crop yield.However,the molecular mechanisms underlying N-deficiency-induced early leaf senescence remain unclear,even in the model species Arabidopsis thaliana.In this study,we identified Growth,Development and Splicing 1(GDS1),a previously reported transcription factor,as a new regulator of nitrate(NO3)signaling by a yeast-one-hybrid screen using a NO3enhancer fragment from the promoter of NRT2.1.We showed that GDS1 promotes NO3 signaling,absorption and assimilation by affecting the expression of multiple NO3 regulatory genes,including Nitrate Regulatory Gene2(NRG2).Interestingly,we observedthat gds1mutants show early leaf senescence as well as reduced NO3-contentand Nuptake under N-deficient conditions.Further analyses indicated that GDS1 binds to the promoters of several senescence-related genes,including Phytochrome-lnteracting Transcription Factors 4 and 5(PIF4 and PIF5)and represses their expression.Interestingly,we found that N deficiency decreases GDS1 protein accumulation,and GDS1 could interact with Anaphase Promoting Complex Subunit 10(APC10).Genetic and biochemical experiments demonstrated that Anaphase Promoting Complex or Cyclosome(APC/C)promotes the ubiquitination and degradation of GDS1 under N deficiency,resulting in loss of PIF4 and PiF5 repression and consequent early leaf senescence.Furthermore,we discovered that overexpression of GDS1 could delay leaf senescence and improve seed yield and N-use efficiency(NUE)in Arabidopsis.In summary,our study uncovers a molecular framework illustrating a new mechanism underlying low-N-induced early leaf senescence and provides potential targets for genetic improvement of crop varieties with increased yield and NUE.

关 键 词：nitrate signaling GDS1 nitrogen-deficiency-induced leaf senescence PIF4/PIF5 APC/C ubiquitina-tion NUE 

分 类 号：Q945[生物学—植物学]