The HB40-JUB1 transcriptional regulatory network controls gibberellin homeostasis in Arabidopsis  

作　　者：Shuchao Dong Danuse Tarkowska Mastoureh Sedaghatmehr Maryna Welsch Saurabh Gupta Bernd Mueller-Roeber Salma Balazadeh 

机构地区：[1]Max-Planck Institute of Molecular Plant Physiology,Am Mühlenberg 1,14476 Potsdam-Golm,Germany [2]Institute of Biology,Leiden University,Sylviusweg 72,2333 BE Leiden,The Netherlands [3]Laboratory of Growth Regulators,Czech Academy of Sciences,Institute of Experimental Botany&Palacky University,Šlechtitelû27,78371 Olomouc,Czech Republic [4]University of Potsdam,Institute of Biochemistry and Biology,Karl-Liebknecht-Stra?e 24-25,Haus 20,14476 Potsdam-Golm,Germany

出　　处：《Molecular Plant》2022年第2期322-339,共18页分子植物（英文版）

基　　金：supported by the European Rogional Dovelop-ment Fund Project Center for Experimental Plant Biology(no.CZ.02.1.01/0.00.0/16.0190000738)and the Czech Sc ence Foundation(no.18-10349S).

摘　　要：The gibberellins(GAs)are phytohormones that play fundamental roles in almost every aspect of plant growth and development.Although GA biosynthetic and signaling pathways are well understood,the mechanisms that control GA homeostasis remain largely unclear in plants.Here,we demonstrate that the homeobox transcription factor(TF)HB40 of the HD-Zip family regulates GA content at two additive con-trol levels in Arabidopsis thaliana.We show that HB40 expression is induced by GA and in turn reduces the levels of endogenous bioactive GAs by simultaneously reducing GA biosynthesis and increasing GA deac-tivation.Consistently,HB40 overexpression leads to typical GA-deficiency traits,such as small rosettes,reduced plant height,delayed flowering,and male sterility.By contrast,a loss-of-function hb40 mutation enhances GA-controlled growth.Genome-wide RNA sequencing combined with molecular-genetic ana-lyses revealed that HB40 directly activates the transcription of JUNGBRUNNEN1(JJUB1),a key TF that re-presses growth by suppressing GA biosynthesis and signaling.HB40 also activates genes encoding GA 2-oxidases(GA2oxs),which are major GA-catabolic enzymes.The effect of HB40 on plant growth is ultimately mediated through the induction of nuclear growth-repressing DELLA proteins.Collectively,our results reveal the important role of the HB40-JUB1 regulatory network in controlling GA homeostasis during plant growth.

关 键 词：ARABIDOPSIS growth GIBBERELLIN HOMEOSTASIS transcription factor HB40 JUB1 GA 2-oxidase DELLA proteins 

分 类 号：Q943.2[生物学—植物学]