Interaction of brassinosteroid and cytokinin promotes ovule initiation and increases seed number per silique in Arabidopsis  

作　　者：Song-Hao Zu Yu-Tong Jiang Jin-Hui Chang Yan-Jie Zhang Hong-Wei Xue Wen-Hui Lin 

机构地区：[1]School of Life Sciences and Biotechnology,The Joint International Research Laboratory of Metabolic and Developmental Sciences,Joint Center for Single Cell Biology,Shanghai Jiao Tong University,Shanghai 200240,China [2]School of Agriculture and Biology,Joint Center for Single Cell Biology,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Journal of Integrative Plant Biology》2022年第3期702-716,共15页植物学报（英文版）

基　　金：funded by the National Natural Science Foundation of China(31771591,32070342,and 31761163003);Project MDS-JF-2020-8 supported by the Shanghai Jiao Tong University JiRLMDS Joint Research Fund;the Agri-X Interdisciplinary Fund of Shanghai Jiao Tong University(Agri-X20200204 and Agri-X2017006);the Bio-X Interdisciplinary Fund of Shanghai Jiao Tong University(20CX-04);the Scientific and Technological Innovation Funds of Shanghai Jiao Tong University(19×160020009)。

摘　　要：Ovule initiation is a key step that strongly influences ovule number and seed yield.Notably,mutants with enhanced brassinosteroid(BR)and cytokinin(CK)signaling produce more ovules and have a higher seed number per silique(SNS)than wild-type plants.Here,we crossed BR-and CKrelated mutants to test whether these phytohormones function together in ovule initiation.We determined that simultaneously enhancing BR and CK contents led to higher ovule and seed numbers than enhancing BR or CK separately,and BR and CK enhanced each other.Further,the BR-response transcription factor BZR1 directly interacted with the CK-response transcription factor ARABIDOPSIS RESPONSE REGULATOR1(ARR1).Treatments with BR or BR plus CK strengthened this interaction and subsequent ARR1 targeting and induction of downstream genes to promote ovule initiation.Enhanced CK signaling partially rescued the reduced SNS phenotype of BR-deficient/insensitive mutants whereas enhanced BR signaling failed to rescue the low SNS of CK-deficient mutants,suggesting that BR regulates ovule initiation and SNS through CK-mediated and-independent pathways.Our study thus reveals that interaction between BR and CK promotes ovule initiation and increases seed number,providing important clues for increasing the seed yield of dicot crops.

关 键 词：BRASSINOSTEROID CYTOKININ ovule initiation protein interaction seed number per silique 

分 类 号：Q945[生物学—植物学]