A transcriptional cascade involving BBX22 and HY5 finely regulates both plant height and fruit pigmentation in citrus

作     者：Jialing Fu Li Liao Jiajing Jin Zhihao Lu Juan Sun Lizhi Song Yue Huang Shengjun Liu Ding Huang Yuantao Xu Jiaxian He Bin Hu Yiqun Zhu Fangfang Wu Xia Wang Xiuxin Deng Qiang Xu 

作者机构：National Key Laboratory for Germplasm Innovation and Utilization of Horticultural CropsCollege of Horticulture and Forestry SciencesHuazhong Agricultural UniversityWuhan 430070P.R.China Hubei Hongshan LaboratoryWuhan 430070P.R.China Science and Technology Innovation Research Center of Majia PomeloShangrao 334000China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2024年第66卷第8期

页      面：1752-1768页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 

基　　金：supported by funding from the National Natural Science Foundation of China granted to Q.X.(number 31925034) the National Key Research and Development Program of China granted to Q.X.(number 2022YFF1003100) Major Special Projects and Key R&D Projects in Yunnan Province granted to Q.X.(202102AE090054) the Key Research and Development Program of Hubei granted to X.W.(number 2022BBA155) the Foundation of Hubei Hongshan Laboratory granted to Q.X.(number 2021hszd016) Key Project of Hubei Provincial Natural Science Foundation granted to Q.X.(number 2021CFA017) 

主　　题：anthocyanins BBX22 carotenoids citrus HY5 internode elongation plant height 

摘      要：Dwarfing is a pivotal agronomic trait affecting both yield and *** species exhibit substantial variation in plant height,among which internode length is a core ***,the molecular mechanism governing internode elongation remains ***,we unveiled that the transcriptional cascade consisting of B-BOX DOMAIN PROTEIN 22(BBX22)and ELONGATED HYPOCOTYL 5(HY5)finely tunes plant height and internode elongation in ***-of-function mutations of BBX22 in an early-flowering citrus(Citrus hindsii“SJG)promoted internode elongation and reduced pigment accumulation,whereas ectopic expression of BBX22 in SJG,sweet orange(***),pomelo(***)or heterologous expression of BBX22 in tomato(Solanum lycopersicum)significantly decreased internode ***,exogenous application of gibberellin A3(GA3)rescued the shortened internode and dwarf phenotype caused by *** experiments revealed that BBX22 played a dual role in regulation internode elongation and pigmentation in *** the one hand,it directly bound to and activated the expression of HY5,GA metabolism gene(GA2 OXIDASE 8,GA2ox8),carotenoid biosynthesis gene(PHYTOENE SYNTHASE 1,PSY1)and anthocyanin regulatory gene(Ruby1,a MYB DOMAIN PROTEIN).On the other hand,it acted as a cofactor of HY5,enhancing the ability of HY5 to regulate target genes ***,our results reveal the critical role of the transcriptional cascade consisting of BBX22 and HY5 in controlling internode elongation and pigment accumulation in *** the crosstalk regulatory mechanism between internode elongation and fruit pigmentation provides key genes for breeding of novel types with both dwarf and health-beneficial fortification in citrus.