AUTHOR=Ou Xi , Wang Yudan , Li Jingyi , Zhang Jiewen , Xie Zhenbin , He Bing , Jiang Zhehao , Wang Yuting , Su Wei , Song Shiwei , Hao Yanwei , Chen Riyuan 

TITLE=Genome-wide identification of the KNOTTED HOMEOBOX gene family and their involvement in stalk development in flowering Chinese cabbage

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1019884

DOI=10.3389/fpls.2022.1019884

ISSN=1664-462X

ABSTRACT=Gibberellin and cytokinin synergistically regulate the bolting and flowering of flowering Chinese cabbage. Previous studies have displayed that KNOX proteins act as general orchestrators of the shoot apex to promote meristem activity by simultaneously activating CTK and repressing GA biosynthesis. Little is known about the roles of BcKNOX family in the regulation of the bolting and flowering. In this study, 9 BcKNOX genes were identified and mapped unevenly on 6 of 10 flowering Chinese cabbage chromosomes. The BcKNOXs were clustered into three subfamilies based on sequences and gene structure. Four conserved domains were widely present in the proteins. Three key genes (BcKNOX1, BcKNOX3, and BcKNOX5) showed high expression levels on tested tissues at eight stages. the majority of BcKNOX genes exhibited preferential expression patterns in response to low-temperature, ZT, and GA3 treatment, suggesting that the genes were involved in bud differentiation and bolting. BcKONX1 showed high correlation coefficients within BcRGA1 and BcRGL1. Besides, BcKNOX1 and BcKNOX5 showed high correlation level with gibberellins synthetase, and CTK metabolic genes. In addition, BcKNOX1 interacted with BcRGA1 and BcRGL1, as confirmed by Y2H and biomolecular fluorescence complementation assay. This study has provided valuable foundation for the future functional characterization of flowering Chinese cabbage KNOX genes