Evolution, expression and functional analysis of cultivated allotetraploid cotton DIR genes

BMC Plant Biology

Jinhua Wu¹  Liqiang Wu¹  Huifeng Ke¹  Guoning Wang¹  Guiyin Zhang¹  Xingfen Wang¹  Chengsheng Meng¹  Zhiying Ma¹  Zhengwen Sun¹  Yan Zhang¹  Jun Yang¹  Yuanyuan Yan¹  Zhengwen Liu¹  Bin Chen¹  Zhikun Li¹ 

[1] State Key Laboratory of North China Crop Improvement and Regulation, North China Key Laboratory for Crop Germplasm Resources of Education Ministry, Hebei Agricultural University, 071001, Baoding, China;

关键词: Cotton;    Dirigent proteins;    Evolution;    RNA-seq;    Verticillium wilt;    Fiber development;    Overexpression;   

DOI  :  10.1186/s12870-021-02859-0

来源: Springer

【 摘 要 】

BackgroundDirigent (DIR) proteins mediate regioselectivity and stereoselectivity during lignan biosynthesis and are also involved in lignin, gossypol and pterocarpan biosynthesis. This gene family plays a vital role in enhancing stress resistance and in secondary cell-wall development, but systematical understanding is lacking in cotton.ResultsIn this study, 107 GbDIRs and 107 GhDIRs were identified in Gossypium barbadense and Gossypium hirsutum, respectively. Most of these genes have a classical gene structure without intron and encode proteins containing a signal peptide. Phylogenetic analysis showed that cotton DIR genes were classified into four distinct subfamilies (a, b/d, e, and f). Of these groups, DIR-a and DIR-e were evolutionarily conserved, and segmental and tandem duplications contributed equally to their formation. In contrast, DIR-b/d mainly expanded by recent tandem duplications, accompanying with a number of gene clusters. With the rapid evolution, DIR-b/d-III was a Gossypium-specific clade involved in atropselective synthesis of gossypol. RNA-seq data highlighted GhDIRs in response to Verticillium dahliae infection and suggested that DIR gene family could confer Verticillium wilt resistance. We also identified candidate DIR genes related to fiber development in G. barbadense and G. hirsutum and revealed their differential expression. To further determine the involvement of DIR genes in fiber development, we overexpressed a fiber length-related gene GbDIR78 in Arabidopsis and validated its function in trichomes and hypocotyls.ConclusionsThese findings contribute novel insights towards the evolution of DIR gene family and provide valuable information for further understanding the roles of DIR genes in cotton fiber development as well as in stress responses.

【 授权许可】

CC BY