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Genome‐scale analysis of the cotton KCS gene family revealed a binary mode of action for gibberellin A regulated fiber growth
Author(s) -
Xiao GuangHui,
Wang Kun,
Huang Gai,
Zhu YuXian
Publication year - 2016
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12429
Subject(s) - gene , biology , gibberellin , mutant , genome , promoter , gene family , cell wall , gossypium , genetics , biochemistry , microbiology and biotechnology , gene expression
Production of β‐ketoacyl‐CoA, which is catalyzed by 3‐ketoacyl‐CoA synthase ( KCS ), is the first step in very long chain fatty acid (VLCFA) biosynthesis. Here we identified 58 KCS genes from Gossypium hirsutum , 31 from G. arboreum and 33 from G. raimondii by searching the assembled cotton genomes. The gene family was divided into the plant‐specific FAE1‐type and the more general ELO‐type. KCS transcripts were widely expressed and 32 of them showed distinct subgenome‐specific expressions in one or more cotton tissues/organs studied. Six GhKCS genes rescued the lethality of elo2Δelo3Δ yeast double mutant, indicating that this gene family possesses diversified functions. Most KCS genes with GA‐responsive elements (GAREs) in the promoters were significantly upregulated by gibberellin A 3 (GA). Exogenous GA 3 not only promoted fiber length, but also increased the thickness of cell walls significantly. GAREs present also in the promoters of several cellulose synthase ( CesA ) genes required for cell wall biosynthesis and they were all induced significantly by GA 3 . Because GA treatment resulted in longer cotton fibers with thicker cell walls and higher dry weight per unit cell length, we suggest that it may regulate fiber elongation upstream of the VLCFA‐ethylene pathway and also in the downstream steps towards cell wall synthesis.