title: Genome-scale analysis of the cotton KCS gene family revealed a binary mode of action for gibberellin A regulated fiber growth.
abstract: 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 A3 (GA). Exogenous GA3 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 GA3 . 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.
authors.affiliation: The State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.|College of Life Sciences, Shaanxi Normal University, Xi'an, 710062, China.
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Xiao
authors.affiliation: Institute for Advanced Studies/College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.affiliation: The State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.
authors.forename: Gai
authors.initials: G
authors.lastname: Huang
authors.affiliation: The State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, 100871, China.|Institute for Advanced Studies/College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Yu-Xian
authors.initials: YX
authors.lastname: Zhu
mesh_terms: D005227:Fatty Acids / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D005875:Gibberellins / Q000494:pharmacology; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D003368:Gossypium / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D005875:Gibberellins; D010940:Plant Proteins; D005964:Glucosyltransferases; C478648:cellulose synthase
keywords: 3-Ketoacyl-CoA synthase; cotton; expression patterns; gibberellins; very long chain fatty acids