title: Gibberellin overproduction promotes sucrose synthase expression and secondary cell wall deposition in cotton fibers.
abstract: Bioactive gibberellins (GAs) comprise an important class of natural plant growth regulators and play essential roles in cotton fiber development. To date, the molecular base of GAs' functions in fiber development is largely unclear. To address this question, the endogenous bioactive GA levels in cotton developing fibers were elevated by specifically up-regulating GA 20-oxidase and suppressing GA 2-oxidase via transgenic methods. Higher GA levels in transgenic cotton fibers significantly increased micronaire values, 1000-fiber weight, cell wall thickness and cellulose contents of mature fibers. Quantitative RT-PCR and biochemical analysis revealed that the transcription of sucrose synthase gene GhSusA1 and sucrose synthase activities were significantly enhanced in GA overproducing transgenic fibers, compared to the wild-type cotton. In addition, exogenous application of bioactive GA could promote GhSusA1 expression in cultured fibers, as well as in cotton hypocotyls. Our results suggested that bioactive GAs promoted secondary cell wall deposition in cotton fibers by enhancing sucrose synthase expression.
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Wen-Qin
authors.initials: WQ
authors.lastname: Bai
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Xiao
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Shui-Qing
authors.initials: SQ
authors.lastname: Song
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Hu
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Jian-Yan
authors.initials: JY
authors.lastname: Zeng
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Xian-Bi
authors.initials: XB
authors.lastname: Li
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Hou
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Luo
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: De-Mou
authors.initials: DM
authors.lastname: Li
authors.affiliation: Biotechnology Research Center, Southwest University, Beibei, Chongqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Pei
mesh_terms: D000595:Amino Acid Sequence; D002473:Cell Wall / Q000201:enzymology* / Q000235:genetics; D002482:Cellulose / Q000096:biosynthesis; D032561:Cotton Fiber / Q000592:standards*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000378:metabolism* / Q000494:pharmacology; D005964:Glucosyltransferases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics; D018546:Hypocotyl / Q000201:enzymology / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D002482:Cellulose; D006899:Mixed Function Oxygenases; C089210:gibberellin, 2-oxoglutarate-oxygen oxidoreductase (20-hydroxylating, oxidizing); D005964:Glucosyltransferases; C022699:sucrose synthase