Open AccessCotton ( G ossypium hirsutum ) 14‐3‐3 proteins participate in regulation of fibre initiation and elongation by modulating brassinosteroid signalling
Author(s) -
Zhou Ying,
Zhang ZeTing,
Li Mo,
Wei XinZheng,
Li XiaoJie,
Li BingYing,
Li XueBao
Publication year - 2015
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12275
Subject(s) - brassinosteroid , biology , elongation , rna , promoter , gene , transgene , phosphorylation , microbiology and biotechnology , gene expression , biochemistry , mutant , arabidopsis , ultimate tensile strength , materials science , metallurgy
Summary Cotton ( Gossypium hirsutum ) fibre is an important natural raw material for textile industry in the world. Understanding the molecular mechanism of fibre development is important for the development of future cotton varieties with superior fibre quality. In this study, overexpression of Gh14‐3‐3L in cotton promoted fibre elongation, leading to an increase in mature fibre length. In contrast, suppression of expression of Gh14‐3‐3L , Gh14‐3‐3e and Gh14‐3‐3h in cotton slowed down fibre initiation and elongation. As a result, the mature fibres of the Gh14‐3‐3 RNA i transgenic plants were significantly shorter than those of wild type. This ‘short fibre’ phenotype of the 14‐3‐3 RNA i cotton could be partially rescued by application of 2,4‐epibrassinolide ( BL ). Expression levels of the BR ‐related and fibre‐related genes were altered in the Gh14‐3‐3 transgenic fibres. Furthermore, we identified Gh14‐3‐3 interacting proteins (including Gh BZR 1) in cotton. Site mutation assay revealed that Ser163 in Gh BZR 1 and Lys51/56/53 in Gh14‐3‐3L/e/h were required for Gh14‐3‐3‐Gh BZR 1 interaction. Nuclear localization of Gh BZR 1 protein was induced by BR , and phosphorylation of Gh BZR 1 by Gh BIN 2 kinase was helpful for its binding to Gh14‐3‐3 proteins. Additionally, 14‐3‐3‐regulated Gh BZR 1 protein may directly bind to Gh XTH 1 and Gh EXP promoters to regulate gene expression for responding rapid fibre elongation. These results suggested that Gh14‐3‐3 proteins may be involved in regulating fibre initiation and elongation through their interacting with Gh BZR 1 to modulate BR signalling. Thus, our study provides the candidate intrinsic genes for improving fibre yield and quality by genetic manipulation.