Cotton KNL1, encoding a class II KNOX transcription factor, is involved in regulation of fibre development.
In this study, the GhKNL1 (KNOTTED1-LIKE) gene, encoding a classical class II KNOX protein was identified in cotton (Gossypium hirsutum). GhKNL1 was preferentially expressed in developing fibres at the stage of secondary cell wall (SCW) biosynthesis. GhKNL1 was localized in the cell nucleus, and could interact with GhOFP4, as well as AtOFP1, AtOFP4, and AtMYB75. However, GhKNL1 lacked transcriptional activation activity. Dominant repression of GhKNL1 affected fibre development of cotton. The expression levels of genes related to fibre elongation and SCW biosynthesis were altered in transgenic fibres of cotton. As a result, transgenic cotton plants produced aberrant, shrunken, and collapsed fibre cells. Length and cell-wall thickness of fibres of transgenic cotton plants were significantly reduced compared with the wild type. Furthermore, overexpression and dominant repression of GhKNL1 in Arabidopsis resulted in a reduction in interfascicular fibre cell-wall thickening of basal stems of transgenic plants. Complementation revealed that GhKNL1 rescued the defective phenotype of Arabidopsis knat7 mutant in some extent. These data suggest that GhKNL1, as a transcription factor, participates in regulating fibre development of cotton.
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Si-Ying
SY
Gong
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Geng-Qing
GQ
Huang
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Xiang
X
Sun
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Li-Xia
LX
Qin
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Yang
Y
Li
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Li
L
Zhou
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China xbli@mail.ccnu.edu.cn.
Xue-Bao
XB
Li
D032561:Cotton Fiber; D003368:Gossypium / Q000254:growth & development / Q000378:metabolism*; D010641:Phenotype; D063245:Plant Development; D010940:Plant Proteins / Q000302:isolation & purification / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D010940:Plant Proteins; D014157:Transcription Factors
Cotton (Gossypium hirsutum); dominant repression of gene expression; fibre development; knotted-like homeobox protein (KNOX); protein–protein interaction; secondary cell wall (SCW) biosynthesis.