Abstract:
【Objective】To clone
GhMYB6 gene of MYB family in upland cotton and analyze its function in response to cotton
Verticillium wilt,so as to provide reference for exploring cotton genes related to disease-resistance and disease-resistant cotton breeding.【Method】Based on data of cotton transcriptome,the gene
GhMYB6 in response to
Verticillium wilt infection was screened and cloned,and its sequences was analyzed by bioinformatics. Its expression patterns induced by
Verticillium wilt were detected by real-time fluorescence quantitative PCR(qRT-PCR). Biological function of cotton resistance to
Verticillium wilt was preliminarily verified by virus-induced gene silencing(VIGS) technology.【Result】
GhMYB6 open reading frame(ORF) was 258 bp,encoding 85 amino acid residues,with a theoretical point(pI) of 9.34,fat coefficient of 73.41,average hydrophobicity of-0.793,relative molecular mass of 9.86 kD,instability index of 73.41,indicating that it encoded non-transmembrane,alkaline,hydrophilic protein located in the nucleus,with a SANT domain in the 11
th -63
rd amino acids. Protein GhMYB6 and
Gossypium raimondii GrMYB6 were clustered in the same small branch,indicating a close relationship between the two. After V991 infection,relative expression of
GhMYB6 was extremely significantly down-regulated compared that of control(uninfected treatment,CK) (
P<0.01) at 6 and 12 h,significantly up-regulated(
P<0.05,the same below) at 72 h and no significant difference between it and CK was found at 24 and 48 h(
P>0.05).After inhibiting
GhMYB6 gene expression by VIGS technology,compared with the negative control plant TRV:00,wilting and leaf yellowing of
GhMYB6 gene silenced plants was more serious,the disease index was significantly higher,stem brow-ning was more serious,and the number of fungal hyphae in stem segments was higher.【Conclusion】
GhMYB6 gene responds to
Verticillium dahliae V991 infection. After inhibiting
GhMYB6 gene expression,cotton is more sensitive to
Verticillium wilt and the resistance is significantly reduced,so it is speculated that GhMYB6 is a positive regulator of cotton
Verticillium wilt resistance.