MaMYB13 is involved in response to chilling stress via activating expression of VLCFAs and phenylpropanoids biosynthesis-related genes in postharvest banana fruit.

ABSTRACT

Fruit chilling injury is the result of physiological dysfunction due to membrane lipid phase change, oxidative damage of biomacromolecules and respiratory metabolism abnormality. However, the involvement of transcription factors in response to fruits chilling tolerance remains largely unclear. Here, MaMYB13 was identified to participate in banana fruit response to chilling stress. MaMYB13 has transcriptional activation activity. When exposed to low temperature, expression of MaMYB13 was enormously induced. Moreover, MaMYB13 promoter was activated by chilling stress. MaMYB13 bound to the promoters of several important very-long-chain fatty acids (VLCFAs) and phenylpropanoids biosynthesis-related genes, including MaKCS11, Ma4CL6 and MaAAE1, and activated their transcription. Furthermore, MaKIN10 X1/3 interacted with MaMYB13 and enhanced MaMYB13-mediated transcriptional activation possibly via phosphorylation. Altogether, our results unravel the mechanism of MaMYB13-MaKIN10 X1/3 interaction regulating banana fruit chilling tolerance through activating the expression of MaKCS11, Ma4CL6 and MaAAE1, providing new insights into the regulatory network of MYB transcription factor.