GhMYB36, an R2R3 MYB transcriptional factor, confer drought tolerance and Verticillium dahliae resistance by enhancing PR1 gene expression in plants

Drought conditions and Verticillium wilt disease are two main factors limit production by preventing cotton from reaching their genetically predetermined maximum yields. Here, we isolated GhMYB36, a gene encoding a R2R3-type MYB protein in Gossypium hirsutum, which is confer drought tolerance and Verticilium wilt resistance both in Arabidopsis and cotton. GhMYB36 was highly induced by PEG-simulated drought stress (PSDS) in cotton. GhMYB36-silenced cotton plants were more sensitive to drought stress and Verticillium wilt resistance. GhMYB36 overexpression transgenic Arabidopsis and cotton plants showed better drought tolerance and Verticillium wilt resistance compared to wild type. The agro-infiltration-based transient expression of fused GhMYB36-GFP in tobacco cells indicated that GhMYB36 was located in the cell nucleus. In addition, the analysis of RNA-seq data together with qRT-PCR validation indicated that GhMYB36 improve the expression level of PR1 in GhMYB36 transgenic Arabidopsis. Luciferase interaction assays showed GhMYB36 was likely bind to the promoters of PR1 to activate the expression of PR1 and the interaction was confirmed by Yeast one hybrid. Collectively, our results suggest that GhMYB36 functions as a R2R3-type MYB protein and is essential to the improvement of drought tolerance and Verticillium wilt resistance in Arabidopsis and cotton by enhancing the expression of PR1.