Gene Expression Correlation Analysis Reveals MYC-NAC Regulatory Network in Cotton Pigment Gland Development.

Plant NAC (NAM, ATAF1/2, and CUC2) family is involved in various development processes including Programmed Cell Death (PCD) associated development. However, the relationship between NAC family and PCD-associated cotton pigment gland development is largely unknown. In this study, we identified 150, 153 and 299 genes in newly updated genome sequences of , and , respectively. All genes were divided into 8 groups by the phylogenetic analysis and most of them were conserved during cotton evolution. Using the vital regulator of gland formation as bait, expression correlation analysis screened out 6 genes which were low-expressed in glandless cotton and high-expressed in glanded cotton. These 6 genes acted downstream of and were induced by MeJA. Silencing , another MYC-coding gene, caused almost glandless phenotype and down-regulated expression of and the genes, indicating a MYC-NAC regulatory network in gland development. In addition, predicted regulatory mechanism showed that the   genes were possibly regulated by light, various phytohormones and transcription factors as well as miRNAs. The interaction network and DNA binding sites of the 6 NAC transcription factors were also predicted. These results laid the foundation for further study of gland-related genes and gland development regulatory network.