Genome-wide identification of the cotton ANK gene family and functional study of GhANK169 in response to heat stress.

BACKGROUND

High temperatures significantly impair the yield and quality of cotton. Ankyrin-repeat proteins (ANKs) are among the largest superfamilies of proteins in plants and play vital roles in both biotic and abiotic stress responses.

RESULTS

In this study, we identified and characterized members of the cotton ankyrin repeat protein (ANK) gene family, focusing on the ANK-TM subfamily member GhANK169, which was highly upregulated in the RNA-seq data of cotton plants exposed to 42 °C. Overexpression of GhANK169 in tobacco at 42 °C resulted in improved phenotypic resilience, enhanced antioxidant enzyme activity, and reduced relative electrolyte leakage (REL) and malondialdehyde (MDA) content. Conversely, silencing GhANK169 in cotton via virus-induced gene silencing (VIGS) renders plants highly susceptible to heat stress, with symptoms including accelerated water loss, reduced relative water content (RWC), elevated superoxide anion (O) and hydrogen peroxide (HO) levels, and diminished reactive oxygen species (ROS) scavenging capacity. Transcriptome sequencing revealed that crucial genes associated with ABA signaling, ROS response, endoplasmic reticulum protein quality control, cytoskeleton maintenance, and substance transport were affected in the treated plants.

CONCLUSION

This study enhances our understanding of the cotton ANK gene family and offers valuable genetic resources for improving cotton heat tolerance mechanisms and breeding strategies.