Genome-wide identification of ADF gene family in Chinese cabbage (Brassica rapa L. ssp. pekinensis) and functional characterization of BrADF11 under heat stress

Actin depolymerizing factors (ADFs), which function as essential actin-binding proteins (ABPs), are fundamental to plant growth, development, and stress responses by depolymerizing or severing actin filaments. However, research on the ADF gene family in Chinese cabbage remains relatively scarce. In Chinese cabbage, we identified 18 BrADF genes unevenly distributed across eight chromosomes. Phylogenetic analysis revealed that BrADF genes can be classified into four subfamilies. Cis-regulatory elements related to stress response and hormone signaling response were distributed in the promoter sequences of these genes. Expression analysis showed variability in the expression patterns of BrADF genes across different tissues, with most genes responding to heat stress; notably, BrADF11 showed significant upregulation under heat stress conditions. Furthermore, transient silencing and transient overexpression experiments proved that BrADF11 plays a negative regulatory role in the heat tolerance of Chinese cabbage. In conclusion, this study not only systematically analyzed the characteristics of ADF gene family in Chinese cabbage, but also laid a solid foundation for studying the function of Chinese Cabbage ADF genes under abiotic stress.