Genome-Wide Identification of the A20/AN1 Zinc Finger Protein Family Genes in and Its Two Relatives and Function Analysis of in Salinity Tolerance.

Stress-associated protein (SAP) genes-encoding A20/AN1 zinc-finger domain-containing proteins-play pivotal roles in regulating stress responses, growth, and development in plants. They are considered suitable candidates to improve abiotic stress tolerance in plants. However, the gene family in sweetpotato () and its relatives is yet to be investigated. In this study, 20 in sweetpotato, and 23 and 26 in its wild diploid relatives and were identified. The chromosome locations, gene structures, protein physiological properties, conserved domains, and phylogenetic relationships of these were analyzed systematically. Binding motif analysis of indicated that hormone and stress responsive -acting elements were distributed in their promoters. RT-qPCR or RNA-seq data revealed that the expression patterns of , , and genes varied in different organs and responded to salinity, drought, or ABA (abscisic acid) treatments differently. Moreover, we found that driven by the promoter conferred salinity tolerance in transgenic . These results provided a genome-wide characterization of genes in sweetpotato and its two relatives and suggested that is involved in salinity stress responses. Our research laid the groundwork for studying SAP-mediated stress response mechanisms in sweetpotato.