Characterization of the Crsap Family from Canavalia Rosea: Possible Roles for Adaptation to Extreme Environmental Adversities in Tropical Coral Regions

Abstract

Abiotic stressors, such as drought, salinity, alkalinity, and extreme temperature, are major environmental factors limiting plant distribution and productivity. Stress-associated proteins (SAPs), a group of A20/AN1-containing zinc-finger domain proteins, play important roles in response to both biotic and abiotic stress, as well as plant development. In this study, we isolated and characterized 14 SAP genes from the tropical littoral halophyte Canavalia rosea (Sw.) DC based on the analysis of C. rosea genomic and transcriptome sequencing data. The chromosomal localization, phylogenetic relationships, gene exon–intron structures, domain structures, putative promoter features, and expression patterns of CrSAPs in various tissues and under different abiotic treatments were analyzed. Through phylogenetic analysis, CrSAPs were divided into two subfamilies. Transcriptome expression profiling revealed that several CrSAPs in C. rosea showed specificity and differential expression in plants gathered from different habitats and under specific abiotic stressors. The expression of some CrSAPs was affected by these treatments, indicating that CrSAPs may participate in complex physiological processes of stress and ecological adaptability in C. rosea plants. Furthermore, several CrSAP genes were cloned and functionally characterized for their biological roles in abiotic stress tolerance using the yeast expression system. Remarkably, CrSAP4 and CrSAP13 may be vital candidates functioning in salt stress resistance, while several specific CrSAPs showed elevated metal tolerance. This work provides a comprehensive comparison and furthers our understanding of the plant SAP genes in the special habitat species C. rosea, thereby supplying a theoretical foundation for their functional study and further facilitating the molecular breeding of other plants with the purpose of improving stress tolerance.

Keywords: Stress-associated protein (SAP), Abiotic stress, Gene expression, Canavalia rosea