Comprehensive Analysis of the Gene Family in Indicates Its Roles in the Response to Multiple Abiotic Stresses and Adaptation to Tropical Coral Islands.

Heat shock protein 20 (Hsp20) is a major family of heat shock proteins that mainly function as molecular chaperones and are markedly accumulated in cells when organisms are subjected to environmental stress, particularly heat. is an extremophile halophyte with good adaptability to environmental high temperature and is widely distributed in coastal areas or islands in tropical and subtropical regions. In this study, we identified a total of 41 genes in the genome. The gene structures, phylogenetic relationships, chromosome locations, and conserved motifs of each or encoding protein were analyzed. The promoters of s contained a series of predicted -acting elements, which indicates that the expression of different members is regulated precisely. The expression patterns of the family were analyzed by RNA sequencing both at the tissue-specific level and under different abiotic stresses, and were further validated by quantitative reverse transcription PCR. The integrated expression profiles of the s indicated that most genes were greatly upregulated (up to dozens to thousands of times) after 2 h of heat stress. However, some of the heat-upregulated genes showed completely different expression patterns in response to salt, alkaline, or high osmotic stresses, which indicates their potential specific function in mediating the response of to abiotic stresses. In addition, some of s were cloned and functionally characterized for their roles in abiotic stress tolerance in yeast. Taken together, these findings provide a foundation for functionally characterizing s to unravel their possible roles in the adaptation of this species to tropical coral reefs. Our results also contribute to the understanding of the complexity of the response of genes to other abiotic stresses and may help in future studies evaluating the functional characteristics of s for crop genetic improvement.