Genome-Wide Analysis of the HSP20 Gene Family and Expression Patterns of Genes in Response to Abiotic Stresses in .

African bermudagrass ( Burtt-Davy) is an important warm-season turfgrass and forage grass species. Heat shock protein 20 (HSP20) is a diverse, ancient, and important protein family. To date, genes have not been characterized genome-widely in African bermudagrass. Here, we confirmed 41 genes in African bermudagrass genome. On the basis of the phylogenetic tree and cellular locations, the HSP20 proteins were classified into 12 subfamilies. Motif composition was consistent with the phylogeny. Moreover, we identified 15 pairs of paralogs containing nine pairs of tandem duplicates and six pairs of WGD/segmental duplicates of genes. Unsurprisingly, the syntenic genes revealed that African bermudagrass had a closer evolutionary relationship with monocots (maize and rice) than dicots ( and soybean). The expression patterns of genes were identified with the transcriptome data under abiotic stresses. According to the expression profiles, genes could be clustered into three groups (Groups I, II, and III). Group I was the largest, and these genes were up-regulated in response to heat stress as expected. In Group II, one monocot-specific , maintained higher expression levels under optimum temperature and low temperature, but not high temperature. Moreover, a pair of WGD/segmental duplicates and were among the most conserved across different plant species, and they seemed to be positively selected in response to extreme temperatures during evolution. A total of 938 -elements were captured in the putative promoters of genes. Almost half of the -elements were stress responsive, indicating that the expression pattern of genes under abiotic stresses might be largely regulated by the -elements. Additionally, three-dimensional structure simulations and protein-protein interaction networks were incorporated to resolve the function mechanism of HSP20 proteins. In summary, the findings fulfilled the HSP20 family analysis and could provide useful information for further functional investigations of the specific (e.g., , , and ) in African bermudagrass.