Abstract：Heat shock protein 20 (Hsp20) family contains a kind of functional proteins that are widely syn-thesized in plants in response to abiotic stresses. Herein, the Hsp20 gene family was analyzed by bioinfor-matics using Arabidopsis thaliana genome database. HMMER search and protein physicochemical property analysis showed that there are at least 30 Hsp20 genes in A. thaliana, encoding 14.6~41.4 kD molecular weight proteins, all of which contain an α-crystallin domain (ACD). Phylogenetic analysis showed that 22 of the 30 A. thaliana Hsp20 members belong to 12 different subfamilies, and the remaining 8 belong to un-known taxa, which may be Hsp20-like proteins. Collinearity analysis showed that fragment replication and tandem replication are the main amplification events of Hsp20 members, and most Hsp20 members contain no or only one intron. Analysis using MEME showed that motifs 1, 2, and 9 are common conserved motifs in Hsp20 family. Transcriptome analysis indicated that the expression levels of 15 Hsp20 genes were up-regu-lated after drought and (or) salt stress, which was verified by qRT-PCR assay. These results provide theoreti-cal basis for further investigation of the biological functions of Hsp20 genes.
