Genome-wide bioinformatics analysis of DELLA-family proteins from plants

DELLA-family proteins have been implicated as negative modulators of the gibberellin signaling pathway, which regulates many aspects of plant growth and development. Despite the importance of DELLA proteins, a genome-wide overview of the DELLA gene family is not yet available. Here, based on conserved domain searching, we identified 60 different DELLA-encoding genes from 29 plant genomes, including 49 complete length sequences. Phylogenetic analysis indicated that these DELLAs can be grouped into four different subfamilies, including Algae, Bryophyte, monocots and dicots. Analysis of domains and motifs in the DELLA gene family showed the following domains including DELLA, TVHYNP, VHIID, RKVATYFGEALARR, AVNSVFELH, RVER, and SAW are strictly conserved in the DELLAs. Gene duplication events were the main reason for expansion of the DELLA family; selective pressure operated on the DELLAs after gene duplication, resulting in the formation of distinct DELLA groups. Our results provide new insights into the evolutionary relationships of DELLA proteins.