Phylogenetic and transcriptional analysis of chrysanthemum GRAS transcription factors

Abstract

The GRAS transcription factors encoding proteins ranging from 400 to 700 residues are recognized by their conserved C terminus. Here, a set of 23 CmGRAS genes was identified from a scan of the chrysanthemum (Chrysanthemum morifolium) transcriptome. A phylogenetic analysis implied that nine of these genes could be assigned orthologs to the GRAS gene family, and that four of them formed two pairs of paralogs. A phylogenetic analysis of the GRAS protein family based on the chrysanthemum and recent study of eight representative species of angiosperms showed that most of the CmGRAS genes belonged to a recognized sub-group. CmGRAS4 and CmGRAS10 were strongly transcribed in flowers and roots, respectively. The DELLA subfamily transcript abundance of the CmGRAS19 and CmGRAS20 was high in the reproductive tissues and they were responsive to phytohormones and stresses. Establishment of the orthology relationships between the known representative GRAS genes and CmGRAS, and transcriptional profiles of CmGRASs after phytohormone treatments or stresses will facilitate subsequent functional analyses in the GRAS gene family.

Keywords

• abscisic acid
• chrysanthemum morifolium
• cold
• heat
• methyl jasmonate
• osmotic stress
• salicylic acid
• salinity
• wounding