Genome wide identification and expression profiling of Early responsive to dehydration 6 (ERD6)-like gene family in chickpea (Cicer arietinum L.)

Early responsive to dehydration 6 (ERD6)-like is one of the least studied subfamily in plants. Initial evidences based on couple of genes suggest that members of this family are tonoplastic and export glucose to cytosol from tonoplast. However, no information is available on ERD6-like genes in agricultural crops except limited information on Brassica species. In this study, we identified 8, 12, 6 and 7 ERD6-like genes, respectively in Cicer arietinum, Arachis hypogea, Oryza sativa and Glycine max. These and A. thaliana genes were divided into five subgroups based on phylogenetic analysis of proteins. C. arietinum genes were characterized in detail and new nomenclature to these genes was proposed to overcome ambiguities in names of genes. Intron/exon numbers did not vary much among the genes, however, gene/mRNA/coding region/ untranslated regions and proteins showed considerable length variations. Though isoforms were reported for two genes, isoforms of only CaERD6like 6.3 could be confirmed experimentally. While motifs and transmembrane domains varied among the ERD6like proteins, all belonged to glucose transport subfamily suggesting those to be glucose transporters. Transcription of genes varied among four chickpea organs with higher expression in some organs and lower in others. Under cold-stress, three genes over-expressed in leaves and roots whereas four genes down-regulated in leaves and two in roots. This is the first report on genome wide identification of ERD6-like genes in four crops of agricultural importance and detailed characterization and expression analysis in chickpea organs under normal growth conditions and cold-stress.