Isolation and characterization of a novel dehydrin gene from Capsella bursa-pastoris

A novel dehydrin gene designated as Cbcor29 was cloned from Capsella bursa-pastoris by rapid amplification of cDNA ends (RACE) and genome walker technique. The full-length cDNA of Cbcor29 was 1101 bp long with a 783 bp open reading frame (ORF), encoding a putative protein of 261 amino acids. Like other dehydrin proteins, CbCOR29 contained a high percentage of charged and polar amino acids, in which Cys and Trp amino acids were absent. Besides, predicted CbCOR29 protein possesses three conserved repeats of the characterized Lys-rich domains (K-segments), and a Ser-rich domain (S-segment) prior to the first Lys-rich domain, which presented a typical SK3 structure of dehydrins. Analysis of Cbcor29 genomic DNA revealed that it contained 2 exons and I intron, which was a typical character of dehydrin genes. Subsequent bioinformatic analysis also showed that the sequence of CbCOR29 had high homology with other dehydrin proteins, especially with cor,47 from Arabidopsis thaliana. Moreover, semi-quantitative RT-PCR revealed that the expression of Cbcor29 could be induced by exposure to drought, low-temperature, NaCl and exogenous ABA treatment respectively. Our study implied that the Cbcor29 gene was a new member of the dehydrin gene family and might exert functions in drought-, cold- and salt- responsiveness in Capsella bursa-pastoris.