DIFFERENTIAL EXPRESSION OF A GENE ENCODING AN ACIDIC DEHYDRIN IN CHILLING SENSITIVE AND FREEZING TOLERANT GRAMINEAE SPECIES

We have characterized a new wheat cold-regulated cDNA clone, Wcor410, that accumulates to equivalent levels in root, crown and leaf tissues during cold acclimation. The Wcor410 cDNA contains an ORF encoding a dehydrin-like glutamate-rich protein of 28 kDa with a pI of 5.1. However, the acidic nature, the absence of the glycine-rich repeat and of the conserved N-terminal region, DEYGNP, suggest that Wcor410 belongs to a different subgroup of the D11 protein family. Northern analysis showed that this gene is expressed only in freezing tolerant gramineae, whereas Southern analysis showed that the Wcor410 gene is present in all monocot species tested. The presence of freezing tolerance-associated genes in sensitive species such as rice and corn is interesting. Characterization of the regulatory factors controlling these genes may help to establish an appropriate strategy to improve freezing tolerance.