Identification and characterization of a low temperature regulated gene encoding an actin-binding protein from wheat.

A cDNA corresponding to a putative actin-binding protein was cloned from a cold-acclimated wheat cDNA library. The cDNA, designated Wcor719, encodes a polypeptide of 142 amino acids with a calculated molecular mass of 15.8 kDa and a pI of 4.27. The protein has the two conserved domains identified as actin and phosphatidylinositol 4,5-biphosphate (PIP2) binding sites found in members of the cofilin family. Northern analyses revealed that Wcor719 transcript accumulation is rapid and strongly up-regulated by low temperature. This accumulation was greater in the tolerant winter wheat and rye species compared to the less tolerant ones. The rapidity of transcript induction and the significant homology with actin-binding proteins (ABP) from different organisms suggest that the product of this gene might be involved in the dynamic reorganization of the cytoskeleton during low temperature acclimation. It may also serve as a key factor in the signal transduction pathway during cold acclimation.