Molecular characterization of a wheat protein induced by vernalisation

Using a PCR strategy we isolated from winter wheat (Triticum aestivum L. cv. Bolero) the ver2 gene coding for a modular protein constituted by an N-terminal domain called "dirigent", found in several defence-related genes, and a C-terminal domain related to jacalin-related lectin (JRL). ver2 transcript as well as native Ver2 levels increased during vernalisation and upon methyl jasmonate treatment of young seedlings. ver2 transcript levels were kept constant either in infected tissues or in wounded samples indicating that Ver2 is not directly involved in plant defence mechanisms. The Ver2 protein was expressed in bacteria as a recombinant GST-Ver2 fusion protein. The purified recombinant protein was further characterized using an affinity chromatography approach based on its interaction with mannose-agarose beads. GST-Ver2 tightly bound to the matrix. Molecular modelling of the jacalin domain and mannose docking confirmed that Ver2 possesses D: -mannose binding capacity.