Abstract
Previously, we reported that exposure of tobacco plants to low level cadmium ion blocks the systemic spread of tobamovirus. Our group identified a tobacco glycine-rich protein, cdiGRP, that induced by low concentrations of cadium and expressed in the cell walls of plant vascular tissues. We found out that constitutive cdiGRP overexpression induces callose accumulation at plasmodesmata in vascular tissue. These observations suggest that cdiGRP exerted its inhibitory effect on virus transport by enhancing callose deposits in the vasculature.
Currently, we are working to elucidate the mechanism of callose induction by cdiGRP overexpression using two plant systems, Arabidopsis thaliana and Nicotiana tabacum. We identified four cdiGRP homologs in Arabidopsis thaliana, and at least two of them localize specifically at plasmodesmata. We would like to present possible roles of cdiGRP in regulation of callose accumulation level at plasmodesmata.
