부산대학교 도서관

Although an association between chilling tolerance and aquaporins has been reported, the exact mechanisms involved in this relationship remain unclear. We performed the expression profiles of aquaporin genes using real-time PCR, suggested that PIP1;3 gene is the most closely related to low temperature. Although OsPIP1;3 showed a much lower water permeability than members of the OsPIP2 family, OsPIP1;3 enhanced the water permeability of OsPIP2;2 and OsPIP2;4 when coexpressed with either of these proteins in oocytes. Transgenic rice plants overexpressing OsPIP1;3 showed an enhanced level of chilling tolerance and the ability to maintain high OsPIP1;3 expression levels under low temperature treatment, similar to that of chilling tolerant rice plants. We assume that OsPIP1;3, constitutively overexpressed in the leaf and root of transgenic plants, interacts with members of the OsPIP2 subfamily thereby improving water balance of the plants under low temperatures and resulting in the observed chilling tolerance of the plants.