Abstract
Plant reproductive development is more sensitive to abiotic stresses than vegetative growth, and these sensitivities are often reflected in crop yields. In particular, rice plant (Oryza sativa L.) frequently shows cold injury to microsporogenesis. In this study, we performed trasncriptome analysis of phytohormone related genes in response to cold in a cold tolerant line Hitomebore and a cold susceptible line Sasanishiki. The results indicated that 1) GA synthesis and response genes are upregulated by cold stress, and these are dominantly observed in Hitomebore. Moreover, high temperatures oppositely induce these expressions. 2) Cold stress induces Auxin response genes, 3) JA response gene MYC through repression of JAZ repressors in both lines, and 4) Expression of ethylene response gene increases by cold stress. These results suggest that global alterations of certain phytohormones occur during cold injury of rice plants. We are now attempting to construct an experimental system of cold injury under manufactory control conditions.
