Abstract
Phospholipase D (PLD) plays an important role in plant biotic and abiotic stress responses. To study the function of PLD in rice, we made knockdown plants by introduction of a PLD gene specific RNA interference (RNAi) constructs. OsPLDβ1-RNAi-silenced transgenic rice was found to develop spontaneous lesions on the leaves in the absence of pathogen infection. The transgenic rice exhibited that genes associated with activation of disease resistance, including probenazole- inducible protein (PBZ1), chitinase, ribosome-inactivating protein (RIP2), and thaumatin-like protein (TLP) were significantly up-regulated. The amount of phytoalexine on the leaves of the transgenic rice was strongly increased approximately 100-200-fold relative to the wild-type levels. These results suggest that the transgenic rice is the disease lesion mimic that shows spontaneous hypersensitive reaction in the absence of pathogens. Possible functions of OsPLDβ1 in induction of hypersensitive reaction are discussed.
