Increase of disease resistance in phospholipase D-silenced transgenic rice

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 RNA interference (RNAi) constructs specific to each PLD gene. OsPLDβ1-silenced transgenic rice was found to exhibit the disease lesion-mimic phenotype that shows spontaneous hypersensitive response (HR)-like reactions in the absence of pathogen infection, suggesting that OsPLDβ1 negatively regulates HR. The amounts of hydrogen peroxide (H2O2) in leaf extracts of the silenced lines increased relative to the vector control levels. Furthermore, OsPLDβ1-silenced lines exhibited the increased resistance to infection of a major fungal pathogen of rice, Pyricularia grisea. The possible functions of OsPLDβ1 in induction of HR-like reactions and defense response are also discussed.