Suppression of phospholipase D genes improves chalky grain production by high temperature during the grain-filling stage in rice

摘要

High temperature (HT) during the grain developing stage causes deleterious effects on rice quality resulting in mature grains with a chalky appearance. Phospholipase D (PLD) plays an important role in plants, including responses to environmental stresses. OsPLD1, 3 and 2-knockdown (KD) plants showed decreased production of chalky grains at HT. HT ripening increased H2O2 accumulated in the developing grains. However, the increase was canceled by the knockdown of OsPLD2. Expression levels of OsCATA which is one of three rice catalase genes, in developing grains of OsPLD2-KD plants at 10 DAF were increased compared with that in vector-controls in HT growth conditions. Overexpression of OsCATA markedly suppressed the production of chalky grains in HT growth conditions. These results suggested that OsPLD2 functions as a negative regulator of the induction of OsCATA and is involved in the production of chalky grains in HT growth conditions.