Regulates Seed Setting Rate by Affecting Hydrogen Peroxide Dynamics and Mitochondrial Integrity in Rice.

Seed setting rate is one of the most important components of rice grain yield. To date, only several genes regulating setting rate have been identified in plant. In this study, we showed that (), a member of laccase family genes which are known for their roles in modulating phenylpropanoid pathway and secondary lignification in cell wall, exerts a regulatory function in rice seed setting rate. expressed in anthers and promotes hydrogen peroxide production both and in the filaments and anther connectives. Knock-out of showed significantly increased seed setting rate, while overexpression of this gene exhibited induced mitochondrial damage and suppressed sugar transportation in anthers, which in turn affected seed setting rate. also induced HO production and mitochondrial damage in the root tip cells which caused the lethal phenotype. We also showed that high abundant of OsmiR397, the suppressor of mRNA, increased the seed setting rate of rice plants, and restrains HO accumulation in roots during oxidative stress. Our results suggested a novel regulatory role of gene in regulating seed setting rate by affecting HO dynamics and mitochondrial integrity in rice.