OsNCED5 Controls Abscisic Acid‐Mediated Anther Dehiscence and Male Fertility in Rice

Proper anther dehiscence is essential for successful pollination and male fertility in flowering plants. However, many gaps remain in the regulatory mechanisms underlying anther dehiscence in plants, including a possible role for abscisic acid (ABA) in anther dehiscence. Here, we reported a member of 9-cis-epoxycarotenoid dioxygenase family (NCED), OsNCED5, which regulates proper anther dehiscence for male fertility in rice. OsNCED5 encodes a chloroplast-localized ABA biosynthetic enzyme highly expressed in anther during the late phase. Disruption of OsNCED5 by CRISPR/Cas9-mediated mutagenesis led to the reduction of ABA accumulation in anthers, thus the failure of secondary cell wall (SCW) thickening in anther endothecium due to loss of lignin biosynthesis, which eventually resulting in indehiscent anthers and significantly reduced fertility. Further analysis indicated that OsNCED5 probably confer a conserved fertility regulation mechanism between japonica and indica subspecies. Taken together, we have identified a key OsNCED regulator involved anther dehiscence -based male fertility, and provide a valuable genetic resource for fertility improvement in rice.