Gibberellic acid sensitive dwarf encodes an ARPC2 subunit that mediates gibberellic acid biosynthesis, effects to grain yield in rice

The plant hormone gibberellic acid (GA) is important for plant growth and productivity. Actin-related proteins (ARPs) also play central roles in plant growth, including cell elongation and development. However, the relationships between ARPs and GA signaling and biosynthesis are not fully understood. Here, we isolated , encoding an ARP subunit from rice ( ), using the Ac/Ds knockout system. The knockout (Ko) mutation reduced GA3 content in shoots as well as plant growth and height. However, GA application restored the plant height of the Ko mutant to a height similar to that of the wild type (WT). Rice plants overexpressing (Ox) showed increased plant height and grain yield compared to the WT. Transcriptome analysis of flag leaves of Ox and Ko plants revealed that OsGASD regulates cell development and the expression of elongation-related genes. These observations suggest that is involved in maintaining GA homeostasis to regulate plant development, thereby affecting rice growth and productivity.