WEAK SEED DORMANCY 1, an aminotransferase protein, regulates seed dormancy in rice through the GA and ABA pathways
Yunshuai Huang, Jiawei Song, Qixian Hao, Changling Mou, Hongming Wu, Fulin Zhang, Ziyan Zhu, Ping Wang, Tengfei Ma, Kai Fu, Yaping Chen, Thanhliem Nguyen, Shijia Liu, Ling Jiang, Jianmin Wan
Abstract
Seed dormancy is a critical trait that enhances plant survival by preventing seed germination at the wrong time or under unsuitable conditions. Lack of seed dormancy in rice can lead to pre-harvest sprouting on mother plants leading to reduced yield and seed quality. Although some genes have been identified, knowledge of regulation of seed dormancy is limited. Here, we characterized a weak seed dormancy mutant named weak seed dormancy 1 (wsd1) that showed a higher seed germination percentage than the wild-type following the harvest ripeness. We cloned the WSD1 encoding an aminotransferase protein using a MutMap approach. WSD1 was stably expressed after imbibition and its protein was localized in the endoplasm reticulum. A widely targeted metabolomics assay and amino acid analysis showed that WSD1 had a role in regulating homeostasis of amino acids. PAC treatment and RNA-seq analysis showed that WSD1 regulates seed dormancy by involvement in the GA biosynthesis pathway. GA1 content and expression of GA biosynthesis-related genes were increased in the wsd1 mutant compared with the wild-type. The wsd1 mutant had reduced sensitivity to ABA. Our overall results indicated that WSD1 regulates seed dormancy by balancing the ABA and GA pathways.