College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Sanya Institute of Breeding and Multiplication, Hainan University, Sanya 572025, China.
Genes (Basel). 2024 Aug 7;15(8):1040. doi: 10.3390/genes15081040.
In angiosperms, seed size is a critical trait that is influenced by the complex interplay between the endosperm and seed coat. The () pathway, involving the transcription factor WRKY10, plays a crucial role in regulating seed size in . However, the downstream targets of WRKY10 and their roles in seed size determination remain largely unexplored. Here, we identified (), a laccase gene involved in lignin biosynthesis, as a new downstream target of WRKY10. We observed that the expression of was upregulated in the mutant, which is defective in WRKY10. We demonstrated that WRKY10 directly binds to the promoter of miR397a, activating its expression. miR397a, in turn, represses the expression of . Genetic analyses revealed that a mutation in or overexpression of miR397a partially rescued the small seed phenotype of the () mutant . Conversely, the overexpression of in the wild type led to a decrease in seed size. These findings suggest that functions as a negative regulator of seed size, and its expression is modulated by WRKY10 through miR397a. Our study uncovers a novel WRKY10-miR397a-LAC2 pathway that regulates seed size in , providing new insights into the complex regulatory network governing seed development in plants.
在被子植物中，种子大小是一个关键特征，受胚乳和种皮之间复杂相互作用的影响。WRKY10 转录因子参与的 ()途径在调控 中的种子大小方面起着至关重要的作用。然而，WRKY10 的下游靶标及其在种子大小决定中的作用在很大程度上仍未得到探索。在这里，我们鉴定了 ()，一个参与木质素生物合成的漆酶基因，作为 WRKY10 的一个新的下游靶标。我们观察到在 ()突变体中 ()的表达上调，该突变体中 WRKY10 有缺陷。我们证明 WRKY10 直接结合 miR397a 的启动子，激活其表达。miR397a 反过来又抑制 ()的表达。遗传分析表明，或 miR397a 的过表达部分挽救了 ()突变体的小种子表型。相反，在野生型中过表达 导致种子大小减小。这些发现表明 作为种子大小的负调控因子发挥作用，其表达受 WRKY10 通过 miR397a 进行调节。我们的研究揭示了一个新的 WRKY10-miR397a-LAC2 途径，该途径调节 中的种子大小，为植物中种子发育的复杂调控网络提供了新的见解。
