Maize (Zea mays) is a monoecious plant, in which inflorescence morphogenesis involves complicated molecular regulatory mechanisms. Although many related genes have been cloned, our understanding of the molecular mechanism underlying maize inflorescence development remains limited. Here, we identified a maize semi-dominant mutant Silky3 (Si3), which displays pleiotropic defects during inflorescence development, including loss of determinacy and identity in meristems and floral organs, as well as the sexual transformation of tassel florets. We cloned the si3 gene using a map-based approach. Functional analysis reveals that SI3 is a nuclear protein and may act as a transcriptional regulator. Transcriptome analysis reveals that the ectopic expression of si3 strongly represses multiple biological processes, especially the flower development pathways. RNA in situ hybridization similarly shows that the expression patterns of genes responsible for flower development are changed in the Si3 mutant. In addition, the homeostasis of jasmonic acid and gibberellic acid are altered in the Si3 young tassels, and application of exogenous jasmonic acid can rescue the sex reversal phenotype of Si3. The defects we characterized in various regulatory pathways can explain the complex phenotypes of Si3 mutant, and this study deepens our knowledge of maize inflorescence development.

玉米（Zea mays）是雌雄同株植物，其花序形态发生涉及复杂的分子调控机制。尽管已经克隆了许多相关基因，但我们对玉米花序发育的分子机制的了解仍然有限。在这里，我们鉴定了一个玉米半显性突变体Silky3 ( Si3 )，它在花序发育过程中表现出多效性缺陷，包括分生组织和花器官的确定性和同一性的丧失，以及流苏小花的有性转化。我们克隆了si3基因使用基于图谱的方法。功能分析表明，SI3 是一种核蛋白，可以作为转录调节因子。转录组分析表明si3的异位表达强烈抑制多种生物过程，尤其是花发育途径。RNA 原位杂交同样表明，负责花发育的基因的表达模式在Si3突变体中发生了变化。此外，Si3幼穗中茉莉酸和赤霉酸的稳态发生改变，外源茉莉酸的应用可以挽救Si3的性别逆转表型。我们在各种调控途径中表征的缺陷可以解释复杂的表型Si3突变体，这项研究加深了我们对玉米花序发育的认识。