Table 4_GmWRKY33a is a hub gene responsive to brassinosteroid signaling that suppresses nodulation in soybean (Glycine max).xlsx

Brassinosteroids (BRs) are key phytohormones influencing soybean development, yet their role in symbiosis remains unclear. Here, the RNA-Seq was used to identify important gene associated with BRs and symbiotic nitrogen fixation, and the function of candidate gene was verified by transgenic hairy roots. The result shows that the RNA-Seq analysis was conducted in which BR signaling was found to suppress nodule formation and many DEGs enriched in immunity-related pathways. WGCNA analyses led to the identification of GmWRKY33a as being responsive to BR signaling in the context of symbiosis establishment. Transgenic hairy roots analyses indicated that GmWRKY33a served as a negative regulator of the establishment of symbiosis. The qRT-PCR analysis confirmed that BR signaling upregulates GmWRKY33a, leading to nodulation suppression and activation of soybean immune responses. In summary, our research revealed that BR suppresses root nodule formation by modulating the immune signaling pathway in soybean roots. We further identified that GmWRKY33a, a crucial transcription factor in BR signaling, plays a negative role in the symbiotic establishment.

油菜素内酯（Brassinosteroids, BRs）是调控大豆生长发育的关键植物激素，但其在共生过程中的功能仍未明确。本研究通过RNA测序（RNA-Seq）技术筛选与油菜素内酯及共生固氮相关的关键基因，并通过转基因毛根体系验证了候选基因的功能。测序分析结果显示，油菜素内酯信号通路可抑制根瘤形成，且大量差异表达基因（Differentially Expressed Genes, DEGs）富集于免疫相关通路。通过加权基因共表达网络分析（Weighted Gene Co-expression Network Analysis, WGCNA），本研究鉴定得到在共生建立过程中响应油菜素内酯信号通路的GmWRKY33a基因。转基因毛根实验表明，GmWRKY33a作为共生建立的负调控因子发挥作用。实时定量荧光PCR（qRT-PCR）验证证实，油菜素内酯信号通路可上调GmWRKY33a的表达，进而抑制根瘤形成并激活大豆免疫响应。综上，本研究揭示了油菜素内酯通过调控大豆根部免疫信号通路抑制根瘤形成的分子机制，并进一步明确了作为油菜素内酯信号通路关键转录因子的GmWRKY33a在共生建立过程中发挥负调控作用。