Yang Huan, Li Yi, Hu Zixuan, Li Jiaru
State Key Laboratory of Hybrid Rice, College Life Sciences, Wuhan University, Wuhan 430072, China.
Int J Mol Sci. 2025 Apr 28;26(9):4185. doi: 10.3390/ijms26094185.
Diosgenin, a crucial precursor for steroidal drug production, has poorly understood regulatory pathways. Diosgenin is the primary active component of . Notably, also possesses the highest diosgenin content among species, reaching up to 16.15% of dry weight. This study identified DZHDZ32 as a potential regulator of diosgenin biosynthesis in through transient overexpression. To validate its function, we developed an optimized genetic transformation method for and generated two -overexpressing lines. The DZHDZ32 transcription factor belongs to the HD-ZIP I subfamily and is localized to the nucleus. Notably, overexpression of resulted in a significant increase in its transcript levels in leaves (264.59- and 666.93-fold), leading to elevated levels of diosgenin and its biosynthetic intermediates, including cholesterol and β-sitosterol. Specifically, diosgenin content increased by 41.68% and 68.07%, cholesterol by 10.29% and 16.03%, and β-sitosterol by 12.33% and 19.49% in leaves compared to wild-type plants. Yeast one-hybrid and dual-luciferase assays demonstrated that DZHDZ32 directly binds to the promoters of and , consistent with the significant upregulation of and expression (3.69- and 4.87-fold and 4.75- and 6.53-fold, respectively) in the overexpressing lines. This study established an optimized genetic transformation method for and identified DZHDZ32 as a key regulator of diosgenin biosynthesis. The discovery of DZHDZ32 has significant implications for enhancing diosgenin production and advancing steroidal drug development.
薯蓣皂苷元是甾体药物生产的关键前体，其调控途径尚不清楚。薯蓣皂苷元是[植物名称]的主要活性成分。值得注意的是，[植物名称]在[植物种类]中也具有最高的薯蓣皂苷元含量，高达干重的16.15%。本研究通过瞬时过表达鉴定出DZHDZ32是[植物名称]中薯蓣皂苷元生物合成的潜在调节因子。为了验证其功能，我们开发了一种优化的[植物名称]遗传转化方法，并获得了两个[植物名称]过表达株系。DZHDZ32转录因子属于HD-ZIP I亚家族，定位于细胞核。值得注意的是，[植物名称]的过表达导致其在叶片中的转录水平显著增加（分别为264.59倍和666.93倍），导致薯蓣皂苷元及其生物合成中间体（包括胆固醇和β-谷甾醇）的水平升高。具体而言，与野生型植物相比，叶片中薯蓣皂苷元含量分别增加了41.68%和68.07%，胆固醇增加了10.29%和16.03%，β-谷甾醇增加了12.33%和19.49%。酵母单杂交和双荧光素酶试验表明，DZHDZ32直接与[基因名称1]和[基因名称2]的启动子结合，这与过表达株系中[基因名称1]和[基因名称2]表达的显著上调（分别为3.69倍和4.87倍以及4.75倍和6.53倍）一致。本研究建立了一种优化的[植物名称]遗传转化方法，并鉴定出DZHDZ32是薯蓣皂苷元生物合成的关键调节因子。DZHDZ32的发现对提高薯蓣皂苷元产量和推进甾体药物开发具有重要意义。
