Study on brassinosteroid-mediated regulation of stem cell regeneration in roots

油菜素类固醇介导的根干细胞再生调控研究

• 批准号: 22K15143
• 负责人: ZHANG YE
• 金额: $ 3万
• 依托单位: Nara Institute of Science and Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Early-Career Scientists
• 财政年份: 2022
• 资助国家: 日本
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22K15143/
• 关键词: stem cell; DNA damage; cell division; regeneration; brassinosteroid; plant stem cell; DNA damage response

I have experimentally tested the effects of brassinosteriod (brassinolide) application and the effects of inhibiting brassinosteroid biosynthesis (by brassinozole treatment) on DNA damage induced stem cell death and the replenishing cell division afterwards. The results showed that brassinosteroid plays a positive role both in promoting DNA damage-induced stem cell death and the replenishing cell division afterwards.I have examined the regeneration capacity of transgenic plants in which the feedback activation on BRL3 expression is defective. Quantification analysis revealed that the feedback defective lines showed less replenishing cell division than brl3 mutant but not comparable to the wildtype, indicating that the feedback effect BRL3 contributes to activate replenishing cell division.Using translational fusion of fluorescent proteins, I have examined the expression pattern of BRL3 in the root tip during genotoxic stress exposure (before and after stem cell death) and during the afterward stem cell regeneration phase. The result revealed a positive correlation between the expression level of BRL3 and the activation of replenishing cell division. At the time point prior to the activation of replenishing cell division, the expression level of the mutant version of BRL3, on which the feedback activation is defective, was significantly lower than that of the wild type BRL3.

我通过实验测试了油菜素内酯（油菜素内酯）的应用和抑制油菜素内酯生物合成（通过油菜素唑处理）对DNA损伤诱导的干细胞死亡和随后的补充细胞分裂的影响。结果表明，油菜素类固醇在促进DNA损伤诱导的干细胞死亡和随后的补充细胞分裂方面都发挥着积极的作用。我检测了BRL3表达反馈激活有缺陷的转基因植物的再生能力。定量分析显示，反馈缺陷系表现出比brl3突变体更少的补充性细胞分裂，但与野生型不具有可比性，这表明反馈效应BRL3有助于激活补充性细胞分裂。利用荧光蛋白的翻译融合，我检查了在基因毒性应激暴露期间（干细胞死亡之前和之后）以及之后的干细胞再生阶段，BRL3 位于根尖。结果显示BRL3的表达水平与补充性细胞分裂的激活呈正相关。在补充性细胞分裂激活之前的时间点，反馈激活有缺陷的突变型BRL3的表达水平显着低于野生型BRL3。