Zhong Xuanbo, Hong Wei, Shu Yue, Li Jianfei, Liu Lulu, Chen Xiaoyang, Islam Faisal, Zhou Weijun, Tang Guixiang
Zhejiang Provincial Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou, Zhejiang, China.
Hainan Institute of Zhejiang University, Sanya, Hainan, China.
Front Plant Sci. 2022 Aug 19;13:988505. doi: 10.3389/fpls.2022.988505. eCollection 2022.
The HD-Zip transcription factors play a crucial role in plant development, secondary metabolism, and abiotic stress responses, but little is known about HD-Zip I genes in soybean. Here, a homeodomain-leucine zipper gene designated was isolated. Chimeric soybean plants, overexpressing (), and gene-editing CRISPR/Cas9 () in hairy roots, were generated to examine the gene response to polyethylene glycol (PEG)-simulated drought stress. Bioinformatic analysis showed belonged to clade δ, and was closely related to other drought tolerance-related HD-Zip I family genes such as , , and . The was located in the plant nucleus and showed transcriptional activation activity by yeast hybrid assay. Quantitative real-time PCR analysis revealed that expression varied in tissues and was induced by PEG-simulated drought stress. The showed promoted growth of aboveground parts, and its root system architecture, including the total root length, the root superficial area, and the number of root tips were significantly higher than those of even the non-transgenic line (NT) on root tips number. The better maintenance of turgor pressure by osmolyte accumulation, and the higher activity of antioxidant enzymes to scavenge reactive oxygen species, ultimately suppressed the accumulation of hydrogen peroxide (HO), superoxide anion (O), and malondialdehyde (MDA), conferring higher drought tolerance in compared with both and NT. Together, our results provide new insights for future research on the mechanisms by which gene-editing CRISPR/Cas9 system could promote drought stress and provide a potential target for molecular breeding in soybean.
HD-Zip转录因子在植物发育、次生代谢和非生物胁迫反应中起着关键作用，但大豆中HD-Zip I基因的相关研究较少。在此，分离出一个命名为 的同源异型域-亮氨酸拉链基因。构建了过表达（ ）和在毛状根中进行基因编辑的CRISPR/Cas9（ ）的嵌合大豆植株，以检测 基因对聚乙二醇（PEG）模拟干旱胁迫的反应。生物信息学分析表明 属于δ进化枝，与其他耐旱相关的HD-Zip I家族基因如 、 和 密切相关。 定位于植物细胞核中，通过酵母杂交试验显示具有转录激活活性。定量实时PCR分析表明， 基因的表达在不同组织中存在差异，并受PEG模拟干旱胁迫诱导。 表现出地上部分生长促进作用，其根系结构，包括总根长、根表面积和根尖数量均显著高于 ，甚至在根尖数量上高于非转基因株系（NT）。通过渗透溶质积累更好地维持膨压，以及抗氧化酶清除活性氧的较高活性，最终抑制了过氧化氢（HO）、超氧阴离子（O）和丙二醛（MDA）的积累，与 和NT相比， 具有更高的耐旱性。总之，我们的结果为未来研究CRISPR/Cas9系统基因编辑促进干旱胁迫的机制提供了新的见解，并为大豆分子育种提供了一个潜在靶点。
