Lamichhane Tirtha, Su Hang, Huang Xiaoen, Wang Nian
Citrus Research and Education Center, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Lake Alfred, FL, U.S.A.
Department of Plant Pathology, IFAS, University of Florida, Lake Alfred, FL, U.S.A.
Mol Plant Microbe Interact. 2025 May;38(3):479-488. doi: 10.1094/MPMI-12-24-0164-R. Epub 2025 May 28.
mediated transient expression (AMTE) is an important tool in plant genetics studies and biotechnology. AMTE remains problematic in citrus and many plant species. Previous research has shown that pretreatment of citrus leaves with subsp. (), which causes citrus canker, significantly improves the AMTE efficacy. Here, we have shown that promotes AMTE mainly through triggering cell division and upregulating plant cell wall-degrading enzymes. We demonstrate that improves AMTE via PthA, a transcription activator-like effector known to trigger cell division in citrus, and mutation of abolished the promoting effect of Mutation of the effector (PthA4)-binding element in the promoter region and coding region of , which is known to be directly activated by PthA4, significantly reduced promotion of AMTE. Mutation of significantly reduced the expression of cell division-related genes (, , and ) compared with wild-type and the complemented strain. Cell division inhibitor mimosine but not colchicine also significantly decreased promotion of AMTE. In addition, PthA4 is known to upregulate plant growth hormones auxin (indole-3-acetic acid), gibberellin, and cytokinin, as well as cell wall-degrading enzymes (e.g., cellulase). Exogenous application of indole-3-acetic acid, cytokinin, and cellulase but not gibberellin significantly improved AMTE in leaves of sweet orange, pummelo, Meiwa kumquat, lucky bamboo, and rose mallow. Our study provides a mechanistic understanding of how promotes AMTE and develops practical measures to improve AMTE via pretreatment with plant hormones (i.e., auxin and cytokinin) and cellulase. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
农杆菌介导的瞬时表达（AMTE）是植物遗传学研究和生物技术中的一项重要工具。在柑橘和许多植物物种中，AMTE仍然存在问题。先前的研究表明，用引起柑橘溃疡病的 亚种（）对柑橘叶片进行预处理，可显著提高AMTE的效率。在这里，我们已经表明， 主要通过触发细胞分裂和上调植物细胞壁降解酶来促进AMTE。我们证明， 通过PthA改善AMTE，PthA是一种已知能在柑橘中触发细胞分裂的转录激活因子样效应子，而 的突变消除了 的促进作用。已知由PthA4直接激活的 在启动子区域和编码区域中的效应子（PthA4）结合元件的突变，显著降低了 对AMTE的促进作用。与野生型 和互补菌株相比， 的突变显著降低了细胞分裂相关基因（、 和 ）的表达。细胞分裂抑制剂含羞草碱而非秋水仙碱也显著降低了 对AMTE的促进作用。此外，已知PthA4可上调植物生长激素生长素（吲哚-3-乙酸）、赤霉素和细胞分裂素，以及细胞壁降解酶（如纤维素酶）。外源施加吲哚-3-乙酸、细胞分裂素和纤维素酶而非赤霉素，可显著改善甜橙、柚子、梅湾金橘、富贵竹和扶桑叶片中的AMTE。我们的研究提供了关于 如何促进AMTE的机制理解，并制定了通过用植物激素（即生长素和细胞分裂素）和纤维素酶进行预处理来改善AMTE的实际措施。[公式：见正文] 版权所有©2025作者。这是一篇根据知识共享署名-非商业性使用-禁止演绎4.0国际许可协议分发的开放获取文章。
