State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China.
School of Public Health, Guangxi Medical University, Nanning, 530021, China.
Plant J. 2024 Sep;119(5):2423-2436. doi: 10.1111/tpj.16929. Epub 2024 Jul 12.
Bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzicola (Xoc), is a major bacterial disease in rice. Transcription activator-like effectors (TALEs) from Xanthomonas can induce host susceptibility (S) genes and facilitate infection. However, knowledge of the function of Xoc TALEs in promoting bacterial virulence is limited. In this study, we demonstrated the importance of Tal10a for the full virulence of Xoc. Through computational prediction and gene expression analysis, we identified the hexokinase gene OsHXK5 as a host target of Tal10a. Tal10a directly binds to the gene promoter region and activates the expression of OsHXK5. CRISPR/Cas9-mediated gene editing in the effector binding element (EBE) of OsHXK5 significantly increases rice resistance to Xoc, while OsHXK5 overexpression enhances the susceptibility of rice plants and impairs rice defense responses. Moreover, simultaneous editing of the promoters of OsSULTR3;6 and OsHXK5 confers robust resistance to Xoc in rice. Taken together, our findings highlight the role of Tal10a in targeting OsHXK5 to promote infection and suggest that OsHXK5 represents a potential target for engineering rice resistance to Xoc.
细菌性条斑病（BLS）由稻黄单胞菌水稻致病变种（Xoc）引起，是水稻的一种主要细菌性病害。黄单胞菌中的转录激活样效应子（TALEs）可以诱导宿主感病（S）基因，促进感染。然而，对于 Xoc TALEs 在促进细菌毒力方面的功能知之甚少。在本研究中，我们证明了 Tal10a 对于 Xoc 的完全毒力至关重要。通过计算预测和基因表达分析，我们确定己糖激酶基因 OsHXK5 是 Tal10a 的宿主靶标。Tal10a 直接结合到基因启动子区域并激活 OsHXK5 的表达。CRISPR/Cas9 介导的 OsHXK5 效应子结合元件（EBE）基因编辑显著增加了水稻对 Xoc 的抗性，而 OsHXK5 的过表达增强了水稻植株的易感性并损害了水稻的防御反应。此外，同时编辑 OsSULTR3;6 和 OsHXK5 的启动子赋予了水稻对 Xoc 的强大抗性。总之，我们的研究结果强调了 Tal10a 靶向 OsHXK5 以促进感染的作用，并表明 OsHXK5 代表了工程水稻对 Xoc 抗性的潜在靶标。
