College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana 141004, India.
Microbiol Res. 2022 May;258:126981. doi: 10.1016/j.micres.2022.126981. Epub 2022 Feb 11.
Sclerotinia sclerotiorum, the causal agent of Sclerotinia stem rot, is a devastating necrotrophic pathogen which causes severe yield losses to oilseed production worldwide. Most of efforts at the genetic mitigation of the disease have not been successful. Present investigation was conducted to functionally characterize the effect of down-regulating Ssoah1 during host infection and explore the possibility of boosting host resistance by silencing this gene. We utilized host-induced gene silencing (HIGS) to silence Ssoah1 gene in the S. sclerotiorum fungus. A HIGS based vector was constructed and transformed into Arabidopsis thaliana. The pathogenicity assays in the transgenic A. thaliana lines revealed three T transformants with significantly higher resistance to S. sclerotiorum in comparison to untransformed controls. There was a concomitant reduction in expression of Ssoah1 and accumulation of oxalic acid in the necrotic regions of transgenic lines as compared to the non-transgenic controls. Specific Ssoah1-siRNA was highly expressed in HIGS Ssoah1 transgenic lines, as compared with WT and EV plants. The outcomes of oxalic acid estimation revealed that silencing of Ssoah1 results in decreased OA accumulation. The recovered mycelium plugs from HIGS Ssoah1 transgenic lines showed decreased Ssoah1 expression and pathogenesis. These results provide the possibility of using HIGS of Ssoah1 for engineering resistance against S. sclerotiorum.
核盘菌（Sclerotinia sclerotiorum）是导致菌核病的病原菌，属于一种毁灭性的坏死型病原菌，会在全世界范围内给油料作物的生产造成严重的产量损失。大多数针对该病害的遗传缓解措施都没有取得成功。本研究旨在通过下调 Ssoah1 在宿主感染过程中的功能来对其进行深入研究，并探索通过沉默该基因来提高宿主抗性的可能性。我们利用宿主诱导基因沉默（HIGS）技术在核盘菌真菌中沉默 Ssoah1 基因。构建了基于 HIGS 的载体并转化到拟南芥中。在转基因拟南芥品系中的致病性测定表明，与未转化的对照相比，有 3 个 T 转化体对核盘菌具有更高的抗性。与非转基因对照相比，转基因系的 Ssoah1 表达和坏死区域的草酸积累均有降低。与 WT 和 EV 植物相比，HIGS Ssoah1 转基因系中高度表达了特异性的 Ssoah1-siRNA。草酸估计的结果表明，沉默 Ssoah1 会导致 OA 积累减少。从 HIGS Ssoah1 转基因系中回收的菌丝体塞显示出 Ssoah1 表达和致病能力的降低。这些结果为利用 HIGS 技术对 Ssoah1 进行工程改造以提高对核盘菌的抗性提供了可能性。
