State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China.
Key Laboratory of Agro-Biodiversity and Pest Management of the Ministry of Education, Yunnan Agricultural University, Kunming, People's Republic of China.
Plant Mol Biol. 2022 Jan;108(1-2):15-30. doi: 10.1007/s11103-021-01201-4. Epub 2021 Oct 7.
MoSDT1, a rice blast fungus transcription factor, is as an inducer to activate defense response through mainly mediating phosphorylated proteins in rice. Pathogen effector proteins play a dual role in infecting the host or triggering a defense response. Our previous research found a Magnaporthe oryzae effector, MoSDT1, which could activate the rice defense response when it was overexpressed in rice. However, we still know little about the mechanisms on how MoSDT1 in vivo or in vitro influences the resistance ability of rice. Our results showed that decreased ROS and increased lignin contents appeared along with significant upregulation of defense-related genes, raffinose synthesis gene, and phenylalanine ammonialyase gene. Moreover, we revealed that the contents of lignin were increased, which was in accordance with the upregulation of its precursor phenylalanine gene despite the fact that the glutamate-/thiamine-responsive genes were inhibited in MoSDT1 transgenic rice, and these indicated that MoSDT1 triggered the defense system of rice in vivo. Interestingly, in vitro studies, we further found that MoSDT1 induced the defense system by ROS synthesis, callose deposition, PR gene expression and SA/JA synthesis/signal genes using the purified prokaryotic expression system in rice plants. In addition, this defense response was confirmed to be activated by the zinc finger domain of MoSDT1 via prokaryotic expression of MoSDT1 truncated mutants in rice plants. To elucidate the regulative effects of MoSDT1 on protein phosphorylation in rice, phosphoproteome analysis was performed in both MoSDT1-transgenic and wild type rice. We found that MoSDT1 specifically up-regulated the expression levels of a few phosphorylated proteins, which were involved in multiple functions, such as biotic/abiotic stress and growth. In addition, the motifs in these specific proteins ranked the top among the top-five conserved motifs in the MoSDT1-transgenic rice. MoSDT1 played a crucial role in enhancing rice resistance by modulating several genes and signaling pathways.
水稻白叶枯病菌转录因子 MoSDT1 通过主要介导水稻中的磷酸化蛋白，作为诱导子激活防御反应。病原体效应蛋白在感染宿主或触发防御反应中起双重作用。我们之前的研究发现，稻瘟病菌效应蛋白 MoSDT1 在水稻中过表达时可以激活水稻的防御反应。然而，我们仍然不太了解 MoSDT1 体内或体外如何影响水稻抗性的机制。
我们的研究结果表明，ROS 含量降低，木质素含量增加，同时防御相关基因、棉子糖合成基因和苯丙氨酸解氨酶基因显著上调。此外，我们还发现木质素含量增加，尽管 MoSDT1 转基因水稻中谷氨酸/硫胺素反应基因受到抑制，但它的前体苯丙氨酸基因上调，这表明 MoSDT1 在体内触发了水稻的防御系统。有趣的是，在体外研究中，我们进一步发现 MoSDT1 通过 ROS 合成、胼胝质沉积、PR 基因表达和 SA/JA 合成/信号基因诱导防御系统，使用在水稻植物中纯化的原核表达系统。此外，通过在水稻植物中表达 MoSDT1 截断突变体，证实了这种防御反应是由 MoSDT1 的锌指结构域激活的。为了阐明 MoSDT1 对水稻中蛋白质磷酸化的调节作用，我们在 MoSDT1 转基因和野生型水稻中进行了磷酸蛋白质组分析。我们发现 MoSDT1 特异性地上调了少数磷酸化蛋白的表达水平，这些蛋白参与了多种功能，如生物/非生物胁迫和生长。此外，这些特定蛋白质中的基序在 MoSDT1 转基因水稻中排名前 5 个保守基序中的前 5 位。
MoSDT1 通过调节几个基因和信号通路在增强水稻抗性方面发挥着关键作用。
