Abstract:
Viral suppressor RNA silencing (VSR) is essential for successful infection. Nucleotide-binding and leucine-rich repeat (NLR)-based and autophagy-mediated immune responses have been reported to target VSR as counter-defense strategies. Here, we report a protein arginine methyltransferase 6 (PRMT6)-mediated defense mechanism targeting VSR. The knockout and overexpression of PRMT6 in tomato plants lead to enhanced and reduced disease symptoms, respectively, during tomato bush stunt virus (TBSV) infection. PRMT6 interacts with and inhibits the VSR function of TBSV P19 by methylating its key arginine residues R43 and R115, thereby reducing its dimerization and small RNA-binding activities. Analysis of the natural tomato population reveals that two major alleles associated with high and low levels of PRMT6 expression are significantly associated with high and low levels of viral resistance, respectively. Our study establishes PRMT6-mediated arginine methylation of VSR as a mechanism of plant immunity against viruses.
摘要:
病毒抑制RNA沉默(VSR)对于成功感染至关重要。据报道,基于核苷酸结合和富含亮氨酸的重复序列(NLR)和自噬介导的免疫反应可靶向VSR作为反防御策略。这里,我们报道了蛋白精氨酸甲基转移酶6(PRMT6)介导的防御机制靶向VSR。PRMT6在番茄植株中的敲除和过表达导致疾病症状的增强和减少,分别,在番茄灌木特技病毒(TBSV)感染期间。PRMT6通过甲基化其关键精氨酸残基R43和R115与TBSVP19相互作用并抑制其VSR功能,从而降低其二聚化和小RNA结合活性。对自然番茄种群的分析表明,与高和低水平的PRMT6表达相关的两个主要等位基因与高和低水平的病毒抗性显着相关,分别。我们的研究确立了PRMT6介导的VSR精氨酸甲基化作为植物抗病毒免疫机制。