Aphid feeding induces the relaxation of epigenetic control and the associated regulation of the defense response in Arabidopsis

Environmentally induced changes in the epigenome help individuals to quickly adapt to fluctuations in the conditions of their habitats. Here we explored those changes in Arabidopsis thaliana plants subjected to multiple biotic and abiotic stresses, and identified transposable element (TE) activation in plants infested with the green peach aphid, Myzus persicae. We performed a genome-wide analysis of DNA methylation, mRNA expression, mRNA degradation and small RNAs accumulation. Our results demonstrate that aphid feeding induces loss of methylation of hundreds of loci, mainly TEs with labile chromatin characteristics. This loss of methylation has the potential to regulate gene expression and we found evidence that it is involved in the control of key plant immunity genes. Accordingly, we find that mutant plants deficient in epigenetic silencing show increased resistance to M.persicae infestation. Collectively, our results show that changes in DNA methylation play a significant role in the regulation of the plant transcriptional response and induction of defence response against aphid feeding. Analysis of RNA, sRNA and bisulfite sequencing during aphid infestation at 72hrs in Arabidopsis thaliana rosette leaves

表观基因组（epigenome）受环境诱导产生的变化，可帮助生物体快速适应栖息环境的波动。本研究以经受多种生物与非生物胁迫的拟南芥（Arabidopsis thaliana）为对象，探究此类表观基因组变化，并在被绿色桃蚜（Myzus persicae）侵染的植株中检测到转座因子（transposable element, TE）的激活。我们对DNA甲基化、信使RNA（mRNA）表达、mRNA降解以及小RNA（small RNA, sRNA）的积累情况开展了全基因组范围分析。研究结果显示，蚜虫取食会导致数百个基因位点发生甲基化丢失，此类丢失主要发生在携带染色质不稳定性特征的转座因子上。此类甲基化丢失具备调控基因表达的潜力，且我们找到了其参与调控关键植物免疫基因的相关证据。据此，我们发现表观遗传沉默功能缺陷的突变体植株对桃蚜（M.persicae）侵染的抗性显著增强。综上，本研究结果表明，DNA甲基化变化在植物转录响应调控以及抵御蚜虫取食的防御反应诱导过程中发挥着重要作用。本数据集涵盖拟南芥莲座叶在被蚜虫侵染72小时后的RNA、小RNA（sRNA）以及亚硫酸氢盐测序分析数据。