Transcriptome analysis reveals rapid defence responses in wheat induced by phytotoxic aphid Schizaphis graminum feeding
Transcriptome analysis reveals rapid defence responses in wheat induced by phytotoxic aphid Schizaphis graminum feeding
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DOI：
10.1186/s12864-020-6743-5
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发表时间：
2020-01
期刊：
影响因子：
4.4
通讯作者：
Yong Zhang;Yu Fu;Qian Wang;Xiaobei Liu;Qian Li;Julian Chen
中科院分区：
文献类型：
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作者：
Yong Zhang;Yu Fu;Qian Wang;Xiaobei Liu;Qian Li;Julian Chen
背景
麦二叉蚜（Schizaphis graminum）是世界范围内危害最严重的禾谷类蚜虫之一，其取食可引起小麦黄化和坏死。然而，关于S.禾本科植物在分子水平上的取食。
结果
在这里，我们收集并分析了来自受S侵染的小麦叶组织的转录组测序数据。在2、6、12、24和48 hpi（侵染后小时）时，总共有44，835个基因被上调或下调，并且在对蚜虫进食的反应中显着不同。许多基因（9761个基因）的表达水平在2 hpi内显著改变，并在整个48 h实验期间持续变化。Gene Ontology分析表明，下调的DEGs主要富集在光合作用和捕光方面，小麦叶片中总叶绿素含量在S.禾本科侵染在24和48 hpi。然而，水杨酸（SA）介导的防御信号通路和MAPK-WRKY通路的一些相关基因在早期喂养时间点（2和6 hpi）显着上调。此外，抗氧化酶，如过氧化物酶和超氧化物歧化酶的基因表达和活性迅速增加，在2，6和12 hpi。DAB染色结果表明，S.禾本科蚜虫取食诱导了2 hpi时取食部位H2 O2的积累，且随着取食时间的延长，H2 O2的产生量增加。用NADPH氧化酶抑制剂二苯碘鎓预处理，抑制了小麦中H2 O2的积累和SA相关防御基因的表达水平。
结论
我们的转录组学分析表明，防御相关的途径和氧化应激在小麦迅速诱导后几个小时内蚜虫开始进食。此外，NADPH氧化酶在蚜虫诱导的小麦防御反应和H2 O2积累中起重要作用。这些结果为深入研究小麦叶片对蚜虫取食的动态反应和蚜虫与植物相互作用的分子机制提供了有价值的信息。
Background
Schizaphis graminum is one of the most important and devastating cereal aphids worldwide, and its feeding can cause chlorosis and necrosis in wheat. However, little information is available on the wheat defence responses triggered by S. graminum feeding at the molecular level.
Results
Here, we collected and analysed transcriptome sequencing data from leaf tissues of wheat infested with S. graminum at 2, 6, 12, 24 and 48 hpi (hours post infestation). A total of 44,835 genes were either up- or downregulated and differed significantly in response to aphid feeding. The expression levels of a number of genes (9761 genes) were significantly altered within 2 hpi and continued to change during the entire 48 h experiment. Gene Ontology analysis showed that the downregulated DEGs were mainly enriched in photosynthesis and light harvesting, and the total chlorophyll content in wheat leaves was also significantly reduced after S. graminum infestation at 24 and 48 hpi. However, a number of related genes of the salicylic acid (SA)-mediated defence signalling pathway and MAPK-WRKY pathway were significantly upregulated at early feeding time points (2 and 6 hpi). In addition, the gene expression and activity of antioxidant enzymes, such as peroxidase and superoxide dismutase, were rapidly increased at 2, 6 and 12 hpi. DAB staining results showed that S. graminum feeding induced hydrogen peroxide (H2O2) accumulation at the feeding sites at 2 hpi, and increased H2O2 production was detected with the increases in aphid feeding time. Pretreatment with diphenylene iodonium, an NADPH oxidase inhibitor, repressed the H2O2 accumulation and expression levels of SA-associated defence genes in wheat.
Conclusions
Our transcriptomic analysis revealed that defence-related pathways and oxidative stress in wheat were rapidly induced within hours after the initiation of aphid feeding. Additionally, NADPH oxidase plays an important role in aphid-induced defence responses and H2O2 accumulation in wheat. These results provide valuable insight into the dynamic transcriptomic responses of wheat leaves to phytotoxic aphid feeding and the molecular mechanisms of aphid-plant interactions.