College of Horticulture, Northwest A&F University, Yangling 712100, China.
Int J Mol Sci. 2018 Mar 30;19(4):1038. doi: 10.3390/ijms19041038.
RNA silencing is an evolutionarily conserved mechanism that regulates variety of cellular processes in plants. Argonaute protein (AGO), Dicer-like protein (DCL) and RNA-dependent RNA polymerase (RDR) are critical components of RNA silencing. These efficient and indispensable components of the RNAi pathway have not been identified and characterized in pepper. In this study, we identified 12 , 4 and 6 genes in pepper and compared them with those of Arabidopsis, tobacco, potato and tomato. Detailed phylogenetic analyses revealed that each CaAGO, CaDCL and CaRDR protein family were classified into four clades. The tissue specific expression and respond to abiotic or biotic stress were studied. The real-time quantitative polymerase chain reaction (PCR) results demonstrated that , , and were upregulated with cucumber mosaic virus (CMV), potato virus Y (PVY) and tobacco mosaic virus (TMV) infections, whereas they showed difference expression patterns in response to abiotic stress. In addition, we found that many of the candidate genes were induced by phytohormones and H₂O₂ treatment. Our results provide useful information for further elucidation of gene silencing pathways and RNAi-mediated host immunity in pepper.
RNA 沉默是一种进化上保守的机制，可调节植物中多种细胞过程。Argonaute 蛋白（AGO）、Dicer 样蛋白（DCL）和 RNA 依赖性 RNA 聚合酶（RDR）是 RNA 沉默的关键组成部分。在辣椒中，这些 RNAi 途径的高效且不可或缺的成分尚未被鉴定和表征。在本研究中，我们在辣椒中鉴定了 12 个、4 个和 6 个基因，并将它们与拟南芥、烟草、土豆和番茄进行了比较。详细的系统发育分析表明，每个 CaAGO、CaDCL 和 CaRDR 蛋白家族都分为四个分支。研究了组织特异性表达和对非生物或生物胁迫的反应。实时定量聚合酶链反应（PCR）结果表明，与黄瓜花叶病毒（CMV）、马铃薯 Y 病毒（PVY）和烟草花叶病毒（TMV）感染后，和上调，而对非生物胁迫的表达模式不同。此外，我们发现许多候选基因受植物激素和 H₂O₂处理的诱导。我们的研究结果为进一步阐明辣椒中的基因沉默途径和 RNAi 介导的宿主免疫提供了有用的信息。
