Kumar Animesh, Farooqi Mohammad Samir, Mishra Dwijesh Chandra, Kumar Sanjeev, Rai Anil, Chaturvedi Krishna Kumar, Lal Shashi Bhushan, Sharma Anu
Centre for Agricultural Bioinformatics, ICAR-Indian Agricultural Statistics Research Institute, Library Avenue, Pusa, New Delhi 110012, India.
Microrna. 2018;7(1):11-19. doi: 10.2174/2211536607666171213123038.
Late blight is a serious disease in potato caused by Phytophthora infestans. To date only few miRNA have been discovered which are related to late blight disease of potato during host pathogen interaction. Recent studies showed that miRNA, an important gene expression regulator, plays a very important role in host-pathogen interaction by silencing genes either by destructing or blocking of translation of mRNA.
Homology search was performed between non-redundant mature miRNA sequences from miRBase database and Solanum tuberosum EST sequences from NCBI database. Screening of the potential miRNA was done after secondary structure prediction. The target related to late blight disease of respective miRNA was functionally annotated. To identify the relationship between the predicted and mature miRNAs, multiple sequence alignment and evolutionary relationships were established.
34 Candidate miRNA related to late blight disease of potato were identified which were associated to five target genes. These miRNAs were linked with Avr3a, INF1, INF2b genes which are elicitin like protein and triggers a hypersensitive response to host cell. Mapping of target sequences showed similarity with Solanum lycopersicum NRC1 gene of chr.1, which are reported as a casual protein required for Pto-mediated cell death and resistance in N. benthamiana. NRC1 are considered as a RX-CC_like domain-containing protein which shows similarity with coiledcoil domain of the potato virus X resistance protein (RX) in Solanum tuberosum. RX recognizes pathogen effector proteins and triggers a response that may be as severe as localized cell death thereby providing resistance against potato virus X.
晚疫病是由致病疫霉引起的马铃薯严重病害。迄今为止，在寄主与病原体相互作用过程中，仅发现少数与马铃薯晚疫病相关的微小RNA（miRNA）。最近的研究表明，miRNA作为一种重要的基因表达调节因子，通过破坏或阻断mRNA翻译来沉默基因，在寄主与病原体相互作用中发挥着非常重要的作用。
在miRBase数据库的非冗余成熟miRNA序列与NCBI数据库的马铃薯EST序列之间进行同源性搜索。在二级结构预测后对潜在的miRNA进行筛选。对各个miRNA的晚疫病相关靶标进行功能注释。为了确定预测的miRNA与成熟miRNA之间的关系，建立了多序列比对和进化关系。
鉴定出34个与马铃薯晚疫病相关的候选miRNA，它们与5个靶基因相关。这些miRNA与Avr3a、INF1、INF2b基因相关，这些基因是类激发素蛋白，可引发对寄主细胞的过敏反应。靶序列图谱显示与番茄1号染色体的NRC1基因相似，该基因被报道为在本氏烟草中Pto介导的细胞死亡和抗性所需的偶然蛋白。NRC1被认为是一种含有RX-CC样结构域的蛋白，与马铃薯中马铃薯X病毒抗性蛋白（RX）的卷曲螺旋结构域相似。RX识别病原体效应蛋白并引发可能与局部细胞死亡一样严重的反应，从而提供对马铃薯X病毒的抗性。
