Rahman Faiz Ur, Khan Irshad Ahmad, Aslam Ali, Liu Ruitao, Sun Lei, Wu Yandi, Aslam Muhammad Muzammal, Khan Asad Ullah, Li Peng, Jiang Jianfu, Fan Xiucai, Liu Chonghuai, Zhang Ying
Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China.
Institute of Horticultural Sciences, University of Agriculture Faisalabad, Faisalabad, Pakistan.
Front Genet. 2022 Oct 20;13:1033288. doi: 10.3389/fgene.2022.1033288. eCollection 2022.
Salicylic acid (SA) is a well-studied phenolic plant hormone that plays an important role in plant defense against the hemi-biothrophic and biothrophic pathogens and depends on the living cells of host for the successful infection. In this study, a pathogenesis test was performed between and cultivars against grape white rot disease (). was found to be resistant against this disease. SA contents were found to be higher in the resistant grape cultivar after different time points. RNA-seq analysis was conducted on susceptible grapevine cultivars after 12, 24, and 48 h of SA application with the hypothesis that SA may induce defense genes in susceptible cultivars. A total of 511 differentially expressed genes (DEGs) were identified from the RNA-seq data, including some important genes, , , and for the SA defense pathway. DEGs related to phytohormone signal transduction and flavonoid biosynthetic pathways were also upregulated. The quantitative real-time PCR (qRT-PCR) results of the significantly expressed transcripts were found to be consistent with the transcriptome data, with a high correlation between the two analyses. The pathogenesis-related gene 1 (), which is an important marker gene for plant defense, was selected for further promoter analysis. The promoter sequence showed that it contains some important cis-elements (W-box, LS7, as-1, and TCA-element) to recruit the transcription factors , and to express the gene in response to SA treatment. Furthermore, the promoter was serially deleted into different fragments (-1,837, -1,443, -1,119, -864, -558, -436, and -192 ) bp and constructed vectors with the GUS reporter gene. Deletion analysis revealed that the promoter between -1837 bp to -558 bp induced significant GUS expression with respect to the control. On the basis of these results, the -558 bp region was assumed to be an important part of the promoter, and this region contained the important cis-elements related to SA, such as TCA-element (-1,472 bp), LS7 (-1,428 bp), and (-520 bp), that recruit the TFs and induce the expression of the gene. This study expanded the available information regarding SA-induced defense in susceptible grapes and recognized the molecular mechanisms through which this defense might be mediated.
水杨酸（SA）是一种经过充分研究的酚类植物激素，在植物抵御半活体营养型和活体营养型病原体的过程中发挥着重要作用，这些病原体成功感染依赖于宿主的活细胞。在本研究中，对[品种名称1]和[品种名称2]两个品种进行了针对葡萄白腐病（[病原体名称]）的发病机制测试。发现[品种名称1]对这种疾病具有抗性。在不同时间点后，抗性葡萄品种中的SA含量较高。对易感葡萄品种在施用SA 12、24和48小时后进行了RNA测序分析，假设SA可能诱导易感品种中的防御基因。从RNA测序数据中总共鉴定出511个差异表达基因（DEG），包括一些参与SA防御途径的重要基因，如[基因名称1]、[基因名称2]和[基因名称3]。与植物激素信号转导和类黄酮生物合成途径相关的DEG也上调。显著表达转录本的定量实时PCR（qRT-PCR）结果与转录组数据一致，两种分析之间具有高度相关性。选择植物防御的重要标记基因病程相关基因1（[基因名称4]）进行进一步的启动子分析。启动子序列显示它包含一些重要的顺式元件（W-box、LS7、as-1和TCA元件），以招募转录因子[转录因子名称1]和[转录因子名称2]，从而在SA处理时表达[基因名称4]基因。此外，将[基因名称4]启动子依次缺失为不同片段（-1,837、-1,443、-1,119、-864、-558、-436和-192）bp，并构建带有GUS报告基因的载体。缺失分析表明，相对于对照，-1837 bp至-558 bp之间的[基因名称4]启动子诱导了显著的GUS表达。基于这些结果，-558 bp区域被认为是[基因名称4]启动子的重要部分，该区域包含与SA相关的重要顺式元件，如TCA元件（-1,472 bp）、LS7（-1,428 bp）和[顺式元件名称]（-520 bp），它们招募转录因子并诱导[基因名称4]基因的表达。本研究扩展了关于SA诱导易感葡萄防御的现有信息，并认识到这种防御可能介导的分子机制。
