Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran.
Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran; Plant Protection Research Division, Isfahan Center for Research and Education in Agricultural Science and Natural Resources, (AREEO), Isfahan, Iran.
Plant Physiol Biochem. 2019 Sep;142:500-509. doi: 10.1016/j.plaphy.2019.08.011. Epub 2019 Aug 16.
Early blight disease of tomato is one of the most devastating biotic stresses worldwide, and in Iran, Alternaria alternata is one of the most predominant species causing the disease. In the current study, a diverse collection of 35 tomato genotypes and implication of 5 SlWRKYs and 7 PR genes as well as enzymatic activity were evaluated on resistant and susceptible cultivars through real-time polymerase chain reaction at transplanting and maturing stages and by measuring product formation using spectrophotometry. The results indicated that the expression of these antifungal genes in 14 genotypes at two growth stages after inoculation with A. alternata highly enhanced by 1-50-fold. There was also significant upregulation of WRKYs and PRs genes among the resistant tomato varieties in comparison to susceptible and control varieties at both stages. These findings demonstrate the varieties that showed increased or decreased SlWRKY1 expression also displayed similar changes in the expression of PR1 and PR2 genes. Furthermore, the differential expression patterns of SlWRKY1 and SlWRKY11 were consistent with PR7 and PDF1.2 expression patterns. The analysis of enzymatic activity of PR2 and PR3 proteins, β-1,3-glucanase, and chitinase showed the highest level of activity in resistant inoculated genotypes against A. alternata. Therefore, the current findings suggest the possible involvement of these transcription factors in the increased expression of PR genes in response to A. alternata infection.
番茄早疫病是全球破坏性最大的生物胁迫之一，在伊朗，交链格孢菌是引起该病的最主要的物种之一。在本研究中，通过实时聚合酶链反应（PCR）在移栽和成熟阶段对 35 个番茄基因型进行了评估，同时利用分光光度法测量产物形成来评估 5 个 SlWRKY 和 7 个 PR 基因的表达以及酶活性。结果表明，在接种交链格孢菌后，14 个基因型在两个生长阶段的这些抗病基因表达水平提高了 1-50 倍。在两个阶段，与敏感品种和对照品种相比，抗病番茄品种的 WRKY 和 PR 基因的表达也显著上调。这些发现表明，SlWRKY1 表达增加或减少的品种，其 PR1 和 PR2 基因的表达也会发生类似的变化。此外，SlWRKY1 和 SlWRKY11 的差异表达模式与 PR7 和 PDF1.2 的表达模式一致。PR2 和 PR3 蛋白、β-1,3-葡聚糖酶和几丁质酶的酶活性分析表明，在接种的抗性基因型中，这些酶对交链格孢菌的活性最高。因此，目前的研究结果表明，这些转录因子可能参与了 PR 基因在对交链格孢菌感染的反应中表达的增加。
