Shanghai Collaborative Innovation Center of Agri-Seeds/Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China.
Shanghai Collaborative Innovation Center of Agri-Seeds/Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Plant Sci. 2023 Apr;329:111623. doi: 10.1016/j.plantsci.2023.111623. Epub 2023 Feb 5.
High temperature stress is one of the primary abiotic stresses that restrict fruit tree production. Grapevine (Vitis vinifera) with high economic value throughout the world is a cultivated fruit crop, and its growth and development is often influenced by high temperature stress. Studying the heat stress-response mechanism of grapevine has great significance for understanding the acclimation to heat stress. In this study, we identified a series of heat stress responsive miRNAs and analyzed their function during the heat tolerance response. CK (control group, 25 °C) and heat treatment stress (TS, 45 °C) small RNA (sRNA) libraries were constructed and sequenced by high-throughput sequencing in 'Thompson seedless' grapevine. 873 known-miRNAs and 86 novel-miRNAs were identified, of which 88 known and three novel miRNAs were expressed differentially under heat stress. 322 genes were predicted to be targeted by the miRNAs. Eight selected miRNAs and its targets were confirmed by real time quantitative PCR (RT - qPCR), indicating that these "miRNA - target" were responsive to heat stress. In addition, most of the predicted target genes were negatively regulated by corresponding miRNAs. Gene function and pathway analyses indicated that these genes probably play crucial roles in heat stress tolerance. Vvi-miR167b transiently overexpression in grapevine leaves decreased target gene vvARF6, vvARF6-like and vvARF8 expression. The function of vvi-miR167 was verified by ectopic transformation in Arabidopsis thaliana, and the heat tolerance in transgenic lines was enhanced significantly, suggesting that the vvi-miR167 plays a positive regulatory role in grape thermostability. Comparison of miRNA expression patterns between heat treatment stress and CK can help elucidate the heat stress response and resistance mechanisms in grapes. In conclusion, these results gave us useful information to better understand the heat stress-response during domestication as well as for breeding new cultivars with heat stress resistance in fruit trees.
高温胁迫是限制果树生产的主要非生物胁迫之一。葡萄（Vitis vinifera）在全球范围内具有很高的经济价值，是一种栽培水果作物，其生长发育常受到高温胁迫的影响。研究葡萄对热胁迫的响应机制对于理解其对热胁迫的适应具有重要意义。在本研究中，我们鉴定了一系列热胁迫响应的 miRNA，并分析了它们在耐热响应过程中的功能。通过高通量测序构建并测序了‘Thompson seedless’葡萄的 CK（对照组，25°C）和热处理应激（TS，45°C）小 RNA（sRNA）文库。鉴定出 873 个已知 miRNA 和 86 个新 miRNA，其中 88 个已知和 3 个新 miRNA在热胁迫下表达差异。预测 322 个基因被 miRNA 靶向。通过实时定量 PCR（RT-qPCR）验证了 8 个选定的 miRNA 及其靶标，表明这些“miRNA-靶标”对热胁迫有反应。此外，大多数预测的靶基因被相应的 miRNA 负调控。基因功能和通路分析表明，这些基因可能在耐热性中发挥关键作用。葡萄叶片中 Vvi-miR167b 的瞬时过表达降低了靶基因 vvARF6、vvARF6-like 和 vvARF8 的表达。通过拟南芥异位转化验证了 vvi-miR167 的功能，转基因株系的耐热性显著增强，表明 vvi-miR167 在葡萄耐热性中发挥正调控作用。热处理应激与 CK 之间 miRNA 表达模式的比较有助于阐明葡萄的热应激响应和抗性机制。总之，这些结果为我们提供了有用的信息，有助于更好地理解在驯化过程中对热胁迫的响应以及在果树中培育具有耐热性的新品种。
