Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
AgriGenome Labs Pvt. Ltd., BTIC, MN iHub, Shamirpet, India.
PLoS One. 2021 Nov 4;16(11):e0251167. doi: 10.1371/journal.pone.0251167. eCollection 2021.
Field pea (Pisum sativum L.), a cool-season legume crop, is known for poor heat tolerance. Our previous work identified PR11-2 and PR11-90 as heat tolerant and susceptible lines in a recombinant inbred population. CDC Amarillo, a Canadian elite pea variety, was considered as another heat tolerant variety based on its similar field performance as PR11-2. This study aimed to characterize the differential transcription. Plants of these three varieties were stressed for 3 h at 38°C prior to self-pollination, and RNAs from heat stressed anthers and stipules on the same flowering node were extracted and sequenced via the Illumina NovaSeq platform for the characterization of heat responsive genes. In silico results were further validated by qPCR assay. Differentially expressed genes (DEGs) were identified at log2 |fold change (FC)| ≥ 2 between high temperature and control temperature, the three varieties shared 588 DEGs which were up-regulated and 220 genes which were down-regulated in anthers when subjected to heat treatment. In stipules, 879 DEGs (463/416 upregulation/downregulation) were consistent among varieties. The above heat-induced genes of the two plant organs were related to several biological processes i.e., response to heat, protein folding and DNA templated transcription. Ten gene ontology (GO) terms were over-represented in the consistently down-regulated DEGs of the two organs, and these terms were mainly related to cell wall macromolecule metabolism, lipid transport, lipid localization, and lipid metabolic processes. GO enrichment analysis on distinct DEGs of individual pea varieties suggested that heat affected biological processes were dynamic, and variety distinct responses provide insight into molecular mechanisms of heat-tolerance response. Several biological processes, e.g., cellular response to DNA damage stimulus in stipule, electron transport chain in anther that were only observed in heat induced PR11-2 and CDC Amarillo, and their relevance to field pea heat tolerance is worth further validation.
田野豌豆（Pisum sativum L.）是一种冷季豆科作物，耐热性差。我们之前的工作在重组自交群体中鉴定出 PR11-2 和 PR11-90 为耐热和敏感系。CDC Amarillo 是一种加拿大的优良豌豆品种，因其与 PR11-2 相似的田间表现而被认为是耐热品种。本研究旨在对其进行差异转录特征分析。在自花授粉前，将这三个品种的植株在 38°C 下热应激 3 小时，然后从热应激的花药和同一开花节点的托叶中提取 RNA，并通过 Illumina NovaSeq 平台进行测序，以鉴定热响应基因。通过 qPCR 进一步验证了计算机模拟结果。在高温和对照温度之间的 log2 |fold change (FC)|≥2 时，鉴定出差异表达基因（DEGs）。三种品种的花药在热处理时共有 588 个上调基因和 220 个下调基因，托叶中有 879 个 DEGs（463/416 上调/下调）。这两个植物器官的上述热诱导基因与几个生物学过程有关，如对热的反应、蛋白质折叠和 DNA 模板转录。两个器官的一致下调 DEGs 有 10 个基因本体论（GO）术语过表达，这些术语主要与细胞壁大分子代谢、脂质转运、脂质定位和脂质代谢过程有关。对个别豌豆品种的特异 DEGs 的 GO 富集分析表明，热影响生物学过程是动态的，品种间的差异反应为耐热性响应的分子机制提供了线索。几个生物学过程，如托叶中的细胞对 DNA 损伤刺激的反应、花药中的电子传递链，仅在热诱导的 PR11-2 和 CDC Amarillo 中观察到，它们与田野豌豆的耐热性有关，值得进一步验证。
