Abstract Perennial ryegrass (Lolium perenne L.) is a cool-season forage and turf grass species cultivated world-wide. Natural variations of stress tolerance of perennial ryegrass varieties and mechanisms of stress tolerance are of great interest for breeders. In this study, stress tolerances of seventeen varieties and function of HSFC1b have been characterized. The results showed seventeen varieties exhibited contrasting tolerance to drought, heat and cold stresses. Tolerant varieties had higher proline than sensitive ones after stress treatments. Drought, heat and cold stresses extensively reprogrammed transcriptome of perennial ryegrass and modulated expression of 4797, 4329 and 4635 genes, respectively. LpHSFC1b was significantly induced after stress treatments and characterized as the core regulators through protein interaction network analysis. Ectopic expression of LpHSFC1b in Arabidopsis improved plant thermotolerance, but not drought and cold tolerances. Transgenic Arabidopsis had decreased electrolyte leakage (EL), malondialdehyde (MDA) content and chlorosis⁄necrosis severity indices, and increased expression of heat stress responsive genes. These data indicated that perennial ryegrass exhibited divergent stress tolerances, and HSFC1b likely functioned as a positive regulator in heat stress response, that may provide detailed insight for understanding of abiotic stress response clues in perennial ryegrass.

中文翻译：

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多年生黑麦草对非生物胁迫响应的自然变异分析强调 LpHSFC1b 作为热胁迫的正调节因子

摘要 多年生黑麦草（Lolium perenne L.）是世界范围内栽培的冷季牧草和草坪草品种。多年生黑麦草品种胁迫耐受性的自然变异和胁迫耐受机制引起育种者的极大兴趣。在这项研究中，已经表征了 17 个品种的胁迫耐受性和 HSFC1b 的功能。结果表明，17 个品种对干旱、热和冷胁迫表现出不同的耐受性。胁迫处理后耐受品种的脯氨酸含量高于敏感品种。干旱、热和冷胁迫对多年生黑麦草的转录组进行了广泛的重编程，并分别调节了 4797、4329 和 4635 个基因的表达。LpHSFC1b 在应激处理后被显着诱导，并通过蛋白质相互作用网络分析表征为核心调节剂。LpHSFC1b 在拟南芥中的异位表达提高了植物的耐热性，但没有提高植物的耐旱性和耐寒性。转基因拟南芥降低了电解质泄漏 (EL)、丙二醛 (MDA) 含量和萎黄/坏死严重程度指数，并增加了热应激反应基因的表达。这些数据表明多年生黑麦草表现出不同的胁迫耐受性，并且 HSFC1b 可能在热应激反应中起正调节作用，这可能为了解多年生黑麦草的非生物胁迫反应线索提供详细的见解。转基因拟南芥降低了电解质泄漏 (EL)、丙二醛 (MDA) 含量和萎黄/坏死严重程度指数，并增加了热应激反应基因的表达。这些数据表明多年生黑麦草表现出不同的胁迫耐受性，并且 HSFC1b 可能在热应激反应中起正调节作用，这可能为了解多年生黑麦草的非生物胁迫反应线索提供详细的见解。转基因拟南芥降低了电解质泄漏 (EL)、丙二醛 (MDA) 含量和萎黄/坏死严重程度指数，并增加了热应激反应基因的表达。这些数据表明多年生黑麦草表现出不同的胁迫耐受性，并且 HSFC1b 可能在热应激反应中起正调节作用，这可能为了解多年生黑麦草的非生物胁迫反应线索提供详细的见解。