Coronatine (COR) is a phytotoxin produced by Pseudomonas syringae and is a functional analogue of the bioactive hormone JA-Ile, which is widely involved in plant defence responses. In this study, we explored the effects of exogenous applications of COR on tobacco plants under polyethylene glycol-induced drought stress. Compared with control (CK), COR-treated tobacco plants exhibited higher leaf relative water content and better photosynthetic performance under drought exposure. Ultrastructural examination revealed that drought led to stomatal closure and disorganization of granum stacking in the chloroplasts (with obvious accumulation of plastoglobuli), and mitochondria in the CK samples presented injured cristae. In the leaf tissue of the COR-treated plants, regularly stacked granum thylakoids, few plastoglobuli and intact mitochondrial membranes and cristae were observed. Totals of 1803 and 6207 differentially expressed genes (DEGs) were identified between the samples from the COR-treated and CK plants under well-watered and drought conditions. Functional annotation analysis revealed that these DEGs were involved mainly in plant hormone signal transduction, cellular carbohydrate metabolic processes and photosynthesis processes. Six hundred forty transcription factor genes were also identified among the DEGs. This study provides a global view of COR-induced drought stress tolerance in tobacco from both physiological and transcriptional aspects.

中文翻译：

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生理学和转录组分析揭示了冠毒碱在提高烟草耐旱性方面的重要作用

Coronatine (COR) 是一种由丁香假单胞菌产生的植物毒素，是生物活性激素 JA-Ile 的功能类似物，广泛参与植物防御反应。在这项研究中，我们探讨了外源应用 COR 对聚乙二醇诱导的干旱胁迫下烟草植物的影响。与对照（CK）相比，COR处理的烟草植物在干旱暴露下表现出更高的叶片相对含水量和更好的光合性能。超微结构检查显示干旱导致气孔关闭和叶绿体中颗粒堆积的解体（具有明显的质体球积累），CK样品中的线粒体呈现受损的嵴。在 COR 处理过的植物的叶组织中，有规律地堆积着颗粒类囊体，观察到很少的质体球和完整的线粒体膜和嵴。在充分浇水和干旱条件下，在来自 COR 处理和 CK 植物的样品之间鉴定了 1803 和 6207 个差异表达基因 (DEG)。功能注释分析表明，这些DEGs主要参与植物激素信号转导、细胞碳水化合物代谢过程和光合作用过程。在 DEG 中还鉴定了 640 个转录因子基因。这项研究从生理和转录方面提供了烟草中 COR 诱导的干旱胁迫耐受性的全局视图。在充分浇水和干旱条件下，在来自 COR 处理和 CK 植物的样品之间鉴定了 1803 和 6207 个差异表达基因 (DEG)。功能注释分析表明，这些DEGs主要参与植物激素信号转导、细胞碳水化合物代谢过程和光合作用过程。在 DEG 中还鉴定了 640 个转录因子基因。这项研究从生理和转录方面提供了烟草中 COR 诱导的干旱胁迫耐受性的全局视图。在充分浇水和干旱条件下，在来自 COR 处理和 CK 植物的样品之间鉴定了 1803 和 6207 个差异表达基因 (DEG)。功能注释分析表明，这些DEGs主要参与植物激素信号转导、细胞碳水化合物代谢过程和光合作用过程。在 DEG 中还鉴定了 640 个转录因子基因。这项研究从生理和转录方面提供了烟草中 COR 诱导的干旱胁迫耐受性的全局视图。