BACKGROUND Drought is one of the most harmful abiotic stresses for plants, leading to reduced productivity of several economically important crops and, consequently, considerable losses in the agricultural sector. When plants are exposed to stressful conditions, such as drought and high salinity, they modulate the expression of genes that lead to developmental, biochemical, and physiological changes, which help to overcome the deleterious effects of adverse circumstances. Thus, the search for new specific gene promoter sequences has proved to be a powerful biotechnological strategy to control the expression of key genes involved in water deprivation or multiple stress responses. RESULTS This study aimed to identify and characterize the GmRD26 promoter (pGmRD26), which is involved in the regulation of plant responses to drought stress. The expression profile of the GmRD26 gene was investigated by qRT-PCR under normal and stress conditions in Williams 82, BR16 and Embrapa48 soybean-cultivars. Our data confirm that GmRD26 is induced under water deficit with different induction folds between analyzed cultivars, which display different genetic background and physiological behaviour under drought. The characterization of the GmRD26 promoter was performed under simulated stress conditions with abscisic acid (ABA), polyethylene glycol (PEG) and drought (air dry) on A. thaliana plants containing the complete construct of pGmRD26::GUS (2.054 bp) and two promoter modules, pGmRD26A::GUS (909 pb) and pGmRD26B::GUS (435 bp), controlling the expression of the β-glucuronidase (uidA) gene. Analysis of GUS activity has demonstrated that pGmRD26 and pGmRD26A induce strong reporter gene expression, as the pAtRD29 positive control promoter under ABA and PEG treatment. CONCLUSIONS The full-length promoter pGmRD26 and the pGmRD26A module provides an improved uidA transcription capacity when compared with the other promoter module, especially in response to polyethylene glycol and drought treatments. These data indicate that pGmRD26A may become a promising biotechnological asset with potential use in the development of modified drought-tolerant plants or other plants designed for stress responses.

中文翻译：

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GmRD26 大豆启动子响应非生物胁迫的鉴定和表征：生物技术应用的潜在工具。


背景技术干旱是对植物最有害的非生物胁迫之一，导致几种重要经济作物的生产力降低，并因此导致农业部门的巨大损失。当植物暴露在干旱和高盐度等应激条件下时，它们会调节基因的表达，从而导致发育、生化和生理变化，这有助于克服不利环境的有害影响。因此，寻找新的特定基因启动子序列已被证明是控制缺水或多重应激反应中涉及的关键基因表达的强大生物技术策略。结果本研究旨在鉴定和表征 GmRD26 启动子 (pGmRD26)，该启动子参与植物对干旱胁迫反应的调节。通过 qRT-PCR 研究了 Williams 82、BR16 和 Embrapa48 大豆品种在正常和胁迫条件下 GmRD26 基因的表达谱。我们的数据证实，GmRD26 在缺水条件下被诱导，所分析的品种之间的诱导倍数不同，这些品种在干旱下表现出不同的遗传背景和生理行为。 GmRD26 启动子的表征是在模拟胁迫条件下用脱落酸 (ABA)、聚乙二醇 (PEG) 和干旱（空气干燥）对含有 pGmRD26::GUS (2.054 bp) 完整构建体和两个拟南芥植物进行的。启动子模块 pGmRD26A::GUS (909 pb) 和 pGmRD26B::GUS (435 bp)，控制 β-葡萄糖醛酸酶 (uidA) 基因的表达。 GUS 活性分析表明，pGmRD26 和 pGmRD26A 在 ABA 和 PEG 处理下作为 pAtRD29 阳性对照启动子诱导强报告基因表达。 结论 与其他启动子模块相比，全长启动子 pGmRD26 和 pGmRD26A 模块提供了改进的 uidA 转录能力，特别是在响应聚乙二醇和干旱处理时。这些数据表明pGmRD26A可能成为一种有前途的生物技术资产，可用于开发改良的耐旱植物或其他专为应激反应而设计的植物。