Sweet potato (Ipomoea batatas L.), typically cultivated in temperate climates under low inputs, is one of the most important crops worldwide. Abscisic acid (ABA) is an important plant stress-induced phytohormone. Hitherto, few works analyzed the ABA function in sweet potato tissue growth. Very scarce information is available concerning the ABA role in sweet potato response to water scarcity conditions. Here, we show the ABA content variation in shoots and tubers of eight sweet potato accessions subjected to drought stress. ABA was also related to other resistance traits, such as chlorophyll content index (CCI), carbon isotopic discrimination (Δ13 C), oxalic acid (OA), and water use efficiency (WUE), to assess stress response mechanisms to water deficit between their organs. The most resilient drought-stressed sweet potato plants accumulated ABA-shoot, and significantly decreased the ABA-tuber content. ABA signaling was related to Δ13 C and CCI decrease and WUE increment, as an attempt to cope with water stress by partially closing the stomata. The partial closure of stomata could be in part due to the presence of OA-shoots, known to affect the intensity of the ABA-shoot signal in stomatal closure. Higher CCI content and minimal Δ13 C-shoot differences indicated good carboxylation fractionation, with higher Δ13 C-tuber content as an indicator of efficient tuber 13 C fixation and growth. Our work demonstrated that ABA could be used in conjunction with the other traits in the study for the assessment of sweet potato whole-plant responses to environmental stresses, and thus aid the selection of the best drought tolerant genotypes for breeding programs. This article is protected by copyright. All rights reserved.

中文翻译：

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使用竞争免疫学测定长期干旱胁迫的番薯块茎和枝条中脱落酸植物激素

甘薯 (Ipomoea batatas L.) 通常在低投入的温带气候中种植，是世界上最重要的作物之一。脱落酸（ABA）是一种重要的植物胁迫诱导的植物激素。迄今为止，很少有研究分析 ABA 在甘薯组织生长中的功能。关于 ABA 在甘薯对缺水条件的反应中的作用的信息非常稀少。在这里，我们展示了受到干旱胁迫的 8 个甘薯种质的芽和块茎中 ABA 含量的变化。ABA 还与其他抗性性状有关，如叶绿素含量指数 (CCI)、碳同位素歧视 (Δ13 C)、草酸 (OA) 和水分利用效率 (WUE)，以评估它们之间水分亏缺的应激反应机制。器官。抗旱能力最强的甘薯植株积累了ABA-茎，显着降低了ABA-块茎的含量。ABA 信号与 Δ13 C 和 CCI 减少和 WUE 增加有关，试图通过部分关闭气孔来应对水分胁迫。气孔的部分关闭可能部分是由于 OA 枝条的存在，已知会影响气孔关闭中 ABA 枝条信号的强度。较高的 CCI 含量和最小的 Δ13 C 茎差异表明良好的羧化分馏，较高的 Δ13 C 块茎含量作为有效块茎 13 C 固定和生长的指标。我们的工作表明，ABA 可与研究中的其他性状结合使用，以评估甘薯整株对环境胁迫的反应，从而有助于为育种计划选择最佳的耐旱基因型。本文受版权保护。版权所有。