The effects of an inhibitor (Abz-E3M) of abscisic acid (ABA) 8′-hydroxylase, which is a primary enzyme of ABA catabolism, on dehydration tolerance and root formation in grape cuttings under drought conditions were investigated. Cuttings of ‘Kyoho’ grape (Vitis labrusca L. × Vitis vinifera L.) were sprayed with 100 μM of Abz-E3M and subjected to water deficit conditions at the stage when their first leaves fully expanded. The physiological and morphological changes in the leaves and basal portions of the cuttings were determined. In Abz-E3M-treated leaves, lower ABA metabolite and higher ABA and indole-3-acetic acid (IAA) concentrations were observed. Compared to the untreated control leaves, higher water potential was significantly maintained in Abz-E3M-treated leaves. Abz-E3M applications resulted in lower proline accumulation and 2,2-diphenyl-2-picrylhydrazyl radical scavenging activity in the leaves and led to enhanced dehydration tolerance. In addition, the percentage of rooted cuttings was significantly increased by Abz-E3M application. In the basal portion of Abz-E3M-treated cuttings, endogenous IAA concentrations and the gene expressions of VvARF6 and VvARF8, which are positive regulators of adventitious root formation, were significantly increased. Moreover, the expression levels of the negative regulator, VvARF17, were significantly lower. These results suggested that the inhibition of ABA 8′-hydroxylase enhanced dehydration tolerance and adventitious rooting and may be an effective strategy for achieving drought stress tolerance in grape cuttings.

中文翻译：

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在干旱胁迫条件下，脱落酸 8'-羟化酶的抑制影响葡萄 (Vitis labrusca L. × Vitis vinifera L. cv. Kyoho) 插条的脱水耐受性和根形成

研究了脱落酸 (ABA) 8'-羟化酶抑制剂 (Abz-E3M) 对干旱条件下葡萄插条的脱水耐受性和根形成的影响，脱落酸 (ABA) 8'-羟化酶是 ABA 分解代谢的主要酶。'Kyoho' 葡萄 (Vitis labrusca L. × Vitis vinifera L.) 的插条用 100 μM 的 Abz-E3M 喷洒，并在它们的第一片叶子完全展开的阶段经受缺水条件。测定了插条的叶片和基部的生理和形态变化。在 Abz-E3M 处理的叶子中，观察到较低的 ABA 代谢物和较高的 ABA 和吲哚-3-乙酸 (IAA) 浓度。与未处理的对照叶子相比，Abz-E3M 处理的叶子显着保持了更高的水势。Abz-E3M 应用导致较低的脯氨酸积累和 2, 叶中 2-diphenyl-2-picrylhydrazyl 自由基清除活性并导致增强的脱水耐受性。此外，Abz-E3M 应用显着增加了生根插条的百分比。在 Abz-E3M 处理的插条的基部，内源性 IAA 浓度和 VvARF6 和 VvARF8 的基因表达显着增加，它们是不定根形成的正调节因子。此外，负调节因子 VvARF17 的表达水平显着降低。这些结果表明，ABA 8'-羟化酶的抑制增强了脱水耐受性和不定生根，可能是实现葡萄插条耐旱性的有效策略。Abz-E3M 应用显着增加了生根插条的百分比。在 Abz-E3M 处理的插条的基部，内源性 IAA 浓度和 VvARF6 和 VvARF8 的基因表达显着增加，它们是不定根形成的正调节因子。此外，负调节因子 VvARF17 的表达水平显着降低。这些结果表明，ABA 8'-羟化酶的抑制增强了脱水耐受性和不定生根，可能是实现葡萄插条耐旱性的有效策略。Abz-E3M 应用显着增加了生根插条的百分比。在 Abz-E3M 处理的插条的基部，内源性 IAA 浓度和 VvARF6 和 VvARF8 的基因表达显着增加，它们是不定根形成的正调节因子。此外，负调节因子 VvARF17 的表达水平显着降低。这些结果表明，ABA 8'-羟化酶的抑制增强了脱水耐受性和不定生根，可能是实现葡萄插条耐旱性的有效策略。不定根形成的正调节因子显着增加。此外，负调节因子 VvARF17 的表达水平显着降低。这些结果表明，ABA 8'-羟化酶的抑制增强了脱水耐受性和不定根，可能是实现葡萄插条耐旱性的有效策略。不定根形成的正调节因子显着增加。此外，负调节因子 VvARF17 的表达水平显着降低。这些结果表明，ABA 8'-羟化酶的抑制增强了脱水耐受性和不定生根，可能是实现葡萄插条耐旱性的有效策略。