Previous studies have demonstrated that the freezing tolerance (FT) of grapevine was enhanced by foliar application of exogenous abscisic acid (exo-ABA), a treatment which might be incorporated into cultural practices to mitigate cold damage in vineyards. To investigate the underlying mechanisms of this response, a two-year (2017 and 2018) study was conducted to characterize the effects of exo-ABA on greenhouse-grown 'Cabernet franc' grapevine. In control grapevines, both physiological (deeper dormancy) and biochemical (sugar accumulation in buds) changes occurred, indicating that grapevines initiated cold acclimation in the greenhouse. Compared to control, exo-ABA decreased stomatal conductance 2 h after application. Two weeks post application, exo-ABA treated grapevines showed accelerated transition of grapevine physiology during cold acclimation (increased depth of dormancy, decreased bud water content and enhanced bud FT), relative to control. Exo-ABA induced the accumulation of several sugars in buds including the raffinose family oligosaccharides (RFOs), and the RFO precursor, galactinol. The expression of raffinose and galactinol synthase genes was higher in exo-ABA treated grapevine buds, compared to control. The new findings from this study have advanced our understanding of the role of ABA in grapevine FT, which will be useful to develop future strategies to protect grapevines from cold damage.

中文翻译：

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外源脱落酸增强温室种植葡萄藤的生理、代谢和转录冷驯化反应

先前的研究表明，葡萄藤的抗冻性 (FT) 通过叶面施用外源脱落酸 (exo-ABA) 增强，这种处理可能会被纳入栽培实践以减轻葡萄园的冷害。为了研究这种反应的潜在机制，进行了一项为期两年（2017 年和 2018 年）的研究，以表征 exo-ABA 对温室种植的“品丽珠”葡萄藤的影响。在对照葡萄藤中，生理（更深的休眠）和生化（芽中的糖积累）都发生了变化，表明葡萄藤在温室中开始了冷驯化。与对照相比，exo-ABA 在施用后 2 小时降低了气孔导度。申请后两周，与对照相比，exo-ABA 处理的葡萄藤在冷驯化过程中表现出加速的葡萄藤生理转变（休眠深度增加、芽含水量降低和芽 FT 增强）。Exo-ABA 诱导芽中几种糖的积累，包括棉子糖家族寡糖 (RFO) 和 RFO 前体半乳糖醇。与对照相比，外置ABA处理的葡萄芽中棉子糖和半乳糖醇合酶基因的表达更高。这项研究的新发现加深了我们对 ABA 在葡萄藤 FT 中作用的理解，这将有助于制定未来保护葡萄藤免受冷害的策略。Exo-ABA 诱导芽中几种糖的积累，包括棉子糖家族寡糖 (RFO) 和 RFO 前体半乳糖醇。与对照相比，外置ABA处理的葡萄芽中棉子糖和半乳糖醇合酶基因的表达更高。这项研究的新发现增进了我们对 ABA 在葡萄藤 FT 中作用的理解，这将有助于制定未来保护葡萄藤免受冷害的策略。Exo-ABA 诱导芽中几种糖的积累，包括棉子糖家族寡糖 (RFO) 和 RFO 前体半乳糖醇。与对照相比，外置ABA处理的葡萄芽中棉子糖和半乳糖醇合酶基因的表达更高。这项研究的新发现加深了我们对 ABA 在葡萄藤 FT 中作用的理解，这将有助于制定未来保护葡萄藤免受冷害的策略。