In this research, the effects of exogenous application of certain biostimulants [amino acid (AA), humic acid (HA), fulvic acid (FA), and seaweed extract (SE)] on the fruit yield and quality, leaf mineral contents, and some critical physio-chemical characteristics of grapevine (Vitis vinifera L.) cv. ‘Yaghouti’ were investigated under well-watered (WW) and drought-stressed (DS) conditions. Drought stress caused a remarkable reduction in the weight of 20 berries and fruit yield, and meanwhile a marked increase in the titratable acidity (TA) and total soluble solid (TSS) content of fruits. Application of biostimulants, especially SE, enhanced the weight of 20 berries, fruit yield, and TSS content, and decreased TA in fruits of DS vines. Although drought stress had a negative effect on the chlorophyll content of grapevine, this effect was alleviated by the application of biostimulants, especially SE. Moreover, drought stress made the accumulation of abscisic acid (ABA), proline, total phenol, and soluble carbohydrates, the level of hydrogen peroxide (H2O2) and malondialdehyde (MDA), as well as the activity of guaiacol peroxidase (GPX) and catalase (CAT) enzymes increased in leaves. Application of biostimulants, especially SE, further increased the accumulation of ABA, proline, total phenol, and soluble carbohydrates and the activity of the antioxidant enzymes, but reduced the level of MDA and H2O2 in DS vines. Under drought stress conditions, concentrations of N, P, and K increased, and concentrations of Fe and Zn decreased; however, DS grapevines treated with biostimulants and especially SE accumulated a higher level of these mineral nutrients than CON vines. In sum, as evidenced by the study results, biostimulants have a high potential for promoting fruit yield and quality of grapevine in drought-prone regions.

中文翻译：

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生物刺激剂诱导葡萄的耐旱性与生理和生化变化有关

在这项研究中，外源施用某些生物刺激剂[氨基酸（AA），腐殖酸（HA），黄腐酸（FA）和海藻提取物（SE）]对果实产量和品质，叶片矿物质含量和葡萄（Vitis vinifera L.）cv的一些重要的理化特性。“ Yaghouti”在水源充足（WW）和干旱胁迫（DS）条件下进行研究。干旱胁迫导致20个浆果的重量显着减少，水果产量显着降低，同时水果的可滴定酸度（TA）和总可溶性固形物（TSS）含量显着增加。生物刺激剂（特别是SE）的应用增加了20个浆果的重量，果实产量和TSS含量，并降低了DS藤本植物的TA。尽管干旱胁迫对葡萄的叶绿素含量有负面影响，通过使用生物刺激剂，尤其是SE，可以减轻这种影响。此外，干旱胁迫使脱落酸（ABA），脯氨酸，总酚和可溶性碳水化合物，过氧化氢（H2O2）和丙二醛（MDA）的含量以及愈创木酚过氧化物酶（GPX）和过氧化氢酶的活性得以积累。叶片中的（CAT）酶增加。生物刺激剂（尤其是SE）的应用进一步增加了ABA，脯氨酸，总酚和可溶性碳水化合物的积累以及抗氧化酶的活性，但降低了DS葡萄藤中MDA和H2O2的含量。在干旱胁迫条件下，氮，磷和钾的浓度增加，而铁和锌的浓度减少；然而，用生物刺激剂特别是SE处理的DS葡萄藤比CON葡萄藤积累的这些矿质养分含量更高。