Krishankumar Sonu, Hunter Jacobus J, Alyafei Mohammed, Souka Usama, Subramaniam Sreeramanan, Ramlal Ayyagari, Kurup Shyam S, Amiri Khaled M A
Integrative Agriculture Department, College of Agriculture and Veterinary Medicine, UAE Uiversity (UAEU), Al Ain, United Arab Emirates.
ARC Infruitec-Nietvoorbij, Agricultural Research Council, Stellenbosch, South Africa.
Front Plant Sci. 2025 Jun 27;16:1559095. doi: 10.3389/fpls.2025.1559095. eCollection 2025.
Grapevines are an important and economically significant fruit plant that is cultivated worldwide. Most of the world's emerging wine-growing regions are in arid or semi-arid regions that are severely affected by drought. Grafting has emerged as an effective strategy to enhance drought tolerance, but the influence of scion-rootstock combinations on key biochemical and antioxidant parameters under water deficit conditions is not fully understood.
The study investigates the effects of grafting on antioxidant enzymes, malondialdehyde (MDA), polyamines and sugar metabolism in five grafted grapevine combinations exposed to three irrigation levels to optimise sustainable grape production in the arid regions of the UAE. Leaf samples were analysed for polyamines, MDA and sugars using liquid chromatography.
The study found that the drought-tolerant rootstocks Paulsen, R110 and Ramsey increased cell activity, reduced ROS production, lowered MDA levels and increased antioxidant capabilities. SOD activity increased significantly under 75% and 50% FC by 225% in V1, 316% in V3, 133% in V4 and 1025% in V5. In response to severe drought at 75% and 50% FC, V2 and V5 showed a decrease in MDA accumulation (by 34.2% and 50% in V2 and 23.7% and 57.6% in V5, respectively) compared to 100% FC (0.76 nmoL mL-1 in V2 and 1.18 nmoL mL-1 in V5). Polyamines generally showed an increase with decreasing field capacity, indicating drought tolerance. Different polyamine contents were observed in grafted vines. V1, V2 and V5 showed higher levels of spermine and free spermidine, while V3 and V4 were more sensitive to drought stress. Organic osmolytes positively influenced the enzymatic activity in drought-tolerant grafts. Sugars built up in the grafts and had a signalling function as Osmo protective molecules. The shoots improved sugar metabolism, which led to increased resistance to drought. There was a significant increase in glucose sugar content at 75% and 50% FC, which was 85.7% to 133% at V1, 19% to 76.9% at V2, and decreased by 30% and 53% at V4.
The results suggest that grafted grapevines have a strong ability to cope with drought stress by upregulating antioxidant enzymes and altering other compounds such as MDA, PA and sugars that are conducive to stress tolerance.
葡萄是一种重要且具有经济意义的水果植物，在全球范围内广泛种植。世界上大多数新兴的葡萄酒产区位于干旱或半干旱地区，受到干旱的严重影响。嫁接已成为提高耐旱性的有效策略，但在水分亏缺条件下，接穗 - 砧木组合对关键生化和抗氧化参数的影响尚未完全了解。
本研究调查了在阿联酋干旱地区，三种灌溉水平下，五种嫁接葡萄组合中嫁接对抗氧化酶、丙二醛（MDA）、多胺和糖代谢的影响，以优化可持续葡萄生产。使用液相色谱法分析叶片样本中的多胺、MDA和糖。
研究发现，耐旱砧木保尔森、R110和拉姆齐提高了细胞活性，减少了活性氧的产生，降低了MDA水平，并增强了抗氧化能力。在75%和50%田间持水量（FC）条件下，超氧化物歧化酶（SOD）活性显著增加，V1增加了225%，V3增加了316%，V4增加了133%，V5增加了1025%。在75%和50% FC的严重干旱条件下，与100% FC（V2为0.76 nmoL mL-1，V5为1.18 nmoL mL-1）相比，V2和V5的MDA积累量有所下降（V2分别下降34.2%和50%，V5分别下降23.7%和57.6%）。多胺一般随着田间持水量的降低而增加，表明具有耐旱性。嫁接葡萄藤中观察到不同的多胺含量。V1、V2和V5显示出较高水平的精胺和游离亚精胺，而V3和V4对干旱胁迫更敏感。有机渗透剂对耐旱嫁接中的酶活性有积极影响。糖在嫁接中积累，并作为渗透保护分子具有信号传导功能。新梢改善了糖代谢，从而提高了对干旱的抗性。在75%和50% FC时，葡萄糖含量显著增加，V1增加了85.7%至133%，V2增加了19%至76.9%，V4下降了30%和53%。
结果表明，嫁接葡萄藤具有很强的应对干旱胁迫的能力，通过上调抗氧化酶并改变其他有助于胁迫耐受性的化合物，如MDA、多胺和糖。
