EGFV, Univ. Bordeaux, Bordeaux Sciences Agro, Villenave d'Ornon, France.
Unité de recherche Oenologie, EA 4577, USC 1366 INRAE, ISVV, Université de Bordeaux, Villenave d'Ornon, France.
Plant Cell Environ. 2023 Dec;46(12):3871-3886. doi: 10.1111/pce.14693. Epub 2023 Aug 30.
Grafting is widely used in horticulture. Shortly after grafting, callus tissues appear at the graft interface and the vascular tissues of the scion and rootstock connect. The graft interface contains a complex mix of tissues, we hypothesised that each tissue has its own metabolic response to wounding/grafting and accumulates different metabolites at different rates. We made intact and wounded cuttings and grafts of grapevine, and then measured changes in bulk flavonoid, phenolic acid and stilbenoid concentration and used metabolite imaging to study tissue-specific responses. We show that some metabolites rapidly accumulate in specific tissues after grafting, for example, stilbene monomers accumulate in necrotic tissues surrounding mature xylem vessels. Whereas other metabolites, such as complex stilbenes, accumulate in the same tissues at later stages. We also observe that other metabolites accumulate in the newly formed callus tissue and identify genotype-specific responses. In addition, exogenous resveratrol application did not modify grafting success rate, potentially suggesting that the accumulation of resveratrol at the graft interface is not linked to graft union formation. The increasing concentration of complex stilbenes often occurs in response to plant stresses (via unknown mechanisms), and potentially increases antioxidant activity and antifungal capacities.
嫁接在园艺中被广泛应用。嫁接后不久，接穗和砧木的愈伤组织会出现在嫁接界面上，并且维管束组织相互连接。嫁接界面包含复杂的混合组织，我们假设每个组织对创伤/嫁接都有自己的代谢反应，并以不同的速度积累不同的代谢物。我们制作了完整和受伤的葡萄插条和嫁接，然后测量了大量类黄酮、酚酸和芪类化合物浓度的变化，并使用代谢物成像来研究组织特异性反应。我们表明，一些代谢物在嫁接后很快在特定组织中积累，例如，芪单体在成熟木质部周围的坏死组织中积累。而其他代谢物，如复杂的芪类，在后期会在相同的组织中积累。我们还观察到其他代谢物在新形成的愈伤组织中积累，并确定了特定基因型的反应。此外，外源性白藜芦醇的应用并没有改变嫁接成功率，这可能表明在嫁接界面处白藜芦醇的积累与嫁接愈合形成无关。复杂芪类化合物浓度的增加通常是对植物胁迫的反应（通过未知机制），并可能增加抗氧化活性和抗真菌能力。
