ABSTRACT To determine whether grafting increases cadmium (Cd) accumulation in the post-grafting generation of hyperaccumulator plants, the effects of grafting on Cd accumulation characteristics of post-grafting generations of a potential Cd-hyperaccumulator Solanum photeinocarpum were evaluated in pot and field experiments. The following four grafting combinations were examined: ungrafted (UG), self-rooted grafting involving one S. photeinocarpum seedling (SG), self-rooted grafting involving two S. photeinocarpum seedling developmental stages (DG), and grafting on wild potato rootstock (PG). Grafting did not induce genetic changes in S. photeinocarpum, and increased the shoot biomass and the amount of Cd extracted by the shoots of the first, second, and third generations of S. photeinocarpum (PG > DG > SG > UG). Additionally, enhanced superoxide dismutase, peroxidase, and catalase activities and increased soluble protein contents of the first post-grafting generation were observed for the DG and PG, whereas only enhanced superoxide dismutase and peroxidase activities were observed for the SG. Grafting increased the DNA methylation levels by inducing hypermethylation in the first post-grafting generation (PG > DG > SG > UG). Therefore, grafting can enhance the Cd accumulation (phytoremediation) ability of post-grafting generations of S. photeinocarpum by enhancing DNA methylation levels, especially when wild potato rootstock is used.

中文翻译：

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嫁接增加了潜在镉超富集植物 Solanum photeinocarpum 嫁接后世代的镉积累

摘要 为了确定嫁接是否会增加超富集植物嫁接后世代中镉 (Cd) 的积累，在盆栽和田间试验中评估了嫁接对潜在的镉超富集植物 Solanum photeinocarpum 嫁接后几代镉积累特性的影响。研究了以下四种嫁接组合：未嫁接 (UG)、涉及一棵 S. photeinocarpum 幼苗 (SG) 的自生嫁接、涉及两个 S. photeinocarpum 幼苗发育阶段 (DG) 的自生嫁接，以及在野生马铃薯砧木上嫁接（ PG）。嫁接没有诱导光果树的遗传变化，并增加了光果树第一代、第二代和第三代（PG > DG > SG > UG）的枝条生物量和枝条提取的镉量。此外，DG 和 PG 的超氧化物歧化酶、过氧化物酶和过氧化氢酶活性增强，移植后第一代可溶性蛋白含量增加，而 SG 仅观察到超氧化物歧化酶和过氧化物酶活性增强。移植通过在移植后的第一代（PG > DG > SG > UG）中诱导高甲基化来增加 DNA 甲基化水平。因此，嫁接可以通过提高 DNA 甲基化水平来增强 S. photeinocarpum 嫁接后几代的镉积累（植物修复）能力，尤其是在使用野生马铃薯砧木时。而对于 SG，仅观察到增强的超氧化物歧化酶和过氧化物酶活性。移植通过在移植后的第一代（PG > DG > SG > UG）中诱导高甲基化来增加 DNA 甲基化水平。因此，嫁接可以通过提高 DNA 甲基化水平来增强 S. photeinocarpum 嫁接后几代的镉积累（植物修复）能力，尤其是在使用野生马铃薯砧木时。而对于 SG，仅观察到增强的超氧化物歧化酶和过氧化物酶活性。移植通过在移植后的第一代（PG > DG > SG > UG）中诱导高甲基化来增加 DNA 甲基化水平。因此，嫁接可以通过提高 DNA 甲基化水平来增强 S. photeinocarpum 嫁接后几代的镉积累（植物修复）能力，尤其是在使用野生马铃薯砧木时。