In horticulture, grafting is a popular technique used to combine positive traits from two different plants. This is achieved by joining the plant top part (scion) onto a rootstock which contains the stem and roots. Rootstocks can provide resistance to stress and increase plant production, but despite their wide use, the biological mechanisms driving rootstock-induced alterations of the scion phenotype remain largely unknown. Given that epigenetics plays a relevant role during distance signalling in plants, we studied the genome-wide DNA methylation changes induced in eggplant (Solanum melongena) scion using two interspecific rootstocks to increase vigour. We found that vigour was associated with a change in scion gene expression and a genome-wide hypomethylation in the CHH context. Interestingly, this hypomethylation correlated with the downregulation of younger and potentially more active long terminal repeat retrotransposable elements (LTR-TEs), suggesting that graft-induced epigenetic modifications are associated with both physiological and molecular phenotypes in grafted plants. Our results indicate that the enhanced vigour induced by heterografting in eggplant is associated with epigenetic modifications, as also observed in some heterotic hybrids.

中文翻译：

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嫁接活力与茄子DNA去甲基化有关

在园艺中，嫁接是一种流行的技术，用于结合两种不同植物的积极特征。这是通过将植物顶部（接穗）连接到包含茎和根的砧木上来实现的。砧木可以提供对压力的抵抗力并增加植物产量，但尽管它们被广泛使用，但驱动砧木诱导的接穗表型改变的生物学机制仍然很大程度上未知。鉴于表观遗传学在植物的距离信号传导过程中发挥了相关作用，我们研究了茄子中诱导的全基因组 DNA 甲基化变化。茄子) 接穗使用两个种间砧木来增加活力。我们发现活力与接穗基因表达的变化和 CHH 环境中的全基因组低甲基化有关。有趣的是，这种低甲基化与年轻且可能更活跃的长末端重复逆转录转座因子（LTR-TEs）的下调相关，这表明嫁接诱导的表观遗传修饰与嫁接植物的生理和分子表型有关。我们的研究结果表明，茄子异种移植诱导的活力增强与表观遗传修饰有关，这在一些杂种优势杂种中也观察到。