Aims

Grafting is an effective strategy to reduce the accumulation of cadmium (Cd) from the soil to the aerial plant parts. However, few studies have investigated the mechanisms involved.

Methods

DNA methylation and high-throughput sequencing were used to explore the mechanism of the Cd reduction in grafted eggplants (Solanum melongena) on Torubamu (Solanum torvum) as a rootstock.

Results

Compared to un-grafted eggplants, grafting significantly reduced Cd accumulation in the leaves and fruits by 65.21% and 81.48%, respectively, of grafted eggplants cultivated in 3 mg kg⁻¹ Cd-contaminated soil. In addition, the total methylation levels of CG, CHG, and CHH were reduced in grafted eggplants, leading to lower total cytosine methylation level than in un-grafted eggplants. The most significant change occurred in CHH methylation in the repeat elements. Furthermore, there were 55 hypomethylated and 23 hypermethylated genes in the leaves of grafted eggplants, most of which were involved in S metabolism, correlating with a decrease in S compounds.

Conclusion

Grafting using S. torvum as a rootstock could impact S compounds regulation by altering DNA methylation levels, and thereby, reducing Cd accumulation in scions of grafted eggplants.

中文翻译：

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茄子 (Solanum melogena) 嫁接导致镉积累和含硫化合物的减少与 DNA 甲基化有关

宗旨

嫁接是减少镉 (Cd) 从土壤到地上植物部分积累的有效策略。然而，很少有研究调查所涉及的机制。

方法

通过DNA甲基化和高通量测序，探讨了以Torubamu（Solanum torvum）为砧木的嫁接茄子（Solanum melongena）中Cd还原的机制。

结果

与未嫁接的茄子相比，嫁接在 3 mg kg ^-1镉污染土壤中种植的嫁接茄子叶片和果实中镉的积累量分别显着降低了 65.21% 和 81.48% 。此外，嫁接茄子中CG、CHG和CHH的总甲基化水平降低，导致总胞嘧啶甲基化水平低于未嫁接的茄子。最显着的变化发生在重复元件中的 CHH 甲基化中。此外，嫁接茄子的叶子中有 55 个低甲基化和 23 个高甲基化基因，其中大部分与 S 代谢有关，与 S 化合物的减少相关。

结论

使用S. torvum作为砧木嫁接可以通过改变 DNA 甲基化水平来影响 S 化合物的调节，从而减少嫁接茄子接穗中 Cd 的积累。