Abstract: A field experiment was conducted with two low cadmium enriched varieties as rootstocks and two high cadmium enriched varieties as scions from eight soybean varieties, with the aim to study the changes in cadmium accumulation of grafted plants and its first filial generation, and to explore the mechanism and genetic stability of the graftinginduced effect. The results showed that cadmium accumulation had significant differences among soybean varieties. By choosing soybeans with low Cd accumulation (TF29 and DX01) as rootstocks, the Cd concentrations of the scions (QRH01 and ZH38) were reduced by 50%-70% through grafting. Results of highthroughput sequencing and qRT-PCR analysis showed a differential expression of related sulfur metabolism genes induced by grafting. Compared to the self-rooted individuals, the expression levels of APX2, PAPRa, SAM1a and ATPs in grafted plants were downregulated by 72.53%, 67.62%, 42.37% and 75.78% respectively, whereasAPK4 was upregulated to 2.83 times. As a combination with the highest reduction of cadmium content, QRH01-DX01’s first filial generation remained low cadmium accumulation induced by grafting from its parental generation, with a 30%-50% reduction compared to the self-rooted one. Our results indicate that grafting can affect cadmium accumulation in soybean shoots by regulating the synthesis and metabolism of sulfur compounds, and that such change can be stably inherited in the filial generation.

Key words: grafting, cadmium accumulation, soybean, genetic stability, sulfur metabolism.