It is challenging to determine the mechanism involved in only Cd hyperaccumulation by Solanum nigrum L. owing to the uniqueness of the process. Isobaric tags for relative and absolute quantitation (iTRAQ) were used to explore the mechanism by which S. nigrum hyperaccumulates Cd by comparing the differentially expressed proteins (DEPs) for Cd and Zn accumulation (non-Zn hyperaccumulator). Based on the comparison between the DEPs associated with Cd and Zn accumulation, the relative metabolic pathways reflected by 17 co-intersecting specific proteins associated with Cd and Zn accumulation included phagosome, aminoacyl-tRNA biosynthesis, and carbon metabolism. Apart from the 17 co-intersecting specific proteins, the conjoint metabolic pathways reported by 21 co-intersecting specific proteins associated with Cd accumulation and 30 co-intersecting specific proteins associated with Zn accumulation, the most differentially expressed metabolic pathways might cause Cd TF (Translocation factor)> 1 and Zn TF< 1, including protein export, ribosome, amino sugar, and nucleotide sugar metabolism. The determined DEPs were verified using qRT-PCR with the four key proteins M1CW30, A0A3Q7H652, A0A0V0IFB9, and A0A0V0IAC4. The plasma membrane H⁺-ATPase protein was identified using western blotting. Some physiological indices for protein-related differences indirectly confirmed the above results. These results are crucial to further explore the mechanisms involved in Cd hyperaccumulation.

由于该过程的独特性，很难确定龙葵仅参与 Cd 超富集的机制。用于相对和绝对定量的等压标签 (iTRAQ) 被用于探索S. nigrum的机制通过比较 Cd 和 Zn 积累的差异表达蛋白 (DEP) 来超积累 Cd（非 Zn 超富集剂）。基于与 Cd 和 Zn 积累相关的 DEP 之间的比较，17 个与 Cd 和 Zn 积累相关的共相交特定蛋白质反映的相对代谢途径包括吞噬体、氨酰-tRNA 生物合成和碳代谢。除了 17 种共相交特定蛋白外，21 个与 Cd 积累相关的共相交特定蛋白和 30 个与 Zn 积累相关的共相交特定蛋白报道的联合代谢途径中，表达差异最大的代谢途径可能导致 Cd TF（易位因子）> 1 和 Zn TF< 1，包括蛋白质输出、核糖体、氨基糖和核苷酸糖代谢。确定的 DEP 使用 qRT-PCR 对四种关键蛋白 M1CW30、A0A3Q7H652、A0A0V0IFB9 和 A0A0V0IAC4 进行验证。质膜 H⁺ -ATPase 蛋白使用蛋白质印迹法进行鉴定。蛋白质相关差异的一些生理指标间接证实了上述结果。这些结果对于进一步探索 Cd 超富集的机制至关重要。