Abstract Cadmium (Cd) is a heavy metal used in industrial processes that impedes the growth of plants. Although intensive work has concentrated on the mechanism of rice under Cd stress, few studies compared the proteomic information on the mechanism between different cultivars. Different rice cultivars were screened and two cultivars, the japonica cultivar Bancanggengnuo (BCGN) and indica cultivar Yuzhenxiang (YZX) were selected to be the varieties for proteomic experiments. High-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS) with an isobaric tag for relative and absolute quantitation (iTRAQ) was used to analyze the global protein profiles of these two cultivars. There were 109 and 209 differentially expressed proteins (DEPs) in the Cd treatment groups for BCGN and YZX respectively and 61 additional DEPs between cultivars after treatment. Pathway enrichment analysis showed that three pathways were altered in the cultivars, which affected photosynthesis and redox reactions. A total of 37 up- and 27 down-regulated proteins were identified in both cultivars exposed to Cd. The molecular regulatory network revealed that several proteins associated with carbohydrate metabolism, redox reaction and signal transduction were involved in and acted as the intersection point of disturbed metabolism. This is the first report on the comprehensive proteomic characterization of Cd-exposed leaf proteomes in rice. These findings may facilitate the unraveling molecular mechanism underlying Cd stress response in rice, and provide fundamental insights into the development of Cd-resistant rice cultivars. This work has explored the mechanism of Cd resistance at the protein level, which may be a novel target for improving the resistance of rice to this heavy metal.

中文翻译：

---

用高效液相色谱-串联质谱 (HPLC-MS/MS) 与等压标记进行相对定量和绝对定量 (iTRAQ) 来表征水稻幼苗对镉胁迫的抗性的比较蛋白质组学

摘要 镉 (Cd) 是工业过程中使用的一种重金属，会阻碍植物的生长。尽管大量的工作集中在水稻在镉胁迫下的机制上，但很少有研究比较不同品种之间机制的蛋白质组学信息。筛选了不同的水稻品种，选择粳稻品种板苍庚诺（BCGN）和籼稻品种玉珍香（YZX）两个品种作为蛋白质组学实验品种。使用具有用于相对和绝对定量 (iTRAQ) 的同量异位标记的高效液相色谱 - 串联质谱 (HPLC-MS/MS) 来分析这两个品种的全局蛋白质谱。BCGN 和 YZX 镉处理组分别有 109 和 209 个差异表达蛋白（DEP），处理后栽培品种之间有 61 个额外的 DEP。通路富集分析表明，该品种的三个通路发生了改变，影响了光合作用和氧化还原反应。在暴露于 Cd 的两个栽培品种中，总共鉴定出 37 个上调和 27 个下调的蛋白质。分子调控网络揭示了与碳水化合物代谢、氧化还原反应和信号转导相关的几种蛋白质参与并作为干扰代谢的交点。这是关于水稻中 Cd 暴露的叶蛋白质组的综合蛋白质组学表征的第一份报告。这些发现可能有助于阐明水稻对镉胁迫反应的分子机制，并为抗镉水稻品种的开发提供基本见解。该工作在蛋白质水平上探索了Cd抗性的机制，这可能是提高水稻对这种重金属的抗性的新靶点。