Low-abundance proteins (LAPs) play a very important role in interaction, regulation, and metabolism of plant biological processes. A combinatorial peptide ligand library (CPLL) can solve the problem of high-abundance proteins (HAPs) masking LAPs and enlarging the dynamic range of protein concentrations perfectly and be considered as one of the most advanced approaches for plant proteomics research. In this paper, a proper CPLL method to rice leaf proteins was established for the first time and 1056 proteins were identified in rice leaf extracts, and 624 (59.1%) LAPs were newly detected after CPLL. Based on this technology, we detected the response of rice to Cd stress and analyzed the differential LAPs and the biological significance of misexpressed proteins before and after Cd stress by bioinformatics analysis. An important contribution has also been made to a better understanding of the complex mechanisms by which rice adapts to Cd stress.

Graphical abstract

低丰度蛋白质（LAP）在植物生物过程的相互作用，调控和代谢中起着非常重要的作用。组合肽配体库（CPLL）可以解决高丰度蛋白（HAP）掩盖LAP并完美扩大蛋白浓度动态范围的问题，被认为是植物蛋白质组学研究的最先进方法之一。本文首次建立了一种适用于水稻叶片蛋白质的CPLL方法，并在水稻叶片提取物中鉴定出1056种蛋白质，CPLL后新检测到624种（59.1％）LAP。基于该技术，我们通过生物信息学分析检测了水稻对Cd胁迫的响应，并分析了LAPs差异和Cd胁迫前后错表达蛋白质的生物学意义。

图形概要