Insight of low-abundance proteins in rice leaves under Cd stress using combinatorial peptide ligand library technology

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.