Biochemical characterization and protein expression analysis of common bean under mineral stress

Abstract

newline Common bean (Phaseolus vulgaris) is the most important legume for human consumption and majorly limited by reduced phosphorus levels in soil. Improving P use efficiency in legumes is a worldwide challenge and the present study was carried out on P stressed common bean to compare differences in the morphological, physiological, biochemical and structural parameters under in vitro conditions. The study was a multi-omic approach (such as proteomics, transcriptomics, phenomics, ionomics as well as metabolomics) to analyze the impact of mineral stress. The results indicated that mineral stress induces large disturbances inside the plant which causes profound metabolic changes (e.g., in photosynthesis, energy generation, cell wall composition, generation of secondary metabolites, free amino acids, antioxidants, osmolyte production) and leads to inhibition of plant growth and development. It was observed that there was significant variation in the morphological, physiological, biochemical as well as structural parameters of common bean shoot under P stress as compared to the plant growing in presence of P or control (P+). FTIR spectroscopy, SEM, SEM-EDX and fluorescence spectroscopy, assisted in validating the modifications in structural and metabolic composition of plant under P deficiency stress. The proteomic analysis was carried out using SDS-PAGE (gel based) as well as LC-MS (gel free) to identify the proteins that are responsible for providing adaptation to the plant under essential mineral deficiency stress. Candidate proteins identified may contribute shoot adaptation to P deficiency and may be useful for improvement of common bean. The two differentially identified shoot proteins - homocysteine methyltransferase and DDB1-CUL4 associated factor 1 like, are located in the cytoplasm and nucleus respectively. Both genes expressed 2.56 and 3.13 fold expression under P deficiency common bean shoot which validated their expression at the transcription level using qRT-PCR. To conclude, common bean is th