Differential expression and bioinformatics analysis of proteins in response to NaCl stress in purslane

Abstract

Proteomics serves as a crucial method for elucidating plant stress resistance mechanisms under environmental pressures. Purslane (Portulaca oleracea), valued for its medicinal, edible, and halophytic properties, holds significant nutritional importance with diverse applications. Despite its importance, limited studies have explored the salt tolerance mechanisms in purslane. Differential protein expression in two purslane genotypes (‘PL’ and ‘LCL’) under NaCl stress were analyzed using tandem mass tag technology. The function of differentially expressed proteins was analyzed using bioinformatics tools. According to KEGG and COG analysis, carbohydrate metabolism and lipid metabolism were the most important metabolite pathways in purslane under salt stress. Compared with control, 48 up-regulated and 43 down-regulated proteins in ‘PL’ and 22 up-regulated and 26 down-regulated proteins in ‘LCL’ were found under 72 h of 200 mM NaCl stress. Six proteins were up-regulated and six down-regulated in both genotypes due to salt stress. Among them, four up-regulated proteins and two down-regulated proteins were related to carbohydrate metabolism. Specific protein expressions in carbohydrate metabolism pathway may be the vital reason of salt-tolerance in purslane. The differential protein expression in two purslane genotypes under salt stress unveiled significant up-regulation of seven proteins belonging to the ribosomal protein family, along with two non-specific lipid-transfer proteins and two lipid transfer-like proteins in the ‘PL’ genotype. Additionally, the down-regulation of relatively few photosynthesis-related proteins were observed in the ‘PL’ genotype. Differential expression of these proteins might be associated with the salt tolerance in the salt-tolerant variety.