Comparative analysis of proteomic changes during cadmium stress metabolic responses by quantitative iTRAQ in maize (Zea mays L.) seedling roots

Cadmium (Cd), a nonessential heavy metal, has become the most important metal pollutant in soils.Cd inhibits plant growth and development and causes substantial reductions in crop yield.However, limited information is available regarding the heavy metal stress-related proteome of maize.We aimed to analyze the proteomic alterations induced by Cd exposure during maize root development to identify potential genes or pathways related to Cd stress.Consequently, an isobaric tag for relative and absolute quantification (iTRAQ)-based proteomic approach was used to analyze the protein expression from seedling roots of the non-hyperaccumulator inbred line B73 and hyperaccumulator inbred line Mo17 at four developmental stages (0, 12, 24, and 48 h) under heavy metal cadmium pollution.The results showed that 209, 294, 422, and 384, 352, 489 proteins were screened as differentially expressed proteins (DEPs) between the control and Cd-treated roots for 12, 24, and 48 h in B73 and Mo17, respectively.Ten DEPs were identified as commonly expressed in both B73 and Mo17, including Ribosomal protein L15, L17c, and L36, Peroxidase 3, GST, ADP-ribosylation factor A1B, voltage-dependent anion channel protein 1b, among others.In B73, DEPs related to ribosomal protein synthesis were significantly upregulated, while they were downregulated in Mo17.Simultaneously, CRPs associated with antioxidant activity were identified, suggesting that B73 might enhance cadmium tolerance by improving protein synthesis and ROS scavenging capacity.These discoveries will offer valuable perspectives into the molecular mechanisms of maize responses to cadmium toxicity and detoxification at the protein level.