Photosynthesis-Related Proteins Play Crucial Role During Senescence Stage in Flue-Cured Tobacco Plants: A Combine iTRAQ-PRM Study

Leaf aging is a significant process during herbaceous plant senescence, which is influenced by various internal and external factors. During leaf aging, chlorophyll catabolism is one of the most important metabolism pathways and results in leaf yellowing. Understanding the underlying mechanism is important for the regulation of senescence in tobacco leaf. However, there are few studies on explaining tobacco leaf senescence from the proteomics level. Here, photosynthesis experiments, cell ultrastructure, and proteomics were used to study tobacco leaves of different growth stages. We applied iTRAQ-based quantitative proteomics and parallel reaction monitoring (PRM) to determine the accumulation of proteins in aging tobacco leaves. Overall, we screened 4747 proteins. The result of KEGG pathways analysis showed that differently expressed proteins (DEPs) were involved in four pathways: metabolic pathways, biosynthesis of secondary metabolites, microbial metabolism in diverse environments, and starch and sucrose metabolism. This would be first report based on iTRAQ-PRM technique, in which we identified proteins related to photosynthesis showed a differently expressed during senescence stage in flue-cured tobacco plants.