Abstract
Deregulation of reduction-oxidation (redox) metabolism under
environmental stresses results in enhanced production of intracellular
reactive oxygen species (ROS), which ultimately leads to
posttranslational modifications (PTMs) in structure and molecular
function of responsive proteins. Redox PTMs are important mediators of
cellular signalling and regulation and several proteomic approaches
attempted to quantify them under various stresses in plants. We aimed to
generate large-scale redox proteomics data in response to short-term
salt stress in Brassica napus by analyzing reversible cysteine
modification. We employed iodoTMT approach to analyze the redox proteome
of Brassica napus seedlings under control and salt stress conditions. We
identified 2,010 peptides in 1,017 proteins, of which 1,821 sites in 912
proteins had oxidative modification. The redox homeostasis of biology
processes in chloroplast and cytoplasm were mainly affected and the
modification levels of proteins involved in photosynthesis and
glycolysis pathways were significantly changed. Two oxidatively modified
proteins were selected from the candidates and their in vitro activity
under oxidative stress was assayed and validated the findings of this
proteomics study. This targeted approach should contribute to the
understanding of redox-based molecular changes prevailing in Brassica
napus proteome subjected to salt stress and the mechanism adopted to
cope with it.