Nitric oxide-induced proteomic analysis in rice leaves

Nitric oxide (NO) is a ubiquitous bimolecule that regulates various physiological processes in plants. Despite the widespread study of NO in plants, the involvement of NO in proteomic regulation has been poorly investigated compared to the physiological processes. To explore the NO-induced proteomic regulation in rice leaves, 2-week-old leaves were exposed to sodium nitroprusside for 12 h. Protein profiles were analyzed by two-dimensional gel electrophoresis. A total of 53 NO-regulated proteins were identified by the matrix-assisted laser desorption/ionization-time of flight mass spectrometry analysis. Out of these proteins, 41 were up-regulated, 7 were down-regulated, and 5 were newly induced. The identified proteins were involved in photosynthesis, carbohydrate and energy metabolism, growth and development, metabolite biosynthesis, signal transduction, lignin modification, and defense response. Importantly, several key proteins including glutathione reductase, monodehydroascorbate reductase, dehydroascorbate reductase, ascorbate peroxidase, superoxide dismutase, catalase, 2 - cysteine peroxiredoxin, peroxidase (newly induced), and glutathione S - transferase were significantly up-regulated in rice leaves and these proteins were associated with the ascorbate–glutathione cycle and ROS homeostasis system in plants. Thus, the identification of several key and newly induced proteins has provided a new insight into NO-mediated overall molecular response in plants.