Seed germination is a complex process involving various physical and biochemical cues such as water, light and phytohormones. This study focused on the cross talk between Nitric Oxide (NO) and hemoglobin in the regulation of the seed germination process in wheat (Triticum durum). The levels of NO, hemoglobin, catalase and S-nitrosylated proteins increased during sensu stricto germination but rapidly dropped off within 48 h of imbibition. At least thirteen S-nitrosylated proteins were detected by using modified Biotin switch method. S-nitrosylated protein bands with molecular mass 93, 80, 71, 52, 45.7, 38, 32, 27.5, 25, 20, 15, 12 and 10 kD were observed during the 24 h period. The levels of these proteins decreased during 48 h. The NO scavenger c-PTIO-treated tissue exhibited suppressed levels of synthesis for 93, 80 and 71 kD proteins during 24 h when radicles emerged. It drastically lowered the NO levels in the germinating seeds but did not inhibit the germination process, suggesting the possibility that NO is not directly involved in the regulation process. The S-nitrosylation process is the switch which regulates the seed germination process. Ideas along these lines are discussed in the study.