Biochemical Aspects of Protein Changes in Seed Physiology and Germination

Seed storage proteins are synthesized as sources of carbon, nitrogen and sulfur for the next generation of plants. Reactive oxygen species serve as second messengers for signal transduction; however, molecular targets of oxidant signaling have not been defined. Here, many researchers showes that ligand–receptor mediated signaling promotes reactive oxygen species– dependent protein carbonylation. Carbonylation of the majority of proteins occurred transiently. Protein carbonylation in response to ligand–receptor interactions represents a novel mechanism in redox signaling. The role of protein oxidation in dormancy alleviation could be discussed in relation to the nature of the carbonylated proteins. Carbonylation of storage proteins has previously been reported in dry mature Arabidopsis seeds, and it was suggested that carbonylation of these proteins facilitates their mobilization during germination. Also, in sunflower seeds, breaking of dormancy in the dry state may be associated with preparation for storage protein mobilization. Hence, ROS accumulation appears to be a key signal governing cell activity during afterripening. The role of specific proteins in maintenance of seed viability or longevity has been well documented However, quality and hardiness in seeds determined by protein contrnt