Proteomic analysis of seeds of early maturing line of barley, Eam9

Double cropping of barley and rice in Korea increases agricultural income and better uses land resources. For proper planting of rice, barley seeds need to be early matured. Two barley germlines, Bunong (a medium maturing barley) and Eam9 (an early maturing barley), have been developed for this reason and were used in this study to profile seed proteins and to assess protein changes in relation to early maturity and delayed germination. Using 2-DE and MALDI-TOF MS or LC-MS/MS, 44 proteins including 10 Btype hordeins, thaumatin-like protein and AC004557 were up-regulated in Bunong seeds, whereas 32 proteins including a-amylase inhibitors, oxygen evolving enhancer protein, peroxidase and peroxiredoxin were over-expressed in Eam9 seeds. α-Amylase inhibitors and oxygen evolving enhancer protein in Eam9 seeds should be related to inhibit seed germination, referring to prolong dormancy. Eam9 germline also expressed peroxidase and peroxiredoxins to protect oxidative stress in early maturing barley seeds. Therefore, early maturity in barley may change a series of proteins concerning germination proceeding in barley.