Proteomic Analysis Of Chilling Injury And PEG Priming In Soybean Seed

Chilling injury is a prevalent agricultural disaster in alp zones and low temperature seasons of many areas. Chilling stress can reduce seed germination, seed vigor, seedling growth, plant growth and pollination, which will result in yield-decrease. PEG priming could induce chilling tolerance in seeds. The mechanism of PEG priming is yet to be resolved. To gain better understanding of chilling injury and PEG priming in soybean (Glycine max) seeds, we conducted a proteomic analysis based on the study of the physiological and biochemical levels.Chilling treatment resulted in decreased germination rate, vigor index, dehydrogenase activity, and increased relative electrical conductivity, which were recuperated by PEG priming at subsequently chilling treatment. Germination rate improved 90%.The results on the proteomic aspects were obtained through the method fitted for soybean seed proteome.(1) Approximately 706, 585, 670, 658 protein spots from control (CK), chilling treatment (CT), PEG treatment (PT), and chilling treatment after PEG priming (PC) were separated, respectively.(2) Twenty-five distinct and nine high abundant proteins were identified. These proteins mainly involved in cell growth/division, disease/defense, protein destination and storage.(3) We found that nucleoside diphosphate kinase and Os12g0160400 could have more expression at chilling, and have no influence by osmoconditioning.(4) A number of proteins like heat-shock protein 90, tubulin A, 35 kDa seed maturation protein, molybdopterin synthase, soybean proglycinin A1ab1b homotrimer, soybean trypsin inhibitor, induced by PEG priming, further resisted chilling stress.(5) The seed maturation protein PM25 was induced both chilling and PEG priming suggested that the protein related with these two factors, which may be a novel stress protein.To summary, we found that chilling stress lead to decline quantity of protein spots, but enhanced approximately 70 protein spots by PEG priming. And nucleoside diphosphate kinase and Os12g0160400 were chilling stress protein, as well as seed maturation protein PM25 is a novel stress protein.The results provided not only new insights into chilling injury but also the evidence and mechanism of osmoconditioning in preventing chilling injury in seeds.