Effect Of Reversible Protein Tyrosine Phosphorylation In Signal Transduction Of Seed Osmoconditioning

PEG (polyethylene glycol) is a permeable agent with big molecular weight, its main advantage is that it impermeable into viable cells. PEG priming is osmocoditioning. which could result in faster emergence and uniformity of seed, better tolerance to cold, drought and salt stress. Cold-Sensitive Soybean (Glycine max ZhongHuang No.22) seeds were used to investigate whether reversible protein tyrosine phosphorylation participate in signal transduction during osmoconditioning. The Results showed that the effect of enhance seed vigor by PEG priming was restrained obviously, such as the germination index and vigor of soybean seed declined distinctly, because of adding protein-tyrosine phosphatase(PTP) inhibitor (PAO) during osmoconditioning process. SDS-PAGE and western blotting analysis showed that 87KD protein phosphate-tyrosine may immunologically react with the PT antibody, and protein was dephosphorylated as priming time prolonged. All above results provide direct evidence that PT exists in plant and reversible tyrosine phosphorylation might be involved in signal transduction induced by PEG priming. At the same time, the research has laid a very good foundation for study PEG priming mechanism and revealing the function of the signal components in PTK/PTP cascade in the future.In this research, we also study changes of membrane lipid and fatty acid under osmoconditioning from signal transduction, which might reveal that these whether also relation with PTK/PTP signal system. Results are as follows: treated seed with 33% PEG6000, as the osmoconditioning time was prolonged, the ratio of unsaturated phospholipid (PC and PE) in soybean seed increased, composition of polar lipid fatty acid...