Hev B 7 Protein In C-serum Involves In The Prolongation Of Duration Of Latex Flow Stimulated By Ethrel In Rubber Tree

The duration of latex flow after tapping is one of the three key factors that determine the yield of natural rubber. Ethrel is the most effective stimulant that increases the natural rubber yield to date, which is ascribed to its effect on significantly prolonging the duration of latex flow.By now it is indefinite for the mechanism of the duration of latex flow prolonged by ethrel stimulation. The main reason is of little known about the mechanism for laticifer plugging at the end of severed laticifers. To elucidate the mechanism for the duration of latex flow prolonged by ethrel stimulation is of important application value with respect to exploiting novel latex flow stimulus and developing biochemical molecular marks related to the potential of latex flow. Recently, we have isolated and identificated two proteins from C-serum (cytoplasmic matrix of laticifer cell). They have an effect on regulating rubber particle aggregation. And moreover, we have found that C-serum collected from latex of virgin tree treated by ethrel delays rubber particle aggregation. Based on these findings, we speculate that ethrel-induced prolongation of the duration of latex flow is mediated by these two proteins via regulating rubber particle aggregation. This is an innovative new academic ideology. In this paper, ethrel-inducing impact on the content of two kinds of protein and its relationship with the duration fo latex flow,and the difference of the content of two kinds of protein in C-serum of rubber tree clones with various charactors of latex flow were investigated by a combination of biochemical, physiological and proteomic techniques. Results are to establish a good foundation for further clarifying the biochemical and molecular mechanism for ethrel promoted latex flow.The results as following:1. Glyceraldehyde-3-phosphate dehydrogenase and Hev b 7 protein from C-serum were separated by precipitating with different concentration of ammonium sulfate solution, and then purfied by size-based column chromatography followed by ion exchange column chromatography and polyclonal antibody. Polyclonal antibodies raised agaist the purified proteins were obtained.2. Western-blot assy showed that the level of Hev b 7 protein was increased in the C-serum from the virgin trees treated with ethrel.3. The effect of C-serum in latex of virgin tree treated with ethrel on rubber particle aggregation was weakened. 4. Antibody inhibition assay indicated that glyceraldehydes-3-phosphate dehydrogenase involved in enhancing the effect of C-serum on rubber particle aggregation while Hev b 7 protein in weakening the effect of C-serum on rubber particle aggregation.5. There was significant difference in the level of Hev b 7 protein in the C-serum from rubber tree clones with various charators of latex flow, which was positive correlation with the duration of latex flow.6. B-serum was more effective than the B-serum treated by ultrafiltration on rubber particle aggregation, indicating that some small molecular substances permeating the filtrer membrance were involed in rubber particle aggregation.7. The effect of B-serum on rubber particle aggregation could be inhibited by Hev b 7 protein.8. Three main ingredients of lutoid protein inclusions were Hevein, (3-1.3-glucanase and chitinase. Hevein andβ-1.3-glucanase could promote small rubber particle aggregation seperately, but chitinase itself weakened small rubber particle aggregation.9. Combination of (β-1.3-glucanase with chitinase had more significant effect on promoting small rubber particle aggregation.The results of this paper established a good foundation for further investigating the biochemical and molecular mechanism for ethrel-promoted latex flow and provided a theoretical basis for exploiting novel latex flow stimulus and developing biochemical molecular marks related to the potential of latex flow.