Functional Analysis Of Farnesyl Pyrophosphate Pynthase And Preliminary Establishment Of The Detection System Of Rubber Synthesis Efficiency In Vitro Of Rubber Tree

Rubber tree (Hevea brasiliensis Muell. Arg.) is the main resource of natural rubber in the world. In natural rubber production, latex is obtained from laticifers by tapping and used as raw materials for refining natural rubber. The latex regeneration, especially high efficiency of rubber biosynthesis between successive tappings is one of the key factors that determine the yield of Hevea. Farnesyl pyrophosphate (FPP) is an important initiator which is necessary for rubber biosynthesis. It is biosynthesized by the farnesyl pyrophosphate synthase (HbFDPS) catalyzed the1,4craniocaudal continuous condensation reaction of one dimethylallyl pyrophosphate molecule and two molecules of isopentenyl pyrophosphate. So, HbFDPS may be one of the key links that limit the efficiency of rubber biosynthesis. In the present study, an in vitro experiment system for checking the efficiency of rubber biosynthesis detected by stable isotope was estabolishment, the relationship between the expression of both HbFDPS and its encoding protein and the efficiency of rubber biosynthesis was analyzed by using real time PCR, SDS-PAGE and antibody neutralization, and assessment of the difference in the efficiency of rubber biosynthsis among Hevea germplasm was performed. The main results as follows.1. Estabolishment of an in vitro experiment system for checking the efficiency of rubber biosynthesis detected by stable isotope, which lay a good foundation for assessing the efficiency of Hevea germplasm.2. Tapping, methyl jasmonate and ethrel could improve the efficiency of rubber biosynthesis in latex in vitro. The effect of methyl jasmonate on improving the efficiency of rubber biosynthesis was even stronger than that of ethrel.3. Tapping, methyl jasmonate and ethrel could up-regulate the expression of both HbFDPS and its encoding protein. The effect of methyl jasmonate was much stronger than ethrel.4. HbFDPS was mainly distributed in cytosol (C-serum) of laticifer cells. Small amounts of the protein were also present in the fraction of small rubber particles.5. Initiating stage was necessary for rubber biosynthesis in vitro.6. The expression of key enzymes for rubber biosynthesis was rhythmic to some extent, which was mainly genetic.The results mentioned above will aid to develop molecular markers related to the efficiency of rubber biosynthesis.