Studies On The Regulation Of The Formation Of Plug Materials At Laticifer Cuts In Hevea Brasiliensis Muell.Arg

The formation of plug materials at the end of laticifer cut is one of the most important factors that limits rubber yield. For this reason, the mechanism by which the wounded laticifers are plugged has been a fundamentally theoretical barrier that challenges natural rubber production. Through the observation of ultrastructure of plug materials at the end of laticifer cut, reasearcher in China reveal the real stutas of laticifer plugging. It is protein-network that play important role in laticifer plugging.We have proved that the major components of the protein-network were hevein, chitinase and β-1,3-glucanase, which are the main three proteins in the protein inclusions of lutoids.We found the ACTIN protein locating in laticifer plugging though histochemical stain technique. Therefore, we speculate that the "protein-network" was interacted with ACTIN protein resulting in formation of plug materials at the end of laticifer cut. In this paper, we investigated the effect of the ACTIN protein in the formation of plug materials at the end of laticifer cut by means of cytological, biochemical and proteomic techniques. The results as follows:1. Analysis of the protein changes at the end of laticifer cut during latex flow by paraffin section showed that the protein contents increase at the end of laticifer cut along with latex flow.2. Electron microscopy analysis of changes in latex inclusions during latex flow showed that along with the latex flow, the formation of plug materials at the end of laticifer cut continuous increase.3. Successfully constructed a prokaryotic expression vector of ACTIN of rubber tree, purified recombinant protein and obtained of rabbit polyclonal antibody of ACTIN protein.4. Immunohistochemical analysis of ACTIN accumulation at the end of laticifer cut confirmed that ACTIN gradually accumulated at the end of laticifer cut from latex.5. The pull-down analysis showed that ACTIN was interacted with β-1,3-glucanase which was one component of "protein-network".6. Applying cytochalasin D (a depolymerizing agent) on tapping panel showed depolymerization of cytoskeleton including ACTIN by cytochalasin D, which resulting in the prolong of latex flow and retardation of the formation of plug materials at the end of laticifer cut.The results show that the "protein-network" intacted with ACTIN protein through the beta1,3-glucanase and anchored at the end of the laticifer cut leading to the accumulation of laticifer plugging.