title: Ethrel-stimulated prolongation of latex flow in the rubber tree (Hevea brasiliensis Muell. Arg.): an Hev b 7-like protein acts as a universal antagonist of rubber particle aggregating factors from lutoids and C-serum.
abstract: Ethrel is the most effective stimuli in prolonging the latex flow that consequently increases yield per tapping. This effect is largely ascribed to the enhanced lutoid stability, which is associated with the decreased release of initiators of rubber particle (RP) aggregation from lutoid bursting. However, the increase in both the bursting index of lutoids and the duration of latex flow after applying ethrel or ethylene gas in high concentrations suggests that a new mechanism needs to be introduced. In this study, a latex allergen Hev b 7-like protein in C-serum was identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI TOF MS). In vitro analysis showed that the protein acted as a universal antagonist of RP aggregating factors from lutoids and C-serum. Ethrel treatment obviously weakened the effect of C-serum on RP aggregation, which was closely associated with the increase in the level of the Hev b 7-like protein and the decrease in the level of the 37 kDa protein, as revealed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), western blotting analysis and antibody neutralization. Thus, the increase of the Hev b 7-like protein level or the ratio of the Hev b 7-like protein to the 37 kDa protein in C-serum should be primarily ascribed to the ethrel-stimulated prolongation of latex flow duration.
authors.affiliation: Institute of Rubber Research, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737 Hainan, P. R. China and Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Danzhou, 571737 Hainan, P. R. China.
authors.forename: Min-Jing
authors.initials: MJ
authors.lastname: Shi
authors.affiliation: Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Danzhou, 571737 Hainan, P. R. China.
authors.forename: Fu-Ge
authors.initials: FG
authors.lastname: Cai
authors.affiliation: Institute of Rubber Research, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737 Hainan, P. R. China and Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, Danzhou, 571737 Hainan, P. R. China wmtian@163.com.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Tian
mesh_terms: D052179:Antigens, Plant / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000037:antagonists & inhibitors; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000037:antagonists & inhibitors; D028482:Hevea / Q000187:drug effects* / Q000502:physiology*; D007840:Latex / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D037121:Plant Lectins / Q000037:antagonists & inhibitors; D010940:Plant Proteins / Q000494:pharmacology*
chemical_list: D052179:Antigens, Plant; D023181:Antimicrobial Cationic Peptides; D007840:Latex; D009943:Organophosphorus Compounds; D037121:Plant Lectins; D010940:Plant Proteins; C113002:allergen Hev b 7; C045875:hevein; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating); C005073:ethephon
keywords: Hev b 7; Hevea brasiliensis Muell. Arg; duration of latex flow; ethrel; rubber particle aggregation