title: Comparative proteomic analysis of latex from Hevea brasiliensis treated with Ethrel and methyl jasmonate using iTRAQ-coupled two-dimensional LC-MS/MS.
abstract: Ethrel (ET) is an effective and widely used latex yield stimulant of Hevea brasiliensis (Pará rubber tree), and jasmonate (JA) is a key inducer of laticifer differentiation in this plant. To examine variations in the latex proteome caused by these phytohormones, ET and methyl jasmonate (MeJA) were applied to Reyan 7-33-97 rubber tree clones, and comparative proteomic analyses were conducted. On the basis of a transcriptome shotgun assembly (TSA) sequence database and an iTRAQ-coupled two-dimensional LC-MS/MS approach, 1499 latex proteins belonging to 1078 clusters were identified. With a 1.5-fold cut-off value to determine up- and down-regulated proteins, a total of 101 latex proteins were determined to be regulated by ET and/or MeJA via pairwise comparisons among the three exposure durations (0 h, 6 h, and 48 h). Proteins associated with latex regeneration, including phosphoenolpyruvate carboxylase and acetyl-CoA C-acetyltransferase, and those associated with latex flow, such as chitinase and a sieve element occlusion protein, were affected by the application of ET. Chitinase and polyphenol oxidase were also found to be regulated by MeJA. The findings of this study may provide new insight into the roles of phytohormones in latex yield and the causative mechanisms of laticifer differentiation in rubber trees.
  
  
  CONCLUSIONS
  On the basis of a transcriptome shotgun assembly (TSA) sequence database and an iTRAQ-coupled two-dimensional LC-MS/MS approach, the most comprehensive proteome of the latex was profiled, and the ethylene-/jasmonate-responsive proteins were identified in the latex of H. brasiliensis. The findings of this study may provide new insight into the role of phytohormones in latex yield and the causative mechanisms of laticifer differentiation in rubber trees.
authors.affiliation: Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, PR China; State Key Laboratory Incubation Base, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, PR China. Electronic address: dailongjun@126.com.
authors.forename: Longjun
authors.initials: L
authors.lastname: Dai
authors.affiliation: Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, PR China; State Key Laboratory Incubation Base, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, PR China. Electronic address: kangguijuan2010@126.com.
authors.forename: Guijuan
authors.initials: G
authors.lastname: Kang
authors.affiliation: Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, PR China; State Key Laboratory Incubation Base, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, PR China. Electronic address: narzizip@163.com.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Nie
authors.affiliation: Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, PR China; State Key Laboratory Incubation Base, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, PR China. Electronic address: liyu692@gmail.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, PR China; State Key Laboratory Incubation Base, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences (CATAS), Danzhou, Hainan, PR China. Electronic address: hnzrz@aliyun.com.
authors.forename: Rizhong
authors.initials: R
authors.lastname: Zeng
mesh_terms: D000085:Acetates / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D003517:Cyclopentanes / Q000737:chemistry*; D028482:Hevea / Q000737:chemistry*; D007840:Latex / Q000737:chemistry*; D013058:Mass Spectrometry; D009943:Organophosphorus Compounds / Q000737:chemistry*; D054883:Oxylipins / Q000737:chemistry*; D010449:Peptide Mapping / Q000379:methods; D010936:Plant Extracts / Q000737:chemistry; D020543:Proteome / Q000737:chemistry*
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D007840:Latex; D009943:Organophosphorus Compounds; D054883:Oxylipins; D010936:Plant Extracts; D020543:Proteome; C072239:methyl jasmonate; C005073:ethephon
keywords: Ethrel; Hevea brasiliensis; Latex; Methyl jasmonate; Proteomics; iTRAQ