Proteome analysis of interaction between rootstocks and scions in Hevea brasiliensis

The main propagation method of rubber tree (Hevea brasiliensis Muell. Arg.) is by grafting. However, the molecular mechanism underlying rootstock-scion interactions remains poorly understood. Identification and analysis of proteins related to rootstock-scion interactions are the bases of clarifying the molecular mechanism underlying rootstock-scion interactions. To identify proteins associated with rootstock-scion interactions, in vitro plantlets from immature anthers of Hevea brasiliensis Reyan 88-13 (R.88-13) and Haiken 2 (H.2) were used to produce two scion/rootstock combinations, namely R.88-13/H.2 and H.2/R.88-13. In this study, the bark proteins of R.88-13/H.2 scions, H.2/R.88-13 rootstocks and the ungrafted R.88-13 (control) were extracted and separated by two-dimensional gel electrophoresis (2-DE), respectively. 48 differentially expressed protein spots were obtained and subjected to matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) followed by database searching. 38 protein spots were successfully identified and these proteins are mainly involved in response to stimulus, metabolism and photosynthesis. Some of the identified proteins may be closely correlated with rootstock-scion interactions, whose possible functions in rootstock-scion interactions were discussed.