| In order to predict the performance of growth, development and resistance in G1 + HB pummelo cybrid, the total proteins in leaves were compared between the cybrid and its parents. We first optimized the extraction method for total proteins in leaves of citrus, then analyzed the differentially expressed proteins by 2-DE and identified them through MALDI-TOF/TOF. The main results are as follows:1. The total proteins of leaves extracted by TCA extraction, phenol extraction and TCA/phenol extraction were analyzed by visual examination and SDS-PAGE. The pellets precipitated by TCA extraction and phenol extraction were yellow and dark green respectively, while by TCA/phenol extraction were white. In addition, the TCA/phenol extraction method could identify more bands than either TCA extraction method or phenol extraction method.2. The 2-D profiles of the cybrid and its parents were analyzed by PD-Quest. The results showed that at the 99% level, there were 90 significantly differential spots between G1 and G1 + HB, 20 spots between HB and G1 + HB, and 116 spots between G1 and HB. This was accordant with the molecular markers.3. Quantitative analysis showed 59 protein spots were at least 2-fold differentially expressed between G1 + HB and HB, therein, 30 were up-regulated and 29 were down-regulated. 66 spots were at least 2-fold differentially expressed between G1 + HB and G1, therein, 31 were up-regulated and 35 were down-regulated.4. 88 out of the 125 differentially expressed protein spots were undergone the MALDI-TOF/TOF, and 35 spots were successfully identified, representing 25 different proteins. These proteins were related with metabolism (24%), photosynthesis (20%), stress (20%), anti-oxidation (16%), unknown proteins (12%) and other proteins (8%). |
