Analysis of protein profile of tomato root infected with Fusarium oxysporum f. sp lycopersici.

Fusarium wilt caused by Fusarium oxysporum f. sp lycopersici (Fol) is one of the main diseases affecting tomatoes. The BHRS 2,3 genotype of tomato is, however, resistant to this disease. A proteomic approach was used to understand the defense mechanisms of this genotype using the tomato root, the first tissue that interacts with the fungus, as a target. Protein was extracted and separated by two-dimensional electrophoresis followed by staining with Coomassie brilliant blue. The proteins were identified by MALDI-TOF/TOF mass spectrometry. A total of 22 proteins were identified, 21 of which showed differential expression with 12 proteins being upregulated and nine being downregulated. Plants responded to the pathogen with increased expression of pathogenesis-related proteins. We noted the induction of proteins involved in hypersensitivity reaction and other defense mechanisms. The expression of proteins of primary metabolism related to energy production, however, decreased, as did the expression of two proteins related to defense against abiotic stress. These results demonstrate the presence of important mechanisms for defense against Fol in the tomato genotype BHRS 2,3.

Protein extraction method for the proteomic study of Zymomonas mobilis during production of ethanol and levans.

Zymomonas mobilis has aroused considerable interest owing to its rapid metabolism and efficiency in producing ethanol and by-products such as levans, sorbitol, and gluconic acid from simple sugars. We performed a proteomic analysis of Z. mobilis UFPEDA241 to provide a global profile of regulatory proteins. The choice of the methods of extraction and cell lysis are fundamental steps and of great importance for the detection and identification of intra- and extracellular proteins of a proteome. Strains were subjected to protein extraction methods using three different reagents: TRIzol, lysis buffer, and phenol. The optimum method was taken to be the one that produced the greatest quantity and quality of proteins in one dimension for further analysis in two dimensions during the production of ethanol and levans over 72 h. The results showed that the greatest amount of protein was obtained by the phenol method (1.44 ± 0.07 mg/mL), which was significantly different (P < 0.05) to the TRIzol (1.11 ± 0.01 mg/mL), and lysis buffer (0.93 ± 0.01 mg/mL) methods (both with P > 0.05). Fermentation at 20°C produced the highest level of levans, and using two-dimensional electrophoresis and mass spectrometry it was possible to identify 34 differentially expressed spots.