| The banana fusarium wilt is one of the most important fascicular systemic disease in the production of banana. Fusarium. oxysporum f. sp. cubense(Foc) is the causal agent of fusarium wilt of banana. It can be divided into four physiological races, race 1, 2, 3 and 4. Among them, race 1 and race 4 are more widely distributed in our country. The main methods prevention of banana fusarium wilt disease are resistance breeding, chemical control and biological control, but few effective options for managing this ineradicable pathogen. Therefore, formulating effective control methods for fusarium wilt of bananas is a thing of great urgency, and this argely requires better understanding of the mechanism of banana interaction with Foc. As a kind of important pathogenic factors, secreted proteins play an important role in the process of Foc infection, but at the moment, it is still lack of comprehensive understanding of Foc secreted proteins.This study makes the mycelium of Foc1 and Foc4 induced by Brazil banana tissue extracts and uses marker protein quantitative technology(Label-free) to analysis the two races of Foc mycelia secreted proteins. Then combing with bioinformatics methods analysis the function of differentially expressed secreted proteins. Specific results are as follows:1. Using TCA-DOC precipitation, acetone precipitation and ammonium sulfate precipitation three commonly used methods to extract the Foc secreted proteins. Compared with the SDS-PAGE and extraction efficiency, it shows that the improved DOC-TCA precipitation method for Foc secreted protein extraction is fit for the requirements of mass spectrometry secretome analysis.2. Based on the Label-free quantitative proteomic techniques and combined with bioinformatics technology, we analyzed the Foc1 and Foc4 secretome. Results show that compared with Foc1 controls, under the induced condition of Foc1, there are a total of 42 secreted proteins differentially expressed, including 30 classical secretory proteins, accounting for 62.5% of the total differentially expressed secreted proteins; 12 nonclassical secretory proteins, accounting for 25% of the total differentially expressed secreted proteins. Compared with Foc1 controls, under the induced condition of Foc4, there are a total of 57 secreted proteins differentially expressed, including 30 classical secreted proteins, accounting for 65.2% of the total differentially expressed secreted proteins; 14 non-classical secretory proteins, accounting for 21.2% of the total differentially expressed secreted proteins. Compared with Foc1 controls, under the uninduced condition of Foc4, a total of 52 secreted proteins differentially expressed, including 30 classical secretedproteins, accounting for 64.4% of the total differentially expressed secreted proteins; 14 non-classical secretory proteins, accounting for 23.7% of the total differentially expressed secreted proteins. Compared with Foc1 treated, under the induced condition of Foc4, a total of 106 secreted proteins differentially expressed, including 75 classical secreted proteins, accounting for 23.7% of the total differentially expressed secreted proteins;31 non-classical secretory proteins, accounting for 25.2% of the total differentially expressed secreted proteins.3. The function annotation, GO analysis and KEGG function classification show that the molecular function of Foc1 differentially expressed secreted proteins are mainly about catalytic activity、binding activity and molecular transport activity; Biological processes are mainly about metabolism, signal transduction and colonization process; The pathways are mainly about endoplasmic reticulum protein synthesis pathway and plant pathogens interactions, carbon metabolic pathways, AMPK kinase signaling pathways.The molecular function of Foc4 differentially expressed secreted proteins are mainly about catalytic activity, molecular transport activity and antioxidant activity. Biological processes are mainly about metabolism, signal transduction and process of stress reaction. The pathways are mainly about amino acid biosynthesis pathway, TCA cycle, nicotinic acid and nicotinamide salt metabolism pathway and plant pathogens interactions.4. Comparative analysis differentially expressed secreted proteins between Foc1 and Foc4 under the induced condition. The results show that the main functions of the 92 differentially expressed secreted proteins are involved in cell wall degradation, protein modification, ROS detoxification process, oxidation-reduction process and energy metabolism. Among them, the glutamine synthetase, Serine and threonine protein phosphatase only differentially expressed in Foc1; The phosphorylated kinase, cutin enzyme, β-1,6-glucoside enzyme, β-1,3-glucoside enzyme, chitin deacetylase, carboxypeptidase, aspartic acid protease only differentially expressed in Foc4; The catalase and aminopeptidase differentially expressed both in Foc1 and Foc4. According to the biological function of the secreted proteins, we think β-1,6-glucoside enzyme, β-1,3-glucoside enzyme, chitin deacetylase, carboxypeptidase, aspartic acid protease and catalase may be related to the pathogenicity of Foc, the secreted proteins differentially expressed between the two races may be the important factor for the two races difference in pathogenicity. |
