Comparative Study of Secretory Proteins and CAZymes in Different Types of Plant Pathogens

PurposeThrough systematic comparative analysis of secretory proteins and carbohydrate-active enzymes (CAZymes) in different types of plant pathogens, this study provides a theoretical basis for in-depth analysis of the important roles of secretory proteins and CAZymes in the pathogenesis of different plant pathogens.

MethodsA total of 23 pathogens of different types, including nine fungi, five bacteria and nine oomycetes, were selected as research objects. According to the basic characteristics of secretory proteins, online analysis programs such as SignalP v5.0 were used to predict secretory proteins in pathogens; CAZymes prediction of secretory proteins was performed by online tool dbCAN. Finally, the prediction results of three kinds of plant pathogens were compared systematically.

ResultsThe number of secretory proteins in fungi ranged from 71 to 510, accounting for 0.74% to 3.93%, the number of secretory proteins in bacteria ranged from 105 to 227, accounting for 2.05% to 3.91%, and the number of secretory proteins in oomycetes ranged from 119 to 768, accounting for 0.96% to 2.90%. The average number of CAZymes in fungi, bacteria and oomycetes was 26, 4 and 26, respectively, and there were 62-76, 8-14 and 24-36 kinds of CAZymes, respectively. Among them, fungi had more CAZymes of AA9, GH11 and GH28; bacteria had more GH25 and PL_6, while oomycetes had more PL3_2 and GH17.

ConclusionThe proportion of secretory proteins in oomycetes is relatively small, and the maximum proportion of secretory proteins in fungi varies greatly. The number and kinds of CAZymes in bacteria were the least, while the kinds of CAZymes in fungi were the most. The study indicated that there were common and differentiated toxicity strategies in the coevolution process of different plant pathogens interacting with plants and competing among species.