In Silico Characterization of the Secretome of the Fungal Pathogen Thielaviopsis punctulata, the Causal Agent of Date Palm Black Scorch Disease

Abstract

The black scorch disease of date palm caused by Thielaviopsis punctulata is a serious threat to the cultivation and productivity of date palm in Arabian Peninsula. The virulence factors that contribute to pathogenicity of T. punctulata have not been identified yet. In the present study, using bioinformatics approach, secretory proteins of T. punctulata were identified and functionally characterized. A total of 197 putative secretory proteins were identified, of which 74 were identified as enzymes for carbohydrate degradation (CAZymes), 25 were proteases, and 47 were predicted as putative effectors. Within the CAZymes, 50 cell wall-degrading enzymes, potentially to degrade cell wall components such as cellulose, hemicellulose, lignin, and pectin, were identified. Of the 47 putative effectors, 34 possessed at least one functional domain. The secretome of T. punctulata was compared to the predicted secretome of five closely related species (T. musarum, T. ethacetica, T. euricoi, T. cerberus, and T. populi) and identified species specific CAZymes and putative effector genes in T. punctulata, providing a valuable resource for the research aimed at understanding the molecular mechanism underlying the pathogenicity of T. punctulata on Date palm.

In Silico Evaluation, Phylogenetic Analysis, and Structural Modeling of the Class II Hydrophobin Family from Different Fungal Phytopathogens

“…From the forty-five HFBII proteins, forty-two proteins were classified as apoplastic effectors and two putative proteins were classified as apoplastic/cytoplasmic effectors that belonged to Verticillium spp., while one protein (CDK12896.1, Geosmithia langdonii) was found with no effector prediction (Figure 6a, Table S4). PHI-based data were used to compare the putative effectors with virulence genes that showed homology with other phytopathogens and classify the proteins into different categories [91,92]. According to the PHI annotation, all the effector proteins were categorized as having a reduced virulence that was encoded by the Fghyd5 [3] (PHI:9245) of Fusarium graminearum with different scores (Table S5), which helps the fungal hyphae to penetrate through the water-air interface and likely helps conidia adhere to the plant host [3].…”

Secretome Analysis for a New Strain of the Blackleg Fungus Plenodomus lingam Reveals Candidate Proteins for Effectors and Virulence Factors

“…The Pathogen-Host Interaction database (PHI base) was used to compare and blast the putative effector proteins with pathogenicity genes homologous to other phytopathogens [86]. These data classify the proteins into different categories, such as reduced virulence, unaffected pathogenicity, hypervirulence, loss of pathogenicity, and effector (plant avirulent determinant), among others [87]. Based on the PHI annotation, most effector proteins were classified as reduced virulence and unaffected pathogenicity (Table 3), meaning that the transgenic strain which expresses no, or reduced, levels of a specific gene product has wild-type disease.…”