Title: Complementary Genomics, Proteomics and Metabolomics Approaches Unravels Complexity Involved in Molecular Pathogenesis of Karnal Bunt Incited by Tilletia indica in Wheat

Biography:

Vishakha Pandey has her expertise in biotic stress and host-pathogen interaction. Her work on Karnal bunt- Tilletia indica as a model system, resulted in the identification of novel pathogenicity factors. She has elucidated the molecular mechanism of Karnal bunt disease pathogenesis. by complementing hi-throughput Genomics, Proteomics and Metabolomics approach. Such integrated omics approaches resulted in the identification of oxalic acid as key pathogenicity factor in Karnal bunt pathogenesis. 

Abstract

Karnal bunt (KB) is a major disease of wheat, caused by the hemibiotrophic fungus, Tilletia indica. It is regarded as an economically important disease as the pathogen is quarantined in more than 70 countries. Despite its quarantine significance, there is meager information on the molecular mechanisms of pathogenesis employed by this important fungus to cause disease. Moreover, all the methods used to manage the disease have proven futile. To develop an effective disease management strategy, it is essential to unravel the pathogenic mechanisms utilized by T. indica. In order to understand the molecular mechanisms involved in KB pathogenesis, hi-throughput Genomics, Proteomics and Metabolomics approaches were used. Comparative proteomic analysis of the proteins from T. indica isolates varying in their virulence behavior resulted in identification of putative pathogenicity factors (such as oxalic acid and melanin production by malate dehydrogenase, enolase, respectively), proteins that play crucial role in adhesion, invasion and colonization (Glyceraldehyde-3-phosphate dehydrogenase, Fructose-bisphosphate aldolase, Triose phosphate isomerase), penetration (Secretory lipase), degradation of cell wall and antifungal proteins (Glycoside hydrolase family GH45, Aspartate proteases), MAP kinase signaling (Ste7), protection against host-derived reactive oxygen species (Mannitol dehydrogenase, Thioredoxins). Complementation of proteomic analysis with hybrid genome sequence resulted in the identification of homologs of candidate pathogenicity/virulence factors in T. indica. Further, GC- MS-based metabolic profiling validated the role of oxalic acid as a potential virulence factor in T. indica. Unraveling such complexity of molecular pathogenesis would further help in devising novel and effective disease management strategies including the development of resistant plant genotypes through classical plant breeding or genetic engineering, novel biomarkers for pathogen detection and new targets for fungicide development.