The Department of Biological Sciences is organising an Expert Talk on “SWR1 Chromatin Remodeler Orchestrates the Molecular Dialogue Between Pathogen and Host” by Prof. Saravanan Matheshwaran, Associate Professor, Microbial Adaptation and Chromatin Dynamics Laboratory, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur.
Dr Saravanan is a distinguished researcher in the areas of microbial adaptation, chromatin dynamics, and host–pathogen interactions. This expert lecture will benefit students, research scholars, and faculty by providing insights into cutting-edge research and lending opportunities for future academic collaborations.
Abstract
Chromatin remodelers such as SWR1 regulate gene expression through ATP dependent deposition of the histone variant H2A.Z, thereby coordinating genome stability, transcription, and cellular adaptation. While the functions of SWR1 have been extensively studied in yeast, its role in fungal pathogenesis and host interaction remains largely unexplored. Here, we investigated the role of the SWR1 chromatin remodeling complex in the maize smut fungus Ustilago maydis by deleting its catalytic ATPase subunit, swr1. The Δswr1 mutant exhibited elongated pseudohyphal morphology, hypersensitivity to DNA damage, and enhanced melanin production, indicating defects in genome maintenance, cell cycle progression, and metabolic homeostasis. Transcriptome analysis revealed widespread transcriptional reprogramming, including altered expression of genes involved in secondary metabolism, stress adaptation, nutrient transport, and melanin biosynthesis. Dual RNA sequencing of infected maize tissues demonstrated that SWR1 is indispensable for successful biotrophic development and coordinated cross-kingdom gene regulation. The Δswr1 mutant showed reduced expression of fungal effectors, carbohydrate-active enzymes, transporters, and iron acquisition systems required for host colonization. Correspondingly, maize infected with the mutant displayed extensive transcriptional reprogramming, including activation of defense responses, cell wall reinforcement, hormone signaling, reactive oxygen species homeostasis, and nutrient metabolism. Together, these findings establish SWR1 as a central epigenetic regulator that integrates fungal metabolism, virulence, and host transcriptional reprogramming to promote successful biotrophic interaction between U. maydis and maize.