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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Peanut and Small Grains Research Unit » Research » Publications at this Location » Publication #422638
Research Project: High Oleic Peanut Cultivars and Germplasm with Improved Disease Resistance for the Southwestern United States

Location: Peanut and Small Grains Research Unit

Title: Dissecting resistance mechanisms to Agroathelia rolfsii in peanut (Arachis hypogaea l.) through comparative RNA-seq profiling of resistant and susceptible genotypes

Author
item VERMA, PANKAJ - Texas Tech University
item DAS, ARINDAM - New Mexico State University
item OJHA, MANISHA - New Mexico State University
item GHOSE, KOUSHIK - Texas Tech University
item PATIL, GUNVANT - Texas Tech University
item SRIPATHI, VENKATESWARA - Alabama A & M University
item Bennett, Rebecca
item PUPPALA, NAVEEN - New Mexico State University
item JANGA, MADHUSUDHANA - Texas Tech University

Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: The soilborne fungal pathogen Agroathelia rolfsii causes one of the most devastating diseases in peanut (Arachis hypogaea L.) around the world. While there are a small number of cultivars that are resistant to this disease, the mechanisms underlying the resistance are not well understood. To address the knowledge gap, this study examined which genes were expressed by resistant and susceptible genotypes when inoculated with the pathogen and under normal conditions. After infection, several defense-related genes were turned on in the resistant cultivar, whereas the susceptible cultivar showed limited activation of these genes. These findings provide insights into the molecular basis of stem rot resistance in peanut, and offer a foundation for breeding or genetic engineering approaches to enhance disease resistance in susceptible cultivars.

Technical Abstract: Stem rot, caused by the fungal pathogen Agroathelia rolfsii, is a devastating disease in peanut (Arachis hypogaea L.), resulting in substantial global agricultural losses. This study employed RNA sequencing to unravel the molecular mechanisms of resistance by analyzing the gene expression profiles of a resistant peanut genotype (Georgia 03L) and a susceptible genotype (Valencia C) under both normal and infected conditions. From the sequencing data, a total of 405.9 million high-quality reads were successfully mapped to the A. hypogaea reference genome, achieving an average mapping rate of 97%. The alignment showed that out of the 67,124 annotated genes in the Tifrunner genome, 49,598 were expressed in at least one sample. In the resistant genotype, key defense-related genes, including receptor-like kinases (RLKs), NBS-LRR resistance genes, and transcription factors such as MYB and zinc finger proteins, were strongly induced upon infection were uniquely regulated in Georgia03L. Weighted Gene Co-Expression Network Analysis (WGCNA) identified a module (Sienna4) associated with resistance enriched in genes involved in oxidative stress response, secondary metabolism, and cell wall reinforcement. In contrast, the susceptible genotype displayed a limited activation of these defense pathways, emphasizing its vulnerability to A. rolfsii. Functional annotation highlighted critical pathways, such as oxidoreductase activity, glutathione metabolism, and peroxidase-mediated responses, as pivotal to the resistance mechanism. These findings provide valuable insights into the molecular basis of stem rot resistance in peanut, offering a foundation for breeding or genetic engineering approaches to enhance disease resistance in susceptible cultivars.