Harnessing Indigenous Plant Growth Promoting Rhizobacteria for Virus Management and Soil Restoration in Southeastern Crop Systems

2/27/2025: No annual report available. To date, project subaward contract not fully executed.

Commodities

Practices

This project addresses the need for sustainable agricultural practices to combat viral pathogens and soil degradation in southeastern crop systems. Our project aims to investigate the efficacy of indigenous Plant Growth Promoting Rhizobacteria (PGPR) in enhancing crop growth and combating viral infections. The 20th-century Green Revolution led to increased crop yields through intensive chemical inputs but at the expense of environmental degradation and threats to agricultural sustainability. Challenges such as soil health degradation, monoculture, and chemical dependency underscore the necessity for a transition toward organic agriculture. Soil degradation diminishes fertility, disrupts nutrient cycling, and compromises resilience to climate change-induced events, endangering long-term agricultural viability. Our project proposes a solution by harnessing native soil-associated bacteria to bolster crop resilience against viral diseases while restoring soil health. By implementing biocontrol measures using beneficial soil microbes, we aim to mitigate the incidence and severity of viral diseases, reduce reliance on chemical interventions, and promote overall ecosystem health. Our project will evaluate the efficacy of PGPR in enhancing plant defense mechanisms against viral pathogens, which cause loss in important southeastern vegetable crops, and restore soil fertility through trials and molecular analysis. Ultimately, this project seeks to promote sustainable agriculture, foster long-term resilience in agricultural systems, and provide economic benefits to farmers while safeguarding environmental integrity.

The long-term goal of our research, including the proposed project, is to evaluate and develop PGPR-based practices for disease management caused by viral pathogens. The goal of this project is to assess the reproducibility and efficacy of PGPR application against viral pathogens.  Auburn University, as the founding institute for PGPR research, possesses an extensive collection of PGPR strains amassed by various research groups over the years. While some bacterial strains from this collection have been evaluated for the past three decades regarding their impact on viral infections, questions have arisen regarding the reproducibility and reliability of the observed effects. This is a crucial matter as it relates to the real-world application of PGPR as an alternative agricultural practice. Since previous assessments were conducted before recent advancements in molecular methods, there is now an opportunity to investigate with greater precision in both quality and quantity. We will accomplish our goal through the following project objectives.

• Objective 1. Determine the virus infection in plant species: Potato virus Y (PVY) and Cucumber mosaic virus (CMV) are two major virus species that cause substantial yield losses and increase economic burdens for cucumber and tomato producers, which are vital vegetable crops in the southeastern region of the United States. These virus species will be tested for their replication and distribution within the host plants by monitoring the viral loads using RT-qPCR and ELISA.
• Objective 2. Assess the efficacy of PGPR treatment in enhancing plant defense: Among the vast array of PGPR strains collected from the southeastern region of the United States, certain strains have previously been reported to exhibit antiviral effects through visual and limited gene analysis. Four selected local PGPR strains—Pseudomonas fluorescens, Serratia marcescens, Bacillus amyloliquifaciens, and B. subtilis—will be evaluated for their post-treatment regulation of plant defense-related genes.
• Objective 3. Quantify the impact of PGPR treatment on virus replication and distribution: Once the virus monitoring and plant gene expression analysis are established and validated through Objectives 1 and 2, the impact of PGPR treatment on virus replication and distribution within the host plants will be evaluated by analyzing the virus titer at different parts of the plants.

Overall, the proposed project seeks to equip producers with potent tools to combat destructive viruses while promoting sustainable agriculture by leveraging the potential of beneficial microbes.