UV-C light treatment to enhance peanut plant disease resistance through phytoalexin upregulation

Overview

Fungal pathogens such as Sclerotium rolfsii pose significant challenges to peanut production worldwide. This research proposes a novel, non-chemical disease management approach: exposing peanut plants to short-duration UV-C light (254nm) on a weekly basis to stimulate the plant's natural defense mechanisms. The central hypothesis is that this treatment will upregulate the production of phytoalexins, particularly resveratrol, which are plant secondary metabolites with antimicrobial properties. Higher concentrations of these compounds are expected to reduce disease severity, including wilting and cell death, when plants are challenged by fungal pathogens.

This approach could offer peanut growers an alternative or complement to conventional fungicide programs, potentially reducing chemical inputs while maintaining crop health and yield.

Technical specifications

Treatment protocol:

• UV-C light exposure at 254nm wavelength
• Duration: 5 minutes per treatment session
• Frequency: once per week
• Application timing: nighttime exposure
• Total treatment duration: 6 weeks (6 treatments)

Delivery system:

• Tunnel-shaped cart covered in reflective material
• Cart lined with UV lamps emitting at 254nm
• Designed to be rolled along plant rows in greenhouse settings

Measurement and validation:

• Resveratrol levels assayed via high performance liquid chromatography (HPLC)
• Pre- and post-inoculation phytoalexin concentration comparison
• Disease progression and severity monitored until pod-set
• Comparison of treated versus untreated plants following Sclerotium rolfsii inoculation

Expected outcomes:

• Increased phytoalexin (especially resveratrol) production
• Reduced disease symptoms including wilting and cell death
• Enhanced fungal pathogen tolerance

Technology readiness level

This research is at an early experimental stage (TRL 2-3). The hypothesis is based on established findings that biotic and abiotic stresses can trigger phytoalexin production in plants, combined with recent proposals suggesting nighttime UV exposure as a viable elicitation method. Validation will be conducted in a controlled greenhouse environment at the University of Florida, with planned HPLC-based biochemical assays and disease progression monitoring through pod-set stage. The proposed tunnel-cart delivery system represents a prototype approach that would require further development and field-scale testing before commercial deployment.