Related Experiment Video
Updated: Jan 18, 2026
Inoculation Strategies to Infect Plant Roots with Soil-Borne Microorganisms
Published on: March 1, 2022
Inoculation with Trichoderma atroviride and T. virens Induces ROS Overaccumulation and Compromises Pathogen
Ever Trinidad Astorga-Arzola1, Enrique González-Pérez1, Alicia Becerra Flora1
1Laboratorio de Biotecnología Molecular de Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, A. C. (IPICYT), San Luis Potosí 78216, Mexico.
Constitutive expression of the EPL1 protein in Arabidopsis enhanced growth but compromised pathogen resistance when co-inoculated with Trichoderma species. Elevated reactive oxygen species (ROS) levels in the transgenic line may disrupt defense priming, leading to reduced immunity.
Area of Science:
- Plant-microbe interactions
- Plant immunity
- Molecular plant pathology
Background:
- Constitutive expression of the cerato-platanin protein EPL1 from *Trichoderma atroviride* in *Arabidopsis thaliana* (35S::TaEPL1-3 line) has been shown to promote plant growth and enhance pathogen resistance.
- Trichoderma species are known for their beneficial effects on plants, including growth promotion and biocontrol capabilities.
Purpose of the Study:
- To evaluate the effect of inoculating the 35S::TaEPL1-3 Arabidopsis line with *T. atroviride* and *T. virens* on plant growth and defense responses.
- To investigate the role of reactive oxygen species (ROS) in the altered defense responses observed in the transgenic line upon Trichoderma inoculation.
Main Methods:
- Plant growth assays were conducted on 35S::TaEPL1-3 plantlets inoculated with *T. atroviride* and *T. virens*.
- Infection assays were performed on leaves of 35S::TaEPL1-3 and wild-type (WT) Col-0 plants pre-inoculated with *Trichoderma* species and subsequently challenged with *Pseudomonas syringae* and *Botrytis cinerea*.
- Reactive oxygen species (ROS) levels, specifically hydrogen peroxide (H2O2), were measured in inoculated and challenged plants.
Main Results:
- Inoculation with *T. atroviride* and *T. virens* increased fresh weight and lateral root formation in the 35S::TaEPL1-3 line compared to controls.
- Dual *Trichoderma* inoculation compromised the resistance of the 35S::TaEPL1-3 line to *P. syringae* and *B. cinerea* compared to WT plants.
- Dual inoculation led to higher H2O2 accumulation in the 35S::TaEPL1-3 line, particularly when co-inoculated with both *Trichoderma* species and challenged with both pathogens.
Conclusions:
- Elevated ROS levels in the 35S::TaEPL1-3 line may compromise defense priming activation during co-inoculation with *T. atroviride* and *T. virens*.
- Synergistic elicitor accumulation from *Trichoderma* species, combined with constitutively high ROS, can lead to defense signal dysregulation and loss of resistance in transgenic plants.
- The study highlights a complex interplay between constitutive elicitor expression, microbial co-inoculation, ROS accumulation, and plant defense responses.
