Modulation of H2O2 produced by wheat plant using Pseudomonas fluorescens UTPf298 under Fusarium pseudograminearum crown and root rot disease

Document Type : Research Paper

Authors

• Nilofar Mohammadi Fesharaki ¹
• Keivan Behboudi ²
• Majid Talebi ³

¹ Department of Plant Protection, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran

² Department of Plant Protection, University of Tehran, Karaj, Iran.

³ Department of Biotechnology, Isfahan University of Technology, Isfahan, Iran.

Abstract

Keywords

• Active oxygen
• Biological stress
• Severity of pathogenicity
• Biological fertilizer

Extended Abstract

Introduction

    Fusarium crown and root rot (FCR) caused by Fusarium pseudograminearum reduces the yield and quality of many important plant species around the world, including cereals, especially in arid and semi-arid agricultural areas. This disease, like many different biotic and abiotic environmental stresses, induces the plant stress hormone ethylene. The increase in ethylene concentration causes plants to be unable to grow in adverse environmental conditions. Ethylene stress causes the accumulation of reactive oxygen species (ROS) in plant cells and tissues. Accumulation of ROS in cells and tissues causes lipid peroxidation, protein oxidation, nucleic acid damage, enzyme inhibition, activation of the programmed cell death pathway, and ultimately causes cell death. One of the ways to control oxidative stress is the use of Plant growth promoting rhizobacteria (PGPR) bacteria, including pseudomonads.

Materials and Methods

The pathogenic fungus F. pseudograminearum was obtained from Kermanshah Agricultural and Natural Resources Research Institute. In this research, to control this disease, the bacterium Pseudomonas fluorescens strain EB298 was isolated and identified from the soil infected with this disease in Andimeshk city. After the inoculation of this bacterium, the effect of fungal pathogenicity the control of the intensity of pathogenicity and growth, and the reduction of ethylene and H₂O₂ in wheat plants were investigated.

Results and Discussion

The results of this research show that the pathogenicity of this fungus was 4 under normal greenhouse conditions. Wheat seedlings face a decrease in growth and biomass during crown and root rot disease. At this time, the rate of seed germination is greatly reduced, the growth of roots and aerial parts of seedlings is reduced, and the rate of cell death and aging increases, which is due to the increase in the production of ethylene finally active oxygen, which in this research The amount of H₂O₂ was investigated as a representative of active oxygen. The obtained results indicate that plant aging and death during stress are directly related to the amount of ethylene and H₂O₂ production. After the inoculation of P. fluorescens strain EB298, this isolate was able to reduce the amount of plant ethylene from 30 nmol/gr to 20 nmol/gr. As a result of reducing the amount of ethylene, the amount of hydrogen peroxide, which was representative of active oxygen in this research, decreased from 45 M/gFWµ in the control sample to 27 M/gFWµ in the sample inoculated with bacteria. As a result, the damage caused by crown rot fungus (pathogenic intensity) was significantly reduced from grade 4 in the control to grade 2.

Conclusion

The results of this research also show that seed inoculation with P. fluorescens EB298 (UTPf298) bacteria, in addition to controlling root rot disease, has reduced ethylene and hydrogen peroxide and ultimately the severity of pathogenicity in wheat. Also, this bacterium, by affecting the growth of the plant, strengthened the plant and the greenness of the wheat plant.