# Study of selected mechanisms of oat tolerance to cadmium and powdery mildew

## TL;DR

This study explores how different oat varieties respond to cadmium exposure, powdery mildew infection, and both combined, revealing how they manage stress and disease.

## Contribution

The study identifies genotype-specific defense mechanisms and interactions between cadmium stress and powdery mildew infection in oats.

## Key findings

- Oat varieties showed higher sensitivity to powdery mildew than to cadmium stress.
- Cadmium increased calcium content in leaves and may prime defense mechanisms against pathogens.
- Glutathione plays different roles in cadmium and pathogen defense.

## Abstract

This study evaluates the tolerance mechanisms of different varieties of oats (Avena sativa L., vars. Aragon, Bay Yan 2, Ivory, Racoon, and Vaclav) to cadmium (50 mg·kg⁻1 soil applied on day 22, Cd treatment), the pathogen (Blumeria graminis f. sp. avenae, applied on day 35, P treatment), and their simultaneous effect (P + Cd treatment). Cd accumulation was generally higher in the infected plants (P + Cd) and depended on the genotype. The tested oat vars. were more sensitive to P than to Cd, which was reflected in a significant reduction (> 40%) in photosynthetic pigment content, an increase in polyphenol content, higher lipid peroxidation in membranes, and increased activity of total β-1,3-glucanase and catalase in infected leaves. A significant increase in calcium content was observed in the leaves of the P + Cd treatment. The reduced glutathione content in the Cd and P + Cd treatments (compared to the P treatment) in most of the tested vars. suggests different roles for glutathione in defence against Cd (metal sequestration) and P (antioxidant role). The reduction in lipid peroxidation, polyphenol content, and total β-1,3-glucanase activity in plants of the P + Cd treatment suggests a potential priming effect of cadmium on defence mechanisms. The obtained results have the potential to predict oat behaviour not only under cadmium stress or powdery mildew infection, but also under combined stress conditions.

The online version contains supplementary material available at 10.1007/s11356-025-36951-x.