# Physiological and biochemical markers associated with root lignification and micronutrient uptake in wheat genotypes with contrasting resistance to Gaeumannomyces tritici

## TL;DR

This study explores how wheat genotypes resist a root disease by examining factors like lignin content and micronutrient levels.

## Contribution

The study identifies biochemical markers and mechanisms linked to wheat resistance against Gaeumannomyces tritici.

## Key findings

- Resistant wheat genotypes had higher root lignin content, manganese, and iron levels, correlating with lower disease severity.
- Seed manganese levels were positively linked to root lignin and negatively linked to disease severity.
- Enzymatic activities like phenylalanine ammonia lyase and peroxidase were higher in resistant genotypes after infection.

## Abstract

Take-all disease, caused by Gaeumannomyces tritici, is one of the most destructive root diseases of wheat (Triticum aestivum) worldwide. This study aimed to clarify the physiological and biochemical mechanisms underlying take-all resistance through analysis of root lignification, manganese and iron concentration in roots and seeds, and defense enzyme activities. In the first step, 17 bread wheat genotypes were evaluated under controlled greenhouse conditions in both control and infected treatments. Resistant genotypes showed higher mean root lignin content, root manganese and iron concentration, and root dry weight, which were significantly correlated with lower disease severity under greenhouse conditions. Seed Mn levels were positively correlated with root lignin (r = 0.579, p = 0.015) and negatively correlated with disease severity (r = –0.601, p = 0.011), suggesting that inherent seed nutrient reserves influence early defense activation. In the second step, five representative genotypes (two resistant and three susceptible) were analyzed for defense-related enzymes. G. tritici infection significantly induced phenylalanine ammonia lyase and peroxidase activities and total protein content in resistant genotypes, suggesting that enzymatic activity contributes to enhanced lignin biosynthesis. Stepwise regression identified root manganese concentration and total protein as the strongest predictors of lignin content, highlighting their potential role in structural defense. These findings suggest a possible dual role for manganese and iron in cell wall lignification and defense-related metabolism. The integration of seed and root micronutrient levels, lignin deposition, and enzyme activity provides a comprehensive framework for understanding take-all resistance and offers practical biochemical markers for breeding resistant wheat cultivars.

The online version contains supplementary material available at 10.1038/s41598-026-39324-7.