Differential Strategies of Ectomycorrhizal Development between Suillus luteus and Pinus massoniana in Response to Nutrient Changes

TL;DR

This study explores how the ectomycorrhizal fungus Suillus luteus interacts with Pinus massoniana under different nutrient conditions and identifies a key gene involved in root colonization.

Contribution

The study identifies a GST gene in Suillus luteus that is involved in root colonization and is independent of nutrient levels.

Findings

Suillus luteus LS88 promotes Pinus massoniana seedling growth without mature ectomycorrhiza.

The GST gene in LS88 is likely involved in colonizing P. massoniana roots and is induced by the host.

GST gene expression is independent of nutrient levels and could serve as a colonization marker.

Abstract

Ectomycorrhizal fungi employ different strategies for mycelial growth and host colonization under varying nutrient conditions. However, key genes associated with mycorrhizal interaction should be influenced solely by the inoculation treatment and not by nutrient variations. To utilize subtle nutrient differences and rapidly screen for key genes related to the interaction between Suillus luteus and Pinus massoniana, we performed an inoculation experiment using culture bottles containing high- and low-nutrient media. Interestingly, S. luteus LS88 promoted the growth of P. massoniana seedlings without mature ectomycorrhiza, and the impact of LS88 inoculation on P. massoniana roots was greater than that of nutrient changes. In this study, the resequenced genome of the LS88 strain was utilized for transcriptome analysis of the strain. The analysis indicated that a unique gene encoding glutathione S-transferase (GST) in LS88 is likely involved in colonizing P. massoniana roots. In this study, the GST gene expression was independent of nutrient levels. It was probably induced by P. massoniana and could be used as a marker for S. luteus colonization degree.

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