Aboveground plant-to-plant communication reduces root nodule symbiosis and soil nutrient concentrations

Yuta Takahashi,Kaori Shiojiri,Akira Yamawo

doi:10.1038/s41598-021-92123-0

Yuta Takahashi, Kaori Shiojiri + Show 1 more

Open Access

https://doi.org/10.1038/s41598-021-92123-0

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Journal: Scientific Reports	Publication Date: Jun 16, 2021
Citations: 3	License type: open-access

Affiliation: Hirosaki University, Ryukoku University

Abstract

Aboveground communication between plants is well known to change defense traits in leaves, but its effects on belowground plant traits and soil characteristics have not been elucidated. We hypothesized that aboveground plant-to-plant communication reduces root nodule symbiosis via induction of bactericidal chemical defense substances and changes the soil nutrient environment. Soybean plants were exposed to the volatile organic compounds (VOCs) from damaged shoots of Solidago canadensis var. scabra, and leaf defense traits (total phenolics, saponins), root saponins, and root nodule symbiosis traits (number and biomass of root nodules) were measured. Soil C/N ratios and mineral concentrations were also measured to estimate the effects of resource uptake by the plants. We found that total phenolics were not affected. However, plants that received VOCs had higher saponin concentrations in both leaves and roots, and fewer root nodules than untreated plants. Although the concentrations of soil minerals did not differ between treatments, soil C/N ratio was significantly higher in the soil of communicated plants. Thus, the aboveground plant-to-plant communication led to reductions in root nodule symbiosis and soil nutrient concentrations. Our results suggest that there are broader effects of induced chemical defenses in aboveground plant organs upon belowground microbial interactions and soil nutrients, and emphasize that plant response based on plant-to-plant communications are a bridge between above- and below-ground ecosystems.

Highlights

Aboveground communication between plants is well known to change defense traits in leaves, but its effects on belowground plant traits and soil characteristics have not been elucidated
volatile organic compounds (VOCs) from goldenrod Solidago canadensis increased the defenses of soybean plants against h erbivores[11] through changes in chemical traits, saponin concentrations, or total phenolics[16]
Shoot-to-root ratio and total phenolics in leaves were not affected (Fig. 1a–c), the saponins in both leaves and roots were significantly higher in the VOC-exposed plants (Fig. 1e,f)

Summary

Introduction

Aboveground communication between plants is well known to change defense traits in leaves, but its effects on belowground plant traits and soil characteristics have not been elucidated. VOCs from goldenrod Solidago canadensis increased the defenses of soybean plants against h erbivores[11] through changes in chemical traits, saponin concentrations, or total phenolics[16]. Resource allocation from shoot to root in response to plant communication may reduce the root nodule symbiosis. In the Fabaceae family, plants produce chemical metabolites such as phenols and saponins that induce anti-herbivore defense after when they receiving VOCs released from damaged plants[25,26].

Results

Conclusion