Journal Article

Invasive species allelopathy decreases plant growth and soil microbial activity

Du, Xue, Losapio, Gianalberto, Guo, Weiqiang, Qu, Tongbao, Peng, Yulan, Zhao, Chunli

2021

Overview

According to the ‘novel weapons hypothesis’, invasive success depends on harmful plant biochemicals, including allelopathic antimicrobial roots exudate that directly inhibit plant growth and soil microbial activity. However, the combination of direct and soil-mediated impacts of invasive plants via allelopathy remains poorly understood. Here, we addressed the allelopathic effects of an invasive plant species ( Rhus typhina ) on a cultivated plant ( Tagetes erecta ), soil properties and microbial communities. We grew T . erecta on soil samples at increasing concentrations of R . typhina root extracts and measured both plant growth and soil physiological profile with community-level physiological profiles (CLPP) using Biolog Eco-plates incubation. We found that R . typhina root extracts inhibit both plant growth and soil microbial activity. Plant height, Root length, soil organic carbon (SOC), total nitrogen (TN) and AWCD were significantly decreased with increasing root extract concentration, and plant above-ground biomass (AGB), below-ground biomass (BGB) and total biomass (TB) were significantly decreased at 10 mg·mL -1 of root extracts. In particular, root extracts significantly reduced the carbon source utilization of carbohydrates, carboxylic acids and polymers, but enhanced phenolic acid. Redundancy analysis shows that soil pH, TN, SOC and EC were the major driving factors of soil microbial activity. Our results indicate that strong allelopathic impact of root extracts on plant growth and soil microbial activity by mimicking roots exudate, providing novel insights into the role of plant–soil microbe interactions in mediating invasion success.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Allelochemicals / Allelopathy / Antiinfectives and antibacterials / Biodiversity / Biological activity / Biology and Life Sciences / Botanical research / Carbon / Chemical properties / Earth Sciences / Ecology and Environmental Sciences / Electrical conductivity / Electrical resistivity / Environmental aspects / Exudates / Exudation / Growth (Plants) / Horticulture / Indigenous plants / Introduced species / Invasive plants / Invasive species / Measurement / Microbial activity / Microorganisms / Moisture content / Nonnative species / Organic carbon / Organic soils / Physical Sciences / Physicochemical properties / Physiology / Plant growth / Plant introduction / Seeds / Soil chemistry / Soil microbiology / Soil microorganisms / Soil properties / Soil water / Soils / Substrates / Water content