Autotoxin affects the rhizosphere microbial community structure by influencing the secretory characteristics of grapevine roots

Abstract

Autotoxins secreted by roots into the soil can trigger rhizosphere microecological imbalances and affect root secretory properties resulting in conditions such as replanting disease. However, information on the effect of autotoxins on root secretion characteristics and regulation of the composition of rhizosphere microorganisms by altered root exudates is limited. In this study, autotoxin ρ-hydroxybenzoic acid (4-HBA) was added to the soil of potted grapevine seedlings, CO2 pulse-labeling, and DNA stable isotope probing were used to track the rhizosphere microbiome that assimilates root exudates. Bacterial and fungal microbiomes that assimilated plant-derived carbon were identified by high-throughput sequencing. Results showed that 4-HBA treatment altered bacterial and fungal communities in 13C-labeled organisms, with a lower abundance of beneficial bacteria (e.g., Gemmatimonas, Streptomyces, and Bacillus) and a higher abundance of potential pathogen fungi (e.g., Fusarium, Neocosmospora, Gibberella, and Fusicolla) by changing the composition of root exudates. The exogenous addition of upregulated compound mixtures of root exudates reduced the abundance of beneficial bacterial Bacillus and increased the abundance of potential pathogen fungi Gibberella. These results suggest that 4-HBA can alter root secretion properties and altered root exudates may enrich certain potential pathogens and reduce certain beneficial bacteria, thereby unbalancing the structure of the rhizosphere microbial community.

Long-term Push-pull Cropping System Shifts Rhizosphere and Maize-root Microbiome Diversity Paving Way To Resilient Farming System

“…Still, it increased the presence and abundance of bene cial belowground fungal such as Mortieralla, Exophiala, Paraboeremia, Bionectria, Clitopilus, Marasmius, Pyrenochaetopsis and Trichoderma compared to the Mono cropping system. The ndings of these studies are in line with previous studies, which indicated that bene cial fungi have a positive impact on agroecosystem [31], [107]- [109]. For example, Mortierella spp.…”

“…The presence of these bacteria genera in PPT soils and maize-roots implies that PPT positively in uences below-ground microbial populations compared to Mono. Similar ndings have been observed in various other cropping systems, including long-term intercropping systems, push-pull experimental plots, multiple cropping systems, crop rotation, and cover cropping [7], [8], [31], [79]. Nitrospira were found more in PPT, and these types of bacteria are capable of carrying out nitri cation, which involves the oxidation of ammonia in a single organism [3], [22], [25], [85].…”

“…The genotype of a plant determines its root-associated microbiota, and the plant can shape the belowground microbiome by supporting or suppressing local microbial populations [2], [5]. Plants use root exudates to actively modify rhizosphere microbial populations favoring bene cial microbes [31], [32]. Legume-based intercropping can improve soil health and optimize the soil's physicochemical properties, including increasing microbial abundance and organic matter, controlling soil erosion, and improving soil structure [30], [33], [34].…”

The Responses of a Grapevine Rhizosphere System to Mulching Using Amplicon Sequencing and Transcriptomic Analysis

“…Gibberella and Trichocladium were more abundant in samples obtained after continuous cropping for years than in those obtained after 1 year [50]. Previous results showed that Fusarium and Gibberella act as plant pathogens [51,52].…”

Comparison of the response of microbial communities to region and rootstock disease differences in tobacco soils of southwestern China

“… Wang et al (2023) also found differences in community composition and multifunctionality between healthy and Alternaria solani -infected potato rhizosphere soils. The rootstock diseases of tobacco are mostly caused by fungi ( Modjo and Hendrix, 1986 ; Gonzalez et al, 2011 ; Yang et al, 2020 ), and the pathogens may affect the soil microbial community by changing the rhizosphere secretions of crops in addition to directly attaching to the root surface and contacting the soil ( Liu et al, 2022 ). Of course, such findings do not negate the conclusion that regional differences have a significantly greater impact than rootstock diseases in the analysis of microbial diversity, core taxa, and co-occurrence networks.…”