Pathogen suppression by microbial volatile organic compounds in soils

Abstract

There is increasing evidence that microbial volatile organic compounds (mVOCs) play an important role in interactions between microbes in soils. In this minireview, we zoom in on the possible role of mVOCs in the suppression of plant-pathogenic soil fungi. In particular, we have screened the literature to see what the actual evidence is that mVOCs in soil atmospheres can contribute to pathogen suppression. Furthermore, we discuss biotic and abiotic factors that influence the production of suppressive mVOCs in soils. Since microbes producing mVOCs in soils are part of microbial communities, community ecological aspects such as diversity and assembly play an important role in the composition of produced mVOC blends. These aspects have not received much attention so far. In addition, the fluctuating abiotic conditions in soils, such as changing moisture contents, influence mVOC production and activity. The biotic and abiotic complexity of the soil environment hampers the extrapolation of the production and suppressing activity of mVOCs by microbial isolates on artificial growth media. Yet, several pathogen suppressive mVOCs produced by pure cultures do also occur in soil atmospheres. Therefore, an integration of lab and field studies on the production of mVOCs is needed to understand and predict the composition and dynamics of mVOCs in soil atmospheres. This knowledge, together with the knowledge of the chemistry and physical behaviour of mVOCs in soils, forms the basis for the development of sustainable management strategies to enhance the natural control of soil-borne pathogens with mVOCs. Possibilities for the mVOC-based control of soil-borne pathogens are discussed.

Tillage System and Crop Sequence Affect Soil Disease Suppressiveness and Carbon Status in Boreal Climate

“…The overall aim of sustainable farming is to cut down the use of pesticides (European Commission, 2017). The greater reliance on the beneficial functions and ecosystem services provided by the soil microbiome is a promising approach forward (Sipilä et al, 2012;Constanzo and Barberi, 2014;de Boer et al, 2019). Disease suppressive soils, through the competitive activity of the non-pathogenic residents of the total soil microbiota (general suppression) or the antagonistic capabilities of specific groups of microorganisms (specific suppression), are able to reduce the occurrence or severity of diseases caused by soilborne phytopathogens (Weller et al, 2002;Dignam et al, 2018).…”

“…The complex interplay of soil suppressiveness cannot simply relate to a single microbial taxon or group (de Boer et al, 2007;Legrand et al, 2019). The majority of rhizobacterial taxa indicative of the suppressiveness status of the soil may differ when comparing different types of suppressive soils or even different soils suppressive to a same phytopathogen (de Boer et al, 2019;Wang and Li, 2019).…”

Volatile Organic Compounds From Lysobacter capsici AZ78 as Potential Candidates for Biological Control of Soilborne Plant Pathogens

“…Recently, microbial volatile organic compounds (VOCs) have come into the limelight as potential candidates to substitute the outlawed chemical fumigants (De Boer et al, 2019). Indeed, their physiochemical characteristics such as low boiling point, high vapor pressure and low molecular weight (<300 Da) (Piechulla et al, 2017), their activity in both gas and liquid phases and ability to re-evaporate after diffusing through water-filled pores, allow microbial VOCs to move easily through the soil pores network (Effmert et al, 2012).…”

Underlying Mechanism of Wild Radix pseudostellariae in Tolerance to Disease Under the Natural Forest Cover

“…This might be due to the lower types and concentrations of phenolic acids in rhizosphere soil of wild R. pseudostellariae. Previous studies have shown that the volatiles of the bacterial community had strong negative effects on the assembly of soil fungal colonizers (Li et al, 2020), and competitive interactions within soil beneficial bacterial communities could trigger the production of mVOCs (volatile organic compounds) that suppressed plant pathogenic fungi (De Boer et al, 2019). Our study implied that complex plantmicrobe interactions may have suppressed host-specific pathogen accumulation in the rhizosphere of wild R. pseudostellariae.…”