Fungal volatiles emitted by members of the microbiome of desert plants are diverse and capable of promoting plant growth

Abstract

Fungi represent a group of eukaryotic microorganisms that are an important part of the plant microbiome. They produce a vast array of metabolites, including fungal volatile organic compounds (fVOCs). However, the diversity and biological activities of fVOCs emitted by the mycobiota of plants native to arid and semi-arid environments remain under-explored. We characterized the chemical diversity of fVOCs produced by 22 representative members of the microbiome of agaves and cacti using SPME-GC-MS. We further tested the effects of pure compounds on the growth and development of Arabidopsis thaliana and host plants. Members of the Sordariomycetes (nine strains), Eurotiomycetes (three), Dothideomycetes (eight), Saccharomycetes (one) and Mucoromycetes (one) were included in our study. We identified 94 fungal organic volatiles classified into nine chemical classes. Terpenes showed the greatest chemical diversity, followed by alcohols and aliphatic compounds. We discovered that camphene and benzyl benzoate, together with the widely distributed and already tested benzyl alcohol, 2-phenylethyl alcohol and 3-methyl-1-butanol, improved plant growth and development of A. thaliana, Agave tequilana and Agave salmiana. Our studies on the fungal VOCs from desert plants underscore an untapped chemical diversity with promising biotechnological applications.

Plant Growth Promotion by Two Volatile Organic Compounds Emitted From the Fungus Cladosporium halotolerans NGPF1

“…There are 2.2 to 3.8 million species of fungi ( Hawksworth and Lucking, 2017 ), and they are known to emit a large number of VOCs as mixtures of alcohols, monoterpenes, ketones, esters, small alkenes, sesquiterpenes, and derivatives ( Morath et al, 2012 ; Inamdar et al, 2020 ). According to a recent tally ( Li et al, 2018 ), 400 microorganisms from a total of 10,000 can produce more than 1,000 VOCs ( Morath et al, 2012 ; Inamdar et al, 2020 ; Camarena-Pozos et al, 2021 ). Volatile profiles are influenced by numerous parameters such as environmental conditions like humidity, temperature, and pH, as well as the culture medium, culture time, species, and so on ( Bitas et al, 2013 ; Lee et al, 2015 ; Maki et al, 2019 ; Rinnan et al, 2020 ).…”

The soil crisis: the need to treat as a global health problem and the pivotal role of microbes in prophylaxis and therapy

“…For example, SOM can serve as a source of isothiocyanates that are toxic for nematodes. Moreover, SOM may promote the growth of saprophytic microbes that secrete soluble antifungal and bactericidal compounds, as well as volatiles that are involved in inducing systemic resistance in plants (Hammerbacher et al, 2019;Vlot et al, 2020;Camarena-Pozos et al, 2021). SOM has been proposed to promote plant growth by providing plants with small molecules (i.e.…”

“…This attraction of Streptomyces of arthropods is specific, as insects and arachnids do not respond to geosmin. Signalling between soil organisms via volatiles is pervasive (Audrain et al, 2015;Schulz-Bohm et al, 2017;Tyc et al, 2017;Hammerbacher et al, 2019;Schenkel et al, 2019;Camarena-Pozos et al, 2021;Weisskopf, et al, 2021). However, soil compaction through use of heavy machinery, and flooding events, reduce air spaces and channels in soil, and hence reduce the diffusive flow of signalling volatiles.…”

Bacterias y hongos endófitos de la familia Cactaceae y sus aplicaciones

“…Estas características de importancia ecológica han enfocado los estudios de estas especies en su conservación, principalmente proponiendo distintas formas de propagación y cultivo in vitro. En los últimos diez años, se ha incrementado el estudio sobre la actividad biológica de algunos de los metabolitos secundarios producidos por estas plantas, así como la identificación y actividad de su microbioma (Bezerra et al, 2013;Chávez-Ambriz, Hernández-Morales, Cabrera-Luna, Luna-Martínez & Pacheco-Aguilar, 2016;Bulla et al, 2017;Eke et al, 2019;Camarena-Pozos, Flores-Núñez, López & Partida-Martínez, 2021).…”