Trichoderma atroviride LZ42 releases volatile organic compounds promoting plant growth and suppressing Fusarium wilt disease in tomato seedlings

Abstract

Background The promotion of plant growth and suppression of plant disease using beneficial microorganisms is considered an alternative to the application of chemical fertilizers or pesticides in the field. Results A coconut-scented antagonistic Trichoderma strain LZ42, previously isolated from Ganoderma lucidum-cultivated soil, was investigated for biostimulatory and biocontrol functions in tomato seedlings. Morphological and phylogenetic analyses suggested that strain LZ42 is closely related to T. atroviride. Tomato seedlings showed increased aerial and root dry weights in greenhouse trials after treatment with T. atroviride LZ42 formulated in talc, indicating the biostimulatory function of this fungus. T. atroviride LZ42 effectively suppressed Fusarium wilt disease in tomato seedlings, with an 82.69% control efficiency, which is similar to that of the carbendazim treatment. The volatile organic compounds (VOCs) emitted by T. atroviride LZ42 were found to affect the primary root growth direction and promote the root growth of tomato seedlings in root Y-tube olfactometer assays. The fungal VOCs from T. atroviride LZ42 were observed to significantly inhibit F. oxysporum in a sandwiched Petri dish assay. SPME–GC–MS analysis revealed several VOCs emitted by T. atroviride LZ42; the dominant compound was tentatively identified as 6-pentyl-2H-pyran-2-one (6-PP). The VOC 6-PP exhibited a stronger ability to influence the direction of the primary roots of tomato seedlings but not the length of the primary roots. The inhibitory effect of 6-PP on F. oxysporum was the highest among the tested pure VOCs, showing a 50% effective concentration (EC50) of 5.76 μL mL−1 headspace. Conclusions Trichoderma atroviride LZ42, which emits VOCs with multiple functions, is a promising agent for the biostimulation of vegetable plants and integrated management of Fusarium wilt disease.

Volatile Organic Compound (VOC) Profiles of Different Trichoderma Species and Their Potential Application

“…Characteristic of the Top 20 T. atroviride P1 VOCs was 6-pentyl-alpha-pyrone (6PP) ( m/z 167.099). This volatile is responsible for the coconut-like scent of T. atroviride isolates growing on PDA [ 78 ] and has been correlated with antimicrobial activity and plant defence induction as well as plant growth promotion [ 74 , 79 , 80 ]. Among the T. afroharzianum T22 Top 20 emitted VOCs, there was m/z 121.064, putatively identified as acetophenone, a molecule reported to show antifungal activity in vitro against Penicillium italicum [ 81 ].…”

Diversity and effects of competitive Trichoderma species in Ganoderma lucidum–cultivated soils

“…Solid-phase microextraction coupled with gas chromatography–tandem mass spectrometry (SPME–GC–MS) was used to determine the composition of the volatiles produced by the representative Trichoderma strains ( Stoppacher et al, 2010 ). The detailed procedure and conditions have been described previously ( Rao et al, 2022 ). Trichoderma was cultured on PDA and incubated at 26°C for 5 days.…”

Trichoderma and its role in biological control of plant fungal and nematode disease

“…Many studies have shown that most Trichoderma spp. can produce bioactive substances and have antagonistic effects on plant-pathogenic fungi and plant-pathogenic nematodes ( Şesan et al, 2020 ; Abdelkhalek et al, 2022 ; Organo et al, 2022 ; Rao et al, 2022 ). Bioactive substances, including secondary metabolites and cell wall-degrading enzymes, can effectively improve the resistance of crops, reduce plant diseases, and promote plant growth ( Domínguez et al, 2016 ; Viriyasuthee et al, 2019 ; Jaiswal et al, 2020 ; Tseng et al, 2020 ).…”