Age matters: the effects of volatile organic compounds emitted by Trichoderma atroviride on plant growth

Abstract

Studying the effects of microbial volatile organic compounds (VOCs) on plant growth is challenging because the production of volatiles depends on many environmental factors. Adding to this complexity, the method of volatile exposure itself can lead to different responses in plants and may account for some of the contrasting results. In this work, we present an improved experimental design, a plate-within-a-plate method, to study the effects of VOCs produced by filamentous fungi. We demonstrate that the plant growth response to VOCs is dependent on the age of the plant and fungal cultures. Plants exposed to volatiles emitted by 5-day-old Trichoderma atroviride for 14 days exhibited inhibition, while plants exposed to other exposure conditions had growth promotion or no significant change. Using GC-MS, we compared fungal volatile emission of 5-day-old and 14-day-old T. atroviride. As the fungi aged, a few compounds were no longer detected, but 24 new compounds were discovered.

The volatile 6‐pentyl‐2H‐pyran‐2‐one from Trichoderma atroviride regulates Arabidopsis thaliana root morphogenesis via auxin signaling and ETHYLENE INSENSITIVE 2 functioning

“…Previous reports have shown the VOC profile from T. atroviride grown in potato dextrose agar (PDA), malt extract agar (MEA), or biomalt medium (BM) (Keszler et al ., ; Stoppacher et al ., ; Siddiquee et al ., ; Jeleń et al ., ; Lee et al ., ). All this research identified the compound 6‐PP within the corresponding VOC profile.…”

Effect of Trichoderma harzianum on maize rhizosphere microbiome and biocontrol of Fusarium Stalk rot

“…Secondary metabolites (SMs) such as polyketides and peptaibols derived from the Trichoderma sp., have various biomedical and agriculture applications 16 . Trichoderma derived volatile organic compounds are reportedly promoting plant growth 17, 18 . Also Trichoderma are known to interact with the pathogens and inactivate the pathogenicity related proteins 19 .…”

Arabidopsis thalianaas Bioindicator of Fungal VOCs in Indoor Air

“…Using standardized protocols developed in our laboratory for exposing Arabidopsis thaliana to fungal VOCs [1523], seeds and vegetative plants were exposed to volatile emissions from the two Aspergillus versicolor strains grown on YES. Seeds and plants exhibited differential responses between the two strains and the production of CO 2 was determined not to be a major contributor to these growth responses.…”

“…A double plate-within-a-plate system was used for plant exposure to Aspergillus VOCs according to previously described methods [23]. A small Petri plate (35 × 1 mm) containing Aspergillus grown on YES was placed into a larger partitioned Petri dish (100 × 15 mm) containing five stratified Arabidopsis thaliana seeds.…”