Trichoderma gamsii affected herbivore feeding behaviour on Arabidopsis thaliana by modifying the leaf metabolome and phytohormones

Abstract

SummaryPlants can re‐programme their transcriptome, proteome and metabolome to deal with environmental and biotic stress. It has been shown that the rhizosphere microbiome has influence on the plant metabolome and on herbivore behaviour. In the present study, Trichoderma gamsii was isolated from Arabidopsis thaliana rhizosphere soil. The inoculation of roots of Arabidopsis thaliana with T. gamsii significantly inhibited the feeding behaviour of Trichoplusia ni and affected the metabolome as well as the content of phytohormones in Arabidopsis leaves. T. gamsii‐treated plant leaves had higher levels of amino acids and lower concentrations of sugars. In addition, T. gamsii‐treated plant leaves had more abscisic acid (ABA) and lower levels of salicylic acid (SA) and indole‐3‐acetic acid (IAA) in comparison with the untreated plants. Furthermore, the inoculation with T. gamsii on different signalling mutants showed that the induction of defences were SA‐dependent. These findings indicate that T. gamsii has potential as a new type of biocontrol agent to promote plant repellence to insect attacks.

TRICHODERMA-INDUCED SYSTEMIC RESISTANCE AGAINST THE SCALE INSECT (UNASPIS MABILIS LIT & BARBECHO) IN LANZONES (LANSIUM DOMESTICUM CORR.)

“…In addition, it was observed that uninoculated plants had significantly higher concentration of SA during the second and third observation periods (p<0.0005 for Week 2, and p=0.040 for Week 4). Earlier study by Zhou et al (2018) showed similar results. Lower SA concentration was observed in Trichoderma gamsii inoculated Arabidopsis plants that are subsequently infested with Trichoplusia ni than those that were not inoculated.…”

“…No significant difference in phenolic concentration between the two treatments in any of the observation periods was observed. In addition to the reduced SA concentration, Zhou et al (2018) also observed no significant difference in total phenolic between T. gamsii-inoculated and uninoculated T. ni-infested Arabidopsis plants.…”

Plant physical and chemical traits associated with herbivory in situ and under a warming treatment

“…Hence, a majority of the chemical signatures remains uncharacterized, which limits the understanding of the functions behind the ordination patterns (Da Silva et al, ). While our study suggests an association between metabolomic signature and herbivory, the development of novel machine learning approaches based on metabolomics reference databases could enable the classification of individual molecules and be more informative regarding the underlying physiological mechanisms (Blaženović, Kind, Ji, & Fiehn, ; Zhou, Huang, Guo, & dos‐Santos, and Vivanco, ).…”

Above‐ground plant metabolomic responses to plant–soil feedbacks and herbivory

“…Previous work in our laboratory using the same plant species growing in similar soil (but collected from the same field site several months earlier) showed that the composition of the bacterial and fungal communities depended on the species that conditioned the soil, and that there were clear differences between grass-and forb-conditioned soils (Heinen et al, 2018 metabolomes was due to, for example, pathogens, mycorrhiza or plant growth-promoting rhizobacteria remains to be tested. Other studies have shown, for example, that mycorrhiza (Schweiger et al, 2014) and beneficial soil bacteria can alter plant metabolomes (Zhou, Huang, Guo, dos-Santos, & Vivanco, 2018). We mixed the conditioned soil with sterilized soil to diminish the potential differences in conditioned soils in, for example, soil nutrient availability.…”