The gliotoxin is a diketopiperazine produced by T. viride, T. hamatum, and
T. virens that is very effective against R. solani; this compound also has properties
as an antiviral and antibacterial [16, 98]. T. virens also produces gliovirin, a heterocyclic nitrogen- and sulfur-containing compound of the diketopiperazine class,
which is effective against Pythium ultimum [99]. Lignoren is a cyclonerodiolderived compound produced by Trichoderma lignorum, with moderate antibacterial activity against Bacillus subtilis and Pseudomonas aeruginosa but no
fungistatic nor fungicide activity against Candida albicans, Fusarium culmorum,
or Penicillium notatum [100]. T. harzianum produces the antibiotic T22azaphilone,
which possess an oxygenated bicyclic core, inhibiting the growth of
Gaeumannomyces graminis, P. ultimum, and R. solani [101]. Trichosetin also
has antibacterial activity against Bacillus subtilis and Staphylococcus aureus
[102]. T. koningii and T. viride produce trichoviridin, a cyclopentyl isocyanide
compound [103–105]. Trichodermamides A and B are two modified dipeptides
produced by T. virens [16].
4
Multiple Functions of Fungal Secondary Metabolites
Rhizospheric fungi produce a diversity of VOCs, and the majority of those metabolites are hydrocarbons comprising dozens of carbon skeletons that can form
oxygenated sesquiterpenes [6, 106]. Volatile sesquiterpenes are 15-carbon isoprenoids and constitute a structurally diverse family of natural compounds with
different regio- and stereochemistry (Fig. 8). Due to the wide variety of biochemical
functions in organisms, such as antimicrobial, antifungal, herbicidal, and hormonal
activities, many of these compounds have been found to be useful for medicines,
pesticides, fragrances, and flavors [107, 108]. A recent comparative study among the
VOCs produced by T. atroviride IMI 206040, T. reesei QM6a, and T. virens Gv298 revealed substantial differences in the chemical composition [6]. In that work,
fungal species mainly produced oxylipins and terpenes. Volatile sesquiterpenes from
T. atroviride P1 have been detected, among them α-farnesene, β-farnesene,
nerolidol, γ-curcumene, α-zingiberene, β-bisabolene, and α-bergamotene [109].
More recently, it was reported that T. virens produces a rich blend of isoprenoid
terpenes such as β-caryophyllene, (-)-β-elemene, germacrene D, τ-cadinene,
α-amorphene, τ-selinene, δ-cadinene, etc. [6, 110]. Figure 8 shows some volatile
terpenes produced by fungi, and the majority of them have been reported in several
Trichoderma strains.
The chemical profile of VOCs from T. viride revealed that the fungus produces
the aldehydes 2-methylpropanal, butanal; the isomers 2- and 3-methylbutanal
and pentanal; and the terpenes limonene, β-himachalene, farnesene, and
aromadendrene. Interestingly, Arabidopsis thaliana seedlings exposed to
T. viride VOCs increased both the shoot and root biomass, and that effect was
correlated with the accumulation of total chlorophyll [111]. More recently, it was
reported that VOCs from T. asperellum T-34 and T. harzianum T-78 increased the
expression of the transcription factor MYB72, which plays a dual role in the
278
H. A. Contreras-Cornejo et al.
T. virens that is very effective against R. solani; this compound also has properties
as an antiviral and antibacterial [16, 98]. T. virens also produces gliovirin, a heterocyclic nitrogen- and sulfur-containing compound of the diketopiperazine class,
which is effective against Pythium ultimum [99]. Lignoren is a cyclonerodiolderived compound produced by Trichoderma lignorum, with moderate antibacterial activity against Bacillus subtilis and Pseudomonas aeruginosa but no
fungistatic nor fungicide activity against Candida albicans, Fusarium culmorum,
or Penicillium notatum [100]. T. harzianum produces the antibiotic T22azaphilone,
which possess an oxygenated bicyclic core, inhibiting the growth of
Gaeumannomyces graminis, P. ultimum, and R. solani [101]. Trichosetin also
has antibacterial activity against Bacillus subtilis and Staphylococcus aureus
[102]. T. koningii and T. viride produce trichoviridin, a cyclopentyl isocyanide
compound [103–105]. Trichodermamides A and B are two modified dipeptides
produced by T. virens [16].
4
Multiple Functions of Fungal Secondary Metabolites
Rhizospheric fungi produce a diversity of VOCs, and the majority of those metabolites are hydrocarbons comprising dozens of carbon skeletons that can form
oxygenated sesquiterpenes [6, 106]. Volatile sesquiterpenes are 15-carbon isoprenoids and constitute a structurally diverse family of natural compounds with
different regio- and stereochemistry (Fig. 8). Due to the wide variety of biochemical
functions in organisms, such as antimicrobial, antifungal, herbicidal, and hormonal
activities, many of these compounds have been found to be useful for medicines,
pesticides, fragrances, and flavors [107, 108]. A recent comparative study among the
VOCs produced by T. atroviride IMI 206040, T. reesei QM6a, and T. virens Gv298 revealed substantial differences in the chemical composition [6]. In that work,
fungal species mainly produced oxylipins and terpenes. Volatile sesquiterpenes from
T. atroviride P1 have been detected, among them α-farnesene, β-farnesene,
nerolidol, γ-curcumene, α-zingiberene, β-bisabolene, and α-bergamotene [109].
More recently, it was reported that T. virens produces a rich blend of isoprenoid
terpenes such as β-caryophyllene, (-)-β-elemene, germacrene D, τ-cadinene,
α-amorphene, τ-selinene, δ-cadinene, etc. [6, 110]. Figure 8 shows some volatile
terpenes produced by fungi, and the majority of them have been reported in several
Trichoderma strains.
The chemical profile of VOCs from T. viride revealed that the fungus produces
the aldehydes 2-methylpropanal, butanal; the isomers 2- and 3-methylbutanal
and pentanal; and the terpenes limonene, β-himachalene, farnesene, and
aromadendrene. Interestingly, Arabidopsis thaliana seedlings exposed to
T. viride VOCs increased both the shoot and root biomass, and that effect was
correlated with the accumulation of total chlorophyll [111]. More recently, it was
reported that VOCs from T. asperellum T-34 and T. harzianum T-78 increased the
expression of the transcription factor MYB72, which plays a dual role in the
278
H. A. Contreras-Cornejo et al.