Abstract
BackgroundMany Trichoderma species are applied as biofungicides and biofertilizers to agricultural soils to enhance crop growth. These filamentous fungi have the ability to reduce plant diseases and promote plant growth and productivity through overlapping modes of action including induced systemic resistance, antibiosis, enhanced nutrient efficiency, and myco-parasitism. Trichoderma species are prolific producers of many small metabolites with antifungal, antibacterial, and anticancer properties. Volatile metabolites of Trichoderma also have the ability to induce resistance to plant pathogens leading to improved plant health. In this study, Arabidopsis plants were exposed to mixtures of volatile organic compounds (VOCs) emitted by growing cultures of Trichoderma from 20 strains, representing 11 different Trichoderma species.ResultsWe identified nine Trichoderma strains that produced plant growth promoting VOCs. Exposure to mixtures of VOCs emitted by these strains increased plant biomass (37.1–41.6 %) and chlorophyll content (82.5–89.3 %). Trichoderma volatile-mediated changes in plant growth were strain- and species-specific. VOCs emitted by T. pseudokoningii (CBS 130756) were associated with the greatest Arabidopsis growth promotion. One strain, T. atroviride (CBS 01-209), in our screen decreased growth (50.5 %) and chlorophyll production (13.1 %). Similarly, tomatoes exposed to VOCs from T. viride (BBA 70239) showed a significant increase in plant biomass (>99 %), larger plant size, and significant development of lateral roots. We also observed that the tomato plant growths were dependent on the duration of the volatile exposure. A GC–MS analysis of VOCs from Trichoderma strains identified more than 141 unique compounds including several unknown sesquiterpenes, diterpenes, and tetraterpenes.ConclusionsPlants grown in the presence of fungal VOCs emitted by different species and strains of Trichoderma exhibited a range of effects. This study demonstrates that the blend of volatiles produced by actively growing fungi and volatile exposure time in plant development both influence the outcome of volatile-mediated interactions. Only some of our growth promoting strains produced microbial VOCs known to enhance plant growth. Compounds such as 6-pentyl-2H-pyran-2-one were not common to all promoting strains. We found that biostimulatory strains tended to have a larger number of complex terpenes which may explain the variation in growth induced by different Trichoderma strains.
Highlights
Many Trichoderma species are applied as biofungicides and biofertilizers to agricultural soils to enhance crop growth
We identified nine strains representing six different species that promoted Arabidopsis growth: T. aggressivum; T. asperellum (GJS 02-65); T. harzianum (CBS 226.95); T. longibrachiatum; T. pseudokoningii; and T. viride (GJS 04-379)
The strongest volatile-mediated plant effects were observed in T. aggressivum (IMI 393970) with an increase of 37.1 % in fresh shoot weight and 82.5 % in chlorophyll and in T. pseudokoningii (CBS 130756) with an increase of 41.6 and 89.3 %, respectively
Summary
Many Trichoderma species are applied as biofungicides and biofertilizers to agricultural soils to enhance crop growth These filamentous fungi have the ability to reduce plant diseases and promote plant growth and productivity through overlapping modes of action including induced systemic resistance, antibiosis, enhanced nutrient efficiency, and myco-parasitism. Several Trichoderma species have the ability to reduce plant diseases and promote plant growth and productivity by utilizing overlapping modes of action including induced systemic resistance [3, 4], antibiosis [5], enhanced nutrient efficiency [6], and myco-parasitism [7, 8]. Trichoderma species are prolific producers of many small metabolites with medical and agricultural significance [13, 14] Secondary metabolites such as peptaibols and polyketides exhibit antifungal, antibacterial, and anticancer properties; induce resistance to plant pathogens; or serve as toxins [14, 15]. Little is known about the metabolic origin of these compounds in fungi but in plants, similar volatiles are produced as breakdown products of fatty acids, others are biotransformation products of molecules produced in central metabolism while the terpenes are secondary metabolites [19, 20]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
