Sunday, August 12, 2012
Columbia Hall, Terrace Level (Washington Hilton)
Volatile organic compounds (VOCs) produced by Trichoderma viride have recently been shown to have plant growth promoting effects on Arabidopsis thaliana. This finding adds a new facet to the multiple methods in which fungi in the genus Trichoderma promote plant health. These properties of Trichoderma make it beneficial to humans. GCMS analysis of the VOCs produced by T. viride has resulted in 51 identified compounds. Several compounds from the GCMS data were chosen to determine the effects of individual compounds on the health of A. thaliana. Preliminary experiments have demonstrated a wide range of effects and unique issues with testing. The testing conditions have been changed from those used in previous experiments to compensate for the physical properties of the compounds that were tested. At low concentrations, some compounds sink towards the bottom of the testing vessel, exposing the plants to a higher concentration of the volatile than intended. Agitation has been introduced to resolve this issue. The compound trans-2-octenol at concentrations of 1ppm caused decreased dry weight (14% less than control) and extended root length (16% longer than control), indicative of stress. At 1 and 10ppm, the compound 2,5-dimethylfuran, which has been reported to be produced by Trichoderma but was not found in the aforementioned GCMS analysis, caused only visual differences. The exposed A. thaliana had extended stems as compared to controls but no other differences. The individual compounds of the T. viride volatile profile have varied effects on A. thaliana as compared to the naturally derived mixture.