Analysis of volatile organic compounds emitted by plant growth-promoting fungus Phoma sp. GS8-3 for growth promotion effects on tobacco,”Microbes and Environments

We extracted volatile organic compounds (VOCs) emitted by a plant growth-promoting fungus (PGPF) Phoma sp. GS8-3 by gas chromatography and identified them by mass spectrometry. All of the identified compounds belonged to C4-C8 hydrocarbons. Volatiles varied in number and quantity by the culture period of the fungus (in days). 2-Methyl-propanol and 3-methyl-butanol formed the main components of the volatile blends for all the culture periods of fungus. Growth-promoting effects of the identified synthetic compounds were analyzed individually and in blends using tobacco plants. We found that the mixture of volatiles extracted from 3-day-old culture showed significant growth promotion in tobacco in vitro. The volatile blend showed better growth promotion at lower than higher concentrations. Our results confirm the potential role of volatile organic compounds in the mechanism of growth enhancement by GS8-3. Key words: in vitro, Phoma sp. GS8-3, plant growth-promoting fungus, tobacco, volatile organic compounds Plant growth is influenced by an abundance of abiotic and biotic factors. Plant growth hormones dominatingly affect plant growth, whereas the photosynthetic rate is dominated by temperature, irradiance and gaseous atmosphere (16). These physiological functions have been utilized as classical plant growth regulators; however, along with the compositio