Bacillus subtilis can modulate the growth and root architecture in soybean through volatile organic compounds

Abstract

Bacillus subtilis colonizes rhizosphere of plants and releases some volatile organic compounds (VOCs) that can modulate the growth and root architecture in several plants. However, the influence of VOCs on growth and root architecture in soybean remains unknown. In this study, we hypothesized that VOCs would enhance the growth of soybean and change its root architecture. Thus, experiments under growth chamber were carried out to investigate the effect of VOCs released by B. subtilis AP-3 on growth and root architecture of soybean (control and plants exposed to VOCs) and eight replicates. Plant growth and root architecture parameters in soybean were measured 20 days after soybean emergence. Soybean exposed to microbial VOCs displayed significant increase in plant biomass (88% and 18% for shoot and roots, respectively) than the control. Microbial VOCs changed the root architecture of soybean that exhibited roots with higher length, diameter, surface area, and volume. The principal component analysis differentiated plants exposed to VOCs from those plants without exposure. The findings from this study are important since the modulation of root architecture can improve the absorption of water and nutrients from the soil.