LB 39-361 - Effects of microbial desert scents on plant germination and growth

Soil microbes play an important role in dryland ecology and in soil-plant communications. These microbes produce secondary metabolites, such as volatile organic compounds (VOCs), that can signal nutrition availability, proximity of pathogens, and general stress to their residing plant counterparts. Despite their importance, their function in plant growth and establishment is not fully understood, especially in the context of dryland restoration. Our research aims to analyze the effects of microbial VOCs on plant germination and growth. This research is important in contributing to our understanding of soil microbe-plant interactions, especially in the field of dryland grass restoration as grasses are notoriously difficult to restore. Therefore, our work can provide insight into the role of microbial VOCs in plant seedling emergence and growth.

To investigate microbial VOCs, we isolated 24 soil microbial species of bacteria and fungi from soil samples between (i.e., interspace) and under desert plant vegetation (i.e., under-space). Microbes were grown in vitro alongside Arabidopsis thaliana. Our hypothesis that VOCs from interspace microbes will have hindering effects on plant germination was confirmed from microbe species such as Bacillus mycoides, while under-space microbes such as Arthrobacter agilis, had growth-promoting effects. With the results of the microbial and plant growth assays, analytical chemistry through SPME-GCMS will be performed to classify VOCs from microbes that showed the greatest effect (positive and negative) on plant growth. Our work has important implications for restoration practices of dryland ecosystems and is contributing to the growing knowledge of volatile-mediated microbial-plant interactions.