HS-GC/MS platform for the analysis of plant growth promoter volatiles

Abstract

Despite the advances on agricultural practices to feed the growing world, it is necessary to increase the global food production adopting sustainable practices. Several plant growth-promoting bacteria can greatly increase crop yield through a wide variety of interaction mechanisms. Recently, our group have isolated more than 7,000 bacteria from sugarcane roots or cultivated soil in different regions, and about 100 were able to produce higher quantity of the hormone auxin and/or solubilize phosphate. These features are well-established as pathways that lead to plant growth. Furthermore, in a preliminary assay, we were able to identify species producing volatile organic compounds (VOCs), which were able to promote plant growth. The use of microorganisms VOCs to promote plant growth is promising, since it does not depend on the direct contact and plant colonization, making them ideal molecules for mediating short- and long-distance organism interactions. In model plants, such as Arabidopsis, bacterial VOCs has been recently considered as an important feature to enhance plant growth and health. However, so far, there are only very few studies showing the impact of bacterial VOCs on important agricultural crops, opening perspectives to new discoveries. One of the more precise and used platform that allow these VOCs profiles identification is based on metabolomics, but the establishment of a robust technology to allow the identification of these bacterial VOCs is not trivial, being time-consuming and demanding intensive lab effort. The main objectives of this project are to: (i) establish a metabolomics robust pipeline based on HS-GC/MS to identify and quantify VOCs, (ii) evaluate the potential of different bacteria genera from our collection to promote plant growth mediated by VOCs, (iii) test these VOCs efficiency in relevant Brazilian agricultural crops, and (iv) identify if specific VOCs can promote the plant growth. As a long-term goal, we expect to develop bioinoculants as a sustainable approach to replace or reduce chemical supplies and increase plant productivity as well as reduce food production costs. (AU)