Identification of bacterial volatiles that promotes plant growth through HS-SPME/GC-MS

• Grant number: 19/19121-9
• Support type: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): November 01, 2019
• Effective date (End): January 31, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal researcher: Juliana Velasco de Castro Oliveira
• Grantee: Bruno Henrique Silva Dias
• Supervisor abroad: Choong-Min Ryu
• Home Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovações (Brasil). Campinas , SP, Brazil
• Research place: Korea Research Institute of Bioscience & Biotechnology, Daejeon (KRIBB), South Korea
• Associated to the scholarship: 18/04184-2 - Analysis of bacterial volatiles as plant growth promoters, BP.MS

Abstract

Despite the advances on agricultural practices to feed the growing world, it is necessary to increase the global food production and energy adopting sustainable practices. Several plant growth-promoting bacteria (PGPB) can greatly increase crop yield through a wide variety of interaction mechanisms. Recently many studies are being conducted with volatile organic compounds (VOCs), which are small molecules of lipophilic nature derived from a wide range of biosynthetic pathways. These metabolites are capable of promoting plant growth and their use in agricultural crops is promising, since they do 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 thaliana, 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 C4 plants and important agricultural crops, opening perspectives to new discoveries. One of the most precise and used platform for VOCs identification is based on gas chromatography-mass spectrometry, but the establishment of a robust methodology to allow the identification of these bacterial VOCs is not trivial, being time-consuming and demanding intensive lab effort. Previously, we have tested 14 bacterial strains from our microorganism collection to evaluate the potential of different genera of bacteria in growth promotion of C3 A. thaliana and C4 Setaria viridis model plants mediated by VOCs. From 14 isolates tested, 8 increased the growth of our plants: MTS P6A5 and CRD P6B3 in A. thaliana; ITA P2F2 and FBJ P1E2 S. viridis; MTS P5D6, IAT P3B1, IAT P6F4 and AI2.2-A in both model plants. In addition, we identified an isolate (CTB P6B8) that had an antagonistic effect on the growth of C3 model plant. Our best strains, even under conditions of low nutrient availability, were capable to induce shoot and root growth. Based on these results, it is necessary to identify the VOCs emitted by these bacteria. Thus, the aim of this project is to learn and carry out the identification of the volatiles from nine strains that promote plant growth at Dr. Choong-Min Ryu's research group. In 2003, his group was the pioneer in evaluate and characterize bacterial VOCs as plant growth promoters and in 2017, his group has published the first procedure for metabolome-based bacterial VOC profiling via HS-SPME/GC-MS on Nature Protocols. This group has great expertise with identification and validation of bacterial VOCs and have been worldwide recognized and referenced for their contribution in its biology knowledge, especially in relation to plant-plant/microbe communication, microbe-microbe interactions and discovery of novel bioactive compounds. At the end of this internship, the knowledge acquired will be useful to identify several molecules involved in plant growth promotion. The findings can help 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)