Profile of biogenic volatile organic compounds (BVOC) emission and main metabolomic responses to air pollutants in two Atlantic Forest remnants in SP, Brazil

Abstract

Plants need to deal with different types of biotic and abiotic stresses. In large urban areas, a very common abiotic stress faced by plants is air pollutants, which can trigger an explosion of reactive oxygen species (ROS) in plant tissue. Increased level of ROS within cells leads to oxidative stress. It is known that plants have different antioxidant defense mechanisms involved in ROS neutralization under oxidative stress conditions, which can be enzymatic or non-enzymatic. Several classes of metabolites produced by plants - such as phenolic compounds and biogenic volatile organic compounds (BVOC) - can act as non-enzymatic antioxidants. When subjected to atmospheric pollutants, plants can alter their levels of these compounds to deal with the oxidative stress. Therefore, ecometabolomics, a research area that uses nontargeted metabolomics techniques, especially liquid chromatography-mass spectrometry (LC-MS), to study the responses, acclimation, and adaptation of living organisms in ecological interactions, such as those that occur in plants subject to air pollution, is a powerful tool for understanding the responses of the plant metabolome to different environmental situations. Native species of the Atlantic Forest can be found in different remnants surrounding and inside the Metropolitan Area of São Paulo (MASP). MASP is one of the largest megacities in the world and, as well as other megacities also faces problems due to air pollution. In this way, to fill the gaps in knowledge about plant defense responses to this abiotic stress quite common in megacities, and how these defenses, in turn, influence atmospheric chemistry, a Franco-Brazilian partnership has been established since 2015, resulting in the BIOgenic emissions, chemistry and impacts in the Metropolitan Area of São Paulo (BIOMASP+) project. The BIOMASP+ project took the MASP as a target natural laboratory to reduce gaps in the knowledge of the atmospheric processes resulting from the complex anthropogenic and biogenic urban mixing. Thus, the aim of the present proposal for internship is to understand the metabolic responses of the most representative plant species from two Atlantic Forest remnants with different levels of atmospheric pollution influence, especially in relation to the production of biomarkers of urban stress. It is proposed to carry out this research internship at the University of California Riverside (UC Riverside) because the Functional Metabolomics Lab, where Prof. Dr. Daniel Petras is the principal investigator, is well-equipped with all the equipment necessary for the proposed analyses in this research project. Prof. Dr. Daniel Petras has been working on research involving the combination of natural products, mass spectrometry-based metabolomics, and chemical biology. Additionally, he is one of the developers of Feature-Based Molecular Network (FBMN) analysis in the Global Natural Product Social Molecular Network (GNPS) - GNPS is an open-access online platform that assists in the annotation of compounds detected by mass spectrometry -, a valuable tool in untargeted metabolomics analyses. Therefore, this internship also provides a great opportunity to have specialized supervision in this growing field of research.