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Georgia Tooulakou : Metabolomics in Systems Biology for investigating plant response mechanisms to abiotic stresses

Seminar: Aquatic Biology

2019.05.23 | Anne Kirstine Mehlsen

Date Mon 03 Jun
Time 09:45 10:15
Location Department of Bioscience, Ole Worms Alle 1, building 1135-234

Speaker: Georgia Tooulakou, Metabolic Engineering and Systems Biology Laboratory, Institute of Chemical Engineering Sciences, Foundation for Research & Technology-Hellas (FORTH/ICE-HT), Patras, Greece).

ABSTRACT:

 

Climate change and the ever increasing needs for large amounts of agro-biotechnological products of uncompromised consistent quality have led to a substantial increase of systematic studies investigating the effect of abiotic stresses (e.g. salinity, carbon starvation, drought, temperature) on plant molecular physiology. Ιn the systems biology era, omic analyses enabled a holistic profiling of the plant molecular physiology at various levels of the genetic information flow (i.e. transcriptional, translational, metabolic, phenotypic), supporting the study of cellular function as a dynamic network of biomolecular networks. Metabolomic analysis in systems biology refers to the investigation of the dynamics of the metabolic physiology regulation of a biological system (i.e. cell culture, tissue or biofluid) through the comparative investigation of the concentration profile of its free metabolites at various physiological conditions in the context of the reconstructed metabolic pathway network. Metabolomics in systems biology has been successfully applied to the study of molecular phenotypes of plants in response to abiotic stresses in order to find molecular mechanisms underlying stress tolerance and/or identify characteristic multi-compound profiles that could be used for early diagnosis of stress effects and suggestions of potential actions that could counteract them. While very powerful in providing a broad perspective of the plant metabolic physiology dynamics, the broad deployment of metabolomics requires its standardization in the context of various plant systems and stress conditions for an effective and consistent performance.

In this presentation, I will first describe the multi-step procedure of untargeted Gas Chromatography – Mass Spectrometry (GC-MS) metabolomics in systems and network biology, indicating the steps in the experimental design, pre-analytical, analytical and computational part that require special care to enable the extraction of accurate biological conclusions about the plant system under investigation. In sequence, I will present the value of metabolomic analysis in systems biology for studying the effect of abiotic stresses in plants in the context of two collaborative projects of our laboratory. The first study concerns the elucidation of the role of calcium oxalate (CaOx) crystals in plants as CO2 providers under water stress conditions integrating plant physiological measurements with untargeted GC-MS metabolomics. This discovery is significant, indicating a currently unknown photosynthetic path, which we called “Alarm Photosynthesis” [1,2]. This new photosynthetic path seems to provide a number of adaptive advantages in water deficit conditions (drought, salinity) (i) water economy (ii) limitation of carbon losses and (iii) a lower risk of photoinhibition. In the second nationally funded collaborative study, we investigated whether metabolic profiling analysis could diagnose salinity stress effects in tomato plants (Solanum lycopersicum) in the controlled environment of a commercial greenhouse, much earlier than the standard physiological measurements. I will conclude by discussing how these techniques and perspective applied to ecology is evolving into the new research field of Eco-Metabolomics.

 

[1] Tooulakou G et. al. 2016. Plant Physiol. 171: 2577-85.

[2] Tooulakou  G et al. 2018. Physiol. Plant. 10.1111/ppl.12843

Department of Bioscience, Public / media, Staff