title: Metabolomic Responses of Guard Cells and Mesophyll Cells to Bicarbonate.
abstract: Anthropogenic CO2 presently at 400 ppm is expected to reach 550 ppm in 2050, an increment expected to affect plant growth and productivity. Paired stomatal guard cells (GCs) are the gate-way for water, CO2, and pathogen, while mesophyll cells (MCs) represent the bulk cell-type of green leaves mainly for photosynthesis. We used the two different cell types, i.e., GCs and MCs from canola (Brassica napus) to profile metabolomic changes upon increased CO2 through supplementation with bicarbonate (HCO3-). Two metabolomics platforms enabled quantification of 268 metabolites in a time-course study to reveal short-term responses. The HCO3- responsive metabolomes of the cell types differed in their responsiveness. The MCs demonstrated increased amino acids, phenylpropanoids, redox metabolites, auxins and cytokinins, all of which were decreased in GCs in response to HCO3-. In addition, the GCs showed differential increases of primary C-metabolites, N-metabolites (e.g., purines and amino acids), and defense-responsive pathways (e.g., alkaloids, phenolics, and flavonoids) as compared to the MCs, indicating differential C/N homeostasis in the cell-types. The metabolomics results provide insights into plant responses and crop productivity under future climatic changes where elevated CO2 conditions are to take center-stage.
authors.affiliation: Department of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL, 32610, United States of America.
authors.forename: Biswapriya B
authors.initials: BB
authors.lastname: Misra
authors.affiliation: Training Institute, Thermo Fisher Scientific, 1400 North point Parkway, Ste 10., West Palm Beach, FL, 33407, United States of America.
authors.forename: Evaldo
authors.initials: E
authors.lastname: de Armas
authors.affiliation: Department of Agricultural and Biological Engineering, University of Florida, PO Box 110570, Gainesville, FL 32611, United States of America.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Tong
authors.affiliation: Department of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL, 32610, United States of America.|Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32610, United States of America.
authors.forename: Sixue
authors.initials: S
authors.lastname: Chen
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis; D001639:Bicarbonates / Q000378:metabolism*; D029688:Brassica napus / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D058503:Mesophyll Cells / Q000378:metabolism*; D055442:Metabolome / Q000502:physiology*; D055432:Metabolomics; D054046:Plant Stomata / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001639:Bicarbonates; D002245:Carbon Dioxide