title: Combined effects of CO2 enrichment, diurnal light levels and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers.
abstract: Experiments were conducted in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers using plants grown in pots. Drought treatments were imposed on potato plants (Solanum tuberosum cv. Kennebec) beginning 10 days after tuber initiation. A total of 23 out of 37 foliar metabolites were affected by drought when measured 11 days after initiating water stress treatments. Compounds that accumulated in response to drought were hexoses, polyols, branched chain amino acids (BCAAs) and aromatic amino acids, such as proline. Conversely, leaf starch, alanine, aspartate and several organic acids involved in respiratory metabolism decreased with drought. Depending upon harvest date, a maximum of 12 and 17 foliar metabolites also responded to either CO2 enrichment or diurnal treatments, respectively. In addition, about 20% of the measured metabolites in potato leaflets were simultaneously affected by drought, CO2 enrichment and diurnal factors combined. This group contained BCAAs, hexoses, leaf starch and malate. Polyols and proline accumulated in response to water stress but did not vary diurnally. Water stress also amplified diurnal variations of hexoses and starch in comparison to control samples. Consequently, specific drought responsive metabolites in potato leaflets were dramatically affected by daily changes of photosynthetic carbon metabolism.
authors.affiliation: USDA-ARS, Crop Systems and Global Change Laboratory, Beltsville, MD, 20705, USA.
authors.forename: Jinyoung Y
authors.initials: JY
authors.lastname: Barnaby
authors.forename: David
authors.initials: D
authors.lastname: Fleisher
authors.forename: Vangimalla
authors.initials: V
authors.lastname: Reddy
authors.forename: Richard
authors.initials: R
authors.lastname: Sicher
mesh_terms: D002245:Carbon Dioxide / Q000494:pharmacology*; D002940:Circadian Rhythm / Q000187:drug effects* / Q000528:radiation effects; D003681:Dehydration; D055864:Droughts; D004777:Environment; D008027:Light; D055442:Metabolome / Q000187:drug effects* / Q000528:radiation effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D011198:Solanum tuberosum / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects; D013997:Time Factors; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D002245:Carbon Dioxide