title: Impacts of rising tropospheric ozone on photosynthesis and metabolite levels on field grown soybean.
abstract: The response of leaf photosynthesis and metabolite profiles to ozone (O3) exposure ranging from 37 to 116 ppb was investigated in two soybean cultivars Dwight and IA3010 in the field under fully open-air conditions. Leaf photosynthesis, total non-structural carbohydrates (TNC) and total free amino acids (TAA) decreased linearly with increasing O3 levels in both cultivars with average decrease of 7% for an increase in O3 levels by 10 ppb. Ozone interacted with developmental stages and leaf ages, and caused higher damage at later reproductive stages and in older leaves. Ozone affected yield mainly via reduction of maximum rate of Rubisco carboxylation (Vcmax) and maximum rates of electron transport (Jmax) as well as a shorter growing season due to earlier onset of canopy senescence. For all parameters investigated the critical O3 levels (∼50 ppb) for detectable damage fell within O3 levels that occur routinely in soybean fields across the US and elsewhere in the world. Strong correlations were observed in O3-induced changes among yield, photosynthesis, TNC, TAA and many metabolites. The broad range of metabolites that showed O3 dose dependent effect is consistent with multiple interaction loci and thus multiple targets for improving the tolerance of soybean to O3.
authors.affiliation: Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, United States. Electronic address: jindong.sun@gmail.com.
authors.forename: Jindong
authors.initials: J
authors.lastname: Sun
authors.affiliation: Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, United States.
authors.forename: Zhaozhong
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, United States; Global Change and Photosynthesis Research Unit, USDA/ARS, University of Illinois, Urbana, IL 61801, United States.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Ort
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000187:drug effects; D019069:Cell Respiration / Q000187:drug effects; D002734:Chlorophyll / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D010126:Ozone / Q000009:adverse effects*; D010788:Photosynthesis / Q000187:drug effects*; D010860:Pigments, Biological / Q000378:metabolism; D063245:Plant Development / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D013025:Glycine max / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000596:Amino Acids; D010860:Pigments, Biological; D002734:Chlorophyll; D010126:Ozone; D012273:Ribulose-Bisphosphate Carboxylase
keywords: Crop yield; Metabolites; Ozone; Photosynthesis; Soybean