Ozone exposure alters temporal fluctuations of sup 14 C-labeled assimilate pools in leaves of Pinus taeda L

Conference · Wed May 01 04:00:00 EDT 1991 · Plant Physiology, Supplement; (United States)

OSTI ID:5512205

Friend, A L ^[1]; Tomlinson, P T ^[2]

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1. Mississippi State Univ., Mississippi State (United States)
2. North Central Forest Experiment Station, Rhinelander, WI (United States)

The effects of O{sub 3} on uptake and distribution of {sup 14}C within current-year foliage of 3-year-old loblolly pine (Pinus taeda L.) seedlings were studied using open-top exposure chambers that delivered ozone at three concentrations: sub-ambient O{sub 3} (charcoal-filtered air (CF)); ambient O{sub 3}(AMB); and twice-ambient O{sub 3} (2X). Seedlings were exposed to O{sub 3} from May to Oct. of 1987, 1988, and 1989. In July, Aug., and Sept. 1989, individual foliage fascicles were labeled with {sup 14}CO{sub 2}; harvested at 0, 0.5, 4, 24, and 48h after labeling; and analyzed for {sup 14}C in lipids and pigments, protein, starch, residue, sugars, organic acids, and amino acids. O{sub 3} affected initial (0 h) incorporation of {sup 14}C into different chemical fractions, and the relative distribution of {sup 14}C among fractions at specific points in time. Starch dynamics were particularly responsive to and negatively affected by O{sub 3}. In 2X treatments, only 39-46% of the initial (0 h) {sup 14}C incorporated into starch remained after 48h, compared with a range of 56-90% remaining in CF treatments. The percentage of {sup 14}C in the starch fraction after 48 h decreased by nearly three-fold in August from CF to 2X treatments (%total {sup 14}C in starch: 31% (CF), 17% (AMB), and 11% (2X)). The authors data indicated that foliar starch synthesis and/or retention was depressed by ozone exposure during late-season months, and supported the concept that O{sub 3} decreases growth by depleting carbohydrate reserves. Other findings will be discussed.

• OSTI ID: 5512205
• Report Number(s): CONF-9107184--
• Conference Information: Journal Name: Plant Physiology, Supplement; (United States) Journal Volume: 96:1
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
BIOSYNTHESIS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBOXYLIC ACIDS
CONIFERS
EXPOSURE CHAMBERS
GROWTH
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEAVES
LIPIDS
METABOLISM
ORGANIC ACIDS
ORGANIC COMPOUNDS
OZONE
PINES
PINOPHYTA
PLANT GROWTH
PLANTS
POLYSACCHARIDES
PROTEINS
REAGENTS
SACCHARIDES
SEEDLINGS
STARCH
SYNTHESIS
TOXICITY
TRACER TECHNIQUES
TREES