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Title: Effects of ozone on carbon allocation and partitioning in loblolly pine seedlings

Conference · · Plant Physiology, Supplement; (United States)
OSTI ID:5599000
 [1];  [2]
  1. North Central Forest Experiment Station, Rhinelander, WI (United States)
  2. Mississippi State Univ., Mississippi State (United States)

The effects of O{sub 3} on carbon allocation and partitioning were studied in two-year old loblolly pine (Pinus taeda L.) seedlings during the second season of exposure to charcoal-filtered air (CF) or twice-ambient levels of O{sub 3} (2X) in open-top chambers at Oak Ridge National Laboratory (Oak Ridge, TN). CF and 2X treatments were supplied from May to October in 1988 and 1989. Entire shoots were exposed to {sup 14}CO{sub 2} at times between Dec. 1988 and Aug. 1989: (1) during winter dormancy (no O{sub 3}), (2) just prior to spring bud burst (no O{sub 3}), and (3 and 4) during expansion of the first and third growth flushes (with O{sub 3}). Allocation and metabolism were most sensitive to ozonation in developing shoots. A greater amount of total plant {sup 14}CO{sub 2} was found in expanding buds and foliage of 2X-compared to CF-grown seedlings. More bud {sup 14}CO{sub 2} was partitioned into starch and a lower percentage into protein of 2X-compared to CF-grown seedlings. A greater percentage of foliage {sup 14}CO{sub 2} was found in starch and sugars of 2X-compared to CF-grown seedling. In general, O{sub 3} effects were greater during active shoot growth stages and few interactions between plant growth stage and O{sub 3} were identified. Allocation and metabolism of photosynthate within the plant was more strongly affected by stage of plant growth than by O{sub 3}.

OSTI ID:
5599000
Report Number(s):
CONF-9107184-; CODEN: PPYSA
Journal Information:
Plant Physiology, Supplement; (United States), Vol. 96:1; Conference: Annual meeting of the American Society of Plant Physiology, Albuquerque, NM (United States), 28 Jul - 1 Aug 1991; ISSN 0079-2241
Country of Publication:
United States
Language:
English