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ARS Home » Research » Publications at this Location » Publication #97566
Title: THE INFLUENCE OF CARBON DIOXIDE ENRICHMENT AND NITROGEN STRESS ON CARBOXYLATION EFFICIENCIES AND RUBISCO ACTIVITIES IN WHEAT

Author
item Adam, Neal
item Wall, Gerard
item Kimball, Bruce
item Pinter Jr, Paul
item Adamsen, Floyd
item La Morte, Robert
item LEAVITT, S. - UNIV. OF ARIZONA
item WEBBER, A. - ARIZONA STATE UNIV.

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/19/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Field-grown spring wheat (triticum aestivum L. cv. Yecora Rojo) was exposed to carbon dioxide (CO2) concentrations enriched to 200ppm above ambient (ca. 370ppm) control plots using free-air CO2 enrichment (FACE) apparatus (main plot). Half of each main CO2 plot received ample nitrogen levels of ~350 kg N ha-1, while the other half received ~70 kg N ha-1. Measurements of photosythesis (A) at a range of intercellular CO2 levels (Ci) were made throughout the season on the three uppermost, fully-exposed leaves of the main stem. Biochemical analyses were also conducted on these leaves. Treatment effects on activities of Rubisco and quantities of the large and small subunits of Rubisco protein were similar to treatment effects on the carboxylation efficiencies calculated from the A-Ci relationship. Leaves from both ample and low nitrogen treatments showed reductions in each parameter as a result of CO2 enrichment, indicating that tacclimation of the photosynthetic apparatus to CO2 enrichment occurred. Leaves lower in the canopy showed more pronounced changes in each parameter.