Details

Autor(en) / Beteiligte

• Adam, Neal R
• Wall, Gerard W
• Kimball, Bruce A
• Pinter, Paul J
• Lamorte, Robert L
• Hunsaker, Douglas J
• Adamsen, Floyd J
• Thompson, Tom
• Matthias, Allan D
• Leavitt, Steven W
• Webber, Andrew N

Titel

Acclimation response of spring wheat in a free-air CO2 enrichment (FACE) atmosphere with variable soil nitrogen regimes. 1. Leaf position and phenology determine acclimation response

Ist Teil von

• Photosynthesis research, 2000-01, Vol.66 (1-2), p.65

Ort / Verlag

Dordrecht: Springer Nature B.V

Erscheinungsjahr

2000

Quelle

SpringerLINK Contemporary (Konsortium Baden-Württemberg)

Beschreibungen/Notizen

• We have examined the photosynthetic acclimation of wheat leaves grown at an elevated CO^sub 2^ concentration, and ample and limiting N supplies, within a field experiment using free-air CO^sub 2^ enrichment (FACE). To understand how leaf age and developmental stage affected any acclimation response, measurements were made on a vertical profile of leaves every week from tillering until maturity. The response of assimilation (A) to internal CO^sub 2^ concentration (C^sub i^) was used to estimate the in vivo carboxylation capacity (Vc^sub max^) and maximum rate of ribulose-1,5-bisphosphate limited photosynthesis (A ^sub sat^). The total activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), and leaf content of Rubisco and the Light Harvesting Chlorophyll a/b protein associated with Photosystem II (LHC II), were determined. Elevated CO^sub 2^ did not alter Vc^sub max^ in the flag leaf at either low or high N. In the older shaded leaves lower in the canopy, acclimatory decline in Vc^sub max^ and A ^sub sat^ was observed, and was found to correlate with reduced Rubisco activity and content. The dependency of acclimation on N supply was different at each developmental stage. With adequate N supply, acclimation to elevated CO^sub 2^ was also accompanied by an increased LHC II/Rubisco ratio. At low N supply, contents of Rubisco and LHC II were reduced in all leaves, although an increased LHC II/Rubisco ratio under elevated CO^sub 2^ was still observed. These results underscore the importance of leaf position, leaf age and crop developmental stage in understanding the acclimation of photosynthesis to elevated CO^sub 2^ and nutrient stress.[PUBLICATION ABSTRACT]