Photosynthesis-rubisco relationship in foliage of Pinus sylvestris in response to nitrogen supply and the proposed role of rubisco and amino acid as nitrogen stores
2003
Warren , Charles R. (University of Western Australia(Australie).) | Dreyer , Erwin (INRA (France). UMR 1137 UMR INRA / Univ. Nancy 1 : Ecologie et Ecophysiologie Forestières) | Adams , Mark A. (University of Western Australia(Australie).)
Relationships between photosynthetic capacity, and needle contents of N, Rubisco and amino acids were investigated in potted Pinus sylvestris L. trees. Three-year-old seedlings of P. sylvestris were grown for 4 years with three nutrient regimes. Concentrations of N, amino acids, an-fides and Rubisco were measured and expressed on a needle area basis, and the in vivo performances of Rubisco (maximum rate of carboxylation, V-cmax) and of electron transport (maximum light driven electron flux, J(max)) were estimated via a biochemically based model of photosynthesis. Needle content of Rubisco-N was at least six times that of amino acid + amide-N and was positively related to N-area. The estimated in vivo specific activity of Rubisco (V-cmax/Rubisco content per unit area) was low and negatively related to N content per unit area (N-area). J(max)/Rubisco content was negatively related to N-area, whereas V-cmax/J(max) was unrelated to N-area. Hence, Rubisco content was in excess of the amount required for photosynthesis and this excess was positively related to Narea. These data support the hypothesis that with increasing N-area, Rubisco functions increasingly as a storage protein in addition to its catalytic functions.
显示更多 [+] 显示较少 [-]