caa a22 4500 477100481 CHVBK 20180405111539.0 cr unu---uuuuu 170330e19960101xx s 000 0 eng 10.1007/BF00197597 doi (NATIONALLICENCE)springer-10.1007/BF00197597 Hikosaka Kouki Department of Botany, Faculty of Science, University of Tokyo, Hongo, Bunkyo-ku, 113, Tokyo, Japan aut Effects of leaf age, nitrogen nutrition and photon flux density on the organization of the photosynthetic apparatus in leaves of a vine ( Ipomoea tricolor Cav.) grown horizontally to avoid mutual shading of leaves [Elektronische Daten] [Kouki Hikosaka] Effects of leaf age, nitrogen nutrition and photon flux density (PFD) on the organization of the photosynthetic apparatus in leaves were investigated in a vine, Ipomoea tricolor Cav., which was grown horizontally so as to avoid mutual shading of leaves. The plants were grown hydroponically at two nitrate levels under two growth light treatments. For one group of the plants, leaves were exposed to full sunlight. For another group, respective leaves were artificially shaded in a manner that simulated changes in the light gradient with the development of an erect herbaceous canopy: old leaves were placed under progressively shadier conditions with growth of the plants (canopy-type shading). In all the treatments, chlorophyll (Chl) content gradually decreased with leaf age. Photosystem I (PSI) per Chl was constant, independent of leaf age, nitrogen nutrition and/or PFD. Photosystem II (PSII) and cytochrome / per Chl, and Chl a/b ratio were independent of leaf age and/or nitrogen nutrition but decreased with the decrease in growth PFD. Ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39, RuBPCase) per Chl steeply decreased with decrease in PFD. When leaves grown at the same PFD were compared, RuBPCase/Chl was lower in the plants grown under lower nitrogen availability and also decreased with leaf age in the plants grown without shading. These decreases were attributed to the curvilinear relationship between RuBPCase and Chl in leaves grown at full sunlight, that was independent of nitrogen availability and leaf age. From these results, it is concluded that the composition of the photosynthetic apparatus is independent of leaf age but changes depending on the light environment and total amount of photosynthetic components of the leaf. Springer-Verlag, 1996 Acclimation (photosynthesis) nationallicence Leaf age nationallicence Nitrogen availability nationallicence Photosynthetic apparatus nationallicence Senescence nationallicence Ipomoea nationallicence Chl : chlorophyll nationallicence cyt f : cytochrome f nationallicence PFD : photon flux density nationallicence RuBPCase : ribulose-1,5-bisphosphate carboxylase nationallicence Planta Springer-Verlag 198/1(1996-01-01), 144-150 0032-0935 198:1<144 1996 198 425 https://doi.org/10.1007/BF00197597 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00197597 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Hikosaka Kouki Department of Botany, Faculty of Science, University of Tokyo, Hongo, Bunkyo-ku, 113, Tokyo, Japan aut NATIONALLICENCE 773 0- Planta Springer-Verlag 198/1(1996-01-01), 144-150 0032-0935 198:1<144 1996 198 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 472754335 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer