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Title: Capacity for C/sub 4/ photosynthesis among relatively advanced species of Flaveria. [Flaveria vaginata; Flaveria palmeri; Flaveria australasica; Flaveria bidentis; Flaveria trinervia]

Conference · · Plant Physiol., Suppl.; (United States)
OSTI ID:6073212

Leaves of 5 summer-grown Flaveria species, all thought to be C/sub 4/ plants, were exposed to /sup 14/CO/sub 2/ for 3-16 s. Analysis of /sup 14/C-products and extrapolation of labelling curves to zero time allowed estimation of the percentage of CO/sub 2/ incorporated via the C/sub 4/ cycle. This value was about 90% in F. vaginata and F. palmeri, 95% in F. australasica, 97% in F. bidentis, and 100% in F. trinervia. Localization of leaf carboxylases and decarboxylase was examined after purifying mesophyll and bundle sheath protoplasts by a simplified procedure. All species except F. trinervia showed some enrichment of RuBisCO to NADP-malic enzyme in mesophyll preparations. Mesophyll RuBisCO activities (up to 50 ..mu..mol/mg Chl x h) constituted less than or equal to7% of the total leaf RuBisCO (corrected for Chl distribution). Incomplete compartmentation of NADP-malic enzyme of direct entry of CO/sub 2/ into the bundle sheath may also occur in F. vaginata and F. palmeri. The data indicate that at least these 2 species (along with F. brownii from previous results) should be classified as less advanced, C/sub 4/-like species.

Research Organization:
Washington State Univ., Pullman
OSTI ID:
6073212
Report Number(s):
CONF-8707108-; TRN: 87-037213
Journal Information:
Plant Physiol., Suppl.; (United States), Vol. 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
Country of Publication:
United States
Language:
English