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Flexibility in CO 2 — Fixation Pathway of a Highland Kalanchoë, Kalanchoë petitiana A. Rich.
Author(s) -
Fetene M.,
Lüttge U.,
Ziegler H.
Publication year - 1991
Publication title -
botanica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 0932-8629
DOI - 10.1111/j.1438-8677.1991.tb00244.x
Subject(s) - photosynthesis , crassulacean acid metabolism , carbon fixation , facultative , water stress , flexibility (engineering) , water use efficiency , carbon dioxide , ecology , botany , biology , environmental science , statistics , mathematics
Photosynthetic flexibility and water use efficiency of Kalanchoë petitiana A. Rich., a facultative CAM plant endemic to the highlands of Ethiopia, were investigated to determine the physiological determinants for the ecological success of the plant. Both field measurements of δ 13 C and greenhouse gas exchange studies showed a shift from C 3 photosynthesis to CAM as leaves aged or at the onset of water stress. Recycling of CO 2 was observed in developing leaves without concomitant net CO 2 uptake. Accumulation of malate was positively correlated with increased cell sap osmolality and improved daily water use efficiency. The importance of flexibility in carbon uptake pathway and of recycling CO 2 for the ecological success of the plant is discussed.