The ability of some species of the genus Senecio to perform Crassulacean acid metabolism (CAM) in plants growing both under controlled conditions and outdoors and the anatomy of their photosynthesizing organs, leaves, and/or stems were investigated. The studied species differed in leaf morphology and in degrees of leaf and stem succulence. Malate accumulation differed with environmental conditions. The carbon isotope ratio d13C indicated that, in most of the species, the C3 carboxylation pathway was operating, although malate fluctuations indicated that CAM cycling occurred. In some species, carbon isotope ratios ranged between C3 and C4 values, indicating switching of photosynthetic pathways. Only two leafless species that were apparently obligate CAM species had a d13C typical of plants assimilating CO2 through the phosphoenolpyruvate carboxylase pathway.
Anatomy of succulence and CAM in 15 species of Senecio
FIORETTO, Antonietta;
1988
Abstract
The ability of some species of the genus Senecio to perform Crassulacean acid metabolism (CAM) in plants growing both under controlled conditions and outdoors and the anatomy of their photosynthesizing organs, leaves, and/or stems were investigated. The studied species differed in leaf morphology and in degrees of leaf and stem succulence. Malate accumulation differed with environmental conditions. The carbon isotope ratio d13C indicated that, in most of the species, the C3 carboxylation pathway was operating, although malate fluctuations indicated that CAM cycling occurred. In some species, carbon isotope ratios ranged between C3 and C4 values, indicating switching of photosynthetic pathways. Only two leafless species that were apparently obligate CAM species had a d13C typical of plants assimilating CO2 through the phosphoenolpyruvate carboxylase pathway.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
