title: Ecology of SO2resistance: III. Metabolic changes of C3and C4Atriplex species due to SO2fumigations.
abstract: The photosynthetic processes of two ecologically-matched, herbaceous Atriplex species differed in their response to SO2fumigations. Atriplex triangularis, a C3species, was more sensitive than the C4species, A. sabulosa. This difference in sensitivity can be attributed in part to the higher conductance of the C3species in normal air and saturating light as well as greater stimulation of stomatal opening following exposure to SO2. In addition, photosynthetic mechanisms of the C3species had higher intrinsic SO2sensitivity than the C4species. Differences between photosynthetic responses of these two species may also reflect differences in morphological configuration of mesophyll tissues and greater SO2sensitivity of the initial photosynthetic carboxlating enzyme of the C3species. It is likely that certain of the differences in photosynthetic SO2sensitivity of these contrasting C3and C4Atriplex species are characteristic of C3and C4plants in general.
authors.affiliation: Department of Biological Sciences, Stanford University, 94305, Stanford, California, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Winner
authors.affiliation: Department of Biological Sciences, Stanford University, 94305, Stanford, California, USA.
authors.forename: Harold A
authors.initials: HA
authors.lastname: Mooney