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dc.contributor.authorHarris, Fred S.
dc.contributor.authorMartin, Craig E.
dc.date.accessioned2012-06-06T17:01:20Z
dc.date.available2012-06-06T17:01:20Z
dc.date.issued1991
dc.identifier.citationHarris, F.S. and C.E. Martin. 1991. Correlation between CAM-cycling and photosynthetic gas exchange in five species of Talinum (Portulacaceae). Plant Physiol. 96: 1118-1124.
dc.identifier.urihttp://hdl.handle.net/1808/9867
dc.descriptionThis is the publisher's official version, also available electronically from: http:/​/​dx.​doi.​org/​10.​1104/​pp.​96.​4.​1118
dc.description.abstractPhotosynthetic gat exchange and malic acid fluctuations were monitored in 69 well-watered plants from five morphologically similar species of Talinum in an investigation of the ecophysiological significance of the Crassulacean acid metabolism (CAM)- cycling mode of photosynthesis. Unlike CAM, atmospheric C03 uptake in CAM-cycling occurs exclusively during the day; at night, the stomata are closed and respiratory C 0 2 is recaptured to form malic add. All species showed similar patterns of day-night gas exchange and overnight malic acid accumulation, confirming the presence of CAM-cycling. Species averages for gas exchange parameters and malic acid fluctuation were significantly different such that the species with the highest daytime gas exchange had the lowest malic acid accumulation and vice versa. Also, daytime CO2 exchange and transpiration were negatively correlated with overnight malic acid fluctuation for all individuals examined together, as well as within one species. This suggests that malic acid may effect reductions in both atmospheric CO: uptake and transpiration during the day. No significant correlation between malic acid fluctuation and water-use efficiency was found, although a nonsignificant trend of increasing water-use efficiency with increasing malic acid fluctuation was observed among species averages. This study provides evidence that C 0 2 recycling via malic acid is negatively correlated with daytime transpirational water losses In well-watered plants. Thus, CAM-cycling could be important for survival In the thin, frequently desiccated soils of rock outcrops on which these plants occur.
dc.language.isoen
dc.publisherAmerican Society of Plant Biologists
dc.titleCorrelation Between CAM-Cycling and Photosynthetic Gas Exchange in Five Species of Talinum (Portulacaceae)
dc.typeArticle
kusw.kuauthorHarris, Fred S.
kusw.kuauthorMartin, Craig E.
kusw.kudepartmentBotany
kusw.oastatusfullparticipation
kusw.oaversionScholarly/refereed, publisher version
kusw.oapolicyThis item meets KU Open Access policy criteria.
dc.rights.accessrightsopenAccess


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