scholarly journals Origin and mechanism of crassulacean acid metabolism in orchids as implied by comparative transcriptomics and genomics of the carbon fixation pathway

2016 ◽  
Vol 86 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Liangsheng Zhang ◽  
Fei Chen ◽  
Guo-Qiang Zhang ◽  
Yong-Qiang Zhang ◽  
Shance Niu ◽  
...  
Keyword(s):  
Crassulacean Acid Metabolism ◽  
Carbon Fixation ◽  
Acid Metabolism ◽  
Comparative Transcriptomics

Use of infrared thermography for monitoring crassulacean acid metabolism

2017 ◽  
Vol 44 (1) ◽  
pp. 46 ◽  
Author(s):  
Bronwyn J. Barkla ◽  
Timothy Rhodes
Keyword(s):  
Water Use Efficiency ◽  
Infrared Thermography ◽  
Water Use ◽  
Crassulacean Acid Metabolism ◽  
Crop Production ◽  
Molecular Mechanisms ◽  
Carbon Fixation ◽  
Acid Metabolism ◽  
Cam Plants ◽  
Use Efficiency

Crassulacean acid metabolism (CAM) is an alternative carbon fixation pathway that imparts high water-use efficiency in plants adapted to warm, semiarid climates. With concerns that global warming will negatively influence crop production, turning agricultural focus towards CAM plants may provide a solution to increase productivity using either unconventional crops on marginal land or incorporating CAM molecular mechanisms into conventional crops and improving water-use efficiency. For this to be feasible, deeper insights into CAM pathway regulation are essential. To facilitate this research new tools which simplify procedures for detecting and measuring CAM are needed. Here we describe a non-invasive, non-destructive, simplified method using infrared thermography for monitoring CAM in the annual desert succulent Mesembryanthemum crystallinum L. via detection of changes in leaf temperature brought about by the absence of transpiration due to daytime reduction in stomatal conductance. This method is sensitive, measuring temperature differences of ± 1°C, can be used in both the field and green house and is not restricted by leaf architecture. It offers an alternative to the commonly used gas exchange methods to measure CAM that are technically difficult to acquire and require the use of expensive and cumbersome equipment.

Photosynthetic and anatomical characteristics in the C4–crassulacean acid metabolism-cycling plant Portulaca grandiflora

2002 ◽  
Vol 29 (6) ◽  
pp. 763 ◽  
Author(s):  
Lonnie J. Guralnick ◽  
Gerald Edwards ◽  
Maurice S. B. Ku ◽  
Brandon Hockema ◽  
Vince Franceschi
Keyword(s):  
Water Stress ◽  
Crassulacean Acid Metabolism ◽  
Carbon Fixation ◽  
Acid Metabolism ◽  
Water Storage ◽  
Diurnal Fluctuation ◽  
Carbon Gain ◽  
O2 Evolution ◽  
Storage Tissue ◽  
Portulaca Grandiflora

This paper originates from a presentation at the IIIrd International Congress on Crassulacean Acid Metabolism, Cape Tribulation, Queensland, Australia, August 2001. Portulaca grandiflora (Lind.) is a succulent species with C4 photosynthesis and crassulacean acid metabolism (CAM) cycling in leaves, and CAM-idling type photosynthesis in stems. We investigated the level and localization of carbon fixation enzymes and photosynthetic activity of leaves and stems of P. grandiflora under well-watered and drought conditions. As CAM activity increased during water stress, the leaf water-storage tissue collapsed, presumably transferring water to the bundle sheath and mesophyll cells, and so maintaining the C4 photosynthetic pathway. Tissue prints indicated an increase in phosphoenolpyruvate carboxylase (PEPC) in the water-storage tissue of leaves and the cortex of stems. Immunoblot analyses after 10 d of water stress showed that leaves had a slight decrease in the proteins of the C4-CAM pathway, while at the same time a new isoform of NADP-malic enzyme (NADP-ME) appeared. In contrast, the stem showed increases in proteins of the CAM pathway when water stressed. Under water stress, diurnal fluctuation in acidity in leaves was not accompanied by a net gain or loss of CO2 at night, and there was sustained, but decreased, fixation of CO2 during the day, characteristic of CAM cycling. High gross rates of O2 evolution were maintained during the day under water stress, suggesting induction of alternative electron sinks. With induced diurnal fluctuations in acidity in stems, there was no net carbon gain during the day or night. These results demonstrate, for the first time, that the stem of P. grandiflora is an inducible CAM-idling tissue. Our results also indicate that the C4 and CAM pathways operate independently of one another in P. grandiflora.

Historical aspects and net CO2 uptake for cultivated Crassulacean acid metabolism plants in Mexico

2002 ◽  
Vol 140 (2) ◽  
pp. 133-142 ◽  
Author(s):  
PARK S NOBEL ◽  
EULOGIO PIMIENTA-BARRIOS ◽  
JULIA ZANUDO HERNANDEZ ◽  
BLANCA C RAMIREZ-HERNANDEZ
Keyword(s):  
Crassulacean Acid Metabolism ◽  
Acid Metabolism ◽  
Co2 Uptake ◽  
Historical Aspects ◽  
Net Co2 Uptake

scholarly journals Molecular Genetics of Crassulacean Acid Metabolism

1997 ◽  
Vol 113 (3) ◽  
pp. 667-676 ◽  
Author(s):  
J. C. Cushman ◽  
H. J. Bohnert
Keyword(s):  
Molecular Genetics ◽  
Crassulacean Acid Metabolism ◽  
Acid Metabolism
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