A preliminary survey for crassulacean acid metabolism (CAM) in submerged aquatic macrophytes in New Zealand

Crassulacean acid metabolism (CAM) is a specialised mode of photosynthesis that improves atmospheric CO2 assimilation in water-limited terrestrial and epiphytic habitats and in CO2-limited aquatic environments. In contrast with C3 and C4 plants, CAM plants take up CO2 from the atmosphere partially or predominantly at night. CAM is taxonomically widespread among vascular plants and is present in many succulent species that occupy semiarid regions, as well as in tropical epiphytes and in some aquatic macrophytes. This water-conserving photosynthetic pathway has evolved multiple times and is found in close to 6% of vascular plant species from at least 35 families. Although many aspects of CAM molecular biology, biochemistry and ecophysiology are well understood, relatively little is known about the evolutionary origins of CAM. This review focuses on five main topics: (1) the permutations and plasticity of CAM, (2) the requirements for CAM evolution, (3) the drivers of CAM evolution, (4) the prevalence and taxonomic distribution of CAM among vascular plants with emphasis on the Orchidaceae and (5) the molecular underpinnings of CAM evolution including circadian clock regulation of gene expression.

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Faculty Opinions recommendation of Kalanchoë PPC1 is essential for crassulacean acid metabolism and the regulation of core circadian clock and guard cell signaling genes.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.737370476.793573674 ◽

2020 ◽

Author(s):

Richard Leegood

Keyword(s):

Cell Signaling ◽

Circadian Clock ◽

Guard Cell ◽

Crassulacean Acid Metabolism ◽

Acid Metabolism

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Increased expression of a gene coding for NAD:glyceraldehyde-3-phosphate dehydrogenase during the transition from C3 photosynthesis to crassulacean acid metabolism in Mesembryanthemum crystallinum.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)39796-0 ◽

1990 ◽

Vol 265 (6) ◽

pp. 3497-3502

Author(s):

J A Ostrem ◽

D M Vernon ◽

H J Bohnert

Keyword(s):

Crassulacean Acid Metabolism ◽

Acid Metabolism ◽

Mesembryanthemum Crystallinum ◽

Gene Coding ◽

C3 Photosynthesis

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Use of grass carp (Ctenopharyngodon idella) as a biological control agent for submerged aquatic macrophytes

Planta Daninha ◽

10.1590/s0100-83582014000400011 ◽

2014 ◽

Vol 32 (4) ◽

pp. 765-773

Author(s):

A.F. Silva ◽

C. Cruz ◽

R.L.C.M. Pitelli ◽

R.A. Pitelli

Keyword(s):

Grass Carp ◽

Aquatic Macrophytes ◽

Biological Control Agent ◽

Body Weight Gain ◽

Predation Rate ◽

Control Agent ◽

Ctenopharyngodon Idella ◽

Ceratophyllum Demersum ◽

Grass Carp Ctenopharyngodon Idella ◽

Submerged Aquatic Macrophytes

This study aimed to evaluate feed preference and control efficacy of grass carp (Ctenopharyngodon idella) on the aquatic macrophytes Ceratophyllum demersum, Egeria densa and Egeria najas. An experiment was carried out at mesocosms conditions with 2,000 liters capacity and water residence time of 2.8 days. C. demersum, E. densa e E. najas biomasses were offered individually with sixty g and coupled in similar quantities of 30 g of each species, evaluated during 81 days, envolving 6 treatments. (1 - C. demersum, 2 - E. najas, 3 -E. densa, 4 - C. demersum + E. najas, 5 - C. demersum + E. densa and 6 - E. najas + E. densa). When offered individually, E. najas and C. demersum presented the same predation rate by grass carp, which was higher than E. densa predation rate. When plants were tested in pairs, the order of feed preference was C. demersum > E. najas > E. densa. E. najas and C. demersum percentage control ranged from 73 to 83%. No relation between biomass consumption and grass carp body weight gain was observed, probably due to differences in nutritional quality among macrophyte species according to fish necessities. Therefore, it is concluded that the use of grass carp is one excellent technique to control submersed macrophytes in Brazil.

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