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CAM stands for --------------

Discovered by Heyne (1804) and later by Aubert (1815).

Term coined by Ranson and Thomas (1940)

Mechanism for concentrating CO2

CAM is not restricted to the family Crassulaceae

Enables plants to improve H2O Efficiency

CAM plants have advantage in dry environment

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CAM can be defined according to the following criteria

Succulents plants

Diurnal fluctuation of organic acid

High activities of PEP carboxylase

Stomata opening

Tropical origin and xeric

CAM permits much flexibility and permits survival

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CAM PLANTS

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CO

MALIC ACID

OAA

K* MALATE MALATE

PYRUVIC ACID

CO2

C3 CYCLE

PYRUVATE

STARCHSTARCH

PEP

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• Do photosynthesis in the day time

• Indeed slow growing but they are very competitive

• Advantage in water saving

• Can use Calvin cycle alone

• CAM plants are facultative

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• Requires PEPc and decarboxylase

• To avoid futile cycle : carboxylase at night and decarboxylase during day

• Conversion achieved by ------

C4 vs CAM Summary

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C4 plants

separate 2 steps of C fixation anatomicallyin 2 different cells

CAM plants

separate 2 steps of C fixation temporallyat2 different times

It’s all inthe timing!

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• PHOTOSYNTHETIC SYSTEMS BY

SUSAN M. DANKS,

E.HILARY EVANS

PETER A. WHITTAKER

• CAM BY

IRWIN. P. TING

MARTIN GIBBS

• PLANT PHYSIOLOGY BY

TEIZ AND ZEIGER

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