Diurnal Variation in Aldolase and Phosphatase Activity in the Cactus Plant


WHEREAS considerable information is available regarding the enzymatic mechanism of carbon dioxide fixation during acidification in succulents1–3, very little seems to be known about the role of enzymes in the diurnal variation in acids and carbohydrate. If the 3-carbon atom acceptor of carbon dioxide is derived from starch or sugar by the Embden–Meyerhof–Parnas series of reactions, aldolase may be expected to play an important part in the processes of acidification and de-acidification. We have studied the activity of aldolase in cactus tissue at different hours of the day and night, and have found a marked diurnal variation. Phosphatase activity was also found to undergo rhythmic alteration.

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    Walker, D. A., Biochem. J., 67, 73 (1957).

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    Walker, D. A., and Brown, J. M. A., Biochem. J., 67, 79 (1957).

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    Walker, D. A., Biochem. J., 74, 216 (1960).

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    Sibley, J. A., and Lehninger, A. L., J. Biol. Chem., 177, 859 (1949).

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    Sanwal, G. G., and Krishnan, P. S., Enzymologia, 22, 51 (1960).

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SANWAL, G., KRISHNAN, P. Diurnal Variation in Aldolase and Phosphatase Activity in the Cactus Plant. Nature 188, 664–665 (1960). https://doi.org/10.1038/188664a0

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