Regulation of C4 photosynthesis: modulation of mitochondrial NAD-malic enzyme by adenylates.
Effects of adenylates on the activity of mitochondrial NAD-malic enzyme from NAD-malic-enzyme (NAD-ME)-type and phosphoenolpyruvate-carboxykinase-(PKC)-type C4 plants are examined. At physiological concentrations, ATP, ADP, and AMP all inhibit the enzyme from Atriplex spongiosa and Panicum miliaceum (NAD-ME-type plants), with ATP the most inhibitory species. The degree of inhibition is greater with subsaturating levels of activator, malate, and Mn2+. NAD-malic enzyme from Urochloa panicoides (PCK-type) is activated by ATP (up to 10-fold) and inhibited by ADP and AMP. These effects are discussed in relation to regulation of C4 photosynthesis.
Furbank
R T
RT
CSIRO, Division of Plant Industry, Canberra City, Australia.
Agostino
A
A
Hatch
M D
MD
D000227:Adenine Nucleotides / Q000494:pharmacology; D008291:Malate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D010788:Photosynthesis / Q000502:physiology*; D010944:Plants / Q000378:metabolism
D000227:Adenine Nucleotides; D008291:Malate Dehydrogenase; C046446:malate dehydrogenase-(oxaloacetate-decarboxylating) (NAD+)