Presence of nitric oxide synthase activity in roots and nodules of Lupinus albus.
NO is a widespread messenger molecule in physiology. We were interested in investigating whether an NO-generating system could be present in plants. NO and L-[14C]citrulline were synthesized by roots and nodules of Lupinus albus in an L-arginine-dependent manner. L-[14C]Citrulline production was inhibited by N(G)-monomethyl-L-arginine, a nitric oxide synthase antagonist, in a competitive way. NADPH-diaphorase activity was localized in the vascular bundles in root and nodules, and also in the nodule infected zone. This staining was significantly reduced in the presence of N(G)-monomethyl-L-arginine. These results indicate the presence of a putative nitric oxide synthase in plants.
Cueto
M
M
Departamento de Fisiología y Bioquímica Vegetal, Centro de Ciencias Medioambientales, CSIC, Madrid, Spain.
Hernández-Perera
O
O
Martín
R
R
Bentura
M L
ML
Rodrigo
J
J
Lamas
S
S
Golvano
M P
MP
D001120:Arginine / Q000378:metabolism; D002956:Citrulline / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology*; D010944:Plants / Q000201:enzymology* / Q000382:microbiology; D012230:Rhizobiaceae / Q000502:physiology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D019323:omega-N-Methylarginine; D002956:Citrulline; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D009252:NADPH Dehydrogenase