[Effect of aluminium and cAMP on acid phosphatase from the apoplast of barley and maize root cells].
Acid phosphatase activity inhibited by 1 mM sodium molybdate was detected at the surface of barley seedling roots and in the cell wall fraction isolated from barley and maize seedling roots. This enzyme hydrolyzed NPP, GP, and PPi at low pH (4.0 and below). NPP hydrolysis was stimulated by magnesium (but not calcium or manganese) ions, while PPi hydrolysis was independent of the presence of bivalent ions. The activity of phosphatase localized in the cell walls of the both crops increased in the presence of 100 microM AlCl3 or CuCl2. Stimulation of NPP hydrolysis by micromolar concentrations of aluminium and copper as well as by millimolar concentrations of magnesium decreased in the presence of 25 microM cAMP. This agrees with the previous data on the enzyme localized at the outer side of the properly oriented vesicles in the microscomal fraction of plasmalemma. The role of the root extracellular acid phosphatase loosely associated with various apoplast structures in plant adaptation to toxic effect of aluminium in the acidic soils as well as possible control of this process by cAMP secretion to the apoplast are discussed.
Fedorovskaia
M D
MD
Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya ul. 35, Moscow, 127176, Russia.
Tikhaia
N I
NI
D000135:Acid Phosphatase / Q000187:drug effects* / Q000378:metabolism; D000535:Aluminum / Q000494:pharmacology*; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000494:pharmacology; D002473:Cell Wall / Q000187:drug effects / Q000201:enzymology; D002712:Chlorides / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005994:Glycerophosphates / Q000378:metabolism; D001467:Hordeum / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008274:Magnesium / Q000494:pharmacology; D009596:Nitrophenols / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D003313:Zea mays / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*
D017607:Aluminum Compounds; D002712:Chlorides; D005994:Glycerophosphates; D009596:Nitrophenols; D009943:Organophosphorus Compounds; C008644:nitrophenylphosphate; D000077410:Aluminum Chloride; D003300:Copper; C028419:cuprous chloride; D000535:Aluminum; D000242:Cyclic AMP; D000135:Acid Phosphatase; D008274:Magnesium
Otnoshenie kisloĭ fosfatazy anoplasta kornevykh kletok iachmenia i kukuruzy k deĭstviiu aliuminiia i tsAMF.