[Activity of carbon metabolism enzymes in wheat plants treated with kartolin-4 and exposed to water stress].
Enzymatic activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) (EC 4.1.1.39), phospho(enol)pyruvate carboxylase (EC 4.1.1.31), NAD malate dehydrogenase (EC 1.1.1.37), and NADP glyceraldehydephosphate dehydrogenase complex including phosphoglycerate kinase (EC 2.7.2.3) and glyceraldehydephosphate dehydrogenase (EC 1.2.1.13) were comparatively assayed in wheat seedlings of the cultivar Lyutestsens 758 grown under normal conditions, water deficiency conditions, and subsequent rehydration. Water stress was found to decrease the activity of all enzymes tested, the effect being most pronounced in case of Rubisco. The content of Rubisco in wheat plants exposed to water deficiency was reduced less significantly than the activity of the enzyme. Preliminary treatment of plant seeds with kartolin-4 (o-isopropyl-N-2-hydroxyethyl carbamate), a preparation with cytokinin activity, reduced the dehydration-induced inhibition of enzymatic activity. Upon a subsequent rehydration, kartolin-4 facilitated rapid recovery of the photosynthetic activity, the process being based on the kartolin-induced stimulation of reparation reactions. Under conditions of water stress, a partial decrease in the activity of carbon metabolism enzymes in vitro was accompanied by complete inhibition of photosynthesis in vivo, perhaps, as a result of an abrupt increase in the stomatal resistance.
Cherniad'ev
I I
II
Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 117071 Russia.
Monakhova
O F
OF
D002219:Carbamates / Q000494:pharmacology*; D002244:Carbon / Q000378:metabolism*; D024602:Glyceraldehyde-3-Phosphate Dehydrogenase (NADP+)(Phosphorylating) / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D010730:Phosphoenolpyruvate Carboxylase / Q000378:metabolism; D010735:Phosphoglycerate Kinase / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D014908:Triticum / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D014867:Water
D002219:Carbamates; C445663:o-isopropyl N-2-hydroxyethyl carbamate; D014867:Water; D002244:Carbon; D008291:Malate Dehydrogenase; D024602:Glyceraldehyde-3-Phosphate Dehydrogenase (NADP+)(Phosphorylating); D010735:Phosphoglycerate Kinase; D010730:Phosphoenolpyruvate Carboxylase; D012273:Ribulose-Bisphosphate Carboxylase
Aktivnost' fermentov uglerodnogo metabolizma rasteniĭ pshenitsy v usloviiakh vodnogo stressa pri obrabotke kartolinom-4.