The effects of soil humic matter on the uptake of ions by oat roots and on the (Mg2++K+) ATPase activity, responsible for energy transduction for ion transport at cell membrane, were studied. Four-day-old roots treated for 8 h with unfractionated humic solution (50 μg org C × ml-1) took up K+ and SO4staggered-2 ions at rates, respectively, 33% and 106% higher than the controls. Similar effects were caused by humic and fulvic acids, and by the hot-acid soluble and hot-acid insoluble fractions prepared from humic acids. At org C concentration higher than 1 μg ml-1, the humic extract inhibited both Mg2+ dependent and K+-stimulated ATPase activities of microsomes isolated from roots. At 0.33-1 μg org C ml-1, the Mg2+-dependent activity was inhibited, whereas the activity stimulated by K+ increased. Humic acids and the acid-insoluble fraction inhibited the ATPase activity more than fulvic acids and the acid-soluble fraction. Preliminary results of SDS - PAG electrophoresis of membrane proteins showed two polypeptides associated with membrane of humus treated roots, which where absent in the control. Differences between the two phenomena and structure-activity relationships will be discussed. © 1987.

Action of soil humic matter on plant roots: Stimulation of ion uptake and effects on(Mg2++K+) ATPase activity

PINTON, Roberto
1987-01-01

Abstract

The effects of soil humic matter on the uptake of ions by oat roots and on the (Mg2++K+) ATPase activity, responsible for energy transduction for ion transport at cell membrane, were studied. Four-day-old roots treated for 8 h with unfractionated humic solution (50 μg org C × ml-1) took up K+ and SO4staggered-2 ions at rates, respectively, 33% and 106% higher than the controls. Similar effects were caused by humic and fulvic acids, and by the hot-acid soluble and hot-acid insoluble fractions prepared from humic acids. At org C concentration higher than 1 μg ml-1, the humic extract inhibited both Mg2+ dependent and K+-stimulated ATPase activities of microsomes isolated from roots. At 0.33-1 μg org C ml-1, the Mg2+-dependent activity was inhibited, whereas the activity stimulated by K+ increased. Humic acids and the acid-insoluble fraction inhibited the ATPase activity more than fulvic acids and the acid-soluble fraction. Preliminary results of SDS - PAG electrophoresis of membrane proteins showed two polypeptides associated with membrane of humus treated roots, which where absent in the control. Differences between the two phenomena and structure-activity relationships will be discussed. © 1987.
File in questo prodotto:
File Dimensione Formato  
maggioni1987.pdf

non disponibili

Tipologia: Versione Editoriale (PDF)
Licenza: Non pubblico
Dimensione 574.01 kB
Formato Adobe PDF
574.01 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11390/679141
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 54
  • ???jsp.display-item.citation.isi??? 48
social impact