1992/01/01 by María Dolores Roldán, Andrés Belver, María Pilar Rodríguez‐Rosales +2 · 1 citation
Agricultural and Biological Sciences · Engineering · Chemistry · #Plant Micronutrient Interactions and Effects #Plant Stress Responses and Tolerance #Advanced battery technologies research #Vanadate #Boron #ATPase #Membrane #Chemistry #Helianthus annuus #Microsome #In vivo #In vitro #Biophysics #Efflux #Proton transport #Biochemistry #Nuclear chemistry #Sunflower #Biology #Enzyme #Horticulture
paper · doi:10.1111/j.1399-3054.1992.tb08763.x
openalex publication_date 1992/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/21
The effect of boron excess and deficiency on H + efflux from excised roots from sunflower ( Heliarahus annuus L. cv. Enano) seedlings and on plasma membrane H + ‐ATPase (EC 3.6.1.35) in isolated KI‐washed microsomes has been investigated. When seedlings were grown in media with toxic levels of H 3 BO 3 (5 m M ) or without added boron and exposed to light conditions, an inhibition of the capacity for external acidification by excised roots was observed as compared to roots from seedlings grown with optimal H 3 BO 3 concentration (0.25 m M ). Toxic and deficient boron conditions also inhibited the vanadate‐sensitive H + ‐ATPase of microsomes isolated from the roots. The mechanism of boron toxicity was investigated in vitro with microsorne vesicles. A strong effect of boron on the vanadate‐sensitive, ATP‐dependent H + transport was found, but the vanadate‐sensitive phospho‐bydrolase activity was not affected. These results suggest that boron could exert an effect on the plasma membrane properties, directly or indirectly regulating, proton transport.