RT Journal Article SR Electronic T1 A Hypothesis for the Presence, Activity, and Role of Potassium/Hydrogen, Adenosine Triphosphatases in Grapevines JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 283 OP 287 DO 10.5344/ajev.1980.31.3.283 VO 31 IS 3 A1 Roger Boulton YR 1980 UL http://www.ajevonline.org/content/31/3/283.abstract AB The presence of membrane-bound, potassium/ hydrogen, adenosine triphosphatases in the vegetative and reproductive tissues of grapevines is proposed. The expected role of this enzyme system in the uptake of monovalent metal cations by the roots and the influx of these ions into leaf and berry tissue are discussed. The influences of rootstock, cropping level, water status and mineral nutrition on the pH and titratable acidity of grape juices are interpreted in terms of the activity of this enzyme in grape tissue.