Аннотация:Radial water (JV) and abscisic acid (ABA) flows (JABA) through maize root seedlings have been investigated under different conditions of nutrient deficiency. Whereas JV was reduced under nitrogen deficiency, potassium deficiency stimulated JV. A substantial increase of JABA was observed in roots kept under potassium deficiency. The observed changes of JV might have resulted from changed barrier properties of the endodermis. Nitrogen and potassium deficiency also caused an accumulation of endogenous ABA in root tissues. Under all conditions studied, except under K+-deficiency, external ABA (100 nM) caused an increase of JV. The data of this study were used to analyse the relations between internal and endogenous root ABA, JV, and JABA. The internal ABA of root tissues was positively correlated with JV and was highly significant (P <0.001 for internal and P=0.03 for endogenous root ABA) within the range 2–300 pmol g−1 FW. It was also highly positively correlated to the radial ABA flows. There was also a highly positive correlation between JV and JABA. The data of this study indicate, for the first time, the relations between internal ABA, water, and ABA flows. Independent of treatment with external ABA, an ABA transport by solvent drag across the endodermis is confirmed.