The effects of an @entity2271 ( @entity2272 ) 8'-hydroxylase inhibitor (Abz-F1) on @entity2272 catabolism, stomatal aperture, and water potential were examined in apple seedlings under @entity2700 and rehydration conditions. In this study, @entity25430 dioxigenase (MdNCED) and @entity2272 8'-hydroxylase (MdCYP707A) genes were isolated and their expressions were investigated under @entity2700 and rehydration conditions. The stomatal aperture decreased up to 4 h after spraying with Abz-F1 and the stomatal aperture in the Abz-F1-treated leaves was generally lower than that in the untreated control-leaves during the @entity2700 . Although the water potential in untreated control-leaves decreased with the progress of @entity2700 , it was maintained at a higher level in the Abz-F1 treated-leaves than in the untreated control-leaves during @entity2700 . Endogenous @entity2272 concentrations increased with @entity2700 in both the Abz-F1 treated- and untreated-control-leaves, but the @entity2272 levels in the Abz-F1 treated-leaves were higher than those in the untreated control-leaves throughout @entity2700 . In contrast, the @entity68639 (PA) concentrations in the Abz-F1 treated-leaves were lower than those in the untreated control-leaves during @entity2700 . The expressions of MdNCEDs in the Abz-F1 treated-leaves were lower than those in the untreated control-leaves regardless of the higher endogenous @entity2272 concentrations. Moreover, the expressions of MdCYP707As in the Abz-F1 treated-leaves were also lower than those in the untreated control-leaves. Higher 50% effective concentrations (EC(50)) and @entity620 concentrations were observed in the Abz-F1 treated-leaves, which show that the oxidative damage under @entity2700 may be reduced by Abz-F1 application. These results suggest that prompt stomata closure is required for survival under @entity2700 , and Abz-F1 application may therefore be of practical use. The increase of endogenous @entity2272 , which induced prompt stomata closure in Abz-F1 treated-leaves may depend on inhibition of the expression of MdCYP707As. Furthermore, the results showed the close relationship between MdNCEDs and MdCYP707As on @entity2272 catabolism.

Dehydration tolerance in apple seedlings is affected by an inhibitor of XXXX 8'-hydroxylase CYP707A.

@entity2272 :: ('CHEBI:2365', 'Chemical') :: ['ABA'] @entity2271 :: ('MESH:D000040', 'Chemical') :: ['abscisic acid'] @entity2700 :: ('MESH:D003681', 'Disease') :: ['dehydration condition', 'dehydration'] @entity620 :: ('MESH:D001205', 'Chemical') :: ['ascorbic acid'] @entity25430 :: ('CHEBI:51973', 'Chemical') :: ['9-cis-epoxycarotenoid'] @entity68639 :: ('CHEBI:28205', 'Chemical') :: ['phaseic acid']
@entity2272 :: (CHEBI:2365,Chemical) :: ['ABA']
