Inhibition of plasma membrane redox activities and elongation growth of soybean

Abstract

NADH‐ferricyanide oxido‐reductase (EC 1,6,99,3) of purified plasma membrane vesicles isolated by aqueous two‐phase partition from segments of etiolated soybean [Glycine max (L.) Merr. cv. Williams] hypocotyls was used as a measure of plasma membrane redox activity. Elongation growth of hypocotyl segments floated on the solutions was determined in parallel. Cis‐platinum (II) diammine dichloride (cis‐platin), adriamycin and p‐nitrophenylacetate, agents known to inhibit cell proliferation and plasma membrane redox activities in mammalian cells inhibited both NADH‐ferricyanide oxido‐reductase of the isolated membrane vesicles and elongation growth of intact hypocotyl segments. Auxin(2,4‐dichlorophenoxyacetic acid)‐induced growth of the isolated segments was inhibited preferentially at drug concentrations where control growth was affected only slightly. The findings suggest a connection between plasma membrane redox reactions and the control of elongation growth in plants.