PLANT PHYSIOLOGY , Vol 101, Issue 1 297-301, Copyright © 1993 by American Society of Plant Biologists
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PLANT-MICROBE INTERACTIONS |
Stimulation of Barley Plasmalemma H+-ATPase by Phytotoxic Peptides from the Fungal Pathogen Rhynchosporium secalis
L. Wevelsiep, E. Rupping and W. Knogge
Max-Planck-Institut fur Zuchtungsforschung, Department of Biochemistry, Carl-von-Linne-Weg 10, D-5000 Koln 30, Federal Republic of Germany
A small family of necrosis-inducing peptides has been identified as
virulence factors of Rhynchosporium secalis, a fungal pathogen of barley
(Hordeum vulgare L.) Two members of this family, NIP1 and NIP3, were found
to stimulate the phosphohydrolyzing activity of the Mg2+-dependent,
K+-stimulated H+-ATPase of plasma membrane vesicles isolated from barley
leaves by partitioning in an aqueous two-phase system. Stimulation of
enzyme activity was saturated by 10 to 15 [mu]M fungal protein. Another
member of the peptide family, NIP2, did not affect the enzyme, indicating
that it has a different mode of action.