Journal article

Publication year: 1993

Pages: 41-46

Journal: The Plant Journal

Volume number: 4

Issue number: 1

ISSN: 0960-7412

eISSN: 1365-313X

Open access status: Bronze

DOI Link: https://doi.org/10.1046/j.1365-313X.1993.04010041.x

Publisher: Wiley

Abstract: 
The electrical response of Zea mays protoplasts to different auxins and to antibodies raised against an ER-located auxin binding protein from maize (Zm-ERabp1), was investigated using the patch-clamp technique (whole-cell configuration). Following a lag-phase of 30-40 seconds, indole-3-acetic acid and 1-naphthylacetic acid induced an outwardly directed current of positive charge in a concentration-dependent manner. This current was further increased by the fungal toxin fusicoccin (FC). The current was observed only in the presence of Mg2+-ATP in the patch-pipette and was abolished after addition of erythrosin B, an inhibitor of H+-ATPase, to the protoplasts indicating that the plasma membrane H+-ATPase is activated by auxins and fusicoccin. Addition of antibodies directed against Zm-ERabp1 abolished the current induced by auxins, without affecting the response of protoplasts to fusicoccin. Antibodies directed against a peptide representing part of the putative auxin binding domain of Zm-ERabp1 showed auxin agonist activity, stimulating an outwardly directed membrane current in the absence of auxin. These results suggest that (i) Zm-ERabp1 or antigenically related proteins represent a site for auxin perception through which the plasma membrane H+-ATPase is activated, and (ii) that the activation of the H+-ATPase by such proteins is initiated from outside the plasma membrane.

Harvard Citation style: RUCK, A., PALME, K., VENIS, M., NAPIER, R. and FELLE, R. (1993) PATCH-CLAMP ANALYSIS ESTABLISHES A ROLE FOR AN AUXIN-BINDING PROTEIN IN THE AUXIN STIMULATION OF PLASMA-MEMBRANE CURRENT IN ZEA-MAYS PROTOPLASTS, The Plant Journal, 4(1), pp. 41-46. https://doi.org/10.1046/j.1365-313X.1993.04010041.x

APA Citation style: RUCK, A., PALME, K., VENIS, M., NAPIER, R., & FELLE, R. (1993). PATCH-CLAMP ANALYSIS ESTABLISHES A ROLE FOR AN AUXIN-BINDING PROTEIN IN THE AUXIN STIMULATION OF PLASMA-MEMBRANE CURRENT IN ZEA-MAYS PROTOPLASTS. The Plant Journal. 4(1), 41-46. https://doi.org/10.1046/j.1365-313X.1993.04010041.x