| Authors: |
Hubert H. Felle
and Almut Herrmann
and Patrick Schaefer
and Ralph Hueckelhoven
and Karl-Heinz Kogel
|
| Tags: |
IFZ
apoplastic_pH
barley
compatibility
resistance
surface_pH
|
| Abstract: |
Using ion-selective microprobes, interactive signalling between barley
and Blumeria graminis or Bipolaris sorokiniana has been investigated.
The question was raised whether a biotrophically growing fungus
manipulates the electrical driving forces (membrane potential.,
transmembrane pH), required for H+ cotransport of energy-rich
compounds. Electrodes were positioned in the substomatal cavity of open
stomata or on the leaf surface, and pH was measured continuously up to
several days during fungal development. We demonstrate that surface and
apoplastic fluids are electrically coupled and respond in a similar
manner to stimuli. Apoplastic pH, monitored from the moment of
inoculation with conidia, reveals several phases: 2-4 h after
inoculation of the barley leaf with either fungus, the host displays
rapid transient responses after its first contact with the fungal cell
wall; apoplastic pH and pCa increases, cytoplasmic pH and pCa
decreases. About 1 day after inoculation, the apoplastic pH increases
by up to 2 pH units, which is thought to reflect a resistance response
against the intruder. Whereas barley leaf cells possess a membrane
potential of -152 +/- 5 mV, hyphae of B. graminis yield -251 +/- 8 mV,
indicative of a substantial driving force advantage for the fungus.
Although the resting membrane potential of barley remains constant
during the first days after inoculation, leaves infected with B.
sorokiniona get confronted with an energy problem, indicated by a
retarded repolarization following a ��light-off" stimulus. Five days |
@article{ISI:000252803600006,
title = {Interactive signal transfer between host and pathogen during successful infection of barley leaves by Blumeria graminis and Bipolaris sorokiniana},
author = {Hubert H. Felle and Almut Herrmann and Patrick Schaefer and Ralph Hueckelhoven and Karl-Heinz Kogel},
journal = {JOURNAL OF PLANT PHYSIOLOGY},
number = {1},
pages = {52-59},
volume = {165},
year = {2008},
abstract = {Using ion-selective microprobes, interactive signalling between barley
and Blumeria graminis or Bipolaris sorokiniana has been investigated.
The question was raised whether a biotrophically growing fungus
manipulates the electrical driving forces (membrane potential.,
transmembrane pH), required for H+ cotransport of energy-rich
compounds. Electrodes were positioned in the substomatal cavity of open
stomata or on the leaf surface, and pH was measured continuously up to
several days during fungal development. We demonstrate that surface and
apoplastic fluids are electrically coupled and respond in a similar
manner to stimuli. Apoplastic pH, monitored from the moment of
inoculation with conidia, reveals several phases: 2-4 h after
inoculation of the barley leaf with either fungus, the host displays
rapid transient responses after its first contact with the fungal cell
wall; apoplastic pH and pCa increases, cytoplasmic pH and pCa
decreases. About 1 day after inoculation, the apoplastic pH increases
by up to 2 pH units, which is thought to reflect a resistance response
against the intruder. Whereas barley leaf cells possess a membrane
potential of -152 +/- 5 mV, hyphae of B. graminis yield -251 +/- 8 mV,
indicative of a substantial driving force advantage for the fungus.
Although the resting membrane potential of barley remains constant
during the first days after inoculation, leaves infected with B.
sorokiniona get confronted with an energy problem, indicated by a
retarded repolarization following a ��light-off" stimulus. Five days},
issn = {0176-1617},
keywords = {IFZ apoplastic_pH barley compatibility resistance surface_pH }
}
::