The Rab GTPase RabG3b Positively Regulates Autophagy and Immunity-Associated Hypersensitive Cell Death in Arabidopsis1[W]
A Rab GTPase protein connects autophagy with plant immunity-triggered hypersensitive response and programmed cell death. A central component of the plant defense response to pathogens is the hypersensitive response ( HR ), a form of programmed cell death ( PCD ). Rapid and localized induction of HR...
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Veröffentlicht in: | Plant physiology (Bethesda) 2013-02, Vol.161 (4), p.1722-1736 |
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Sprache: | eng |
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Zusammenfassung: | A Rab GTPase protein connects autophagy with plant immunity-triggered hypersensitive response and programmed cell death.
A central component of the plant defense response to pathogens is the hypersensitive response (
HR
), a form of programmed cell death (
PCD
). Rapid and localized induction of
HR
PCD
ensures that pathogen invasion is prevented. Autophagy has been implicated in the regulation of
HR
cell death, but the functional relationship between autophagy and
HR
PCD
and the regulation of these processes during the plant immune response remain controversial. Here, we show that a small GTP-binding protein, RabG3b, plays a positive role in autophagy and promotes
HR
cell death in response to avirulent bacterial pathogens in Arabidopsis (
Arabidopsis thaliana
). Transgenic plants overexpressing a constitutively active
RabG3b
(RabG3bCA) displayed accelerated, unrestricted
HR
PCD
within 1 d of infection, in contrast to the autophagy-defective
atg5-1
mutant, which gradually developed chlorotic cell death through uninfected sites over several days. Microscopic analyses showed the accumulation of autophagic structures during
HR
cell death in RabG3bCA cells. Our results suggest that RabG3b contributes to
HR
cell death via the activation of autophagy, which plays a positive role in plant immunity-triggered
HR
PCD
. |
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ISSN: | 0032-0889 1532-2548 |
DOI: | 10.1104/pp.112.208108 |