University of Dundee

"The Arabidopsis SUMO E3 ligase SIZ1 mediates the temperature dependent trade-off between plant immunity and growth"

Event Date: 
Monday, March 5, 2018 - 10:00 to 11:00
Event Location: 
New Seminar Room James Hutton Institute Errol Road, Invergowrie, DD2 5DA
Host: 
Dr Edgar Huitema
Event Speaker: 
Dr Harrold van den Burg
Institution: 
University of Amsterdam, Swammerdam Institute for Life Sciences
Event Type: 
Seminar
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Abstract
Increased ambient temperature is inhibitory to plant immunity including auto-immunity. SNC1-dependent auto-immunity is, for example, fully suppressed at 28°C. We found that the Arabidopsis sumoylation mutant siz1 displays SNC1-dependent auto-immunity at 22°C but also at 28°C, which was EDS1 dependent at both temperatures. This siz1 auto-immune phenotype provided enhanced resistance to Pseudomonas at both temperatures. Moreover, the rosette size of siz1 recovered only weakly at 28°C, while this temperature fully rescues the growth defects of other SNC1-dependent auto-immune mutants. This thermo-insensitivity of siz1correlated with a compromised thermosensory growth response, which was independent of the immune regulators PAD4 or SNC1. Our data reveal that this high temperature induced growth response strongly depends on COP1, while SIZ1 controls the amplitude of this growth response. I will discuss how SIZ1 suppresses an SNC1-dependent resistance response at both normal and high temperatures. At the same time, SIZ1 amplifies the dark and high temperature growth response, likely via COP1 and upstream of gene regulation by PIF4 and BRZ1. I will also show cell biology data on how COP1 and SIZ1 come together in nuclear bodies implicated in thermosensing and skoto/photomorphogenesis.