Antagonism between SUMO1/2 and SUMO3 regulates SUMO conjugate levels and fine-tunes immunity.
J Exp Bot
; 72(18): 6640-6658, 2021 09 30.
Article
in En
| MEDLINE
| ID: mdl-34145454
ABSTRACT
The attachment of SMALL UBIQUITIN-LIKE MODIFIER (SUMO) to target proteins regulates a plethora of cellular processes across eukaryotes. In Arabidopsis thaliana, mutants with abnormal SUMO1/2 conjugate levels display a dwarf stature, autoimmunity, and altered stress responses to adverse environmental conditions. Since the SUMO pathway is known to autoregulate its biochemical activity (via allosteric interactions), we assessed whether the emergence of additional SUMO paralogs in Arabidopsis has introduced the capacity of self-regulation by means of isoform diversification in this model plant. By studying the plant defense responses elicited by the bacterial pathogen Pseudomonas syringae pv. tomato, we provide genetic evidence that SUM3, a divergent paralog, acts downstream of the two main SUMO paralogues, SUM1/2. The expression of SUM3 apparently buffers or suppresses the function of SUM1/2 by controlling the timing and amplitude of the immune response. Moreover, SUM1 and SUM2 work additively to suppress both basal and TNL-specific immunity, a specific branch of the immune network. Finally, our data reveal that SUM3 is required for the global increase in SUMO1/2 conjugates upon exposure to biotic and abiotic stresses, namely heat and pathogen exposure. We cannot exclude that this latter effect is independent of the role of SUM3 in immunity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Arabidopsis
/
Arabidopsis Proteins
Type of study:
Prognostic_studies
Language:
En
Journal:
J Exp Bot
Journal subject:
BOTANICA
Year:
2021
Document type:
Article
Affiliation country:
India