Format

Send to

Choose Destination
J Exp Bot. 2012 Mar;63(5):1849-61. doi: 10.1093/jxb/err358. Epub 2012 Jan 2.

Low antioxidant concentrations impact on multiple signalling pathways in Arabidopsis thaliana partly through NPR1.

Author information

1
Department of Biosciences, University of Helsinki, Helsinki, Finland. mikael.brosche@helsinki.fi

Abstract

Production of reactive oxygen species (ROS) is linked to signalling in both developmental and stress responses. The level of ROS is controlled by both production and removal through various scavengers including ascorbic acid and glutathione. Here, the role of low ascorbic acid or glutathione concentrations was investigated on ozone-induced cell death, defence signalling, and developmental responses. Low ascorbic acid concentrations in vtc1 activated expression of salicylic acid (SA)-regulated genes, a response found to be dependent on the redox-regulated transcriptional co-regulator NPR1. In contrast, low glutathione concentrations in cad2 or pad2 reduced expression of SA-regulated genes. Testing different responses to jasmonic acid (JA) revealed the presence of at least two separate JA signalling pathways. Treatment of the vtc1 mutant with JA led to hyper-induction of MONODEHYDROASCORBATE REDUCTASE3, indicating that low ascorbic acid concentrations prime the response to JA. Furthermore, NPR1 was found to be a positive regulator of JA-induced expression of MDHAR3 and TAT3. The vtc1 and npr1 mutants were sensitive to glucose inhibition of seed germination; an opposite response was found in cad2 and pad2. Overall, low ascorbic acid concentrations mostly led to opposite phenotypes to low glutathione concentrations, and both antioxidants interacted with SA and JA signalling pathways.

PMID:
22213815
PMCID:
PMC3295383
DOI:
10.1093/jxb/err358
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center