Mla- and Rom1-mediated control of microRNA398 and chloroplast copper/zinc superoxide dismutase regulates cell death in response to the barley powdery mildew fungus
Article first published online: 18 NOV 2013
No claim to original US Government works. New Phytologist © 2013 New Phytologist Trust
Volume 201, Issue 4, pages 1396–1412, March 2014
How to Cite
Xu, W., Meng, Y. and Wise, R. P. (2014), Mla- and Rom1-mediated control of microRNA398 and chloroplast copper/zinc superoxide dismutase regulates cell death in response to the barley powdery mildew fungus. New Phytologist, 201: 1396–1412. doi: 10.1111/nph.12598
- Issue published online: 3 FEB 2014
- Article first published online: 18 NOV 2013
- Manuscript Accepted: 8 OCT 2013
- Manuscript Received: 26 AUG 2013
- USDA-ARS CRIS. Grant Number: 3625-21000-057-00D
- National Science Foundation-Plant Genome. Grant Numbers: 05-00461, 09-22746
- Blumeria graminis ;
- hypersensitive reaction;
- reactive oxygen species (ROS);
- superoxide dismutase (SOD)
- Barley (Hordeum vulgare L.) Mildew resistance locus a (Mla) confers allele-specific interactions with natural variants of the ascomycete fungus Blumeria graminis f. sp. hordei (Bgh), the causal agent of powdery mildew disease. Significant reprogramming of Mla-mediated gene expression occurs upon infection by this obligate biotrophic pathogen.
- We utilized a proteomics-based approach, combined with barley mla, required for Mla12 resistance1 (rar1), and restoration of Mla resistance1 (rom1) mutants, to identify components of Mla-directed signaling.
- Loss-of-function mutations in Mla and Rar1 both resulted in the reduced accumulation of chloroplast copper/zinc superoxide dismutase 1 (HvSOD1), whereas loss of function in Rom1 re-established HvSOD1 levels. In addition, both Mla and Rom1 negatively regulated hvu-microRNA398 (hvu-miR398), and up-regulation of miR398 was coupled to reduced HvSOD1 expression. Barley stripe mosaic virus (BSMV)-mediated over-expression of both barley and Arabidopsis miR398 repressed accumulation of HvSOD1, and BSMV-induced gene silencing of HvSod1 impeded Mla-triggered H2O2 and hypersensitive reaction (HR) at barley–Bgh interaction sites.
- These data indicate that Mla- and Rom1-regulated hvu-miR398 represses HvSOD1 accumulation, influencing effector-induced HR in response to the powdery mildew fungus.