TY - JOUR
T1 - The OXI1 kinase pathway mediates Piriformospora indica-induced growth promotion in Arabidopsis
AU - Camehl, Iris
AU - Drzewiecki, Corinna
AU - Vadassery, Jyothilakshmi
AU - Shahollari, Bationa
AU - Sherameti, Irena
AU - Forzani, Celine
AU - Munnik, Teun
AU - Hirt, Heribert
AU - Oelmüller, Ralf
PY - 2011/5
Y1 - 2011/5
N2 - Piriformospora indica is an endophytic fungus that colonizes roots of many plant species and promotes growth and resistance to certain plant pathogens. Despite its potential use in agriculture, little is known on the molecular basis of this beneficial plant-fungal interaction. In a genetic screen for plants, which do not show a P. indica- induced growth response, we isolated an Arabidopsis mutant in the OXI1 (Oxidative Signal Inducible1) gene. OXI1 has been characterized as a protein kinase which plays a role in pathogen response and is regulated by H2O2 and PDK1 (3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1). A genetic analysis showed that double mutants of the two closely related PDK1.1 and PDK1.2 genes are defective in the growth response to P. indica. While OXI1 and PDK1 gene expression is upregulated in P. indica-colonized roots, defense genes are downregulated, indicating that the fungus suppresses plant defense reactions. PDK1 is activated by phosphatidic acid (PA) and P. indica triggers PA synthesis in Arabidopsis plants. Under beneficial co-cultivation conditions, H2O2 formation is even reduced by the fungus. Importantly, phospholipase D (PLD)α1 or PLDδ mutants, which are impaired in PA synthesis do not show growth promotion in response to fungal infection. These data establish that the P. indica-stimulated growth response is mediated by a pathway consisting of the PLD-PDK1-OXI1 cascade.
AB - Piriformospora indica is an endophytic fungus that colonizes roots of many plant species and promotes growth and resistance to certain plant pathogens. Despite its potential use in agriculture, little is known on the molecular basis of this beneficial plant-fungal interaction. In a genetic screen for plants, which do not show a P. indica- induced growth response, we isolated an Arabidopsis mutant in the OXI1 (Oxidative Signal Inducible1) gene. OXI1 has been characterized as a protein kinase which plays a role in pathogen response and is regulated by H2O2 and PDK1 (3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1). A genetic analysis showed that double mutants of the two closely related PDK1.1 and PDK1.2 genes are defective in the growth response to P. indica. While OXI1 and PDK1 gene expression is upregulated in P. indica-colonized roots, defense genes are downregulated, indicating that the fungus suppresses plant defense reactions. PDK1 is activated by phosphatidic acid (PA) and P. indica triggers PA synthesis in Arabidopsis plants. Under beneficial co-cultivation conditions, H2O2 formation is even reduced by the fungus. Importantly, phospholipase D (PLD)α1 or PLDδ mutants, which are impaired in PA synthesis do not show growth promotion in response to fungal infection. These data establish that the P. indica-stimulated growth response is mediated by a pathway consisting of the PLD-PDK1-OXI1 cascade.
UR - http://www.scopus.com/inward/record.url?scp=79958068472&partnerID=8YFLogxK
U2 - 10.1371/journal.ppat.1002051
DO - 10.1371/journal.ppat.1002051
M3 - Article
C2 - 21625539
AN - SCOPUS:79958068472
SN - 1553-7366
VL - 7
JO - PLOS Pathogens
JF - PLOS Pathogens
IS - 5
M1 - e1002051
ER -