The OXI1 Kinase Pathway Mediates Piriformospora indica-Induced Growth Promotion in Arabidopsis

PLoS Pathogens

Ralf Oelmüller¹  Bationa Shahollari²  Jyothilakshmi Vadassery²  Irena Sherameti²  Corinna Drzewiecki²  Iris Camehl²  Teun Munnik³  Heribert Hirt⁴  Celine Forzani⁴ 

[1] College of Science, King Saud University, Riyadh, Saudi Arabia;Friedrich Schiller University Jena, Institute of General Botany and Plant Physiology, Jena, Germany;Section Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands;URGV Plant Genomics, INRA-CNRS-University of Evry, Evry, France

关键词: Arabidopsis thaliana;    Fungi;    Protein kinase signaling cascade;    Protein kinases;    Gene expression;    Plant defenses;    Root hairs;    Seedlings;   

DOI  :  10.1371/journal.ppat.1002051

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

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.

【 授权许可】

CC BY