Indole-3-Acetaldoxime-Derived Compounds Restrict Root Colonization in the Beneficial Interaction Between Arabidopsis Roots and the Endophyte Piriformospora indica

• DOI: 10.1094/mpmi-03-12-0071-r
• Publication Date: 2012-08-01T20:29:27Z
• Authors: Pyniarlang L. Non...; Joy Michal Johnson; Irena Sherameti; Erich Glawischnig; Barbara Ann Halkier; Ralf Oelmüller
• Keywords: Phenylalanine ammonia-lyase; Endophyte

The growth-promoting and root-colonizing endophyte Piriformospora indica induces camalexin the expression of CYP79B2, CYP79B3, CYP71A13, PAD3, WRKY33 required for synthesis indole-3-acetaldoxime (IAOx)-derived compounds in roots Arabidopsis seedlings. Upregulation mRNA levels by P. requires cytoplasmic calcium elevation mitogen-activated protein kinase 3 but not root-hair-deficient 2, radical oxygen production, or 3-phosphoinositide-dependent 1/oxidative signal-inducible 1 pathway. Because indica-mediated growth promotion is impaired cyp79B2 cyp79B3 seedlings, while pad3 seedlings-which do accumulate camalexin-still respond to fungus, IAOx-derived other than (e.g., indole glucosinolates) are during early phases beneficial interaction. seedlings more colonized wild-type roots, upregulation defense genes pathogenesis-related (PR)-1, PR-3, PDF1.2, phenylalanine ammonia lyase, germin indicates that mutant responds lack activating processes. After 6 weeks on soil, no longer upregulated wild-type, cyp79B3, roots. This results uncontrolled fungal reduced performance mutants. We propose a long-term harmony between two symbionts restriction root colonization compounds.