Broad-Spectrum Suppression of Innate Immunity Is Required for Colonization of Arabidopsis Roots by the FungusPiriformospora indica
- 7 April 2011
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 156 (2), 726-740
- https://doi.org/10.1104/pp.111.176446
Abstract
Piriformospora indica is a root-colonizing basidiomycete that confers a wide range of beneficial traits to its host. The fungus shows a biotrophic growth phase in Arabidopsis (Arabidopsis thaliana) roots followed by a cell death-associated colonization phase, a colonization strategy that, to our knowledge, has not yet been reported for this plant. P. indica has evolved an extraordinary capacity for plant root colonization. Its broad host spectrum encompasses gymnosperms and monocotyledonous as well as dicotyledonous angiosperms, which suggests that it has an effective mechanism(s) for bypassing or suppressing host immunity. The results of our work argue that P. indica is confronted with a functional root immune system. Moreover, the fungus does not evade detection but rather suppresses immunity triggered by various microbe-associated molecular patterns. This ability to suppress host immunity is compromised in the jasmonate mutants jasmonate insensitive1-1 and jasmonate resistant1-1. A quintuple-DELLA mutant displaying constitutive gibberellin (GA) responses and the GA biosynthesis mutant ga1-6 (for GA requiring 1) showed higher and lower degrees of colonization, respectively, in the cell death-associated stage, suggesting that P. indica recruits GA signaling to help establish proapoptotic root cell colonization. Our study demonstrates that mutualists, like pathogens, are confronted with an effective innate immune system in roots and that colonization success essentially depends on the evolution of strategies for immunosuppression.Keywords
This publication has 54 references indexed in Scilit:
- Phytophthora infestans effector AVR3a is essential for virulence and manipulates plant immunity by stabilizing host E3 ligase CMPG1Proceedings of the National Academy of Sciences, 2010
- Differential innate immune signalling via Ca2+ sensor protein kinasesNature, 2010
- Shedding light on gibberellic acid signallingCurrent Opinion in Plant Biology, 2008
- Arabidopsis MAPKs: a complex signalling network involved in multiple biological processesBiochemical Journal, 2008
- Analyzing real-time PCR data by the comparative CT methodNature Protocols, 2008
- DELLAs Control Plant Immune Responses by Modulating the Balance of Jasmonic Acid and Salicylic Acid SignalingCurrent Biology, 2008
- CERK1, a LysM receptor kinase, is essential for chitin elicitor signaling in ArabidopsisProceedings of the National Academy of Sciences, 2007
- The root endophytic fungus Piriformospora indica requires host cell death for proliferation during mutualistic symbiosis with barleyProceedings of the National Academy of Sciences, 2006
- The plant immune systemNature, 2006
- OXI1 kinase is necessary for oxidative burst-mediated signalling in ArabidopsisNature, 2004