Indica Colonization Research Articles

Piriformospora indica antagonizes cyst nematode infection and development in Arabidopsis roots

The beneficial endophytic fungus Piriformospora indica colonizes the roots of many plant species, including the model plant Arabidopsis thaliana. Its colonization promotes plant growth, development, and seed production as well as resistance to various biotic and abiotic stresses. In the present work, P. indica was tested as potential antagonist of the sedentary plant-parasitic nematode Heterodera schachtii. This biotrophic cyst-forming nematode induces severe host plant damage by changing the morphogenesis and physiology of infected roots. Here it is shown that P. indica colonization, as well as the application of fungal exudates and cell-wall extracts, significantly affects the vitality, infectivity, development, and reproduction of H. schachtii.

Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

Piriformospora indica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P . indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P . indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P . indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P . indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P . indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

Ethylene – a key arbitrator to plant–fungal symbiotic interactions?

Ethylene – a key arbitrator to plant–fungal symbiotic interactions?