Indica Colonization Research Articles

Effect of root colonization with Piriformospora indica and phosphate availability on the growth and reproductive biology of a Cyclamen persicum cultivar

This study examined the effects of root colonization with the symbiotic fungus Piriformospora indica on Cyclamen persicum ‘Melody’ if combined with different supplies of phosphates. The four test groups received a standard supply of phosphorus (P) with P. indica, a standard P supply without P. indica, a limited P supply with P. indica, and a limited P supply without P. indica. We examined the effects on both vegetative features (cultivation period required to obtain marketable plants, numbers of flowers and unfolded leaves, and plant diameter) and generative features (microsporogenesis and the viability of pollen and ovules). Results showed that both the supply of phosphate nutrients and P. indica have a significant impact on the development of vegetative and generative characteristics. It was also demonstrated that a standard P supply had a positive effect. In addition, the combination of a standard P supply and P. indica colonization had an even greater positive effect, with P. indica inoculation enhancing P absorption by a significant amount. The numbers of flowers and unfolded leaves and the plant diameter increased, and the growing period required to obtain marketable plants was reduced by one week. When a standard P supply was combined with P. indica inoculation, flowers developed the highest proportion of homogeneous microspores, and both pollen grains and ovules achieved maximum viability. The poorest results were obtained for the group that received little P fertilizer and no P. indica inoculation. P. indica inoculation improved pollen and ovule viability in both groups, but most significantly in the group that also received ample P. Holding the P supply even, the group without P. indica inoculation displayed lower viability. The P supply was revealed as the dominant factor. Plants that received ample P developed more viable pollen and ovules on average than did plants that were less adequately supplied.

In vitro plant development and root colonization of Coleus forskohlii by Piriformospora indica

The present study was conducted for optimization of in vitro substrates under aseptic conditions for interaction of Piriformospora indica with the medicinal plant Coleus forskohlii. It aims to test the effects of different substrates on P. indica colonization as well as growth parameters of the in vitro raised C. forskohlii. Interaction of in vitro C. forskohlii with root endophyte P. indica under aseptic condition resulted in increase in growth parameters in fungus colonized plants. It was observed that P. indica promoted the plant's growth in all irrespective of substrates used for co-culture study. The growth was found inferior in liquid compared to semisolid medium as well as there was problem of hyperhydricity in liquid medium. P. indica treated in vitro plantlets were better adapted for establishment under green house compared to the non treated plants due to fungal intervention.

Piriformospora indica rescues growth diminution of rice seedlings during high salt stress

Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress.

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?