Interactions of Piriformospora indica with Medicinal Plants

Abstract

The microbial world exerts a negative as well a positive impact on living plants and animals, and forms an association either pathogenic or symbiotic with the other partners of the living world. Mycorrhiza refers to an association or symbiosis between plants and fungi that colonize the roots during periods of active plant growth. The intimate symbiotic relationships developed between mycorrhizal fungi and plants, since the colonization of land by the latter, have led to interdependence between these organisms for many basic processes. The fungi require plants to accomplish their life cycle. Plants depend heavily on mycorrhizal fungi for many different functions, such as mineral nutrition and abiotic and biotic stress resistance. Substantial evidence has accumulated in the recent past about how the use of the microsymbiont could significantly contribute in decreasing use of fertilizers and pesticides in agriculture, forestry and flori-hortriculture, especially if combined with other beneficial soil microorganisms.The most common and prevalent arbuscular mycorrhizal fungi play an indispensable role in upgrading plant growth, vigor and survival by a positive impact on the nutritional and hydratic status of the plant and on soil health, by increasing the reproductive potential, improving root performance, and providing a natural defence against invaders, including pests and pathogens. The described species of arbuscular mycorrhizal fungi mainly belong to Zygomycetes placed in the order Glomerales. However, the growing of arbuscular mycorrhizae in pure culture in the absence of living host roots is a matter of global concern. Unfortunately, their biotechnological applications cannot be exploited to the level they deserve due to their axenically unculturable nature.