Are endophytes an important link between airborne spores and allergen exposure?

Abstract

Grasses represent one of the Earth's most common plant groups, and natural and cultivated habitats dominated by grasses cover about 40% of the land surface. In turn, each grass species hosts multiple fungal species which can behave as endophytes. An analysis of the endophytic taxa identified in surveys conducted in 14 grass species showed that some of the most frequent taxa on each grass were also present across several host grasses. These taxa were Alternaria, Epicoccum, Cladosporium, Fusarium, and a few others. A similar analysis of airborne fungi surveyed at 41 different locations throughout the world showed that some of the most geographically widespread, and most locally frequent airborne fungi belonged to the same genera that are dominant endophytes in grasses (i.e.Cladosporium, Alternaria, Fusarium, etc.). Therefore, airborne spores of genera that are ubiquitous in grasses are common worldwide and attain high atmospheric concentrations. In addition, spores of the above mentioned fungi are also important respiratory allergens. Direct observation indicates that saprobic colonization and sporulation of non-systemic grass endophytes could become unrestrained when their host plant tissue dies. Subsequently, when appropriate environmental conditions favour sporulation on grass host surfaces, the natural cycle for airborne conidia initiates, and large numbers of these conidia disperse as inoculum for new endophytic infections. Therefore, the cycle of endophytism may be an important link between climate, plant biology and public health.

Fungi in a changing world: growth rates will be elevated, but spore production may decrease in future climates

“…It is well documented (Carlile et al 2007;De Aldana et al 2013) that many of the fungal species examined here are either saprotrophs or endophytes or plant parasites. This means that they are closely related with (symbiotic relationship) or dependent on (parasitic relationship) their host organisms, that is plants, living or dead.…”

Long-term trends in airborne fungal-spore concentrations: a comparison with pollen

“…As many of the fungal species examined here are either saprotrophs or endophytes (Carlile et al, 2007;V azquez de Aldana et al, 2013), they are closely related with or dependent on their host, which is plant material, living or dead. A decreasing trend of fungal-spore abundance together with a delayed onset of the spore season could be the outcome of a delayed sporulation stage because of a prolonged vegetative stage.…”

Diversidad de micobiota en diferentes especies de hormigas cortadoras de hojas y sitios de Argentina

“…and Trichoderma spp. can grow in plants, some of them as parasitic organisms (Fisher et al 1996;Fröhlich and Hyde 1999;Hashizume et al 2008;Shali et al 2010;Suryanarayanan et al 2009;Vázquez de Aldana et al 2013). The functional role of the mycobiota present in leaf-cutting ant colonies is still not known.…”