A perceived role of carbon and water management by systemic dark septate fungi in <i>Bouteloua eriopida</i> (Torr.) Torr. in an arid ecosystem

TitleA perceived role of carbon and water management by systemic dark septate fungi in Bouteloua eriopida (Torr.) Torr. in an arid ecosystem
Publication TypeConference Paper
Year of Publication2003
AuthorsBarrow J.R., Aaltonen R.E.
Conference NameFourth International Conference on Mycorrhizae
Date PublishedAugust 10-15, 20
Conference LocationMontreal, Canada
ARIS Log Number147792
AbstractDark septate endophytic (DSE) fungi are the prevalent symbionts of native grasses and shrubs in arid southwestern USA rangelands. The nature and extent of colonization of Bouteloua eriopida (Torr.) Torr., an important native range grass of the northern Chihuahuan Desert, was evaluated using dual staining, light and electron microscopy. Several unique and ecologically important features of DSE fungi were revealed. Fungi preferentially reside in the apoplastic environment and function as protoplasts identified by associated lipid bodies. They form systemic intercellular networks in plants and intracellular structures within sieve elements, parenchyma and cortical cells. Endophyte-free plants have not been developed but some fungi were cultured independently. The composite association results in a hybrid organism better equipped to survive in severe nutrient and water stressed ecosystems. Fungi formed stained and pigmented hyphae and microsclerotia, characteristic of DSE in less active tissues. Loosely organized hyphae, embedded within a mucilaginous matrix on the root surface, suggested a protective barrier from dry soil. A precisely organized hyphal network on the leaf surface suggested a protective barrier from atmospheric stress. Colonization of guard and subsidiary cells of the stomatal complex suggested an influence of stomatal regulation and transpiration. The size and quantity of fungal associated lipid bodies suggested a role of carbon storage and management within the ecosystem.