Submitted to: Mycorrhiza
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/23/2002
Publication Date: 10/1/2003
Citation: BARROW, J.R. ATYPICAL MORPHOLOGY OF DARK SEPTATE FUNGAL ROOT ENDOPHYTES OF BOUTELOUA IN ARID SOUTHWESTERN USA RANGELANDS. MYCORRHIZA. 2003. V. 13(5). P. 239-247. Interpretive Summary: Roots of native range grasses were found to be extensively colonized by symbiotic fungi. Using new methods we found that these fungi produce internal structures not previously reported in other pathogenic or symbiotic fungi. They take photosynthetic carbon from the plant transfer it to developing plant roots and to the root surface where it is converted to mucilage, which protects roots from dry soil. These results indicate that the fungi provide a key ecological function and are important in plant longevity.
Technical Abstract: Roots of native grama grasses (Bouteloua sp) analyzed for internal colonization of fungal endophytes using histochemical stains and differential interference microscopy. Unique and atypical fungal structures were found to form a continuous nonpathogenic colonization of sieve elements, cortical, epidermal cells, and the root hairs and surface. Unique interfaces with sieve elements, the accumulation of large quantitie of lipids and their distribution throughout the root and the deposition of mucilage on the root surface indicates that dark septate fungi manage carbon between the plant and soil and protect the plant from drought stress. The nondestructive colonization of sieve elements suggests a novel plant-fungal association not previously reported.