Submitted to: Wildland Shrub Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/15/2005
Publication Date: 8/1/2007
Citation: Barrow, J.R., Lucero, M.E., Osuna, P., Reyes, I., Aaltonen, R.E. 2007. Fungal genomes that influence basic physiological processes of black grama and fourwing saltbush in arid southwestern rangelands. In: Sosebee, R.E., Wester, D.B., Birton, D.M., McArthur, S.G., compilers. Proceedings: Shrubland Dynamics-Fire and Water, August 10-12, 2004, Lubbock, Texas. U.S. FOrest Service RMRS-P-27. p. 123-131. Interpretive Summary: Interpretive summary not required.
Technical Abstract: Symbiotic fungi confer multiple benefits such as enhanced photosynthetic rates and drought tolerance in host plants. Shrubs and grasses of southwestern deserts are colonized by symbiotic fungi that cannot be removed by conventional sterilization methods. These fungi were extensively studied in Bouteloua eriopoda (Torr.) Torr. and Atriplex canescens (Pursh) Nutt. over a wide range of locations and environmental conditions. Fungi were intrinsically integrated with cells, tissues, and regenerated plant cultures. These composite plant-fungus organisms are comprised of more than one fungal species. Fungal association with photosynthetic cells, accumulation of lipids provided evidence for carbon management. Fungal biofilms that coat cells, tissues, roots, and leaves suggest that they protect cells, roots, and leaves from direct exposure to stressed environments. Associations with vascular tissues suggested a role in resource transport. Association with stomata indicates an influence in gas exchange, photosynthesis, and evapotranspiration. Transfer of fungal endophytes from native plants to nonhost plants resulted in substantial modifications in root, shoot morphology and biomass, chlorophyll content, and fruiting. Host plants are modified by fungi at the genetic, cellular, and physiological levels and positively enhance ecological fitness.