Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2005
Publication Date: 4/1/2006
Citation: Lucero, M.E., Barrow, J.R., Osuna, P., Reyes, I. 2006. Plant-fungal interactions in arid and semi-arid ecosystems: Large-scale impacts from microscale processes. Journal of Arid Environments. 65:276-284. Interpretive Summary: This study describes the identification of several endophytic fungi which we have found living within the cells of two important range plant species, Bouteloa eriopoda (black grama) and Atriplex canescens (four wing saltbush). We believe these fungi serve to enhance plant tolerance to desert environments. Inoculation of black grama seedings with callus tissue from the hardier four-wing saltbush, or from the desert grass, sand dropseed (Sporoboulus cryptandrus), produces black grama with greater biomass and more extensive root systems than were observed in uninnoculated controls. We believe our desert plants contain a multitude of endophytes which could be used in a similar manner to dramatically modify existing plant species. Beneficial applications of this technology could include development of hardier plant species for revegetation as well as for production agricluture.
Technical Abstract: The roles microbes play in shaping plant communities have historically been underestimated. Recent improvements in our abilities to detect, identify, and monitor microbial inhabitants of plant tissues are driving appreciation of amazingly complex dynamics. Microbial endophytes can modify plants at genetic, physiologic, and ecologic levels, inducing profound changes in the way plants respond to their environment. Microscale examination of Bouteloua eriopoda (black grama) and Atriplex canescens (four-wing saltbush) has revealed diverse fungal communities associated with individual plants at the cellular and subcellular levels. To explore thresholds of plant fitness defined by microbial communities, we transferred fungi inhabiting two perennial grasses, B. eriopoda and Sporobolus cryptandrus (sand dropseed), and one shrub, A. canescens, to a variety of nonhost plant species. Dramatic, whole-plant differences in morphology and biomass between treated and untreated plants were observed. In most cases, endophyte transfer at the cellular level produced larger plants with greater reproductive potential than the untransformed counterparts. We hypothesize that these transformed plants will continue to grow, reproduce, and disperse more rapidly than their native counterparts, propagating changes from the plant-microbe interface to ecologically significant scales.