Modification and uses of endophyte-enhanced turfgrasses: A role for molecular technology

Over the past decade, the significance of symbiotic fungal endophytes in turfgrasses was established as having the potential for supplementing the genetics of turfgrass improvement since endophyte-infected grasses frequently show enhanced performance. Endophyte-enhanced traits include insect and mammalian deterrence to herbivory, and often increased tolerance of drought and other abiotic stresses. However, not all endophytes are suited for use in enhancing grass performance, and only those fungi that are symptomless endophytes of grasses are currently being used. The endophytes that are of the major focus for current use include species of Neotyphodium (=Acremonium), e.g., N. coenophialum, N. lolii, and other species of Neotyphodium. The Neotyphodium endophytes do not reproduce sexually, and only produce conidia under laboratory culture, suggesting that they should be genetically stable. These endophytes can be removed from the host, transformed by molecular technology, and reinserted into the host. However, these fungi have other means for genetic variation, which might include chromosome polymorphisms, altered chromosome structures, and loss of nonessential chromosomes. Thus, the genetics related to ani endophyte-enhanced trait of that turfgrass might not be stable. However, the potential for genetic engineering of the endophytes is growing nearer with recent application of DNA mediated techniques. Furthermore, genetic engineering or other approaches may soon lead to endophyte-grass associations that have further enhanced fitness or are more benign to wildlife. Before such genetically modified systems are marketed, particular attention and extensive field tests should be applied to ensure that they retain their beneficial characteristics and have truly acquired their intended improvements. Continued research into the biochemical and genetics basis of endophyte-enhanced traits should eventually identify genes that ultimately can be use for the production of transgenic grasses.