TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation: No preparation method is given. Preferred Components: The grass plant is: an agronomically elite grass plant; or a transgenic grass plant containing a transgene that confers reduced lignin content (preferred), herbicide tolerance, drought resistance, insect resistance, fungus resistance, virus resistance, bacteria resistance, male sterility, cold tolerance, salt tolerance, increased yield, enhanced nutrient use efficiency or increased fermentable carbohydrate content. The grass plant is switchgrass (preferred), wheat, durum wheat, tall wheatgrass, western wheatgrass, maize, rice, Sorghum, meadow Fescue, tall Fescue, cereal rye, Russian wild rye, oats, bermudagrass, Kentucky bluegrass, big bluestem, little bluestem, Miscanthus sp., Miscanthus x giganteus, blue grama, black grama, side-oat grama, johnsongrass, buffalo grass, creeping bentgrass or sugarcane. The switchgrass plant is an agronomically elite switchgrass plant. In the synthetic combination: the fungal endophyte colonizes a root tissue or a stem tissue of the grass plant; the grass plant displays increased biomass or vigor relative to a host grass plant of the same genotype that lacks the endophyte, when grown under the same conditions; and the host grass plant is artificially inoculated with the endophyte; the endophyte protects the host grass plant from biotic or abiotic stresses, where the biotic stress is insect infestation, rust infection, nematode infestation or herbivore grazing. In the synthetic combination, the combination is achieved by introduction of the endophyte to the host grass by a method including inoculation, infection and/or grafting, and the host plant is a forage grass host plant. Preferred Method: In the method of cultivating the grass plant, colonization of the grass is achieved by introduction of the fungal endophyte to the grass by a method including inoculation, infection and/or grafting. ACTIVITY - Plant Growth Stimulant; Plant Protectant.    MECHANISM OF ACTION - Gene therapy.    EXAMPLE - No suitable example given.