A method of protecting a host grass from stress, such as caused by insect pests, by artificially inoculating the host grass with an endophyte-containing composition is disclosed. The endophyte produces loline at a level sufficient to confer protection to the endophyte-infected host grass and does not produce detectable levels of alkaloids having toxicity to ruminant animals such as sheep, cattle, goats, or deer. In vitro cultures of the endophyte Neotyphodium uncinatum, var. U2 are disclosed as well as infected plants and seeds. The infected plants and seeds produce 5.0-20,000 μg lolines per gram dry weight of grass and do not produce detectable levels of alkaloids having toxicity to ruminant animals such as ergovaline, peramine, lolitrem B and epoxy-Janthitrems.
