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Abstract:

The purpose of this article is to discuss the mutualistic mechanism of grass/endophyte. Studies on Epichlo? species and the asexual anamorphic Neotyphodium species indicates that life histories of Epichlo? species have higher plasticity and Neotyphodium species derived from interspecific hybridization of Epichlo? species and consequently evolving higher specifity symbiosis. Benefits of the asexual reproduction are efficient protection by plant and vertical transmission via host seeds. The symbionts have a series of physiological adaptive characters such as enhanced drought tolerance (osmotic adjustment.), induction of plant hormone and endophyt-deriving alkaloids. Endophyte enhance water use efficiency, growth and productivity of plant. Endophyte, meanwhile, as a xenobiotic component of a grass, may induce a permanent internal stress in the host grass. This may precondition or sensitize the plant to drought and other stresses. Alkaloids protect host plants against herbivores, insects, nematodes and other pathogenic fungi. The symbionts may change soil nutriment level in a long time scale and can alter competitive interactions with other plants, reducing biodiversity in successional fields. Fungal endophytes control food-web structure by disrupting the transfer of energy from plants to upper trophic levels and exert a regulatory force on food-web dynamics.