Endophyte effects on dehydrins, antioxidants, and membrane leakage in drought-stressed tall fescue.
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Authors:
R.D. Carson* - Univ. of Arkansas C.P. West - Univ. of Arkansas B.D. De los Reyes - Univ. of Maine S. Rajguru - Univ. of Arkansas C.A. Guerber - Univ. of Arkansas
Abstract:
Tall fescue (Festuca arundinacea Schreb.), a major forage grass grown in the southeastern U.S. has a mutualistic relationship with the endophytic fungus Neotyphodium coenophialum. The endophyte typically enhances survival of
vegetative tillers during summer drought; however, the physiological mechanisms are not understood. Our greenhouse studies used two tall fescue clones containing different native endophyte genotypes. Water potentials, expression of dehydrin proteins,antioxidant levels, membrane damage in tiller bases were measured in response to drought stress and endophyte infection. Endophyte-infected plants maintained higher turgor and lower osmotic potential than endophyte-free plants, accumulated more dehydrin proteins, and had slightly higher antioxidant activities throughout the drought-stress periods. Membrane leakage was slightly, though nonsignificantly, inhibited, and tiller survival was significantly enhanced by endophyte presence. Results suggest that the endophyte may promote tall fescue drought survival by membrane and cell protection mechanisms involving various protein types.
Speaker Information: Rachel Carson, Univ. of Arkansas, Dept. CSES1366 West Altheirmer Dr., Fayetteville, AR 72701; Phone: 479-575-4243; E-mail:
Session Information: Wednesday, November 3, 2004, 8:25 AM-12:00 PM Presentation Start: 11:15 AM
Keywords: Festuca arundinacea; Neotyphodium coenphialum; dehydrin; antioxidant enzymes
