Volatile compounds of endophyte-free and infected tall fescue (Festuca arundinacea Schreb.)

Volatile compounds produced by intact plants and ground leaf tissue from en dophyte-infected (E+) and endophyte-free (E-) tall fescue (Festuca arundina cea Schreb.) were collected by a purge-and-trap procedure and analyzed by g as chromatography/mass spectrometry The volatile compound profile from grou nd leaf tissue was similar between E+ and E- clonal plants however, the she aths of E+ clonal Plants produced higher levels of 1-octen-3-ol, a characte ristic volatile compound derived from lipid peroxidation in fungi, which wa s absent in E- clonal plants. Intact plants produced fewer volatiles than m acerated leaves. At 25 degreesC, (Z)-3-hexen-1-ol acetate was the most abun dant compound, accounting for 77 and 89% of the total volatile emission fro m E+ and E-plants, respectively. Higher temperature (32 degreesC) significa ntly reduced the production of (Z)-3-hexen-1-ol acetate. Nonanal was the mo st abundant compound at 32 degreesC accounting for 52 and 45% of the total volatile emission from E+ and E- plants. Treatment of E+ and E- Plants With jasmonic acid (JA) dramatically altered the volatile compound profile. The levels of (E)-beta -ocimene increased more than 200-fold and accounted for at least 43% of the total volatile emission. Although the presence of endo phyte resulted in some qualitative and quantitative differences in the prod uction of volatile compounds, they are unlikely to account for the differen ces in insect resistance between E I and E- plants. Nevertheless, the produ ction of a unique spectrum of volatiles after JA treatment may represent a significant plant-based defense response in tall fescue that is independent of endophyte. (C) 2001 Elsevier Science Ltd. All rights reserved.