172 New Zealand Grassland Association: Endophyte Symposium (2007) (FOFUJDTUFTUTPGFDPMPHJDBMSPMFTPGFSHPUy $4DIBSEM%1BOBDDJPOF%1PUUFS4'MPSFB6)FTTF&,POOPWB.-JVy
deterred feeding and ergovaline suppressed appetite.
HN CO2H NH2 C OPPi H
#H
HN CO2H NH2 H H#
L-Trp DMAPP
DMATrp (1)
*
HN
2
HNH
chanoclavine-I (3)
CO2H NHCH3
H NHCH3
* OH
NHCH3
HN C *
H
chanoclavine-I- aldehyde (4)
O H
H
agroclavine (5)
N
*
HN
CH3
H H
CH3
elymoclavine (6)
N
HN
H H
CH3
dmaW
CH2OH
ergovaline (8)
N
HN
HCH3
cloA
CO2H
spont.?
N
HN
CH3 C
H O H
N O
N N
O O
H3C
CH3 H3C
OH H
L-Ala L-Val L-Pro lpsB + lpsA
D-lysergic acid (7)
Scheme 1
(FOFUJDTUFTUTPGFDPMPHJDBMSPMFTPGFSHPUBMLBMPJETQSPEVDFECZBOFQJDIMPÑ FOEPQIZUFPGSZFHSBTT
C.L. SCHARDL1, D.G. PANACCIONE2, D.A. POTTER1, S. FLOREA1, U. HESSE1, E. KONNOVA1, M. LIU1, C. MACHADO1 and J.T. STOKES1
1University of Kentucky, 201 PSB, 1405 Veterans Dr., Lexington, KY 40546-0312, U.S.A.
2West Virginia University, Division of Plant and Soil Sciences, 1090 Agricultural Sciences Building, Morgantown WV 26506-6108, U.S.A.
[email protected] Ergot alkaloids are produced by ergot fungi (Claviceps spp.)
that parasitise ears of grain, and related epichloë endophytes (Epichloë and Neotyphodium spp.) that systemically persist in grasses as protective mutualists. These alkaloids can serve as useful pharmaceuticals or can contaminate food, pasture or feed and thereby poison humans or livestock. Current understanding of the ergot alkaloid biosynthetic pathway is shown in Scheme 1, with labelled arrows indicating the roles of characterised genes. We sequenced ergot alkaloid gene clusters from Claviceps fusiformis, which produces elymoclavine (6) as an end product, and from the endophytes Epichloë festucae and Neotyphodium coenophialum, which produce ergovaline (8). Including dmaW, eight shared genes were identified, which may be sufficient
to direct the biosynthesis of 6. In addition, we have produced perennial ryegrass-Neotyphodium sp. symbiota in which the endophyte was disrupted in dmaW (and produced no ergot alkaloids), or in lpsA (and produced clavines), along with controls with the wild-type endophyte (producing ergovaline and clavines) and no endophyte (no ergot alkaloids). These symbiota were tested in preference and satiety tests with rabbits, and in preference and no-choice rearing tests with black cutworm (Agrotis ipsilon). Ergovaline deterred feeding by black cutworm in preference tests, and reduced growth and survival rates of cutworm in rearing tests. In rabbits, clavines deterred feeding and ergovaline suppressed appetite.
