Biosynthesis and accumulation of ergoline alkaloids in a mutualistic association between Ipomoea asarifolia (Convolvulaceae) and a clavicipitalean fungus - Markert, A; Steffan, N; Ploss, K; Hellwig, S; Steiner, U; Drewke, C; Li, S M; Boland, W; Leistner, E (Plant Physiol, 2008)