Sterol distribution in arbuscular mycorrhizal fungi

The sterol composition of spores from 16 species of arbuscular mycorrhizal fungi belonging to the order Glomales were examined by GC-MS. The major com pound was found to be 24-ethylcholesterol (up to 85%) followed by cholester ol (up to 15%). Several other sterols such as 24-methylcholesterol, Delta 5 -avenasterol and 24-ethylcholesta-5,22.dien-3 beta-ol were also detected. S ignificant amounts of alpha-amyrin, a common vascular plant triterpene. war e present in the spores of all the fungal species analyzed. The absence of ergosterol, a classical fungal sterol. is discussed in relation to fungal e volution. (C): 1999 Elsevier Science Ltd. All rights reserved.