Plant Sciences Department, Rothamsted Research, Harpenden, UK.
FEBS Lett. 2020 Jun;594(11):1770-1777. doi: 10.1002/1873-3468.13762. Epub 2020 Mar 3.
Arbuscular mycorrhizal (AM) fungi are oleaginous organisms, and the most abundant fatty acyl moiety usually found in their lipids is palmitvaccenic acid (16:1 ). However, it is not known how this uncommon fatty acid species is made. Here, we have cloned two homologues of lepidopteran fatty acyl-coenzyme A Δ11 desaturases from the AM fungus Rhizophagus irregularis. Both enzymes, DES1 and DES2, are expressed in intraradical mycelium and can complement the unsaturated fatty acid-requiring auxotrophic growth phenotype of the Saccharomyces cerevisiae ole1Δ mutant. DES1 expression leads almost exclusively to oleic acid (18:1 ) production, whereas DES2 expression results in the production of 16:1 and vaccenic acid (18:1 ). DES2 therefore encodes a Δ11 desaturase that is likely to be responsible for the synthesis of 16:1 in R. irregularis.
丛枝菌根（AM）真菌是油性生物体，其脂质中最丰富的脂肪酸部分通常是棕榈油酸（16:1）。然而，目前尚不清楚这种不常见的脂肪酸是如何产生的。在这里，我们从 AM 真菌球毛壳菌中克隆了两种鳞翅目脂肪酸辅酶 A Δ11 去饱和酶的同源物。这两种酶（DES1 和 DES2）都在菌根内菌丝中表达，并能互补酿酒酵母 ole1Δ 突变体不饱和脂肪酸所需的营养缺陷型生长表型。DES1 的表达几乎只导致油酸（18:1）的产生，而 DES2 的表达则导致 16:1 和 蓖麻酸（18:1）的产生。因此，DES2 编码的 Δ11 去饱和酶可能负责合成 R. irregularis 中的 16:1。
