Department of Biology, University of Fribourg, Fribourg, Switzerland.
Laboratoire de Recherche en Sciences Végétales, UPS, CNRS, Université de Toulouse, Castanet-Tolosan 31326, France.
Trends Plant Sci. 2021 Feb;26(2):111-123. doi: 10.1016/j.tplants.2020.09.006. Epub 2020 Sep 30.
Arbuscular mycorrhizal fungi (AMF) live as obligate root symbionts on almost all land plants. They have long been regarded as ancient asexuals that have propagated clonally for millions of years. However, genomic studies in Rhizophagus irregularis and other AMF revealed many features indicative of sex. Surprisingly, comparative genomics of conspecific isolates of R. irregularis revealed an unexpected interstrain diversity, suggesting that AMF carry a high number of lineage-specific (LS) genes. Intriguingly, cryptic sex and LS genomic regions have previously been reported in a number of fungal pathogens of plants and humans. Here, we discuss these genomic similarities and highlight their potential relevance for AMF adaptation to the environment and for symbiotic functioning.
丛枝菌根真菌（AMF）作为专性根共生体存在于几乎所有陆地植物上。长期以来，它们被认为是无性繁殖的古老生物，已经无性繁殖了数百万年。然而，对不规则隔孢丛梗孢菌和其他 AMF 的基因组研究表明，它们具有许多有性特征。令人惊讶的是，对不规则隔孢丛梗孢菌同种分离株的比较基因组学揭示了一种出乎意料的种内多样性，表明 AMF 携带大量谱系特异性（LS）基因。有趣的是，先前在一些植物和人类病原真菌中也报道了隐型有性生殖和 LS 基因组区域。在这里，我们讨论了这些基因组的相似性，并强调了它们对 AMF 适应环境和共生功能的潜在相关性。
