An ancestral signalling pathway is conserved in intracellular symbioses-forming plant lineages

First author: Guru V. Radhakrishnan; Affiliations: John Innes Centre (约翰英纳斯中心): Norwich, UK

Corresponding author: Pierre-Marc Delaux 

Plants are the foundation of terrestrial ecosystems, and their colonization of land was probably facilitated by mutualistic associations with arbuscular mycorrhizal fungi. Following this founding event, plant diversification has led to the emergence of a tremendous diversity of mutualistic symbioses with microorganisms, ranging from extracellular associations to the most intimate intracellular associations, where fungal or bacterial symbionts are hosted inside plant cells. Here, through analysis of 271 transcriptomes and 116 plant genomes spanning the entire land-plant diversity, we demonstrate that a common symbiosis signalling pathway co-evolved with intracellular endosymbioses, from the ancestral arbuscular mycorrhiza to the more recent ericoid and orchid mycorrhizae in angiosperms and ericoid-like associations of bryophytes. By contrast, species forming exclusively extracellular symbioses, such as ectomycorrhizae, and those forming associations with cyanobacteria, have lost this signalling pathway. This work unifies intracellular symbioses, revealing conservation in their evolution across 450 million yr of plant diversification.

植物是陆地生态系统的基础，并且其与丛枝菌根真菌之间互惠的关系可能促进了植物对于陆地环境的殖民。植物的多样化导致了其与微生物之间形成了多种不同形式的互惠关系，从细胞外互惠到真菌或细菌直接寄主在植物细胞内的胞内互惠。本文中，通过对代表整个陆地植物的116个陆地植物基因组以及271个转录组的分析，作者发现一个共同的共生信号通路与细胞内内共生（endosymbioses）一起共同演化，从古老的丛枝菌根到更具现代的被子植物杜鹃科菌根和兰科菌根，以及苔藓植物中的类杜鹃科菌根。相反，只有细胞外共生关系的物种，比如外生菌根以及与蓝细菌形成共生关系的物种，这些物种均丢失了该类共生信号通路。本文的工作说明了植物中的胞内共生属于“同宗同源”，并且揭示了在植物450个百万年的多样化演化过程中，该共生关系仍然保守。

通讯：Pierre-Marc Delaux (http://www.cnrs.fr/en/node/3627)

个人简介：2011年，法国图卢兹大学，博士。

研究方向： 植物与土壤微生物之间的共生相互作用及其进化。

doi: https://doi.org/10.1038/s41477-020-0613-7

Journal: Nature Plants

Published date: March 02, 2020