Transcription activator-like effector protects bacterial endosymbionts from entrapment within fungal hyphae
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
As an endosymbiont of the ecologically and medically relevant fungus Rhizopus microsporus, the toxin-producing bacterium Mycetohabitans rhizoxinica faces myriad challenges, such as evading the host’s defense mechanisms. However, the bacterial effector(s) that facilitate the remarkable ability of M. rhizoxinica to freely migrate within fungal hyphae have thus far remained unknown. Here, we show that a transcription activator-like (TAL) effector released by endobacteria is an essential symbiosis factor. By combining microfluidics with fluorescence microscopy, we observed enrichment of TAL-deficient M. rhizoxinica in side hyphae. High-resolution live imaging showed the formation of septa at the base of infected hyphae, leading to the entrapment of endobacteria. Using a LIVE/DEAD stain, we demonstrate that the intracellular survival of trapped TAL-deficient bacteria is significantly reduced compared with wild-type M. rhizoxinica, indicative of a protective host response in the absence of TAL proteins. Subversion of host defense in TAL-competent endobacteria represents an unprecedented function of TAL effectors. Our data illustrate an unusual survival strategy of endosymbionts in the host and provide deeper insights into the dynamic interactions between bacteria and eukaryotes.
Date Issued
2023-07-10
Date Acceptance
2023-05-12
Citation
Current Biology, 2023, 33 (13), pp.2646-2656.e4
ISSN
0960-9822
Publisher
Cell Press
Start Page
2646
End Page
2656.e4
Journal / Book Title
Current Biology
Volume
33
Issue
13
Copyright Statement
© 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Identifier
http://dx.doi.org/10.1016/j.cub.2023.05.028
Publication Status
Published
Date Publish Online
2023-06-09