Jenkins, D. J. | bioRxiv Science

bioRxiv2021

Characterization of vaginal microbial enzymes identifies amylopullulanases that support growth of Lactobacillus crispatus on glycogen

The healthy human vaginal microbiota is generally dominated by lactobacilli, and the transition to a more diverse community of anaerobic microbes is associated with health risks. Glycogen released by lysed epithelial cells is believed to be an important nutrient source in this environment. However, the mechanism by which vaginal bacteria metabolize glycogen is unclear, with evidence implicating both microbial and human enzymes. Here, we biochemically characterize six glycogen-degrading enzymes (GDEs) from vaginal bacteria that support the growth of amylase-deficient L. crispatus on glycogen. We reveal variations in the pH tolerance and susceptibility to inhibition between enzymes from different organisms. Analysis of vaginal microbiome datasets show these enzymes are expressed in all Community State Types. Finally, we confirm the presence and activity of bacterial GDEs in cervicovaginal fluid. This work establishes that bacterial GDEs can participate in the breakdown of glycogen, providing insight into metabolism that may shape the vaginal microbiota.

biochemistry↗

bioRxiv2018

Cell type identity determines transcriptomic immune responses in Arabidopsis thaliana roots.

Root pathogens are a major threat in global crop production and protection strategies are required to sustainably enhance the efficiency of root immunity. Our understanding of root immunity is still limited relative to our knowledge of immune responses in leaves. In an effort to reveal the organisation of immunity in roots, we undertook a cell type-specific transcriptome analysis to identify gene networks activated in epidermis, cortex and pericycle cells of Arabidopsis roots upon treatment with two immunity elicitors, the bacterial microbe-associated molecular pattern flagellin, and the endogenous damage-associated molecular pattern Pep1. Our analyses revealed that both elicitors induced immunity gene networks in a cell type-specific manner. Interestingly, both elicitors did not alter cell identity-determining gene networks. Using sophisticated paired motif promoter analyses, we identified key transcription factor pairs involved in the regulation of cell type-specific immunity networks. In addition, our data show that cell identity networks integrate with cell immunity networks to activate cell type-specific immune response according to the functional capabilities of each cell type.\n\nMaterial Distribution FootnoteThe author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantcell.org) is: Patrick Schafer (p.schafer@warwick.ac.uk).

plant biology↗