TY  - JOUR
A1  - Botero, David
A1  - Monk, Jonathan
A1  - Rodriguez Cubillos, Maria Juliana
A1  - Rodriguez Cubillos, Andres Eduardo
A1  - Restrepo, Mariana
A1  - Bernal-Galeano, Vivian
A1  - Reyes, Alejandro
A1  - Gonzalez Barrios, Andres
A1  - Palsson, Bernhard O.
A1  - Restrepo, Silvia
A1  - Bernal, Adriana
T1  - Genome-scale metabolic model of Xanthomonas phaseoli pv. manihotis
BT  - an approach to elucidate pathogenicity at the metabolic level
JF  - Frontiers in genetics
N2  - Xanthomonas phaseoli pv. manihotis (Xpm) is the causal agent of cassava bacterial blight, the most important bacterial disease in this crop. There is a paucity of knowledge about the metabolism of Xanthomonas and its relevance in the pathogenic process, with the exception of the elucidation of the xanthan biosynthesis route. Here we report the reconstruction of the genome-scale model of Xpm metabolism and the insights it provides into plant-pathogen interactions. The model, iXpm1556, displayed 1,556 reactions, 1,527 compounds, and 890 genes. Metabolic maps of central amino acid and carbohydrate metabolism, as well as xanthan biosynthesis of Xpm, were reconstructed using Escher (https://escher.github.io/) to guide the curation process and for further analyses. The model was constrained using the RNA-seq data of a mutant of Xpm for quorum sensing (QS), and these data were used to construct context-specific models (CSMs) of the metabolism of the two strains (wild type and QS mutant). The CSMs and flux balance analysis were used to get insights into pathogenicity, xanthan biosynthesis, and QS mechanisms. Between the CSMs, 653 reactions were shared; unique reactions belong to purine, pyrimidine, and amino acid metabolism. Alternative objective functions were used to demonstrate a trade-off between xanthan biosynthesis and growth and the re-allocation of resources in the process of biosynthesis. Important features altered by QS included carbohydrate metabolism, NAD(P)(+) balance, and fatty acid elongation. In this work, we modeled the xanthan biosynthesis and the QS process and their impact on the metabolism of the bacterium. This model will be useful for researchers studying host-pathogen interactions and will provide insights into the mechanisms of infection used by this and other Xanthomonas species.
KW  - Xanthomonas
KW  - Xpm
KW  - cassava bacterial blight
KW  - genome-scale metabolic
KW  - model
KW  - quorum sensing
Y1  - 2020
U6  - https://doi.org/10.3389/fgene.2020.00837
SN  - 1664-8021
VL  - 11
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Smith, Sarah R.
A1  - Dupont, Chris L.
A1  - McCarthy, James K.
A1  - Broddrick, Jared T.
A1  - Obornik, Miroslav
A1  - Horak, Ales
A1  - Füssy, Zoltán
A1  - Cihlar, Jaromir
A1  - Kleessen, Sabrina
A1  - Zheng, Hong
A1  - McCrow, John P.
A1  - Hixson, Kim K.
A1  - Araujo, Wagner L.
A1  - Nunes-Nesi, Adriano
A1  - Fernie, Alisdair
A1  - Nikoloski, Zoran
A1  - Palsson, Bernhard O.
A1  - Allen, Andrew E.
T1  - Evolution and regulation of nitrogen flux through compartmentalized metabolic networks in a marine diatom
JF  - Nature Communications
N2  - Diatoms outcompete other phytoplankton for nitrate, yet little is known about the mechanisms underpinning this ability. Genomes and genome-enabled studies have shown that diatoms possess unique features of nitrogen metabolism however, the implications for nutrient utilization and growth are poorly understood. Using a combination of transcriptomics, proteomics, metabolomics, fluxomics, and flux balance analysis to examine short-term shifts in nitrogen utilization in the model pennate diatom in Phaeodactylum tricornutum, we obtained a systems-level understanding of assimilation and intracellular distribution of nitrogen. Chloroplasts and mitochondria are energetically integrated at the critical intersection of carbon and nitrogen metabolism in diatoms. Pathways involved in this integration are organelle-localized GS-GOGAT cycles, aspartate and alanine systems for amino moiety exchange, and a split-organelle arginine biosynthesis pathway that clarifies the role of the diatom urea cycle. This unique configuration allows diatoms to efficiently adjust to changing nitrogen status, conferring an ecological advantage over other phytoplankton taxa.
KW  - Biochemistry
KW  - Computational biology and bioinformatics
KW  - Evolution
KW  - Microbiology
KW  - Molecular biology
Y1  - 2019
U6  - https://doi.org/10.1038/s41467-019-12407-y
SN  - 2041-1723
VL  - 10
PB  - Nature Publ. Group
CY  - London
ER  -