80 research outputs found
Arabidopsiscell wall composition determines disease resistance specificity and fitness
[EN] Plant cell walls are complex structures subject to dynamic remodeling
in response to developmental and environmental cues and
play essential functions in disease resistance responses. We tested
the specific contribution of plant cell walls to immunity by
determining the susceptibility of a set of Arabidopsis cell wall mutants
(cwm) to pathogens with different parasitic styles: a vascular
bacterium, a necrotrophic fungus, and a biotrophic oomycete. Remarkably,
most cwm mutants tested (29/34; 85.3%) showed alterations
in their resistance responses to at least one of these
pathogens in comparison to wild-type plants, illustrating the relevance
of wall composition in determining disease-resistance phenotypes.
We found that the enhanced resistance of cwm plants to
the necrotrophic and vascular pathogens negatively impacted
cwm fitness traits, such as biomass and seed yield. Enhanced resistance
of cwm plants is not only mediated by canonical immune
pathways, like those modulated by phytohormones or microbeassociated
molecular patterns, which are not deregulated in the
cwm tested. Pectin-enriched wall fractions isolated from cwm
plants triggered immune responses in wild-type plants, suggesting
that wall-mediated defensive pathways might contribute to cwm
resistance. Cell walls of cwm plants show a high diversity of composition
alterations as revealed by glycome profiling that detect
specific wall carbohydrate moieties. Mathematical analysis of glycome
profiling data identified correlations between the amounts of
specific wall carbohydrate moieties and disease resistance phenotypes
of cwm plants. These data support the relevant and specific
function of plant wall composition in plant immune response modulation
and in balancing disease resistance/development trade-offs.SIThis work has been also financially supported by the Severo Ochoa Program for Centers of Excellence in R&D from the Agencia Estatal de Investigación of Spain (Grant SEV-2016-0672 (2017-2021) to the Centro de Biotecnología y Genómica de Plantas). In the frame of this program, H.M. was a postdoctoral fellow. H.M. was also supported by an Individual Fellowship grant (SignWALLINg-624721) from the European Union. E.M. was a Juan de la Cierva Postdoctoral Fellow from MINECO, and L.B. was a Formacion Personal Investigador fellow of MICIU. The generation of the CCRC-series of plant cell glycan-directed monoclonal antibodies used in this work was supported by the US NSF (DBI-0421683 and IOS 0923992) to M.G.H
Human Papillomaviruses and genital co-infections in gynaecological outpatients
<p>Abstract</p> <p>Background</p> <p>High grade HPV infections and persistence are the strongest risk factors for cervical cancer. Nevertheless other genital microorganisms may be involved in the progression of HPV associated lesions.</p> <p>Methods</p> <p>Cervical samples were collected to search for human Papillomavirus (HPV), bacteria and yeast infections in gynaecologic outpatients. HPV typing was carried out by PCR and sequencing on cervical brush specimens. <it>Chlamydia trachomatis </it>was identified by strand displacement amplification (SDA) and the other microorganisms were detected by conventional methods.</p> <p>Results</p> <p>In this cross-sectional study on 857 enrolled outpatients, statistical analyses revealed a significant association of HPV with <it>C. trachomatis </it>and <it>Ureaplasma urealyticum (</it>at high density) detection, whereas no correlation was found between HPV infection and bacterial vaginosis, <it>Streptococcus agalactiae</it>, yeasts, <it>Trichomonas vaginalis </it>and <it>U. urealyticum</it>. <it>Mycoplasma hominis </it>was isolated only in a few cases both in HPV positive and negative women and no patient was infected with <it>Neisseria gonorrhoeae</it>.</p> <p>Conclusion</p> <p>Although bacterial vaginosis was not significantly associated with HPV, it was more common among the HPV positive women. A significant association between HPV and <it>C. trachomatis </it>was found and interestingly also with <it>U. urealyticum </it>but only at a high colonization rate. These data suggest that it may be important to screen for the simultaneous presence of different microorganisms which may have synergistic pathological effects.</p
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