scholarly journals Xanthomonas transcriptome inside cauliflower hydathodes reveals bacterial virulence strategies and physiological adaptation at early infection stages

2021 ◽  
Author(s):  
Julien S. Luneau ◽  
Aude Cerutti ◽  
Brice Roux ◽  
Sébastien Carrère ◽  
Marie-Françoise Jardinaud ◽  
...  
Keyword(s):  
Stress Responses ◽  
Xanthomonas Campestris ◽  
Plant Immunity ◽  
Adaptive Strategy ◽  
Physiological Adaptation ◽  
Transcriptional Reprogramming ◽  
Expression Of Genes ◽  
Rot Disease ◽  
Tissue Alterations ◽  
Type Three Secretion

AbstractXanthomonas campestris pv. campestris (Xcc) bacterium is a seed-transmitted vascular pathogen causing black rot disease on cultivated and wild Brassicaceae. Xcc enters the plant tissues preferentially via hydathodes which are organs localized at leaf margins. In order to decipher both physiological and virulence strategies deployed by Xcc during early stages of infection, the transcriptomic profile of Xcc was analyzed three days after entry into cauliflower hydathodes. Despite the absence of visible plant tissue alterations and a bacterial biotrophic lifestyle, 18% of Xcc genes undergo a transcriptional reprogramming, including a striking repression of chemotaxis and motility functions. Xcc full repertoire of virulence factors was not yet activated but the expression of the 95-gene HrpG regulon, including genes coding for the type three secretion machinery important for suppression of plant immunity, was induced. The expression of genes involved in metabolic adaptations such as catabolism of plant compounds, transport functions, sulfur and phosphate metabolism was upregulated while limited stress responses were observed three days post infection. These transcriptomic observations give information about the nutritional and stress status of bacteria during the early biotrophic infection stages and help to decipher the adaptive strategy of Xcc to the hydathode environment.

scholarly journals Exposure to Cadmium Elevates Expression of Genes in the OxyR and OhrR Regulons and Induces Cross-Resistance to Peroxide Killing Treatment in Xanthomonas campestris

2005 ◽  
Vol 71 (4) ◽  
pp. 1843-1849 ◽  
Author(s):  
Peerakan Banjerdkij ◽  
Paiboon Vattanaviboon ◽  
Skorn Mongkolsuk
Keyword(s):  
Induced Resistance ◽  
Stress Responses ◽  
Xanthomonas Campestris ◽  
Cadmium Toxicity ◽  
Cross Resistance ◽  
Organic Hydroperoxide ◽  
Alkyl Hydroperoxide ◽  
Expression Of Genes ◽  
Low Concentrations ◽  
Peroxide Stress

ABSTRACT Cadmium is an important heavy metal pollutant. For this study, we investigated the effects of cadmium exposure on the oxidative stress responses of Xanthomonas campestris, a soil and plant pathogenic bacterium. The exposure of X. campestris to low concentrations of cadmium induces cross-protection against subsequent killing treatments with either H2O2 or the organic hydroperoxide tert-butyl hydroperoxide (tBOOH), but not against the superoxide generator menadione. The cadmium-induced resistance to peroxides is due to the metal's ability to induce increased levels of peroxide stress protective enzymes such as alkyl hydroperoxide reductase (AhpC), monofunctional catalase (KatA), and organic hydroperoxide resistance protein (Ohr). Cadmium-induced resistance to H2O2 is dependent on functional OxyR, a peroxide-sensing transcription regulator. Cadmium-induced resistance to tBOOH shows a more complex regulatory pattern. The inactivation of the two major sensor-regulators of organic hydroperoxide, OxyR and OhrR, only partially inhibited cadmium-induced protection against tBOOH, suggesting that these genes do have some role in the process. However, other, as yet unknown mechanisms are involved in inducible organic hydroperoxide protection. Furthermore, we show that the cadmium-induced peroxide stress response is mediated by the metal's ability to predominately cause an increase in intracellular concentrations of organic hydroperoxide and, in part, H2O2. Analyses of various mutants of peroxide-metabolizing enzymes suggested that this increase in organic hydroperoxide levels is, at least in part, responsible for cadmium toxicity in Xanthomonas.

scholarly journals The host exocyst complex is targeted by a conserved bacterial type III effector protein that promotes virulence

2020 ◽  
Author(s):  
Vassiliki A. Michalopoulou ◽  
Konstantinos Kotsaridis ◽  
Glykeria Mermigka ◽  
Dina Kotsifaki ◽  
Michael Kokkinidis ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Xanthomonas Campestris ◽  
Plant Immunity ◽  
Gram Negative Bacteria ◽  
Callose Deposition ◽  
Type Iii ◽  
Exocyst Complex ◽  
Successful Infection ◽  
Rot Disease ◽  
Bacterial Type

ABSTRACTFor most Gram-negative bacteria, pathogenicity largely depends on the type-III secretion system that delivers virulence effectors into eukaryotic cells. The subcellular targets for the majority of these effectors remain unknown. Here, we show that Xanthomonas campestris, the causal agent of black rot disease, delivers the highly conserved effector XopP that interacts with host’s EXO70 protein. EXO70 is an essential component of the exocyst complex with a role in plant immunity. The XopP/EXO70 interaction is specific and inhibits exocyst-dependent exocytosis without activating a specific plant NLR receptor that guards EXO70. In this way, Xanthomonas efficiently inhibits the host’s PAMP-triggered immunity (PTI) by blocking exocytosis of PR1, callose deposition and the FLS2 immunity-receptor translocation to the plasma membrane, promoting successful infection.

scholarly journals Whole-Genome DNA Methylation Analysis in Hydrogen Peroxide Overproducing Transgenic Tobacco Resistant to Biotic and Abiotic Stresses

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 178
Author(s):  
Ana L. Villagómez-Aranda ◽  
Luis F. García-Ortega ◽  
Irineo Torres-Pacheco ◽  
Ramón G. Guevara-González
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Methylation ◽  
Transgenic Tobacco ◽  
Stress Responses ◽  
Abiotic Stresses ◽  
Methylation Status ◽  
Physiological Adaptation ◽  
Whole Genome ◽  
Sequencing Analysis ◽  
Biotic And Abiotic Stresses

Epigenetic regulation is a key component of stress responses, acclimatization and adaptation processes in plants. DNA methylation is a stable mark plausible for the inheritance of epigenetic traits, such that it is a potential scheme for plant breeding. However, the effect of modulators of stress responses, as hydrogen peroxide (H2O2), in the methylome status has not been elucidated. A transgenic tobacco model to the CchGLP gene displayed high H2O2 endogen levels correlated with biotic and abiotic stresses resistance. The present study aimed to determine the DNA methylation status changes in the transgenic model to obtain more information about the molecular mechanism involved in resistance phenotypes. The Whole-genome bisulfite sequencing analysis revealed a minimal impact of overall levels and distribution of methylation. A total of 9432 differential methylated sites were identified in distinct genome regions, most of them in CHG context, with a trend to hypomethylation. Of these, 1117 sites corresponded to genes, from which 83 were also differentially expressed in the plants. Several genes were associated with respiration, energy, and calcium signaling. The data obtained highlighted the relevance of the H2O2 in the homeostasis of the system in stress conditions, affecting at methylation level and suggesting an association of the H2O2 in the physiological adaptation to stress functional linkages may be regulated in part by DNA methylation.

scholarly journals WRKY Transcription Factors in Cassava Contribute to Regulation of Tolerance and Susceptibility to Cassava Mosaic Disease through Stress Responses

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1820
Author(s):  
Warren Freeborough ◽  
Nikki Gentle ◽  
Marie E. C. Rey
Keyword(s):  
Transcription Factors ◽  
Stress Responses ◽  
Regulatory Networks ◽  
Large Scale ◽  
Mosaic Disease ◽  
African Cassava Mosaic Virus ◽  
Cassava Mosaic Disease ◽  
Manihot Esculenta Crantz ◽  
Transcriptional Reprogramming ◽  
Negative Role

Among the numerous biological constraints that hinder cassava (Manihot esculenta Crantz) production, foremost is cassava mosaic disease (CMD) caused by virus members of the family Geminiviridae, genus Begomovirus. The mechanisms of CMD tolerance and susceptibility are not fully understood; however, CMD susceptible T200 and tolerant TME3 cassava landraces have been shown to exhibit different large-scale transcriptional reprogramming in response to South African cassava mosaic virus (SACMV). Recent identification of 85 MeWRKY transcription factors in cassava demonstrated high orthology with those in Arabidopsis, however, little is known about their roles in virus responses in this non-model crop. Significant differences in MeWRKY expression and regulatory networks between the T200 and TME3 landraces were demonstrated. Overall, WRKY expression and associated hormone and enriched biological processes in both landraces reflect oxidative and other biotic stress responses to SACMV. Notably, MeWRKY11 and MeWRKY81 were uniquely up and downregulated at 12 and 67 days post infection (dpi) respectively in TME3, implicating a role in tolerance and symptom recovery. AtWRKY28 and AtWRKY40 homologs of MeWRKY81 and MeWRKY11, respectively, have been shown to be involved in regulation of jasmonic and salicylic acid signaling in Arabidopsis. AtWRKY28 is an interactor in the RPW8-NBS resistance (R) protein network and downregulation of its homolog MeWRKY81 at 67 dpi in TME3 suggests a negative role for this WRKY in SACMV tolerance. In contrast, in T200, nine MeWRKYs were differentially expressed from early (12 dpi), middle (32 dpi) to late (67 dpi) infection. MeWRKY27 (homolog AtWRKY33) and MeWRKY55 (homolog AtWRKY53) were uniquely up-regulated at 12, 32 and 67 dpi in T200. AtWRKY33 and AtWRKY53 are positive regulators of leaf senescence and oxidative stress in Arabidopsis, suggesting MeWRKY55 and 27 contribute to susceptibility in T200.

scholarly journals Evaluating the Antibacterial Activity and Mode of Action of Thymol-Loaded Chitosan Nanoparticles Against Plant Bacterial Pathogen Xanthomonas campestris pv. campestris

2022 ◽  
Vol 12 ◽  
Author(s):  
Sarangapani Sreelatha ◽  
Nadimuthu Kumar ◽  
Tan Si Yin ◽  
Sarojam Rajani
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Xanthomonas Campestris ◽  
Membrane Damage ◽  
Chitosan Nanoparticles ◽  
Bacterial Pathogen ◽  
Electron Microscopy Analysis ◽  
Rot Disease ◽  
The Impact

The bacterium Xanthomonas campestris pv. campestris (Xcc) causes black rot disease in cruciferous crops, resulting in severe yield loss worldwide. The excessive use of chemical pesticides in agriculture to control diseases has raised significant concern about the impact on the environment and human health. Nanoparticles have recently gained significant attention in agriculture owing to their promising application in plant disease control, increasing soil fertility and nutrient availability. In the current study, we synthesized thymol-loaded chitosan nanoparticles (TCNPs) and assessed their antibacterial activity against Xcc. The synthesis of TCNPs was confirmed by using ultraviolet–visible spectroscopy. Fourier-transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy analysis revealed the functional groups, size, and shape of TCNPs, with sizes ranging from 54 to 250 nm, respectively. The antibacterial activity of TCNPs against Xcc was investigated in vitro by liquid broth, cell viability, and live dead staining assay, and all of them demonstrated the antibacterial activity of TCNPs. Furthermore, TCNPs were found to directly inhibit the growth of Xcc by suppressing the growth of biofilm formation and the production of exopolysaccharides and xanthomonadin. The ultrastructure studies revealed membrane damage in TCNP-treated Xcc cells, causing a release of intracellular contents. Headspace/gas chromatography (GC)–mass spectrometry (MS) analysis showed changes in the volatile profile of Xcc cells treated with TCNPs. Increased amounts of carbonyl components (mainly ketones) and production of new volatile metabolites were observed in Xcc cells incubated with TCNPs. Overall, this study reveals TCNPs as a promising antibacterial candidate against Xcc.

scholarly journals A Simple and Low-Cost Strategy to Improve Conidial Yield and Stress Resistance of Trichoderma guizhouense through Optimizing Illumination Conditions

2022 ◽  
Vol 8 (1) ◽  
pp. 50
Author(s):  
Yifan Li ◽  
Xiya Meng ◽  
Degang Guo ◽  
Jia Gao ◽  
Qiwei Huang ◽  
...  
Keyword(s):  
Blue Light ◽  
Stress Responses ◽  
Stress Resistance ◽  
Low Cost ◽  
Hog Pathway ◽  
Precise Control ◽  
Blue Light Receptor ◽  
Expression Of Genes ◽  
Low Cost Strategy ◽  
Stress Related Genes

Light is perceived by photoreceptors in fungi and further integrated into the stress-activated MAPK HOG pathway, and thereby potentially activates the expression of genes for stress responses. This indicates that the precise control of light conditions can likely improve the conidial yield and stress resistance to guarantee the low cost and long shelf life of Trichoderma-based biocontrol agents and biofertilizers. In this study, effects of wavelengths and intensities of light on conidial yield and stress tolerance to osmotic, oxidative and pH stresses in Trichoderma guizhouense were investigated. We found that 2 μmol photons/(m2 × s) of blue light increased the conidial yield more than 1000 folds as compared to dark condition and simultaneously enhanced conidial stress resistance. The enhanced conidial stress resistance is probably due to the upregulated stress-related genes in blue light, which is under the control of the blue light receptor BLR1 and the MAP kinase HOG1.

scholarly journals Genome-wide analysis of CrRLK1L genes and their expression profiling during fiber development in cotton

2020 ◽  
Author(s):  
Dongyun Zuo ◽  
Javaria Ashraf ◽  
Hailiang Cheng ◽  
Shang Liu ◽  
Youping Zhang ◽  
...  
Keyword(s):  
Stress Responses ◽  
Plant Immunity ◽  
Fiber Development ◽  
The Other ◽  
Element Analysis ◽  
Specific Expression ◽  
Group Iii ◽  
Group I ◽  
Genome Wide ◽  
Specific Expression Pattern

Abstract Background: Catharanthus roseus receptor-like kinase 1-like (CrRLK1Ls) proteins play important roles in cell growth, plant morphogenesis, reproduction, hormone signaling, plant immunity and stress responses in Arabidopsis. However, not much information is available about their functions during cotton fiber development.Results: We identified a total of 125, 73 and 71 full-length putative CrRLK1L genes in G. hirsutum, G. arboreum and G. raimondii, which are much greater than that of the other plants. The phylogenetic and gene structure analysis divided the cotton CrRLK1L genes into six major groups, among which only group I and II contained AtCrRLK1Ls of Arabidopsis, suggesting that other groups (group III-VI) were expanded by gene duplication during cotton evolution. Genome collinearity analysis revealed that half of the At02 genes in G. hirsutum derived from A02 of G. arboreum, while the other half (GhCrRLK1L6 and GhCrRLK1L7) originated from Dt03 and Dt02 of G. raimondii, indicating segmental duplication between noncorresponding chromosomes during polyploidization of G. hirsutum. In addition, expression and cis-element analysis revealed that only 22 GhCrRLK1Ls showed specific expression pattern during fiber development which are mainly due to the presence of binding sites for NAC, MYB and WRKY transcription factors.Conclusions: This study provides a strong foundation to further explore the molecular mechanism of CrRLK1L genes during fiber development in upland cotton.

scholarly journals Early life adversity and the epigenetic programming of hypothalamic-pituitary-adrenal function

2014 ◽  
Vol 16 (3) ◽  
pp. 321-333 ◽  
Keyword(s):  
Stress Responses ◽  
Childhood Adversity ◽  
Adrenal Function ◽  
Early Life Adversity ◽  
Hypothalamic Pituitary Adrenal ◽  
Expression Of Genes ◽  
Epigenetic Programming ◽  
Social Adversity ◽  
Wide Range ◽  
Nonhuman Species

We review studies with human and nonhuman species that examine the hypothesis that epigenetic mechanisms, particularly those affecting the expression of genes implicated in stress responses, mediate the association between early childhood adversity and later risk of depression. The resulting studies provide evidence consistent with the idea that social adversity, particularly that involving parent-offspring interactions, alters the epigenetic state and expression of a wide range of genes, the products of which regulate hypothalamic-pituitary-adrenal function. We also address the challenges for future studies, including that of the translation of epigenetic studies towards improvements in treatments.

scholarly journals The Hypersensitive Induced Reaction and Leucine-Rich Repeat Proteins Regulate Plant Cell Death Associated with Disease and Plant Immunity

2011 ◽  
Vol 24 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Hyong Woo Choi ◽  
Young Jin Kim ◽  
Byung Kook Hwang
Keyword(s):  
Cell Death ◽  
Xanthomonas Campestris ◽  
Plant Immunity ◽  
Yeast Cells ◽  
Leucine Rich Repeat ◽  
Virus Induced Gene Silencing ◽  
Susceptible Cell ◽  
Gene Transcripts ◽  
Induced Reaction ◽  
Pepper Plants

Pathogen-induced programmed cell death (PCD) is intimately linked with disease resistance and susceptibility. However, the molecular components regulating PCD, including hypersensitive and susceptible cell death, are largely unknown in plants. In this study, we show that pathogen-induced Capsicum annuum hypersensitive induced reaction 1 (CaHIR1) and leucine-rich repeat 1 (CaLRR1) function as distinct plant PCD regulators in pepper plants during Xanthomonas campestris pv. vesicatoria infection. Confocal microscopy and protein gel blot analyses revealed that CaLRR1 and CaHIR1 localize to the extracellular matrix and plasma membrane (PM), respectively. Bimolecular fluorescent complementation and coimmunoprecipitation assays showed that the extracellular CaLRR1 specifically binds to the PM-located CaHIR1 in pepper leaves. Overexpression of CaHIR1 triggered pathogen-independent cell death in pepper and Nicotiana benthamiana plants but not in yeast cells. Virus-induced gene silencing (VIGS) of CaLRR1 and CaHIR1 distinctly strengthened and compromised hypersensitive and susceptible cell death in pepper plants, respectively. Endogenous salicylic acid levels and pathogenesis-related gene transcripts were elevated in CaHIR1-silenced plants. VIGS of NbLRR1 and NbHIR1, the N. benthamiana orthologs of CaLRR1 and CaHIR1, regulated Bax- and avrPto-/Pto-induced PCD. Taken together, these results suggest that leucine-rich repeat and hypersensitive induced reaction proteins may act as cell-death regulators associated with plant immunity and disease.

Sign in / Sign up

Export Citation Format

Share Document