Bacterial blight of cotton

Bacterial blight of cotton (Gossypium ssp.), caused by Xanthomonas citri pathovar malvacearum, is a severe disease occurring in all cotton-growing areas. The interactions between host plants and the bacteria are based on the gene-for-gene concept, representing a complex resistance gene/avr gene system. In light of the recent data, this review focuses on the understanding of these interactions with emphasis on (1) the genetic basis for plant resistance and bacterial virulence, (2) physiological mechanisms involved in the hypersensitive response to the pathogen, including hormonal signaling, the oxylipin pathway, synthesis of antimicrobial molecules and alteration of host cell structures, and (3) control of the disease

Rethinking childhood ependymoma: a retrospective, multi-center analysis reveals poor long-term overall survival

Ependymoma is the third most common brain tumor in children, but there is a paucity of large studies with more than 10 years of follow-up examining the long-term survival and recurrence patterns of this disease. We conducted a retrospective chart review of 103 pediatric patients with WHO Grades II/III intracranial ependymoma, who were treated at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center and Chicago’s Ann & Robert H. Lurie Children’s Hospital between 1985 and 2008, and an additional 360 ependymoma patients identified from the Surveillance Epidemiology and End Results (SEER) database. For the institutional cohort, we evaluated clinical and histopathological prognostic factors of overall survival (OS) and progression-free survival (PFS) using the log-rank test, and univariate and multivariate Cox proportional-hazards models. Overall survival rates were compared to those of the SEER cohort. Median follow-up time was 11 years. Ten-year OS and PFS were 50 ± 5% and 29 ± 5%, respectively. Findings were validated in the independent SEER cohort, with 10-year OS rates of 52 ± 3%. GTR and grade II pathology were associated with significantly improved OS. However, GTR was not curative for all children. Ten-year OS for patients treated with a GTR was 61 ± 7% and PFS was 36 ± 6%. Pathological examination confirmed most recurrent tumors to be ependymoma, and 74% occurred at the primary tumor site. Current treatment paradigms are not sufficient to provide long-term cure for children with ependymoma. Our findings highlight the urgent need to develop novel treatment approaches for this devastating disease. Electronic supplementary material The online version of this article (doi:10.1007/s11060-017-2568-8) contains supplementary material, which is available to authorized users

Relation of Dietary Patterns and Nutritional Profile to Hepatic Fibrosis in a Sample of Lebanese Non-Alcoholic Fatty Liver Disease Patients

International audienceNon-alcoholic fatty liver disease (NAFLD) is considered the most common liver injury worldwide. NAFLD can evolve into non-alcoholic steatohepatitis (NASH) with or without fibrosis. The objectives of this study were to determine the nutritional profile and dietary patterns of NAFLD Lebanese patients and to report the type of diet-related to the presence of hepatic fibrosis. We hypothesized that the traditional pattern was related to a low risk of fibrosis. This cross-sectional study included 320 eligible Lebanese NAFLD patients. Three dietary patterns were identified: the Traditional diet, the High Fruit diet, and the Westernized diet. Multivariate analysis showed a significant relationship between high adherence to the traditional diet and absence of hepatic fibrosis with a decreased risk of 82%, p = 0.031 after adjusting for its covariables. Fruits were absent from this dietary pattern. Although our results pointed to a possible relationship between fibrosis in NAFLD patients and fruit intake, experimental studies are needed to show whether this is a causal relationship. However, the results obtained in this study may contribute to the planning of dietary interventions and recommendations and enable a better follow-up for NAFLD patients with fibrosis

La résistance du cotonnier Gossypium hirsutum à la bactériose causée par Xanthomonas campestris pathovar malvacearum (rôle du gène GhLOX1 dans la réaction hypersensible)

La RH est une réaction de défense. L interaction entre G.hirsutum et Xcm repose sur le concept gène-à-gène. L infection du cultivar Réba B50 possédant les gènes R B2B3 par Xcm18 conduit à une RH associée à une activité LOX, responsable de la peroxydation des lipides, et à la transcription du GhLOX1. Premièrement, 6 génotypes de G.hirsutum contenant divers gènes R ont été retenus pour analyser la variabilité de la réponse LOX suite à l infection par Xcm1, 18 ou 20. Notre étude a porté sur plusieurs critères, le phénotype, la perte en eau, l activité LOX et la transcription du GhLOX1. Les résultats montrent une variabilité du phénotype RH en fonction des sources de résistances. Pour chaque type d interaction incompatible, l activité LOX et la transcription du GhLOX1 révèlent une augmentation significative corrélée à l apparition des symptômes RH et à la diminution de la teneur en eau. La réponse LOX est conservée lors de la RH, quelle que soit la race de Xcm ou le génotype. Le GhLOX1 considère comme un marqueur moléculaire de la résistance spécifique du cotonnier à Xcm. Deuxièmement, le rôle du GhLOX1dans la mise en place de la RH en analysant sa fonction potentielle par surexpression. Des cotylédons ont été transformés avec la séquence codante GhLOX1 fusionnée au CaMV35S. Ces cotylédons transformés ont révélé (i) une activité LOX significativement supérieure à celle des cotylédons témoins montrant que le GhLOX1 code pour une protéine active et (ii) un phénotype sans modifications apparentes par rapport à celui des cotylédons non transformées, sauf dans certains contextes d interactions cotonnier/Xcm où la surexpression de ce gène induit l apparition de symptômes de type RH. L effet de l agro-infiltration sur l expression de certains gènes pendant la transformation a révélé l induction précoce et non spécifique de l expression de gènes de défense. Ces travaux constituent une première étape dans l analyse fonctionnelle du GhLOX1 dans la résistance spécifique du cotonnier à XcmThe HR is a defense strategy. The interaction between G.hirsutum and Xcm is governed by the gene-for-gene concept. The infection of the cultivar Reba B50 that contains B2B3 R genes by race Xcm18 leads to a HR associated with a LOX activity response involved in peroxidation of lipids and with transcription of GhLOX1. First, 6 genotypes of G. hirsutum containing various R genes were tested to analyze the variability of the LOX response following the infection by Xcm1, 18 or 20. Several criteria were investigated including the phenotype, the water loss, the LOX activity and GhLOX1 transcription. The results showed variation in HR phenotype according to the tested R genes. For each type of the incompatible interaction, LOX activity and transcription of GhLOX1 were always significantly increased paralleled the apparition of the HR symptoms and the decrease in the water content. LOX response (enzymatic activity and GhLOX1 transcription) is associated with HR whatever the genotype of both Xcm races and cotton plant. Thus, the GhLOX1 consider as a molecular marker of the cotton specific resistance to Xcm. Second, the role of the GhLOX1 gene in the execution of the cotton HR to Xcm by analyzing its possible function by over-expression, the cotyledons were transformed with the GhLOX1 coding sequence fused to the CaMV35S. These transformed cotyledons revealed (i) a LOX activity significantly higher than that detected in the control, showing that the GhLOX1 encodes for an active protein and (ii) that the phenotype of these cotyledons was indistinguishable as compared to the non transformed cotyledons, except when the HR symptoms were induced in some GhLOX1-over-expressed cotyledons. The effect of agro-infiltration on expression of some plant genes during the transformation revealed early and nonspecific induction of the expression of defense genes. This work constitutes a preliminary investigation for the functional analysis of the GhLOX1 in order to assess its role in the cotton specific resistance to XcmNANCY-INPL-Bib. électronique (545479901) / SudocSudocFranceF

Nutritional Profile and Dietary Patterns of Lebanese Non-Alcoholic Fatty Liver Disease Patients: A Case-Control Study

Nonalcoholic fatty liver disease (NAFLD) is considered the most common liver disease in the world. Dietary habits have a significant impact on the biological and physical profile of patients and increase the risk of NAFLD. The overall pattern of diet intake is more associated with health outcomes than nutrients. The aim of this study was to evaluate the nutritional profile and the dietary patterns of Lebanese NAFLD patients and compare it with controls. During this study; 112 NAFLD Lebanese adult patients (55 men and 57 women); and 110 controls (44 men and 66 women) were recruited. Dietary intake was evaluated by two 24-h recalls and a semi-quantitative 90-item food frequency questionnaire. Dietary patterns were determined by factor analysis. Results from the study demonstrated that 40% of cases belonged to the high fruit group as compared to 30% following a high meat; fast food dietary pattern. Both groups increased the odds of NAFLD by four-fold (p < 0.05). The traditional diet decreases the odds by 33% after adjustment with the covariables. The high fruit diet group was, as with the high meat, fast food dietary pattern, the main potential risk factor for NAFLD in Lebanese patients

Bacterial blight of cotton

International audienceBacterial blight of cotton (Gossypium ssp.), caused by Xanthomonas citri pathovar malvacearum, is a severe disease occurring in all cotton-growing areas. The interactions between host plants and the bacteria are based on the gene-for-gene concept, representing a complex resistance gene/avr gene system. In light of the recent data, this review focuses on the understanding of these interactions with emphasis on (1) the genetic basis for plant resist-ance and bacterial virulence, (2) physiological mechanisms involved in the hypersensitive response to the patho-gen, including hormonal signaling, the oxylipin pathway, synthesis of antimicrobial molecules and alteration of host cell structures, and (3) control of the disease

A 13-lipoxygenase is expressed early in the hypersensitive reaction of cotton plants to Xanthomonas campestris pv. malvacearum

Lipoxygenases (LOXs) are enzymes responsible for lipid peroxidation processes during plant defence responses to pathogen infection. Jasmonates are lipid-derived signals that mediate plant stress responses with chloroplastic LOXs implicated in the biosynthesis of oxylipins like jasmonic acid (JA). Hypersensitive reaction (HR) cell death of cotton to the incompatible race 18 of Xanthomonas campestris pathovar malvacearum (Xcm) is associated with 9S-lipoxygenase activity and expression of a 9-LOX GhLOX1. Here, we report the cloning of cotton (Gossypium hirsutum L.) LOX gene GhLOX2. Sequence analysis showed that GhLOX2 is a putative 13-LOX with a chloroplast-transit peptide in the amino acid terminus. GhLOX2 was found to be significantly expressed in the first hour of Xcm-induced HR. Investigation into LOX signalization on cotyledons incubated with methyl-jasmonate (MeJA) or infiltrated with salicylic acid (SA) or ethylene (ET) revealed that the first two treatments induced GhLOX2 gene expression. Our results show that GhLOX2 gene expression occurred at the stage of the HR prior biochemical events previously highlighted. The role that GhLOX2 may have in the defence strategy of cotton to Xcm is discussed regarding the HR

Association of lipoxygenase response with resistance of various cotton genotypes to the bacterial blight disease

In cotton plants (Gossypium hirsutum L.), the interaction with the bacterial pathogen Xanthomonas campestris pv. malvacearum (Xcm) is governed by the gene-for-gene concept. The interaction between the cultivar Reba B50 and the race 18 of Xcm leads to an hypersensitive reaction (HR); this cultivar is, however, susceptible to the race 20, with the death of the plant as a consequence. Previous work showed that the induced HR was correlated with 9S-lipoxygenase (LOX) activity responsible for lipid peroxidation. A LOX gene (GhLOX1) whose activity is involved in cell death during HR was characterized. In this study, we investigated whether the lipoxygenase response could be related to cotton resistance in different cotton Xcm combinations. Various combinations of R - avr genes were selected to assess whether the GhLOX1 gene transcription and LOX activity could be correlated with the resistance phenotype. Cotton genotypes with the B2B3, B(2)b(6) or B-12 genes, or cotton near-isogenic lines containing single B genes (B-2, b(6)) were infected by race 1, 18 or 20 of Xcm. Phenotypes were analysed for all interactions tested. For incompatible interactions, the LOX response appears to be concomitantly triggered during cotton resistance strengthening the previous evidence that this reaction is a key event of hypersensitive cell death