164 research outputs found
Direct involvement of leucine-rich repeats in assembling ligand-triggered receptor-coreceptor complexes
Receptor kinases with leucine-rich repeat (LRR) extracellular domains form the largest family of receptors in plants. In the few cases for which there is mechanistic information, ligand binding in the extracellular domain often triggers the recruitment of a LRR-coreceptor kinase. The current model proposes that this recruitment is mediated by their respective kinase domains. Here, we show that the extracellular LRR domain of BRI1-ASSOCIATED KINASE1 (BAK1), a coreceptor involved in the disparate processes of cell surface steroid signaling and immunity in plants, is critical for its association with specific ligand-binding LRR-containing receptors. The LRRs of BAK1 thus serve as a platform for the molecular assembly of signal-competent receptors. We propose that this mechanism represents a paradigm for LRR receptor activation in plants
Brassinosteroids modulate the efficiency of plant immune responses to microbe-associated molecular patterns
Metazoans and plants use pattern recognition receptors (PRRs) to sense conserved microbial-associated molecular patterns (MAMPs) in the extracellular environment. In plants, the bacterial MAMPs flagellin and elongation factor Tu (EF-Tu) activate distinct, phylogenetically related cell surface pattern recognition receptors of the leucine-rich repeat receptor kinase (LRR-RK) family called FLS2 and EF-Tu receptor, respectively. BAK1 is an LRR-RK coreceptor for both FLS2 and EF-Tu receptor. BAK1 is also a coreceptor for the plant brassinosteroid (BR) receptor, the LRR-RK BRI1. Binding of BR to BRI1 primarily promotes cell elongation. Here, we tune the BR pathway response to establish how plant cells can generate functionally different cellular outputs in response to MAMPs and pathogens. We demonstrate that BR can act antagonistically or synergistically with responses to MAMPs. We further show that the synergistic activities of BRs on MAMP responses require BAK1. Our results highlight the importance of plant steroid homeostasis as a critical step in the establishment of plant immunity. We propose that tradeoffs associated with plasticity in the face of infection are layered atop plant steroid developmental programs
Barriers to the delivery of diabetes care in the Middle East and South Africa: a survey of 1,082 practising physicians in five countries
SUMMARY Aims: Developing countries face a high and growing burden of type 2 diabetes. We surveyed physicians in a diverse range of countries in the Middle East and Africa (Egypt, Kingdom of Saudi Arabia, United Arab Emirates, South Africa and Lebanon) with regard to their perceptions of barriers to type 2 diabetes care identified as potentially important in the literature and by the authors. Methods: One thousand and eighty-two physicians completed a questionnaire developed by the authors. Results: Most physicians enroled in the study employed guideline-driven care; 80–100% of physicians prescribed metformin (with lifestyle intervention, where there are no contraindications) for newly diagnosed type 2 diabetes, with lifestyle intervention alone used where metformin was not prescribed. Sulfonylureas were prescribed widely, consistent with the poor economic status of many patients. About one quarter of physicians were not undertaking any form of continuing medical education, and relatively low proportions of practices had their own diabetes educators, dieticians or diabetic foot specialists. Physicians identified the deficiencies of their patients (unhealthy lifestyles, lack of education and poor diet) as the most important barriers to optimal diabetes care. Low-treatment compliance was not ranked highly. Access to physicians did not appear to be a problem, as most patients were seen multiple times per year. Conclusions: Physicians in the Middle East and South Africa identified limitations relating to their patients as the main barrier to delivering care for diabetes, without giving high priority to issues relating to processes of care delivery. Further study would be needed to ascertain whether these findings reflect an unduly physician-centred view of their practice. More effective provision of services relating to the prevention of complications and improved lifestyles may be needed. What's known It is known that the success of care for diabetes depends critically on the delivery of optimised care for diabetic patients. Many barriers to the delivery of such care have been identified. Relatively little is known regarding how these barriers influence the delivery of diabetes care in the Middle East and South Africa. What's new Physicians generally followed management guidelines in type 2 diabetes care. Perceived barriers to optimal diabetes care mainly focussed on attributes of patients, rather than process issues in care or aspects of the physicians' practice
The NutriScore logo: A tool for the Moroccan consumer
Le Plan d’Action National pour la réduction de la consommation du Sel, du Sucre et du Gras 2017-2021 (PANSSG) vise à réduire graduellement, en collaboration avec l’industrie alimentaire, la teneur en sel, sucre et graisses (SSG) des produits transformés et à sensibiliser la population aux dangers sur la santé de l’excès de leurs consommations du SSG. Aussi, l’activité 17 du PANSSG traite de la création d’un label ou logo attestant de la qualité nutritionnelle globale des aliments. La mise en place au Maroc d’un logo nutritionnel sur la face avant des emballages des aliments peut donc contribuer à l’objectif de sensibilisation des consommateurs sur la qualité nutritionnelle globale des aliments (intégrant leurs teneurs en SSG et densité calorique) tout en incitant les industriels à améliorer la qualité nutritionnelle de leurs produits en réduisant la teneur en ces nutriments pour bénéficier d’un positionnement plus favorable sur le logo nutritionnel. En effet, le logo nutritionnel Nutri-Score est un logo coloriel couplé à des lettres décrivant 5 classes de qualité nutritionnelle, allant du vert (associé à la lettre A, considérés comme ‘favorables’ sur le plan nutritionnel) à l’orange foncé/rouge (associé à la lettre E, considérés comme ‘défavorables’ sur le plan nutritionnel).
Mots-clés: Logo nutritionnel, aliments transformés, sucres simples, acides gras saturés, sodium et calories.The National Action Plan for Reducing the Consumption of Salt, Sugar and Fat (Saturated and Trans) 2017-2021 (PANSSG-2017-2021) aims to collaborate with the food industry in order to gradually reduce salt, sugar and fat in processed products and to educate the general public about health risks associated with excess consumption of salt, sugar and fat. One of the actions of the PANSSG (number 17) deals with the establishment of a label or a Nutri-Score logo attesting overall nutritional quality of foods and that maximum salt, sugar and fat contents abide by national standards. The Nutri-Score logo is a color logo with letters describing 5 classes of nutritional quality, ranging from green (associated with the letter A, considered as”nutritionally” favorable) to dark orange/red (associated with the letter E, considered as “nutritionally unfavorable”). The establishment in Morocco of a nutritional logo on food packaging can contribute to raise the consumer awareness of the overall nutritional quality of foods (including content levels of sugar, fat, salt and caloric density). It also encourages food industry to improve the nutritional quality of their products by reducing the content of these health risk nutrients so that they can benefit from a favorable positioning on the Nutri-Score logo.
Key words : Nutritional logo, processed foods, simple sugars, saturated fatty acids, sodium and calories
The NutriScore logo: A tool for the Moroccan consumer
Le Plan d’Action National pour la réduction de la consommation du Sel, du Sucre et du Gras 2017-2021 (PANSSG) vise à réduire graduellement, en collaboration avec l’industrie alimentaire, la teneur en sel, sucre et graisses (SSG) des produits transformés et à sensibiliser la population aux dangers sur la santé de l’excès de leurs consommations du SSG. Aussi, l’activité 17 du PANSSG traite de la création d’un label ou logo attestant de la qualité nutritionnelle globale des aliments. La mise en place au Maroc d’un logo nutritionnel sur la face avant des emballages des aliments peut donc contribuer à l’objectif de sensibilisation des consommateurs sur la qualité nutritionnelle globale des aliments (intégrant leurs teneurs en SSG et densité calorique) tout en incitant les industriels à améliorer la qualité nutritionnelle de leurs produits en réduisant la teneur en ces nutriments pour bénéficier d’un positionnement plus favorable sur le logo nutritionnel. En effet, le logo nutritionnel Nutri-Score est un logo coloriel couplé à des lettres décrivant 5 classes de qualité nutritionnelle, allant du vert (associé à la lettre A, considérés comme ‘favorables’ sur le plan nutritionnel) à l’orange foncé/rouge (associé à la lettre E, considérés comme ‘défavorables’ sur le plan nutritionnel).
Mots-clés: Logo nutritionnel, aliments transformés, sucres simples, acides gras saturés, sodium et calories.The National Action Plan for Reducing the Consumption of Salt, Sugar and Fat (Saturated and Trans) 2017-2021 (PANSSG-2017-2021) aims to collaborate with the food industry in order to gradually reduce salt, sugar and fat in processed products and to educate the general public about health risks associated with excess consumption of salt, sugar and fat. One of the actions of the PANSSG (number 17) deals with the establishment of a label or a Nutri-Score logo attesting overall nutritional quality of foods and that maximum salt, sugar and fat contents abide by national standards. The Nutri-Score logo is a color logo with letters describing 5 classes of nutritional quality, ranging from green (associated with the letter A, considered as”nutritionally” favorable) to dark orange/red (associated with the letter E, considered as “nutritionally unfavorable”). The establishment in Morocco of a nutritional logo on food packaging can contribute to raise the consumer awareness of the overall nutritional quality of foods (including content levels of sugar, fat, salt and caloric density). It also encourages food industry to improve the nutritional quality of their products by reducing the content of these health risk nutrients so that they can benefit from a favorable positioning on the Nutri-Score logo.
Key words : Nutritional logo, processed foods, simple sugars, saturated fatty acids, sodium and calories
A novel mitochondrial DnaJ/Hsp40 family protein BIL2 promotes plant growth and resistance against environmental stress in brassinosteroid signaling
Funding Information: Acknowledgments We thank Dr. Tsuyoshi Nakagawa (Shimane University) for the gift of the gateway vectors, pGWB2, pGWB80, pGWB5, and pGWB3. This work was supported in part by funding from the Program for Promotion of Basic Research Activities for Innovation Bioscience (PROBRAIN) to T.N. and T.A., and CREST, Japan Science and Technology Agency to T.N. and T.A.Plant steroid hormones, brassinosteroids, are essential for growth, development and responses to environmental stresses in plants. Although BR signaling proteins are localized in many organelles, i.e., the plasma membrane, nuclei, endoplasmic reticulum and vacuole, the details regarding the BR signaling pathway from perception at the cellular membrane receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) to nuclear events include several steps. Brz (Brz220) is a specific inhibitor of BR biosynthesis. In this study, we used Brz-mediated chemical genetics to identify Brz-insensitive-long hypocotyls 2-1D (bil2-1D). The BIL2 gene encodes a mitochondrial-localized DnaJ/Heat shock protein 40 (DnaJ/Hsp40) family, which is involved in protein folding. BIL2-overexpression plants (BIL2-OX) showed cell elongation under Brz treatment, increasing the growth of plant inflorescence and roots, the regulation of BR-responsive gene expression and suppression against the dwarfed BRI1-deficient mutant. BIL2-OX also showed resistance against the mitochondrial ATPase inhibitor oligomycin and higher levels of exogenous ATP compared with wild-type plants. BIL2 participates in resistance against salinity stress and strong light stress. Our results indicate that BIL2 induces cell elongation during BR signaling through the promotion of ATP synthesis in mitochondria.Peer reviewe
Genomic screens identify a new phytobacterial microbe-associated molecular pattern and the cognate Arabidopsis receptor-like kinase that mediates its immune elicitation
A mathematical model for the burden of diabetes and its complications
BACKGROUND: The incidence and prevalence of diabetes are increasing all over the world. Complications of diabetes constitute a burden for the individuals and the whole society. METHODS: In the present paper, ordinary differential equations and numerical approximations are used to monitor the size of populations of diabetes with and without complications. RESULTS: Different scenarios are discussed according to a set of parameters and the dynamical evolution of the population from the stage of diabetes to the stage of diabetes with complications is clearly illustrated. CONCLUSIONS: The model shows how efficient and cost-effective strategies can be obtained by acting on diabetes incidence and/or controlling the evolution to the stage of complications
Network Properties of Robust Immunity in Plants
Two modes of plant immunity against biotrophic pathogens, Effector Triggered Immunity (ETI) and Pattern-Triggered Immunity (PTI), are triggered by recognition of pathogen effectors and Microbe-Associated Molecular Patterns (MAMPs), respectively. Although the jasmonic acid (JA)/ethylene (ET) and salicylic acid (SA) signaling sectors are generally antagonistic and important for immunity against necrotrophic and biotrophic pathogens, respectively, their precise roles and interactions in ETI and PTI have not been clear. We constructed an Arabidopsis dde2/ein2/pad4/sid2-quadruple mutant. DDE2, EIN2, and SID2 are essential components of the JA, ET, and SA sectors, respectively. The pad4 mutation affects the SA sector and a poorly characterized sector. Although the ETI triggered by the bacterial effector AvrRpt2 (AvrRpt2-ETI) and the PTI triggered by the bacterial MAMP flg22 (flg22-PTI) were largely intact in plants with mutations in any one of these genes, they were mostly abolished in the quadruple mutant. For the purposes of this study, AvrRpt2-ETI and flg22-PTI were measured as relative growth of Pseudomonas syringae bacteria within leaves. Immunity to the necrotrophic fungal pathogen Alternaria brassicicola was also severely compromised in the quadruple mutant. Quantitative measurements of the immunity levels in all combinatorial mutants and wild type allowed us to estimate the effects of the wild-type genes and their interactions on the immunity by fitting a mixed general linear model. This signaling allocation analysis showed that, contrary to current ideas, each of the JA, ET, and SA signaling sectors can positively contribute to immunity against both biotrophic and necrotrophic pathogens. The analysis also revealed that while flg22-PTI and AvrRpt2-ETI use a highly overlapping signaling network, the way they use the common network is very different: synergistic relationships among the signaling sectors are evident in PTI, which may amplify the signal; compensatory relationships among the sectors dominate in ETI, explaining the robustness of ETI against genetic and pathogenic perturbations
Genome-Wide Identification and Mapping of NBS-Encoding Resistance Genes in Solanum tuberosum Group Phureja
The majority of disease resistance (R) genes identified to date in plants encode a nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domain containing protein. Additional domains such as coiled-coil (CC) and TOLL/interleukin-1 receptor (TIR) domains can also be present. In the recently sequenced Solanum tuberosum group phureja genome we used HMM models and manual curation to annotate 435 NBS-encoding R gene homologs and 142 NBS-derived genes that lack the NBS domain. Highly similar homologs for most previously documented Solanaceae R genes were identified. A surprising ∼41% (179) of the 435 NBS-encoding genes are pseudogenes primarily caused by premature stop codons or frameshift mutations. Alignment of 81.80% of the 577 homologs to S. tuberosum group phureja pseudomolecules revealed non-random distribution of the R-genes; 362 of 470 genes were found in high density clusters on 11 chromosomes
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