29 research outputs found
The JAZ family of repressors is the missing link in jasmonate signalling
Jasmonates are essential phytohormones for plant development and survival. However, the molecular details of their signalling pathway remain largely unknown. The identification more than a decade ago of COI1 as an F-box protein suggested the existence of a repressor of jasmonate responses that is targeted by the SCFCOI1 complex for proteasome degradation in response to jasmonate. Here we report the identification of JASMONATE-INSENSITIVE 3 (JAI3) and a family of related proteins named JAZ (jasmonate ZIM-domain), in Arabidopsis thaliana. Our results demonstrate that JAI3 and other JAZs are direct targets of the SCFCOI1 E3 ubiquitin ligase and jasmonate treatment induces their proteasome degradation. Moreover, JAI3 negatively regulates the key transcriptional activator of jasmonate responses, MYC2. The JAZ family therefore represents the molecular link between the two previously known steps in the jasmonate pathway. Furthermore, we demonstrate the existence of a regulatory feed-back loop involving MYC2 and JAZ proteins, which provides a mechanistic explanation for the pulsed response to jasmonate and the subsequent desensitization of the cell.This work was supported by funding from the Ministerio de Educación y Ciencia of Spain (to R.S., J.L.M. and M.R.P.), and the Comunidad de Madrid and European Comission (to R.S.). A.C. was supported by an EMBO long-term Fellowship, and S.F. by a Portuguese FCT fellowship.Peer reviewe
A MYB/ZML complex regulates wound-induced lignin genes in maize
Lignin is an essential polymer in vascular plants that plays key structural roles in vessels and fibers. Lignification is induced by external inputs such as wounding, but the molecular mechanisms that link this stress to lignification remain largely unknown. In this work, we provide evidence that three maize (Zea mays) lignin repressors, MYB11, MYB31, and MYB42, participate in wound-induced lignification by interacting with ZML2, a protein belonging to the TIFY family. We determined that the three R2R3-MYB factors and ZML2 bind in vivo to AC-rich and GAT(A/C) cis-elements, respectively, present in a set of lignin genes. In particular, we show that MYB11 and ZML2 bind simultaneously to the AC-rich and GAT(A/C) cis-elements present in the promoter of the caffeic acid O-methyl transferase (comt) gene. We show that, like the R2R3-MYB factors, ZML2 also acts as a transcriptional repressor. We found that upon wounding and methyl jasmonate treatments, MYB11 and ZML2 proteins are degraded and comt transcription is induced. Based on these results, we propose a molecular regulatory mechanism involving a MYB/ZML complex in which wound-induced lignification can be achieved by the derepression of a set of lignin genes.Research in D.C.-R.'s laboratory was supported by a grant from the Spanish Ministry of Science and Education (AGL2011-30545-C02-01), the “Xarxa de Referència de Biotecnologia” (XarBa) from the Autonomous Government of Catalonia, the CONSOLIDER-INGENIO program (CSD2007-00036) from the Spanish Ministry of Science and Innovation, and the SGR programs (SGR2009-GRC703). Research in M.P.'s laboratory was supported by two grants from the Spanish Ministry of Science and Education (BIO2009-13044-C02-01 and BIO2012-31860), the framework of the XarBa, and the SGR programs (SGR2009-GRC626) from the Autonomous Government of Catalonia. Research in R.S.'s laboratory was supported by grants from the Ministry of Science and Innovation to R.S. (BIO2013-44407). M.P. and R.S. received financial support from the CONSOLIDER-INGENIO program (CSD2007-00057-B) from the Spanish Ministerio de Ciencia e Innovación. Research in the W.S. laboratory is supported by grants from the Ministry of Science and Technology and Academia Sinica. Research in phenylpropanoid gene regulation in the laboratories of E.G. and J.G. was supported by a grant from the National Science Foundation (IOS-1125620). I.-C.V.-B. was supported by a Spanish FPI Fellowship (BES-2007-17316). J.E.S.-H. was supported by the Department of Innovation, Universities and Enterprise of the Generalitatde Catalunya, the European Social Fund FI Fellowship (AGAUR: FI-2006, Resolució EDU/3600/2006; FI-2008, Resolució IUE/2658/2007 and BE-DGR2010), and CRAG.Peer reviewe
Evolution of serum biochemical indicators in anorexia nervosa patients: a 1-year follow-up study
Abstract BACKGROUND: Long-term studies on the evolution of serum biochemical indicators in anorexia nervosa (AN) patients during treatment are lacking in the literature. Thus, a 1-year follow-up of serum biochemical parameters in a homogeneous group of AN patients was performed. METHODS: Fourteen restricting-type AN patients were studied on admission to hospital, after 1 month of inpatient treatment and after 6 and 12 months after admission. RESULTS: Red blood cell count (RBC) and haemoglobin, serum glucose, total protein and the enzyme activities aspartate aminotransferase (AST), alkaline phosphatase (AlP), lactate dehydrogenase (LDH) and creatine kinase (CK) were significantly lower in patients on admission than in the control group. Total protein, high-density lipoprotein cholesterol (HDL-c), AST, AlP and CK showed significant changes among time points (anova, P < 0.05). Significant correlations were found between the change in RBC, haemoglobin, haematocrit, and the change in weight and body mass index (r = 0.74-0.86; P < 0.01). High cholesterol and amylase activity were found at all time points. While AST, LDH and CK reached control values within 6 months of treatment, AlP was always lower. CONCLUSION: Serum AlP, hypercholesterolaemia and RBC seem to need longer periods of treatment with further weight gain to fully normalize. Therefore, these parameters should be monitored in AN patients long-term follow-up.Peer Reviewe
Evolution of serum biochemical indicators in anorexia nervosa patients: a 1-year follow-up study
Abstract BACKGROUND: Long-term studies on the evolution of serum biochemical indicators in anorexia nervosa (AN) patients during treatment are lacking in the literature. Thus, a 1-year follow-up of serum biochemical parameters in a homogeneous group of AN patients was performed. METHODS: Fourteen restricting-type AN patients were studied on admission to hospital, after 1 month of inpatient treatment and after 6 and 12 months after admission. RESULTS: Red blood cell count (RBC) and haemoglobin, serum glucose, total protein and the enzyme activities aspartate aminotransferase (AST), alkaline phosphatase (AlP), lactate dehydrogenase (LDH) and creatine kinase (CK) were significantly lower in patients on admission than in the control group. Total protein, high-density lipoprotein cholesterol (HDL-c), AST, AlP and CK showed significant changes among time points (anova, P < 0.05). Significant correlations were found between the change in RBC, haemoglobin, haematocrit, and the change in weight and body mass index (r = 0.74-0.86; P < 0.01). High cholesterol and amylase activity were found at all time points. While AST, LDH and CK reached control values within 6 months of treatment, AlP was always lower. CONCLUSION: Serum AlP, hypercholesterolaemia and RBC seem to need longer periods of treatment with further weight gain to fully normalize. Therefore, these parameters should be monitored in AN patients long-term follow-up.Peer Reviewe
Transcriptome profiling of liver of non-genetic low birth weight and long term health consequences
[Background] It is believed that the main factors of low prenatal growth in mammals are genetic and environmental. We used isogenic mice maintained in standard conditions to analyze how natural non-genetic microsomia (low birth weight) is produced in inbred mice and its long term effect on health. To better understand the molecular basis of non-genetic microsomia, we undertook transcriptome profiling of both male and female livers from small and normal size mice at birth.[Results] Naturally occurring neonatal microsomia was defined as a gender-specific weanling weight under the 10th percentile of the colony. Birth weight variation was similar in inbred and outbred lines. Mice were phenotyped by weight, size, blood pressure, organ size, their response to a glucose challenge, and survival rates. Regardless of diet, adult mice born with microsomia showed a significantly lower body weight and size, and differences in the weight of several organs of microsomic adult mice compared to normal birth weight adults were found. After a high-fat diet, microsomic mice were less prone to obesity, showing a better glucose tolerance and lower blood pressure. Through a transcriptome analysis, we detected a different pattern of mRNA transcription in the liver at birth comparing male vs female and microsomic vs normal mice, noting some modifications in epigenetic regulatory genes in females and modifications in some growth factor genes in males. Finally, using embryo transfer of embryos of different quality and age, we identified a putative preimplantation origin of this non-genetic microsomia.[Conclusions] (1) neonatal microsomia is not always a risk factor for adult metabolic syndrome, (2) neonatal non-genetic microsomia displays changes in the expression of important epigenetic genes and changes in liver mRNA transcription profile at birth, exaggerating sexual dimorphism, and (3) random preimplantation phenotypic variability could partially explain body birth weight variation in isogenic lines.This work was funded by Grant AGL2012-39652 from the Spanish Ministry of Science and Innovation
Structural basis for DNA binding specificity by the auxin-dependent ARF transcription factors
Boer, Roeland et al.Auxin regulates numerous plant developmental processes by controlling gene expression via a family of functionally distinct DNA-binding auxin response factors (ARFs), yet the mechanistic basis for generating specificity in auxin response is unknown. Here, we address this question by solving high-resolution crystal structures of the pivotal Arabidopsis developmental regulator ARF5/MONOPTEROS (MP), its divergent paralog ARF1, and a complex of ARF1 and a generic auxin response DNA element (AuxRE). We show that ARF DNA-binding domains also homodimerize to generate cooperative DNA binding, which is critical for in vivo ARF5/MP function. Strikingly, DNA-contacting residues are conserved between ARFs, and we discover that monomers have the same intrinsic specificity. ARF1 and ARF5 homodimers, however, differ in spacing tolerated between binding sites. Our data identify the DNA-binding domain as an ARF dimerization domain, suggest that ARF dimers bind complex sites as molecular calipers with ARF-specific spacing preference, and provide an atomic-scale mechanistic model for specificity in auxin response. © 2014 Elsevier Inc.This work was supported by the Netherlands Organization for Scientific Research (NWO; ECHO grant 711.011.002 to D.W.), the Spanish Ministry of Science and Innovation (grant BFU2011-22588 to M.C.), the Generalitat de Catalunya (grant SGR2009-1309 to M.C.), and the European Commission (FP7 Cooperation Project SILVER - GA 260644 to M.C.)Peer Reviewe
Evaluation of nutritional status by immunologic assessment in bulimia nervosa: Influence of body mass index and vomiting episodes
The nutritional status of 21 patients suffering from bulimia nervosa was evaluated by anthropometric and immunologic indexes in comparison with a control group (n = 15). In addition, the influence of body mass index (BMI; in kg/m2) values and vomiting episodes on the nutritional status of bulimic patients was assessed. Anthropometry showed no signs of malnutrition in either group, except for those patients with low weights (BMI 19) bulimic group. The NVBN group had lymphocyte subpopulations similar to those in the control group, except for CD57, which was lower. The bulimic patients with vomiting had the lowest cell subset values. These results suggest a depleted nutritional status in all bulimic patients studied, even those with normal weights. The LWBN group had the most depleted nutritional status and the NVBN group was least affected at a subclinical level. CD57 can be considered a good marker of nutritional status in this syndrome because it was the only subpopulation altered in all groups.Peer Reviewe
Basal differences in the transcriptional profiles of tomato leaves associated with the presence/absence of the resistance gene Mi-1 and changes in these differences after infestation by the whitefly Bemisia tabaci.
The tomato Mi-1 gene mediates plant resistance to whitefly Bemisia tabaci, nematodes, and
aphids. Other genes are also required for this resistance, and a model of interaction between
the proteins encoded by these genes was proposed. Microarray analyses were used previously
to identify genes involved in plant resistance to pests or pathogens, but scarcely in resistance
to insects. In the present work, the GeneChip™ Tomato Genome Array (Affymetrix®) was
used to compare the transcriptional profiles of Motelle (bearing Mi-1) and Moneymaker (lacking
Mi-1) cultivars, both before and after B. tabaci infestation. Ten transcripts were expressed at
least twofold in uninfested Motelle than in Moneymaker, while other eight were expressed half
or less. After whitefly infestation, differences between cultivars increased to 14 transcripts
expressed more in Motelle than in Moneymaker and 14 transcripts less expressed. Half of
these transcripts showed no differential expression before infestation. These results show the
baseline differences in the tomato transcriptomic profile associated with the presence or absence
of the Mi-1 gene and provide us with valuable information on candidate genes to intervene in
either compatible or incompatible tomato–whitefly interactions.This research was funded by a Project (AGL2007-65854/AGR) from the Plan Nacional I+D+I, Spanish Ministry of Education and Science. Clara I. Rodríguez Álvarez was financially supported by a fellowship/contract (AP2006-1035) from the Spanish FPU Program.Peer reviewe
Indicators of nutritional status in restricting-type anorexia nervosa patients: A 1-year follow-up study
Background & aim: Despite severely reduced intakes, anorexia nervosa (AN) patients seem to maintain serum biochemical parameters within the safe limit. The aim of this study was to assess the evolution of some traditional serum biochemical indicators of nutritional status in a 1-year follow-up of patients with restricting-type AN. Methods: 14 adolescent female patients were studied at four different time points: (1) on hospital admission (t0), (2) 1 month later (t1), (3) 6 months after admission (t6) and (4) 12 months after admission (t12). At each time point serum albumin, prealbumin, retinol-binding protein, transferrin, complement factors C3 and C4, zinc and iron status were analysed. 15 healthy adolescents formed the control group. Results: Among the liver-synthesised proteins, a significant time effect was only demonstrated on transferrin and C3 and C4 (ANOVA, P<0.05). Transferrin level in patients on admission was lower than in controls, increased significantly during the first month and showed an opposite pattern in subjects gaining and non-gaining weight between t1 and t12, decreasing only in the group failing to gain further weight. C3 and C4 decreased significantly in t12. Changes in ferritin and zinc showed significant negative correlations with changes in anthropometrical parameters. Conclusions: The changes in transferrin, C3 and C4 levels during the out-patient treatment reveal an increased risk of relapses after 1 year since hospital admission. Ferritin and zinc levels seem to be affected by the nutrient requirements for anabolic processes during nutritional recovery. © 2004 Elsevier Ltd. All rights reserved.Peer Reviewe