Interaction of ammonium nutrition with essential mineral cations.

Plant growth and development depend on sufficient nutrient availability in soils. Agricultural soils are generally nitrogen (N) deficient, and thus soils need to be supplemented with fertilizers. Ammonium (NH4+) is a major inorganic N source. However, at high concentrations, NH4+ becomes a stressor that inhibits plant growth. The cause of NH4+ stress or toxicity is multifactorial, but the interaction of NH4+ with other nutrients is among the main determinants of plants' sensitivity towards high NH4+ supply. In addition, NH4+ uptake and assimilation provoke the acidification of the cell external medium (apoplast/rhizosphere), which has a clear impact on nutrient availability. This review summarizes current knowledge, at both the physiological and the molecular level, of the interaction of NH4+ nutrition with essential mineral elements that are absorbed as cations, both macronutrients (K+, Ca2+, Mg2+) and micronutrients (Fe2+/3+, Mn2+, Cu+/2+, Zn2+, Ni2+). We hypothesize that considering these nutritional interactions, and soil pH, when formulating fertilizers may be key in order to boost the use of NH4+-based fertilizers, which have less environmental impact compared with nitrate-based ones. In addition, we are convinced that better understanding of these interactions will help to identify novel targets with the potential to improve crop productivity.

Putrescine: A Key Metabolite Involved in Plant Development, Tolerance and Resistance Responses to Stress.

Putrescine (Put) is the starting point of the polyamines (PAs) pathway and the most common PA in higher plants. It is synthesized by two main pathways (from ornithine and arginine), but recently a third pathway from citrulline was reported in sesame plants. There is strong evidence that Put may play a crucial role not only in plant growth and development but also in the tolerance responses to the major stresses affecting crop production. The main strategies to investigate the involvement of PA in plant systems are based on the application of competitive inhibitors, exogenous PAs treatments, and the most efficient approaches based on mutant and transgenic plants. Thus, in this article, the recent advances in understanding the role of this metabolite in plant growth promotion and protection against abiotic and biotic stresses will be discussed to provide an overview for future research.

1-Methyltryptophan Treatment Increases Defense-Related Proteins in the Apoplast of Tomato Plants.

The activation of induced resistance in plants may enhance the production of defensive proteins to avoid the invasion of pathogens. In this way, the composition of the apoplastic fluid could represent an important layer of defense that plants can modify to avoid the attack. In this study, we performed a proteomic study of the apoplastic fluid from plants treated with the resistance inducer 1-methyltryptophan (1-MT) as well as infected with Pseudomonas syringae pv. tomato (Pst). Our results showed that both the inoculation with Pst and the application of the inducer provoke changes in the proteomic composition in the apoplast enhancing the accumulation of proteins involved in plant defense. Finally, one of the identified proteins that are overaccumulated upon the treatment have been expressed in Escherichia coli and purified in order to test their antimicrobial effect. The result showed that the tested protein is able to reduce the growth of Pst in vitro. Taken together, in this work, we described the proteomic changes in the apoplast induced by the treatment and by the inoculation, as well as demonstrated that the proteins identified have a role in the plant protection.

Epigenetic regulation of the expression of WRKY75 transcription factor in response to biotic and abiotic stresses in Solanaceae plants.

KEY MESSAGE: SlyWRKY75: gene expression was induced in response to biotic stresses, especially in Botrytis cinerea-infected tomato plants, in which Sly-miR1127-3p is a putative SlyWRKY75 regulator and epigenetic marks were detected. WRKY75 transcription factor involved in Pi homeostasis was recently found also induced in defense against necrotrophic pathogens. In this study, we analyzed by RT-qPCR the expression of SlyWRKY75 gene in tomato plants in response to abiotic stresses (drought or heat) and biotic stresses (Colorado potato beetle larvae infestation, Pseudomonas syringae or Botrytis cinerea infection) being only differentially expressed following biotic stresses, especially upon B. cinerea infection (55-fold induction). JA and JA-Ile levels were significantly increased in tomato plants under biotic stresses compared with control plants, indicating that SlyWRKY75 might be a transcriptional regulator of the JA pathway. The contribution of miRNAs and epigenetic molecular mechanisms to the regulation of this gene in B. cinerea-infected tomato plants was explored. We identified a putative Sly-miR1127-3p miRNA predicted to bind the intronic region of the SlyWRKY75 genomic sequence. Sly-miR1127-3p miRNA was repressed in infected plants (0.4-fold) supporting that it might act as an epigenetic regulation factor of SlyWRKY75 gene expression rather than via the post-transcriptional mechanisms of canonical miRNAs. It has been proposed that certain miRNAs can mediate DNA methylation in the plant nucleus broadening miRNA functions with transcriptional gene silencing by targeting intron-containing pre-mRNAs. Histone modifications analysis by chromatin immunoprecipitation (ChIP) demonstrated the presence of the activator histone modification H3K4me3 on SlyWRKY75 transcription start site and gene body. The induction of this gene in response to B. cinerea correlates with the presence of an activator mark. Thus, miRNAs and chromatin modifications might cooperate as epigenetic factors to modulate SlyWRKY75 gene expression.

Comparative immune responses against Psoroptes ovis in two cattle breeds with different susceptibility to mange.

The sheep scab mite, Psoroptes ovis, is a major problem in the beef cattle industry, especially in Belgian Blue (BB) cattle. This breed is naturally more predisposed to psoroptic mange but reasons for this high susceptibility remain unknown. Different immune responses could be a potential cause; thus in this study, the cutaneous immune response and in vitro cellular immune response after antigen re-stimulation were examined in naturally infested BB. Cytokine production in the skin and in circulating re-stimulated peripheral blood mononuclear cells (PBMC) demonstrated a mixed pro-inflammatory Th2/Th17 profile, with transcription of IL-4, IL-13, IL-6 and IL-17. Strong IL-17 up-regulation in the skin of BB was associated with an influx of eosinophils and other immune cells, potentially leading towards more severe symptoms. Virtually no changes in cutaneous IFN-γ transcription were detected, while there was substantial IFN-γ up-regulation in re-stimulated PBMC from infested and uninfested animals, potentially indicating a role of this pro-inflammatory cytokine in the innate immune response. In Holstein-Friesian (HF) cattle, generally more resistant to P. ovis infection, a largely similar immunologic response was observed. Differences between HF and BB were the lack of cutaneous IL-17 response in infested HF and low transcription levels of IFN-γ and high IL-10 transcription in re-stimulated PBMC from both infested and uninfested animals. Further research is needed to identify potential cell sources and biological functions for these cytokines and to fully unravel the basis of this different breed susceptibility to P. ovis.

Putrescine biosynthetic pathways modulate root growth differently in tomato seedlings grown under different N sources.

The biosynthesis of putrescine is mainly driven by arginine decarboxylase (ADC) and ornithine decarboxylase (ODC). Hence, in this study, we generated independent ADC and ODC transgenic silenced tomato lines (SilADC and SilODC, respectively) to test the effect of defective ADC and ODC gene expression on root development under nitrate (NN) or ammonium (NA) conditions. The results showed that SilODC seedlings displayed an increase in ADC expression that led to polyamine accumulation, suggesting a compensatory effect of ADC. However, this effect was not observed in SilADC seedlings. These pathways are involved in different growth processes. The SilADC seedlings showed an increase in fresh weight, shoot length, lateral root number and shoot:root ratio under the NN source and an enhancement in fresh weight, and shoot and root length under NA conditions. However, SilODC seedlings displayed greater weight and shoot length under the NN source, whereas a decrease in lateral root density was found under NA conditions. Moreover, two overexpressed ODC lines were generated to check the relevance of the compensatory effect of the ADC pathway when ODC was silenced. These overexpressed lines showed not only an enhancement of almost all the studied growth parameters under both N sources but also an amelioration of ammonium syndrome under NA conditions. Together, these results reflect the importance of both pathways in plant growth, particularly ODC silencing, which requires compensation by ADC induction.

Exploiting Tomato Genotypes to Understand Heat Stress Tolerance.

Increased temperatures caused by climate change constitute a significant threat to agriculture and food security. The selection of improved crop varieties with greater tolerance to heat stress is crucial for the future of agriculture. To overcome this challenge, four traditional tomato varieties from the Mediterranean basin and two commercial genotypes were selected to characterize their responses at high temperatures. The screening of phenotypes under heat shock conditions allowed to classify the tomato genotypes as: heat-sensitive: TH-30, ADX2; intermediate: ISR-10 and Ailsa Craig; heat-tolerant: MM and MO-10. These results reveal the intra-genetical variation of heat stress responses, which can be exploited as promising sources of tolerance to climate change conditions. Two different thermotolerance strategies were observed. The MO-10 plants tolerance was based on the control of the leaf cooling mechanism and the rapid RBOHB activation and ABA signaling pathways. The variety MM displayed a different strategy based on the activation of HSP70 and 90, as well as accumulation of phenolic compounds correlated with early induction of PAL expression. The importance of secondary metabolism in the recovery phase has been also revealed. Understanding the molecular events allowing plants to overcome heat stress constitutes a promising approach for selecting climate resilient tomato varieties.

Physiological and Antioxidant Response to Different Water Deficit Regimes of Flag Leaves and Ears of Wheat Grown under Combined Elevated CO2 and High Temperature.

Triticum aestivum L. cv. Gazul is a spring wheat widely cultivated in Castilla y León (Spain). Potted plants were grown in a scenario emulating the climate change environmental conditions expected by the end of this century, i.e., with elevated CO2 and high temperature under two water deficit regimes: long (LWD) and terminal (TWD). Changes in biomass and morphology, the content of proline (Pro), ascorbate (AsA) and glutathione (GSH), and enzymatic antioxidant activities were analyzed in flag leaves and ears. Additionally, leaf gas exchange was measured. LWD caused a decrease in biomass and AsA content but an increase in Pro content and catalase and GSH reductase activities in flag leaves, whereas TWD produced no significant changes. Photosynthesis was enhanced under both water deficit regimes. Increase in superoxide dismutase activity and Pro content was only observed in ears under TWD. The lack of a more acute effect of LWD and TWD on both organs was attributed to the ROS relieving effect of elevated CO2. Gazul acted as a drought tolerant variety with anisohydric behavior. A multifactorial analysis showed better adaptation of ears to water deficit than flag leaves, underlining the importance of this finding for breeding programs to improve grain yield under future climate change.

Theoretical and Experimental Considerations for a Rapid and High Throughput Measurement of Catalase In Vitro.

A rapid and high throughput protocol to measure the catalase activity in vitro has been designed. Catalase is an enzyme with unusual kinetic properties because it does not follow the standard Michaelis-Menten model and is inactivated by H2O2. This makes the analysis of the two rate equations of the second-ordered reactions of the kinetic model rather complex. A two-degree polynomial fitting of the experimental data is proposed after transforming the exponential form of the integrated rate equation of the [H2O2] into a polynomial using the Taylor series. The fitting is validated by establishing an experimental linear relationship between the initial rate of the H2O2 decomposition and the protein concentration, regardless of the suicide inactivation that catalase might undergo beyond t > 0. In addition, experimental considerations are taken into account to avoid statistical bias in the analysis of the catalase activity. ANOVA analyses show that the proposed protocol can be utilized to measure the initial rate of the H2O2 decomposition by catalase in 32 samples in triplicates if kept below 8 mM min-1 in the microplate wells. These kinetic and statistical analyses can pave the way for other antioxidant enzyme activity assays in microplate readers at small scale and low cost.

Association between glycemic index, glycemic load, and fructose with insulin resistance: the CDC of the Canary Islands study.

BACKGROUND: The involvement of carbohydrates in triggering insulin resistance (IR) remains a source of controversy. AIM OF THE STUDY: To study the relation between glycemic index (GI), glycemic load (GL), and fructose with insulin resistance in a predominantly rural population in the Canary Islands. METHODS: Cross-sectional study carried out in 668 nondiabetic people aged 18-75. IR was estimated with serum glucose and C-peptide (HOMA2-IR). Nutrient intakes were obtained from a validated food frequency questionnaire. ANOVA was used to analyze nutrient distribution across quartiles of HOMA2-IR. Four multivariate nutrient density models (dependent variable: log-transformed HOMA2-IR) which differed only in the kinds of carbohydrates included were tested (Model 1: carbohydrates; Model 2: GI and then GL; Model 3: free fructose, other simple sugars and starch; Model 4: total fructose, remaining sugars and starch). RESULTS: There was no association between GI and IR. There was a direct association between GL (P < 0.001), fructose (free [P = 0.001], total [P = 0.013]), energy intake (P < 0.001), fruit fiber (<0.001), and glucose (P = 0.003) with IR. There was an inverse association between cereal (P = 0.008) and vegetable fiber (P < 0.001) and IR. Multivariate models corroborated the association of carbohydrates, GL, fructose, vegetable fiber, and energy intake with IR. The association between GL and IR disappeared when Model 2 was adjusted by total fructose intake. CONCLUSIONS: There was a direct association between fructose intake and IR. There was no relationship between GI and IR. Although a direct association of GL with IR was detected, it was attributable to the consumption of fructose.

[The waist to height ratio as an index of cardiovascular risk and diabetes]. / El cociente perímetro abdominal/estatura como índice antropométrico de riesgo cardiovascular y de diabetes.

BACKGROUND AND OBJECTIVES: To identify the anthropometric index that best detects cardiovascular risk (CVR) and type 2 diabetes (DM2) in the adult Spanish population and to determine its cut-off point. SUBJECTS AND METHODS: Cross-sectional study in the general population (n=6279). Sensitivity and specificity were estimated for the anthropometric indexes: abdominal waist, body mass index, waist to hip ratio and waist to height ratio (WtHR). The areas of these indexes under ROC curve (AUC) were obtained for the following CVR factors: high coronary risk computed with Framingham model, Hypertension, Hyperlipemia, DM2, Metabolic Syndrome (MS) and Impaired Fasting Glucose (IFG). The odds ratio, with 95% confidence interval (CI(95%)), was calculated. RESULTS: WtHR was the index showing the highest AUC for DM2 and the remaining CVR factors, varying between 0.65 (CI(95%)=0.63-0.68) for IFG in men and 0.87 (CI(95%)=0.86-0.89) for MS in women. RA/E reached the maximum sensitivity (0.91) and specificity (0.70) in SM and its optimal cut-off point was 0.55, which displayed the highest risks amongst indexes, varying from 2.30 (1.96-2.70) in IFG to 16'20 (13.68-19.20) in MS. CONCLUSIONS: RA/E is the index presenting the best ability to detect DM2 and CVR in this population, and it shows the stronger association with them. Its cut-off point, 0.55, confirms the convenience of keeping the abdominal waist to less than half the height.

Condom Use Errors and Problems in a Sample of Young Colombian Adults.

Condom effectiveness can be reduced by a number of problems and errors that take place during use. The purpose of the present study was to translate and adapt the Condom Use Errors and Problems Survey (CUES) into Spanish and to use it for testing the prevalence of these issues in a sample of young Colombian adults. A total of 775 people (414 women and 361 men) between 18 and 26 years of age participated in the study. Participants completed the following questionnaires online: Condom Use Errors and Problems Survey, Sexual Opinion Survey, Sexual Assertiveness Scale, Multidimensional Condom Attitudes Scale, a sociodemographic and sexual history questionnaire, plus two questions concerning condom-associated erectile problems. Results showed significant differences in the prevalence of condom use errors/problems associated with gender, sexual orientation, and whether the participant had a stable sexual partner. The occurrence of problems/errors ranged from 9.4% to 69.5%. Except for certain specific practices, observations were similar to those of studies performed in North America. Results indicate that the present linguistic adaptation of the CUES for its use in Colombian Spanish-speaking populations is an effective instrument to assess problems and errors associated with the use of male condoms.

Tomato root development and N assimilation depend on C and ABA content under different N sources.

Root plasticity is controlled by hormonal homeostasis and nutrient availability. In this work, we have determined the influence of different N regimens on growth parameters and on the expression of genes involved in auxin transport and N-assimilation in tomato seedlings. NH4+ nutrition led to an inhibitory effect on root fresh weight (FW), lateral root (LR) number and root density, while an increase in the primary root (PR) length was observed. The expression of N assimilation genes GS2 and ASN1, is affected by NH4+ nutrition. Moreover, in order to relieve the toxic effect of NH4+ on root development, glucose or 2-oxoglutarate was supplied as a C source during NH4+ treatment. The addition of 2-oxoglutarate improved root parameters compared to the NH4+ regimen. N-assimilation gene analysis showed that NH4+-fed tomato plants try to alleviate the toxic effect by concurrently upregulating ASN1 and anaplerotic PEPC2 expression, whereas when 2-oxoglutarate is supplied, ASN1 induction was not observed. The addition of both C skeletons induced the expression of the ROS-scavenging genes GSH and SOD. In addition, since ABA plays a role in root development, the ABA-synthesis-defective mutant flacca was studied under NO3- and NH4+ regimens. It displayed a decrease in LR number under NO3- conditions, whereas, the NH4+-fed seedlings showed a decrease solely in PR length that was reverted when ABA was exogenously supplied. Moreover, flacca seedlings displayed a reprogramming of the N/C assimilation genes. Altogether, these results reflect the importance of N and C sources and ABA homeostasis in root development of tomato seedlings.

Exogenous Carbon Compounds Modulate Tomato Root Development.

NO3- is not only a nutrient, but also a signaling compound that plays an important role in several plant processes, like root development. The present study aimed to investigate the effect of three different exogenous C compounds (sucrose, glucose, 2-oxoglutarate) added to NO3- nutrition on C/N, auxin and antioxidant metabolisms in 10-day-old tomato seedlings. Sucrose and glucose supplementation enhanced primary root (PR) length, lateral root number and root density, while 2-oxoglutarate negatively affected them. This phenomenon was accompanied by a slight increase in NRT2.1 and GS1 gene expression, together with an increase in LAX2 and LAX3 and a decrease in LAX4 in the roots growing under sucrose and glucose sources. The addition of 2-oxoglutarate enhanced the expression of NiR, GDH, PEPC1, LAX1, LAX3 and the antioxidant gene SOD Cl. Taken together, these findings contribute to a better understanding of how these C sources can modulate N uptake and C/N, auxin and antioxidant gene expression, which could be useful for improving nitrogen use efficiency.

The Apoplast: A Key Player in Plant Survival.

The apoplast comprises the intercellular space, the cell walls, and the xylem. Important functions for the plant, such as nutrient and water transport, cellulose synthesis, and the synthesis of molecules involved in plant defense against both biotic and abiotic stresses, take place in it. The most important molecules are ROS, antioxidants, proteins, and hormones. Even though only a small quantity of ROS is localized within the apoplast, apoplastic ROS have an important role in plant development and plant responses to various stress conditions. In the apoplast, like in the intracellular cell compartments, a specific set of antioxidants can be found that can detoxify the different types of ROS produced in it. These scavenging ROS components confer stress tolerance and avoid cellular damage. Moreover, the production and accumulation of proteins and peptides in the apoplast take place in response to various stresses. Hormones are also present in the apoplast where they perform important functions. In addition, the apoplast is also the space where microbe-associated molecular Patterns (MAMPs) are secreted by pathogens. In summary, the diversity of molecules found in the apoplast highlights its importance in the survival of plant cells.

Standardization of a Culture Medium for Megaselia scalaris (Diptera: Phoridae) for Entomotoxicological Studies.

One of the problems faced by entomotoxicological studies is the large variability of experimental set-ups and the absence of harmonized protocols to compare the data and results obtained by different research groups. Among the wide range of influencing factors on the development and growth of insects, food substrates are remarkably relevant. This article proposes a standardized growth medium to be employed in future entomotoxicological studies on the scuttle fly Megaselia scalaris (Loew, 1866), (Diptera: Phoridae). This species plays an important role in forensic cases related to the decomposition of human remains found indoors and/or in concealed environments, because of their small size and ability to enter these locations at an earlier time than many other insects. Because of these traits, it can be used for the estimation of the minimum postmortem interval (mPMI). We achieved the formulation of a medium that overcomes two traditional disadvantages of culture media used to raise necrophagous Diptera, the unknown media composition and different growth rates from those reared in tissue. The proposed medium is a known composition formulation, free of xenobiotics, in which M. scalaris shows growth rates and development times similar to those obtained when it is reared in tissue. This new diet might be used in future studies to test the effect of substances of forensic interest (prescription or illicit drugs, poisons, etc.) on the larval development time, helping to adjust the estimation of mPMI based on the presence of such substances. Additionally, the formulation revealed some interesting data about nutritional requirements of this species.

Evaluating new candidate SNPs as low penetrance risk factors in sporadic breast cancer: a two-stage Spanish case-control study.

OBJECTIVES: A polygenic model has been proposed in order to explain the genetic susceptibility to sporadic breast cancer. According to this model, common population variants would be responsible for low to modest effects on the risk of developing the disease. We have carried out a high-throughput SNP genotyping project in order to shed some light on the complex genetic aetiology of non-familial breast cancer. METHODS: Ninety-one genes have been selected because of their implications in several candidate cell pathways for breast cancer. A total of 640 SNPs in these genes were genotyped in a series of 450 consecutive cases and 448 controls from mainland Spain. Promising SNPs were then studied in an independent series of 294 cases and 299 controls from the Canary Islands. RESULTS: In the first case-control series we identified 25 SNPs with P-values below 0.05 (under a 1 df Chi-square test), five of them with P-values below 0.01 (best=0.0008). In the stage 2 Canary Islands series, odd ratios (OR) for two SNPs in HUS1 were in a consistent direction. CONCLUSIONS: SNPs located at the gene HUS1 are good candidates for further investigation in independent association studies and functional assays.

Expression of miR159 Is Altered in Tomato Plants Undergoing Drought Stress.

In a scenario of global climate change, water scarcity is a major threat for agriculture, severely limiting crop yields. Therefore, alternatives are urgently needed for improving plant adaptation to drought stress. Among them, gene expression reprogramming by microRNAs (miRNAs) might offer a biotechnologically sound strategy. Drought-responsive miRNAs have been reported in many plant species, and some of them are known to participate in complex regulatory networks via their regulation of transcription factors involved in water stress signaling. We explored the role of miR159 in the response of Solanum lycopersicum Mill. plants to drought stress by analyzing the expression of sly-miR159 and its target SlMYB transcription factor genes in tomato plants of cv. Ailsa Craig grown in deprived water conditions or in response to mechanical damage caused by the Colorado potato beetle, a devastating insect pest of Solanaceae plants. Results showed that sly-miR159 regulatory function in the tomato plants response to distinct stresses might be mediated by differential stress-specific MYB transcription factor targeting. sly-miR159 targeting of SlMYB33 transcription factor transcript correlated with accumulation of the osmoprotective compounds proline and putrescine, which promote drought tolerance. This highlights the potential role of sly-miR159 in tomato plants' adaptation to water deficit conditions.

Ammonium mediated changes in carbon and nitrogen metabolisms induce resistance against Pseudomonas syringae in tomato plants.

Predominant NH4+ nutrition causes an "ammonium syndrome" that induces metabolic changes and thereby provides resistance against Pseudomonas syringae infection through the activation of systemic acquired acclimation (SAA). Hence, to elucidate the mechanisms underlying NH4+-mediated SAA, the changes in nutrient balance and C and N skeletons were studied in NH4+-treated plants upon infection by P. syringae. A general decrease in cation and an increase in anion levels was observed in roots and leaves of NH4+-treated plants. Upon NH4+-based nutrition and infection, tomato leaves showed an accumulation of S, P, Zn, and of Mn. Mn accumulation might be required for ROS detoxification since it acts as a cofactor of superoxide dismutase (SOD). Primary metabolism was modified in both tissues of NH4+-fed plants to counteract NH4+ toxicity by decreasing TCA intermediates. A significant increase in Arg, Gln, Asn, Lys, Tyr, His and Leu was observed in leaves of NH4+-treated plants. The high level of the putrescine precursor Arg hints towards the importance of the Glu pathway as a key metabolic check-point in NH4+-treated and infected plants. Taken together, NH4+-fed plants displayed a high level of basal responses allowing them to activate SAA and to trigger defense responses against P. syringae through nutrient imbalances and changes in primary metabolism.

[Presentation of the "CDC de Canarias" cohort: objectives, design and preliminary results]. / Presentación de la cohorte "CDC de Canarias": objetivos, diseño y resultados preliminares.

BACKGROUND: The Canary Islands rank first in Spain with respect to the ischaemic heart disease and diabetes mortality rates. The Islands female population leads the country in deaths from breast cancer. The "CDC de Canarias" is a general population cohort study in order to analyse the prevalence and incidence of these diseases and the exposure to their risk factors (RF) in the adult population of the archipelago. METHODS: Prospective study with a random sampling of the general population, in which 6,729 individuals participated between 2000 and 2005 (aged 18-75). Anthropometric measurements were taken, and blood was drawn for the storage of serum and genetic samples. The following information was gathered through a questionnaire: eating habits, physical activity, personal and family medical history, exposure to occupational or environmental risk factors, smoking, etc. RESULTS: The prevalence of obesity is close to 30%, without differences between sexes, however, more male subjects were overweight than women (45 vs. 33%; p <0.001) and also presented a greater prevalence of diabetes (12 vs. 10%; p =0.005), high blood pressure (43 vs. 33%; p <0.001), excessive intake of alcohol (13 vs. 2%; p <0.001) and lack of sun protection (46 vs. 18%; p <0.001). Exposure to low levels of HDL cholesterol is more frequent in women (37 vs. 30%; p <0.001) as is also the case with a sedentary life style (71 vs. 55%; p <0.001). The exposure to the risk factors studied, including poverty, is greater in advanced age groups, except for smoking (26%) which is greater in the younger subjects. The estimate of relative risks of exposure to cardiovascular and cancer risk factors is higher in low-income social classes. CONCLUSIONS: The current adult population of the Canaries presents a high prevalence of exposure to risk factors for cardiovascular disease, diabetes and cancer, among which overweight, obesity and lack of exercise stand out particularly.