A change in temperature modulates defence to yellow (stripe) rust in wheat line UC1041 independently of resistance gene Yr36

Background Rust diseases are of major importance in wheat production worldwide. With the constant evolution of new rust strains and their adaptation to higher temperatures, consistent and durable disease resistance is a key challenge. Environmental conditions affect resistance gene performance, but the basis for this is poorly understood. Results Here we show that a change in day temperature affects wheat resistance to Puccinia striiformis f. sp tritici (Pst), the causal agent of yellow (or stripe) rust. Using adult plants of near-isogenic lines UC1041 +/- Yr36, there was no significant difference between Pst percentage uredia coverage in plants grown at day temperatures of 18°C or 25°C in adult UC1041 + Yr36 plants. However, when plants were transferred to the lower day temperature at the time of Pst inoculation, infection increased up to two fold. Interestingly, this response was independent of Yr36, which has previously been reported as a temperature-responsive resistance gene as Pst development in adult UC1041 -Yr36 plants was similarly affected by the plants experiencing a temperature reduction. In addition, UC1041 -Yr36 plants grown at the lower temperature then transferred to the higher temperature were effectively resistant and a temperature change in either direction was shown to affect Pst development up to 8 days prior to inoculation. Results for seedlings were similar, but more variable compared to adult plants. Enhanced resistance to Pst was observed in seedlings of UC1041 and the cultivar Shamrock when transferred to the higher temperature. Resistance was not affected in seedlings of cultivar Solstice by a temperature change in either direction. Conclusions Yr36 is effective at 18°C, refining the lower range of temperature at which resistance against Pst is conferred compared to previous studies. Results reveal previously uncharacterised defence temperature sensitivity in the UC1041 background which is caused by a change in temperature and independently of Yr36. This novel phenotype is present in some cultivars but absent in others, suggesting that Pst defence may be more stable in some cultivars than others when plants are exposed to varying temperatures

Improving starch and fibre in wheat grain for human health

Reducing the prevalence of diet- related diseases, including obesity and type 2 diabetes, is a major challenge for health professionals, food manufacturers and governments in both developed and developing countries. Cereals are key targets in meeting this challenge as they are staple foods throughout the world and major sources of energy (derived principally from starch) and dietary fibre. Wheat is the staple cereal in the UK and Europe, and the UK Biotechnology and Biological Sciences Research Council (BBSRC)- supported Designing Future Wheat programme is focused on manipulating the content and composition of starch and fibre to improve health impacts, including reducing the glycaemic response and improving fermentation in the colon. This work is contributing to the development of improved cultivars by breeders and foods by processors. It is also increasing our understanding of the behaviour of these components in the human gastrointestinal (GI) tract and will contribute to the establishment of targets and recommendations for regulatory authorities

International gestational age-specific centiles for umbilical artery Doppler indices: a longitudinal prospective cohort study of the INTERGROWTH-21st Project.

BACKGROUND: Reference values for umbilical artery Doppler indices are used clinically to assess fetal well-being. However, many studies that have produced reference charts have important methodologic limitations, and these result in significant heterogeneity of reported reference ranges. OBJECTIVES: To produce international gestational age-specific centiles for umbilical artery Doppler indices based on longitudinal data and the same rigorous methodology used in the original Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. STUDY DESIGN: In Phase II of the INTERGROWTH-21st Project (the INTERBIO-21st Study), we prospectively continued enrolling pregnant women according to the same protocol from 3 of the original populations in Pelotas (Brazil), Nairobi (Kenya), and Oxford (United Kingdom) that had participated in the Fetal Growth Longitudinal Study. Women with a singleton pregnancy were recruited at <14 weeks' gestation, confirmed by ultrasound measurement of crown-rump length, and then underwent standardized ultrasound every 5±1 weeks until delivery. From 22 weeks of gestation umbilical artery indices (pulsatility index, resistance index, and systolic/diastolic ratio) were measured in a blinded fashion, using identical equipment and a rigorously standardized protocol. Newborn size at birth was assessed using the international INTERGROWTH-21st Standards, and infants had detailed assessment of growth, nutrition, morbidity, and motor development at 1 and 2 years of age. The appropriateness of pooling data from the 3 study sites was assessed using variance component analysis and standardized site differences. Umbilical artery indices were modeled as functions of the gestational age using an exponential, normal distribution with second-degree fractional polynomial smoothing; goodness of fit for the overall models was assessed. RESULTS: Of the women enrolled at the 3 sites, 1629 were eligible for this study; 431 (27%) met the entry criteria for the construction of normative centiles, similar to the proportion seen in the original fetal growth longitudinal study. They contributed a total of 1243 Doppler measures to the analysis; 74% had 3 measures or more. The healthy low-risk status of the population was confirmed by the low rates of preterm birth (4.9%) and preeclampsia (0.7%). There were no neonatal deaths and satisfactory growth, health, and motor development of the infants at 1 and 2 years of age were documented. Only a very small proportion (2.8%-6.5%) of the variance of Doppler indices was due to between-site differences; in addition, standardized site difference estimates were marginally outside this threshold in only 1 of 27 comparisons, and this supported the decision to pool data from the 3 study sites. All 3 Doppler indices decreased with advancing gestational age. The 3rd, 5th 10th, 50th, 90th, 95th, and 97th centiles according to gestational age for each of the 3 indices are provided, as well as equations to allow calculation of any value as a centile and z scores. The mean pulsatility index according to gestational age = 1.02944 + 77.7456*(gestational age)-2 - 0.000004455*gestational age3. CONCLUSION: We present here international gestational age-specific normative centiles for umbilical artery Doppler indices produced by studying healthy, low-risk pregnant women living in environments with minimal constraints on fetal growth. The centiles complement the existing INTERGROWTH-21st Standards for assessment of fetal well-being

LCPUFAs as conditionally essential nutrients for very low birth weight and low birth weight infants. metabolic, functional, and clinical outcomes - how much is enough?

Preterm infants are denied the rapid accumulation of docosahexaenoic acid (DHA) occurring during the third trimester in utero. The potential benefit of long-chain polyunsaturated fatty acids (LCPUFAs) has generated interest over the last 3 decades. Early intervention trials assessed the effects of supplementing infant formulas lacking DHA with concentrations equivalent to LCPUFA in milk of women from Westernized societies, leading to the inclusion of LCPUFA by the year 2000. Recently attention has been on determining the optimal dose of DHA and on whether there is in advantage in matching the higher doses of late pregnancy.Maria Makrides, Ricardo Uau

Genetic screening for mutants with altered seminal root numbers in hexaploid wheat using a high-throughput root phenotyping platform

Roots are the main channel for water and nutrient uptake in plants. Optimization of root architecture provides a viable strategy to improve nutrient and water uptake efficiency and maintain crop productivity under water-limiting and nutrient-poor conditions. We know little, however, about the genetic control of root development in wheat, a crop supplying 20% of global calorie and protein intake. To improve our understanding of the genetic control of seminal root development in wheat, we conducted a high-throughput screen for variation in seminal root number using an exome-sequenced mutant population derived from the hexaploid wheat cultivar Cadenza. The screen identified seven independent mutants with homozygous and stably altered seminal root number phenotypes. One mutant, Cadenza0900, displays a recessive extra seminal root number phenotype, while six mutants (Cadenza0062, Cadenza0369, Cadenza0393, Cadenza0465, Cadenza0818 and Cadenza1273) show lower seminal root number phenotypes most likely originating from defects in the formation and activation of seminal root primordia. Segregation analysis in F2 populations suggest that the phenotype of Cadenza0900 is controlled by multiple loci whereas the Cadenza0062 phenotype fits a 3:1 mutant:wild-type segregation ratio characteristic of dominant single gene action. This work highlights the potential to use the sequenced wheat mutant population as a forward genetic resource to uncover novel variation in agronomic traits, such as seminal root architecture

Retos tecnológicos para evaluar ácidos grasos n-3 poliinsaturados de aceites marinos para uso nutricional y farmacológico

The benefits ascribed to marine oils rich in n-3 polyunsaturated fatty acids has led to efforts to improve the chemical and organoleptic characteristics of these oils and to develop procedures for the obtention of pure or highly concentrated fractions of some n-3 fatty acids. Two n-3 fatty acids are of main interest; the eicosapentaenoic acid (C20:5, EPA) and the docosahexaenoic acid (022:6, DHA). The present review is referred to the identification of the main sources of marine n-3 polyunsaturated fatty acids, and to the stabilization of these fatty acids against oxidative rancidity. In addition the procedures for the obtention of EPA and DHA concentrates and the utilization of these fatty acids for nutritional or pharmacological purposes are also discussed.Los beneficios atribuidos a los aceites marinos ricos en ácidos grasos n-3 poliinsaturados han conducido a un esfuerzo por mejorar las características químicas y organolépticas de estos aceites y al desarrollo de procedimientos para la obtención de fracciones altamente concentradas o puras de ácidos grasos n-3. Dos ácidos grasos n-3 de interés principal son el ácido eicosapentaenoico (C20:5, EPA) y el ácido docosahexaenoico (022:6, DHA). La presente revisión está referida a la identificación de las principales fuentes de ácidos grasos n-3 poliinsaturados marinos, y a la estabilización de estos ácidos frente a la rancidez oxidativa. Además de los procedimientos para la obtención de concentrados de EPA y DHA, es también discutida la utilización de estos ácidos grasos para usos nutricionales y farmacológicos

Delayed development of basal spikelets in wheat explains their increased floret abortion and rudimentary nature

Large differences exist in the number of grains per spikelet across an individual wheat (Triticum aestivum L.) spike. The central spikelets produce the highest number of grains, while apical and basal spikelets are less productive, and the most basal spikelets are commonly only developed in rudimentary form. Basal spikelets are delayed in initiation, yet they continue to develop and produce florets. The precise timing or the cause of their abortion remains largely unknown. Here, we investigated the underlying causes of basal spikelet abortion using shading applications in the field. We found that basal spikelet abortion is likely to be the consequence of complete floret abortion, as both occur concurrently and have the same response to shading treatments. We detected no differences in assimilate availability across the spike. Instead, we show that the reduced developmental age of basal florets pre-anthesis is strongly associated with their increased abortion. Using the developmental age pre-abortion, we were able to predict final grain set per spikelet across the spike, alongside the characteristic gradient in the number of grains from basal to central spikelets. Future efforts to improve spikelet homogeneity across the spike could thus focus on improving basal spikelet establishment and increasing floret development rates pre-abortion