Prior to the availability of whole-genome sequences,our understanding of the structural and functional aspects of Prunus tree genomes was limited mostly to molecular genetic mapping of important traits and development...Prior to the availability of whole-genome sequences,our understanding of the structural and functional aspects of Prunus tree genomes was limited mostly to molecular genetic mapping of important traits and development of EST resources.With public release of the peach genome and others that followed,significant advances in our knowledge of Prunus genomes and the genetic underpinnings of important traits ensued.In this review,we highlight key achievements in Prunus genetics and breeding driven by the availability of these whole-genome sequences.Within the structural and evolutionary contexts,we summarize:(1)the current status of Prunus whole-genome sequences;(2)preliminary and ongoing work on the sequence structure and diversity of the genomes;(3)the analyses of Prunus genome evolution driven by natural and man-made selection;and(4)provide insight into haploblocking genomes as a means to define genome-scale patterns of evolution that can be leveraged for trait selection in pedigree-based Prunus tree breeding programs worldwide.Functionally,we summarize recent and ongoing work that leverages whole-genome sequences to identify and characterize genes controlling 22 agronomically important Prunus traits.These include phenology,fruit quality,allergens,disease resistance,tree architecture,and self-incompatibility.Translationally,we explore the application of sequence-based marker-assisted breeding technologies and other sequence-guided biotechnological approaches for Prunus crop improvement.Finally,we present the current status of publically available Prunus genomics and genetics data housed mainly in the Genome Database for Rosaceae(GDR)and its updated functionalities for future bioinformatics-based Prunus genetics and genomics inquiry.展开更多
Peach(Prunus persica)and almond(Prunus dulcis)are two sexually compatible species that produce fertile offspring.Almond,a highly polymorphic species,is a potential source of new genes for peach that has a strongly ero...Peach(Prunus persica)and almond(Prunus dulcis)are two sexually compatible species that produce fertile offspring.Almond,a highly polymorphic species,is a potential source of new genes for peach that has a strongly eroded gene pool.Here we describe the genetics of a male sterile phenotype that segregated in two almond(‘Texas’)×peach(‘Earlygold’)progenies:an F2(T×E)and a backcross one(T1E)to the‘Earlygold’parent.High-density maps were developed using a 9k peach SNP chip and 135 simple-sequence repeats.Three highly syntenic and collinear maps were obtained:one for the F2(T×E)and two for the backcross,T1E(for the hybrid)and E(for‘Earlygold’).A major reduction of recombination was observed in the interspecific maps(T×E and T1E)compared to the intraspecific parent(E).The E map also had extensive monomorphic genomic regions suggesting the presence of large DNA fragments identical by descent.Our data for the male sterility character were consistent with the existence of cytoplasmic male sterility,where individuals having the almond cytoplasm required the almond allele in at least one of two independent restorer genes,Rf1 and Rf2,to be fertile.The restorer genes were located in a 3.4 Mbp fragment of linkage group 2(Rf1)and 1.4 Mbp of linkage group 6(Rf2).Both fragments contained several genes coding for pentatricopeptide proteins,demonstrated to be responsible for restoring fertility in other species.The implications of these results for using almond as a source of novel variability in peach are discussed.展开更多
Peroxiredoxins （Prx） catalyse the reduction of hydrogen peroxide （H2O2） and, in association with catalases and other peroxidases, may participate in signal transduction by regulating intercel ular H2O2 concentrati...Peroxiredoxins （Prx） catalyse the reduction of hydrogen peroxide （H2O2） and, in association with catalases and other peroxidases, may participate in signal transduction by regulating intercel ular H2O2 concentration that in turn can control gene transcription and cel signaling. Using virus-induced-gene-silencing （VIGS）, 2-Cys Peroxiredoxin （2CysPrx） family and type-II Peroxiredoxin B （PrxI B） gene were silenced in Nicotiana benthamiana, to study the impact that the loss of function of each Prx would have in the antioxidant system under control （22℃） and severe heat stress conditions （48 ℃）. The results showed that both Prxs, although in different organel es, influence the regeneration of ascorbate to a significant extent, but with different purposes. 2CysPrx affects abscisic acid （ABA） biosynthesis through ascorbate, while PrxIIB does it probably;through the xanthophyl cycle. Moreover, 2CysPrx is key in H2O2 scavenging and in consequence in the regulation of ABA signal-ing downstream of reactive oxygen species and PrxIIB provides an important assistance for H2O2 peroxisome scavenges.展开更多
Antigen-presenting cells(APCs)may be resistant to SARS-CoV-2 infection but still contribute to viral pathogenesis.Lectins such as sialic acid-binding Ig-like lectin 1(Siglec-1/CD169)mediate the attachment of viruses t...Antigen-presenting cells(APCs)may be resistant to SARS-CoV-2 infection but still contribute to viral pathogenesis.Lectins such as sialic acid-binding Ig-like lectin 1(Siglec-1/CD169)mediate the attachment of viruses to APCs.Here,we show that APCs effectively capture SARS-CoV-2 within compartments via recognition of Siglec-1.This receptor interacts with sialylated gangliosides on membranes of SARS-CoV-2 variants.展开更多
<b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"><span style="font-family:Verdana;"> Nonanoic acid (NA) is...<b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"><span style="font-family:Verdana;"> Nonanoic acid (NA) is one of a series of straight-chain aliphatic alcohols, aldehydes, acids and their derivatives with a well-documented history of use as a synthetic flavoring in human food. As part of a safety evaluation of NA for use as a flavoring in animal feed, an experiment was conducted to evaluate the ability of turkeys to tolerate NA at levels relevant to practical feeding practices. </span><b></b></span><b><b><span style="font-family:Verdana;">Materials and Methods:</span></b><span style="font-family:Verdana;"></span></b><span style="font-family:Verdana;"> A total of 594</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">day-old BUT Premium turkeys (300 males and 294 females) were allocated at random to 40 floor pens containing either 15 males or 13 to 15 females. Poults were fed one of 4 treatment diets in crumble (0 to 14 days) or pellet (15 to 59 days) form containing 0 (control), 100, 300 or 1000 mg NA/kg complete feed for 59 days. General health and performance were monitored for the duration of the study. At days 57 and 59 of age, blood samples were taken and birds were sacrificed and necropsied for histopathological examination of the digestive tract. Significant differences were considered at </span><i><span style="font-family:Verdana;">P </span></i></span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">≤</span><span><span style="font-family:Verdana;"> 0.05 and near-significant trends at </span><i><span style="font-family:Verdana;">P </span></i></span><span style="font-family:Verdana;">≤</span><span style="font-family:Verdana;"> 0.10.</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-f展开更多
The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages （a reduction in the risk o...The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages （a reduction in the risk of predation） and disadvantages （competition between members of the herd） of group living. In addition, advantages and disadvantages of group living may vary depending on the position of each individual within the herd. Our objective was to study the effect of central vs. peripheral position in the herd on feeding and vigilance behavior in male and female Pyrenean chamois and to ascertain if a group size effect existed. We used focal animal sampling and recorded social interactions when a focal animal was involved. With males, vigilance rate was higher in the central part of the group than at the periphery, probably due to a higher density of animals in the central part of the herd and a higher probability of being disturbed by conspecifics. With females, vigilance rate did not differ according to position in the herd. Females spent more time feeding than males, and males showed a higher frequency of the vigilance behavior than females. We did not observe a clear relationship between group size and vigilance behavior. The differences in vigilance behavior might be due to social interactions展开更多
Studies on the relative bioavailability (RBV) of DL-Methionine (DL-Met) to L-Methionine (L-Met) have produced variable results. An experiment was conducted to determine the RBV of DL to L-Met. A total of 2268 1-day ol...Studies on the relative bioavailability (RBV) of DL-Methionine (DL-Met) to L-Methionine (L-Met) have produced variable results. An experiment was conducted to determine the RBV of DL to L-Met. A total of 2268 1-day old male chicken were housed in 54 floor pens (42 bird/pen). There were 9 treatments (6 repetitions) including the basal diet (BD). The BD was deficient in Met content with 0.27, 0.26 and 0.25 in the starter, grower and finisher periods respectively. Four levels of experimental diets for each DL-Met and L-Met were created by supplementing 0.05%, 0.10%, 0.15% and 0.20% of DL- or L-Met to the BD. The feeding program consisted of starter (0-14 d, 21% CP and 2900 kcal ME/kg), grower (15 - 28 d, 20% CP and 3000 kcal ME/kg) and finisher period (29 - 37 d, 18.5% CP and 3050 kcal ME/kg). Chickens and feed were weighed at the end of each age period. Regression coefficients of a common plateau asymptotic regression were used to calculate RBV. Birds responded to gradual increase in Met levels, BW, FCR and ADG were significantly (P 0.05) higher in treatment groups as compared to control. Through the study period (37 d), the RBVs of DL-Met for BW and FCR were 89 and 77 respectively.展开更多
Infections by the fungus Monilinia laxa,the main cause of brown rot in Europe,result in considerable losses of stone fruit.Herein,we present a comprehensive transcriptomic approach to unravel strategies deployed by ne...Infections by the fungus Monilinia laxa,the main cause of brown rot in Europe,result in considerable losses of stone fruit.Herein,we present a comprehensive transcriptomic approach to unravel strategies deployed by nectarine fruit and M.laxa during their interaction.We used M.laxa-inoculated immature and mature fruit,which was resistant and susceptible to brown rot,respectively,to perform a dual RNA-Seq analysis.In immature fruit,host responses,pathogen biomass,and pathogen transcriptional activity peaked at 14–24 h post inoculation(hpi),at which point M.laxa appeared to switch its transcriptional response to either quiescence or death.Mature fruit experienced an exponential increase in host and pathogen activity beginning at 6 hpi.Functional analyses in both host and pathogen highlighted differences in stage-dependent strategies.For example,in immature fruit,M.laxa unsuccessfully employed carbohydrate-active enzymes(CAZymes)for penetration,which the fruit was able to combat with tightly regulated hormone responses and an oxidative burst that challenged the pathogen’s survival at later time points.In contrast,in mature fruit,M.laxa was more dependent on proteolytic effectors than CAZymes,and was able to invest in filamentous growth early during the interaction.Hormone analyses of mature fruit infected with M.laxa indicated that,while jasmonic acid activity was likely useful for defense,high ethylene activity may have promoted susceptibility through the induction of ripening processes.Lastly,we identified M.laxa genes that were highly induced in both quiescent and active infections and may serve as targets for control of brown rot.展开更多
To understand trophic interactions and the precise ecological role of each predatory species,it is important to know which arthropod and plant resources are used by generalist predators in agroecosystems.Molecular app...To understand trophic interactions and the precise ecological role of each predatory species,it is important to know which arthropod and plant resources are used by generalist predators in agroecosystems.Molecular approaches,such as the use of high-throughput sequencing(HTS),play a key role in identifying these resources.This study develops a multiprimer metabarcoding approach for screening the most common trophic interactions of two predatory arthropods with contrasting morphologies,Rhagonycha fulva(Coleoptera:Cantharidae)and Anthocoris nemoralis(Hemiptera:Anthocoridae)collected from a peach crop.To reduce the time and cost of this metabarcoding approach,we first evaluated the effect of using two different predator-pools of different size(10 and 23 individuals of the same species).We also used our system to analyze the performance of one and two primer pairs in the same library.Our results show that the analysis of 23 individuals together with the use of two primer pairs in the same library optimize the HTS analysis.Using these best-performing conditions,we then analyzed the entire bodies of field-collected predators as well as the washing solutions used to clean the insect bodies.We were able to identify both gut content(i.e.,diet)and external pollen load(i.e.,on the insects’bodies).This study also demonstrates the importance of washing predatory insects’bodies prior to HTS analysis when the target species have a considerable size(>10 mm)and hairy structures.This metabarcoding approach has significant potential for the study of trophic links in agriculture,revealing expected and unexpected trophic relationships.展开更多
In autoparasitoids, females are generally primary endoparasitoids of Hemiptera, while males are hyperparasitoids developing in or on conspecific females or other primary parasitoids. Female-host acceptance can be infl...In autoparasitoids, females are generally primary endoparasitoids of Hemiptera, while males are hyperparasitoids developing in or on conspecific females or other primary parasitoids. Female-host acceptance can be influenced by extrinsic and/or intrinsic factors. In this paper, we are concerned with intrinsic factors such as nutritional status, mating status, etc. We observed the behavior of Encarsia pergandiella Howard （Hymenoptera： Aphelinidae） females when parasitizing primary （3rd instar larvae ofBemisia tabaci Gen- nadius [Homoptera： Aleyrodidae]） and secondary hosts （3rd instar larvae and pupae of Eretmocerus rnundus Mercet [Hymenoptera： Aphelinidae]） for a period of 1 h. Females had different reproductive （virgin or mated younger） and physiological （fed elder or mated elder） status. Virgin females killed a large number of secondary hosts while investing a long time per host. However, they did not feed upon them. Mated females killed a lower number of secondary hosts and host feeding was observed in both consuming primary and secondary hosts. It was common to observe host examining females of all physiological statues tested repeatedly stinging the same hosts when parasitizing, killing or rejecting them. Fed elder females parasitized more B. tabaci larvae than E. mundus larvae or pupae, while investing less time on the primary host than on the secondary host. They also para- sitized more B. tabaci larvae than mated elder females, while investing less time per host. The access of females to honey allowed them to lay more eggs.展开更多
Field experiments were conducted in the Ebro Delta area （Spain）, from 2007 to 2009 with two rice varieties： Gleva and Tebre. The experimental treatments included a series of seed rates, two different water manageme...Field experiments were conducted in the Ebro Delta area （Spain）, from 2007 to 2009 with two rice varieties： Gleva and Tebre. The experimental treatments included a series of seed rates, two different water management systems and two different nitrogen fertilization times. The number of leaves on the main stems and their emergence time were periodically tagged. The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles. Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems. Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems. Final leaf number on the main stems was negatively related to plant density. A relationship between leaf appearance and thermal time was established with a strong nonlinear function. In direct-seeded rice, the length of the phyllochron increases exponentially in line with the advance of plant development. A general model, derived from 2-year experimental data, was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf. An exponential model can be used to predict leaf emergence in direct-seeded rice.展开更多
An urban area is a space with high population density which develops new, major and complex structures in comparison to the areas surrounding it. In order to develop these structures and maintain population and its ac...An urban area is a space with high population density which develops new, major and complex structures in comparison to the areas surrounding it. In order to develop these structures and maintain population and its activity, the metabolism of urban areas needs a lot of external sources of energy and nutrients （water, food, materials...）, which produces heat waste, garbage, sewage and pollution which are some of the major problems for urban sites, and the related areas from it. This metabolism promotes major environmental changes in the urban areas, which promote stress on vegetation used in gardening. The main environmental factors that affect vegetation in urban areas are the same that have been defined in literature from long time ago, but now they are acting as the sum of complementary and synergic effects of these classical stresses at the same moment, in the same place, which happen due to the incredibly amount of energy that we place in the systems. This is called global change. Ecophysiological studies can provide objective information to be used as a tool to improve the vegetation management in urban areas from design to process, and consequently avoiding the potential vulnerabilities associated with global change. Present paper tries to show several examples about the plant response, measurement tools and vulnerabilities and adaptations to global change under urban conditions. It can be concluded that the large availability of vegetal material and the great technical development can be highlighted as strong points of gardening and urban landscaping while, as weak points, it could be mentioned the changing taste of consumers, which can force the introduction of new vegetal material with no time for adaptation, Urban gardening and landscaping can be considered to be exposed to global change, but in our opinion it is necessary to carry out more studies to determine the real degree of vulnerability of this activity to this complex kind of stress.展开更多
The influence of a thermal discharge caused by the cooling system of a nuclear power station on benthic diatom communities was assessed at the lower Ebro River (in Spain), and the information generated could be useful...The influence of a thermal discharge caused by the cooling system of a nuclear power station on benthic diatom communities was assessed at the lower Ebro River (in Spain), and the information generated could be useful to understand the effects of increasing temperature on large Mediterranean rivers. Surveys conducted at sites before and after the effluent and collected from natural and artificial substrate were analyzed and, Non-metrical Multidimensional Scaling (NMDS), Similarity Percentage Analysis (SIMPER) and 1-way Analysis of Similarities (ANOSIM) were performed to assess changes in community structure. The relationship between diatom assemblages and environmental variables was assessed with a multivariate distance-based linear regression model (DISTLM) and the model was visualized through a redundancy analysis (dbRDA). NMDS ordination was obtained with a stress of 0.18 and 0.17 for natural and artificial substrates, respectively. ANOSIM showed significant differences between Control and Impacted sites (p 0.05). Simper analysis showed that the mean dissimilarity between Control and Impacted sites was of 42.22% for natural substrate and of 39.97% for artificial substrate. DISTLM selected a set of explanatory variables (dissolved oxygen, Tº?difference, total phosphorus, pH and chlorophyll) with a 67.24% of fitted variation. Diatoms showed sensitivity to thermal changes, even though when these did not exceed 3℃. The factors that seemed to influence benthic assemblages the most were seasonal variation and the thermal increase caused by the nuclear power station.展开更多
Isoprenoids are a hugely diverse family of compounds derived from the C5 precursors isopentenyl diphosphate （IPP） and dimethylallyl diphosphate （DMAPP）. Although all free-living organisms synthesize isoprenoids, t...Isoprenoids are a hugely diverse family of compounds derived from the C5 precursors isopentenyl diphosphate （IPP） and dimethylallyl diphosphate （DMAPP）. Although all free-living organisms synthesize isoprenoids, they are particularly abun- dant and diverse in plants, with tens of thousands structures known to date. The highest variety of plant isoprenoids are specialized （secondary） metabolites that participate in the interaction of plants with their environment. These include pigments, volatiles, and defense compounds, some of which have applications in industry and agriculture.展开更多
The reversibly red （R）/far-red （FR）-Iight-responsive phytochrome （phy） photosensory system initiates both the deetiolation process in dark-germinated seedlings upon first exposure to light, and the shade-avoidan...The reversibly red （R）/far-red （FR）-Iight-responsive phytochrome （phy） photosensory system initiates both the deetiolation process in dark-germinated seedlings upon first exposure to light, and the shade-avoidance process in fully deetiolated seedlings upon exposure to vegetational shade. The intracellular signaling pathway from the light-activated photoreceptor conformer （Pfr） to the transcriptional network that drives these responses involves direct, physical inter- action of Pfr with a small subfamily of bHLH transcription factors, termed Phy-lnteracting Factors （PIFs）, which induces rapid PIF proteolytic degradation. In addition, there is evidence of further complexity in light-grown seedlings, whereby phyB-PIF interaction reciprocally induces phyB degradation, in a mutually-negative, feedback-loop configuration. Here, to assess the relative contributions of these antagonistic activities to the net phenotypic readout in light-grown seedlings, we have examined the magnitude of the light- and simulated-shade-induced responses of a pentuple phyBpiflpif3pif4pif5 （phyBpifq） mutant and various multiple pif-mutant combinations. The data （1） reaffirm that phyB is the predominant, if not exclusive, photoreceptor imposing the inhibition of hypocotyl elongation in deetiolating seedlings in response to pro- longed continuous R irradiation and （2） show that the PIF quartet （PIF1, PIF3, PIF4, and PIF5） retain and exert a dual capacity to modulate hypocotyl elongation under these conditions, by concomitantly promoting cell elongation through intrinsic transcriptional-regulatory activity, and reducing phyB-inhibitory capacity through feedback-loop-induced phyB degrada- tion. In shade-exposed seedlings, immunoblot analysis shows that the shade-imposed reduction in Pfr levels induces increases in the abundance of PIF3, and mutant analysis indicates that PIF3 acts, in conjunction with PIF4 and PIF5, to promote the known shade-induced acceleration of hypocotyl elongation. Conversely, although 展开更多
Cinnamyl alcohol dehydrogenase （CAD） is a key enzyme involved in the last step of monolignol biosynthesis. The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in mai...Cinnamyl alcohol dehydrogenase （CAD） is a key enzyme involved in the last step of monolignol biosynthesis. The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize. Trans- genic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alter- ations in cell wall composition. Cell walls of CAD-RNAi stems contain a lignin polymer with a slight reduction in the S-to-G ratio without affecting the total lignin content. In addition, these cell walls accumulate higher levels of cellulose and ara- binoxylans. In contrast, cell walls of CAD-RNAi midribs present a reduction in the total lignin content and of cell wall polysaccharides. In vitro degradability assays showed that, although to a different extent, the changes induced by the repression of CAD activity produced midribs and stems more degradable than wild-type plants. CAD-RNAi plants grown in the field presented a wild-type phenotype and produced higher amounts of dry biomass. Cellulosic bioethanol assays revealed that CAD-RNAi biomass produced higher levels of ethanol compared to wild-type, making CAD a good target to improve both the nutritional and energetic values of maize lignocellulosic biomass.展开更多
Despite the availability of whole genome sequences of apple and peach,there has been a considerable gap between genomics and breeding.To bridge the gap,the European Union funded the FruitBreedomics project(March 2011 ...Despite the availability of whole genome sequences of apple and peach,there has been a considerable gap between genomics and breeding.To bridge the gap,the European Union funded the FruitBreedomics project(March 2011 to August 2015)involving 28 research institutes and private companies.Three complementary approaches were pursued:(i)tool and software development,(ii)deciphering genetic control of main horticultural traits taking into account allelic diversity and(iii)developing plant materials,tools and methodologies for breeders.Decisive breakthroughs were made including the making available of ready-to-go DNA diagnostic tests for Marker Assisted Breeding,development of new,dense SNP arrays in apple and peach,new phenotypic methods for some complex traits,software for gene/QTL discovery on breeding germplasm via Pedigree Based Analysis(PBA).This resulted in the discovery of highly predictive molecular markers for traits of horticultural interest via PBA and via Genome Wide Association Studies(GWAS)on several European genebank collections.FruitBreedomics also developed pre-breeding plant materials in which multiple sources of resistance were pyramided and software that can support breeders in their selection activities.Through FruitBreedomics,significant progresses were made in the field of apple and peach breeding,genetics,genomics and bioinformatics of which advantage will be made by breeders,germplasm curators and scientists.A major part of the data collected during the project has been stored in the FruitBreedomics database and has been made available to the public.This review covers the scientific discoveries made in this major endeavour,and perspective in the apple and peach breeding and genomics in Europe and beyond.展开更多
Deposition of the H2A.Z histone variant by the SWR1 complex （SWRI-C） in regulatory regions of specific loci modulates transcription. Characterization of mutations in Arabidopsis thaliana homologs of yeast SWRI-C has...Deposition of the H2A.Z histone variant by the SWR1 complex （SWRI-C） in regulatory regions of specific loci modulates transcription. Characterization of mutations in Arabidopsis thaliana homologs of yeast SWRI-C has revealed a role for H2A.Z exchange in a variety of developmental processes. Nevertheless, the exact composition of plant SWRI-C and how it is recruited to target genes remains to be established. Here we show that SWC4, the Arabidopsis homolog of yeast SANT domain protein Swc4/Eaf2, is a DNA-binding protein that interacts with SWR1-C subunits. We demonstrate that the swc4-1 knockout mutant is embryo- lethal, while SWC4 RNAi knockdown lines display pleiotropic phenotypic alterations in vegetative and repro- ductive traits, including acceleration of flowering time, indicating that SWC4 controls post-embryonic processes. Transcriptomic analyses and genome-wide profiling of H2A.Z indicate that SWC4 represses tran- scription of a number of genes, including the floral integrator FT and key transcription factors, mainly by modulating H2A.Z deposition. Interestingly, SWC4 silencing does not affect H2A.Z deposition at the FLC locus nor expression of this gene, a master regulator of flowering previously shown to be controlled by SWR1-C. Importantly, we find that SWC4 recognizes specific AT-rich DNA elements in the chromatin regions of target genes and that SWC4 silencing impairs SWRI-C binding at FT. Collectively, our data suggest that SWC4 regulates plant growth and development by aiding SWR1-C recruitment and modulating H2A.Z deposition.展开更多
Plant isoprenoids are formed from precursors synthesized by the mevalonate （MVA） pathway in the cytosol or by the methyl-D-erythritol 4-phosphate （MEP） pathway in plastids. Although some exchange of precursors occ...Plant isoprenoids are formed from precursors synthesized by the mevalonate （MVA） pathway in the cytosol or by the methyl-D-erythritol 4-phosphate （MEP） pathway in plastids. Although some exchange of precursors occurs, cytosolic sesquiterpenes are assumed to derive mainly from MVA, while plastidial monoterpenes are produced preferentially from MEP precursors. Additional complexity arises in the first step of the MEP pathway, which is typically catalyzed by two divergent 1-deoxy-D-xylulose 5-phosphate synthase isoforms （DXS1, DXS2）. In tomato （Solanum lycopersicum）, the SIDXS1 gene is ubiquitously expressed with highest levels during fruit ripening, whereas SIDXS2 transcripts are abundant in only few tissues, including young leaves, petals, and isolated trichomes. Specific down-regulation of SIDXS2 expression was performed by RNA interference in transgenic plants to investigate feedback mechanisms. SIDXS2 down-regulation led to a decrease in the monoterpene β-phellandrene and an increase in two sesquiterpenes in trichomes. Moreover, incorporation of MVA-derived precursors into residual monoterpenes and into sesquiterpenes was elevated as determined by comparison of ^13C to ^12C natural isotope ratios. A compensatory up-regulation of SIDXS1 was not observed. Down-regulated lines also exhibited increased trichome density and showed less damage by leaf-feeding Spodoptera littoralis caterpillars. The results reveal novel, non-redundant roles of DXS2 in modulating isoprenoid metabolism and a pronounced plasticity in isoprenoid precursor allocation.展开更多
基金supported in part by grants from the Ministry of Economy and Competitiveness(MINECO/FEDER projects AGL2015-68329-R and RTA2015-00050-00-00,Severo Ochoa Program for Centres of Excellence in R&D 201-2019 SEV-2015-0533 and CERCA Programme-Generalitat de Catalunya)from SpainUSDA-NIFA-Specialty Crop Research Initiative project,RosBREED:“Enabling marker-assisted breeding in Rosaceae”(2009-51181-05808)and RosBREED 2:“Combining disease resistance with horticultural quality in new rosaceous cultivars”(2014-51181-22378)and USDA NIFA Hatch project 1014919 from USAKey Project for New Agricultural Cultivar Breeding in Zhejiang Province(2016C02052-5)from China.
文摘Prior to the availability of whole-genome sequences,our understanding of the structural and functional aspects of Prunus tree genomes was limited mostly to molecular genetic mapping of important traits and development of EST resources.With public release of the peach genome and others that followed,significant advances in our knowledge of Prunus genomes and the genetic underpinnings of important traits ensued.In this review,we highlight key achievements in Prunus genetics and breeding driven by the availability of these whole-genome sequences.Within the structural and evolutionary contexts,we summarize:(1)the current status of Prunus whole-genome sequences;(2)preliminary and ongoing work on the sequence structure and diversity of the genomes;(3)the analyses of Prunus genome evolution driven by natural and man-made selection;and(4)provide insight into haploblocking genomes as a means to define genome-scale patterns of evolution that can be leveraged for trait selection in pedigree-based Prunus tree breeding programs worldwide.Functionally,we summarize recent and ongoing work that leverages whole-genome sequences to identify and characterize genes controlling 22 agronomically important Prunus traits.These include phenology,fruit quality,allergens,disease resistance,tree architecture,and self-incompatibility.Translationally,we explore the application of sequence-based marker-assisted breeding technologies and other sequence-guided biotechnological approaches for Prunus crop improvement.Finally,we present the current status of publically available Prunus genomics and genetics data housed mainly in the Genome Database for Rosaceae(GDR)and its updated functionalities for future bioinformatics-based Prunus genetics and genomics inquiry.
基金This work has been partly funded under grants AGL2012-40228-C02-01 from the Spanish Ministry of Economy and Knowledge and the EU Seventh Framework Programme by the FruitBreedomics project No.265582:Integrated approach for increasing breeding efficiency in fruit tree crops.
文摘Peach(Prunus persica)and almond(Prunus dulcis)are two sexually compatible species that produce fertile offspring.Almond,a highly polymorphic species,is a potential source of new genes for peach that has a strongly eroded gene pool.Here we describe the genetics of a male sterile phenotype that segregated in two almond(‘Texas’)×peach(‘Earlygold’)progenies:an F2(T×E)and a backcross one(T1E)to the‘Earlygold’parent.High-density maps were developed using a 9k peach SNP chip and 135 simple-sequence repeats.Three highly syntenic and collinear maps were obtained:one for the F2(T×E)and two for the backcross,T1E(for the hybrid)and E(for‘Earlygold’).A major reduction of recombination was observed in the interspecific maps(T×E and T1E)compared to the intraspecific parent(E).The E map also had extensive monomorphic genomic regions suggesting the presence of large DNA fragments identical by descent.Our data for the male sterility character were consistent with the existence of cytoplasmic male sterility,where individuals having the almond cytoplasm required the almond allele in at least one of two independent restorer genes,Rf1 and Rf2,to be fertile.The restorer genes were located in a 3.4 Mbp fragment of linkage group 2(Rf1)and 1.4 Mbp of linkage group 6(Rf2).Both fragments contained several genes coding for pentatricopeptide proteins,demonstrated to be responsible for restoring fertility in other species.The implications of these results for using almond as a source of novel variability in peach are discussed.
基金funded by Fundao para a Ciência e Tecnologia (FCT): CBAA (Pest OE/AGR/UI0240/2011)the postdoc grants SFRH/BPD/43898/2008 to PVSFRH/BPD/85767/ 2012 to LC
文摘Peroxiredoxins （Prx） catalyse the reduction of hydrogen peroxide （H2O2） and, in association with catalases and other peroxidases, may participate in signal transduction by regulating intercel ular H2O2 concentration that in turn can control gene transcription and cel signaling. Using virus-induced-gene-silencing （VIGS）, 2-Cys Peroxiredoxin （2CysPrx） family and type-II Peroxiredoxin B （PrxI B） gene were silenced in Nicotiana benthamiana, to study the impact that the loss of function of each Prx would have in the antioxidant system under control （22℃） and severe heat stress conditions （48 ℃）. The results showed that both Prxs, although in different organel es, influence the regeneration of ascorbate to a significant extent, but with different purposes. 2CysPrx affects abscisic acid （ABA） biosynthesis through ascorbate, while PrxIIB does it probably;through the xanthophyl cycle. Moreover, 2CysPrx is key in H2O2 scavenging and in consequence in the regulation of ABA signal-ing downstream of reactive oxygen species and PrxIIB provides an important assistance for H2O2 peroxisome scavenges.
基金The authors also acknowledge the crowdfunding initiative#Yomecorono(https://www.yomecorono.com).N.I.-U.is supported by the grant PID2020-117145RB-I00 from the Spanish Ministry of Science and InnovationJ.M.-P.is supported by the grant PID2019-109870RB-I00 from the Spanish Ministry of Science and Innovation and in part also by Grifols.The C.R.laboratory is funded by RTI2018-094445-B100(MCIU/AEI/FEDER,UE)+1 种基金The NHP study was primarily supported by a YNPRC Coronavirus Pilot Research Project Program grant to M.Pa.under award P51 OD11132,Emergent Venture Fast grant program to M.Pa.under awards#2206 and#2144,and William and Lula Pitts Foundation(to M.Pa.)X.M.-T.is supported by the Spanish Ministry of Science and Innovation and the European Regional Development Fund under agreement BES-2017-082900.The funders had no role in the study design,data collection and analysis,decision to publish,or preparation of the manuscript.
文摘Antigen-presenting cells(APCs)may be resistant to SARS-CoV-2 infection but still contribute to viral pathogenesis.Lectins such as sialic acid-binding Ig-like lectin 1(Siglec-1/CD169)mediate the attachment of viruses to APCs.Here,we show that APCs effectively capture SARS-CoV-2 within compartments via recognition of Siglec-1.This receptor interacts with sialylated gangliosides on membranes of SARS-CoV-2 variants.
文摘<b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"><span style="font-family:Verdana;"> Nonanoic acid (NA) is one of a series of straight-chain aliphatic alcohols, aldehydes, acids and their derivatives with a well-documented history of use as a synthetic flavoring in human food. As part of a safety evaluation of NA for use as a flavoring in animal feed, an experiment was conducted to evaluate the ability of turkeys to tolerate NA at levels relevant to practical feeding practices. </span><b></b></span><b><b><span style="font-family:Verdana;">Materials and Methods:</span></b><span style="font-family:Verdana;"></span></b><span style="font-family:Verdana;"> A total of 594</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">day-old BUT Premium turkeys (300 males and 294 females) were allocated at random to 40 floor pens containing either 15 males or 13 to 15 females. Poults were fed one of 4 treatment diets in crumble (0 to 14 days) or pellet (15 to 59 days) form containing 0 (control), 100, 300 or 1000 mg NA/kg complete feed for 59 days. General health and performance were monitored for the duration of the study. At days 57 and 59 of age, blood samples were taken and birds were sacrificed and necropsied for histopathological examination of the digestive tract. Significant differences were considered at </span><i><span style="font-family:Verdana;">P </span></i></span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">≤</span><span><span style="font-family:Verdana;"> 0.05 and near-significant trends at </span><i><span style="font-family:Verdana;">P </span></i></span><span style="font-family:Verdana;">≤</span><span style="font-family:Verdana;"> 0.10.</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-f
基金part of a "Comision Interministerial de Ciencia y Tecnologia" project (AGF99-0763-C02-02)funded by a grant (2001FI-00449)
文摘The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages （a reduction in the risk of predation） and disadvantages （competition between members of the herd） of group living. In addition, advantages and disadvantages of group living may vary depending on the position of each individual within the herd. Our objective was to study the effect of central vs. peripheral position in the herd on feeding and vigilance behavior in male and female Pyrenean chamois and to ascertain if a group size effect existed. We used focal animal sampling and recorded social interactions when a focal animal was involved. With males, vigilance rate was higher in the central part of the group than at the periphery, probably due to a higher density of animals in the central part of the herd and a higher probability of being disturbed by conspecifics. With females, vigilance rate did not differ according to position in the herd. Females spent more time feeding than males, and males showed a higher frequency of the vigilance behavior than females. We did not observe a clear relationship between group size and vigilance behavior. The differences in vigilance behavior might be due to social interactions
文摘Studies on the relative bioavailability (RBV) of DL-Methionine (DL-Met) to L-Methionine (L-Met) have produced variable results. An experiment was conducted to determine the RBV of DL to L-Met. A total of 2268 1-day old male chicken were housed in 54 floor pens (42 bird/pen). There were 9 treatments (6 repetitions) including the basal diet (BD). The BD was deficient in Met content with 0.27, 0.26 and 0.25 in the starter, grower and finisher periods respectively. Four levels of experimental diets for each DL-Met and L-Met were created by supplementing 0.05%, 0.10%, 0.15% and 0.20% of DL- or L-Met to the BD. The feeding program consisted of starter (0-14 d, 21% CP and 2900 kcal ME/kg), grower (15 - 28 d, 20% CP and 3000 kcal ME/kg) and finisher period (29 - 37 d, 18.5% CP and 3050 kcal ME/kg). Chickens and feed were weighed at the end of each age period. Regression coefficients of a common plateau asymptotic regression were used to calculate RBV. Birds responded to gradual increase in Met levels, BW, FCR and ADG were significantly (P 0.05) higher in treatment groups as compared to control. Through the study period (37 d), the RBVs of DL-Met for BW and FCR were 89 and 77 respectively.
基金supported by national project AGL2017-84389-C2-1-R from the Spanish Government(MINECO),by a PhD grant CPD2016-0159(M.B.-L.)from INIA,by funding received from the CERCA Programme/Generalitat de Catalunya and start-up funds from the College of Agricultural and Environmental Sciences and the Department of Plant Sciences(UC Davis)granted to B.B.-U.All authors declare no commercial,industrial links,or affiliations.
文摘Infections by the fungus Monilinia laxa,the main cause of brown rot in Europe,result in considerable losses of stone fruit.Herein,we present a comprehensive transcriptomic approach to unravel strategies deployed by nectarine fruit and M.laxa during their interaction.We used M.laxa-inoculated immature and mature fruit,which was resistant and susceptible to brown rot,respectively,to perform a dual RNA-Seq analysis.In immature fruit,host responses,pathogen biomass,and pathogen transcriptional activity peaked at 14–24 h post inoculation(hpi),at which point M.laxa appeared to switch its transcriptional response to either quiescence or death.Mature fruit experienced an exponential increase in host and pathogen activity beginning at 6 hpi.Functional analyses in both host and pathogen highlighted differences in stage-dependent strategies.For example,in immature fruit,M.laxa unsuccessfully employed carbohydrate-active enzymes(CAZymes)for penetration,which the fruit was able to combat with tightly regulated hormone responses and an oxidative burst that challenged the pathogen’s survival at later time points.In contrast,in mature fruit,M.laxa was more dependent on proteolytic effectors than CAZymes,and was able to invest in filamentous growth early during the interaction.Hormone analyses of mature fruit infected with M.laxa indicated that,while jasmonic acid activity was likely useful for defense,high ethylene activity may have promoted susceptibility through the induction of ripening processes.Lastly,we identified M.laxa genes that were highly induced in both quiescent and active infections and may serve as targets for control of brown rot.
基金The authors would like to thank Angels Tudo for technical assistance during the field collection of the.samples and laboratory procedures.We would like also to acknowledge the owners of the analyzed crop plot for allowing us access to their fields.This research was funded by the Spanish Ministry of Economy,Industry and Competitiveness(grant AGL2014-53970-C2-2-R)by the CERCA Program(Centres de Recerca de C atalunya)of the Generalitat de Catalunya.Ivan Batuecas received.funding from the grant BES-2015-075700 from the Span-ish Mimistry of Science,Innovation and Universities.
文摘To understand trophic interactions and the precise ecological role of each predatory species,it is important to know which arthropod and plant resources are used by generalist predators in agroecosystems.Molecular approaches,such as the use of high-throughput sequencing(HTS),play a key role in identifying these resources.This study develops a multiprimer metabarcoding approach for screening the most common trophic interactions of two predatory arthropods with contrasting morphologies,Rhagonycha fulva(Coleoptera:Cantharidae)and Anthocoris nemoralis(Hemiptera:Anthocoridae)collected from a peach crop.To reduce the time and cost of this metabarcoding approach,we first evaluated the effect of using two different predator-pools of different size(10 and 23 individuals of the same species).We also used our system to analyze the performance of one and two primer pairs in the same library.Our results show that the analysis of 23 individuals together with the use of two primer pairs in the same library optimize the HTS analysis.Using these best-performing conditions,we then analyzed the entire bodies of field-collected predators as well as the washing solutions used to clean the insect bodies.We were able to identify both gut content(i.e.,diet)and external pollen load(i.e.,on the insects’bodies).This study also demonstrates the importance of washing predatory insects’bodies prior to HTS analysis when the target species have a considerable size(>10 mm)and hairy structures.This metabarcoding approach has significant potential for the study of trophic links in agriculture,revealing expected and unexpected trophic relationships.
文摘In autoparasitoids, females are generally primary endoparasitoids of Hemiptera, while males are hyperparasitoids developing in or on conspecific females or other primary parasitoids. Female-host acceptance can be influenced by extrinsic and/or intrinsic factors. In this paper, we are concerned with intrinsic factors such as nutritional status, mating status, etc. We observed the behavior of Encarsia pergandiella Howard （Hymenoptera： Aphelinidae） females when parasitizing primary （3rd instar larvae ofBemisia tabaci Gen- nadius [Homoptera： Aleyrodidae]） and secondary hosts （3rd instar larvae and pupae of Eretmocerus rnundus Mercet [Hymenoptera： Aphelinidae]） for a period of 1 h. Females had different reproductive （virgin or mated younger） and physiological （fed elder or mated elder） status. Virgin females killed a large number of secondary hosts while investing a long time per host. However, they did not feed upon them. Mated females killed a lower number of secondary hosts and host feeding was observed in both consuming primary and secondary hosts. It was common to observe host examining females of all physiological statues tested repeatedly stinging the same hosts when parasitizing, killing or rejecting them. Fed elder females parasitized more B. tabaci larvae than E. mundus larvae or pupae, while investing less time on the primary host than on the secondary host. They also para- sitized more B. tabaci larvae than mated elder females, while investing less time per host. The access of females to honey allowed them to lay more eggs.
基金supported by the IRTA (Institute for Food and Agricultural Research and Technology), Spain
文摘Field experiments were conducted in the Ebro Delta area （Spain）, from 2007 to 2009 with two rice varieties： Gleva and Tebre. The experimental treatments included a series of seed rates, two different water management systems and two different nitrogen fertilization times. The number of leaves on the main stems and their emergence time were periodically tagged. The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles. Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems. Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems. Final leaf number on the main stems was negatively related to plant density. A relationship between leaf appearance and thermal time was established with a strong nonlinear function. In direct-seeded rice, the length of the phyllochron increases exponentially in line with the advance of plant development. A general model, derived from 2-year experimental data, was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf. An exponential model can be used to predict leaf emergence in direct-seeded rice.
文摘An urban area is a space with high population density which develops new, major and complex structures in comparison to the areas surrounding it. In order to develop these structures and maintain population and its activity, the metabolism of urban areas needs a lot of external sources of energy and nutrients （water, food, materials...）, which produces heat waste, garbage, sewage and pollution which are some of the major problems for urban sites, and the related areas from it. This metabolism promotes major environmental changes in the urban areas, which promote stress on vegetation used in gardening. The main environmental factors that affect vegetation in urban areas are the same that have been defined in literature from long time ago, but now they are acting as the sum of complementary and synergic effects of these classical stresses at the same moment, in the same place, which happen due to the incredibly amount of energy that we place in the systems. This is called global change. Ecophysiological studies can provide objective information to be used as a tool to improve the vegetation management in urban areas from design to process, and consequently avoiding the potential vulnerabilities associated with global change. Present paper tries to show several examples about the plant response, measurement tools and vulnerabilities and adaptations to global change under urban conditions. It can be concluded that the large availability of vegetal material and the great technical development can be highlighted as strong points of gardening and urban landscaping while, as weak points, it could be mentioned the changing taste of consumers, which can force the introduction of new vegetal material with no time for adaptation, Urban gardening and landscaping can be considered to be exposed to global change, but in our opinion it is necessary to carry out more studies to determine the real degree of vulnerability of this activity to this complex kind of stress.
基金funded by the Secretaria de Educacion Superior,Ciencia,Tecnologia e Innovacion(SENESCYT)of Ecuador,which provided a doctoral research fellowship to the first author.
文摘The influence of a thermal discharge caused by the cooling system of a nuclear power station on benthic diatom communities was assessed at the lower Ebro River (in Spain), and the information generated could be useful to understand the effects of increasing temperature on large Mediterranean rivers. Surveys conducted at sites before and after the effluent and collected from natural and artificial substrate were analyzed and, Non-metrical Multidimensional Scaling (NMDS), Similarity Percentage Analysis (SIMPER) and 1-way Analysis of Similarities (ANOSIM) were performed to assess changes in community structure. The relationship between diatom assemblages and environmental variables was assessed with a multivariate distance-based linear regression model (DISTLM) and the model was visualized through a redundancy analysis (dbRDA). NMDS ordination was obtained with a stress of 0.18 and 0.17 for natural and artificial substrates, respectively. ANOSIM showed significant differences between Control and Impacted sites (p 0.05). Simper analysis showed that the mean dissimilarity between Control and Impacted sites was of 42.22% for natural substrate and of 39.97% for artificial substrate. DISTLM selected a set of explanatory variables (dissolved oxygen, Tº?difference, total phosphorus, pH and chlorophyll) with a 67.24% of fitted variation. Diatoms showed sensitivity to thermal changes, even though when these did not exceed 3℃. The factors that seemed to influence benthic assemblages the most were seasonal variation and the thermal increase caused by the nuclear power station.
文摘Isoprenoids are a hugely diverse family of compounds derived from the C5 precursors isopentenyl diphosphate （IPP） and dimethylallyl diphosphate （DMAPP）. Although all free-living organisms synthesize isoprenoids, they are particularly abun- dant and diverse in plants, with tens of thousands structures known to date. The highest variety of plant isoprenoids are specialized （secondary） metabolites that participate in the interaction of plants with their environment. These include pigments, volatiles, and defense compounds, some of which have applications in industry and agriculture.
文摘The reversibly red （R）/far-red （FR）-Iight-responsive phytochrome （phy） photosensory system initiates both the deetiolation process in dark-germinated seedlings upon first exposure to light, and the shade-avoidance process in fully deetiolated seedlings upon exposure to vegetational shade. The intracellular signaling pathway from the light-activated photoreceptor conformer （Pfr） to the transcriptional network that drives these responses involves direct, physical inter- action of Pfr with a small subfamily of bHLH transcription factors, termed Phy-lnteracting Factors （PIFs）, which induces rapid PIF proteolytic degradation. In addition, there is evidence of further complexity in light-grown seedlings, whereby phyB-PIF interaction reciprocally induces phyB degradation, in a mutually-negative, feedback-loop configuration. Here, to assess the relative contributions of these antagonistic activities to the net phenotypic readout in light-grown seedlings, we have examined the magnitude of the light- and simulated-shade-induced responses of a pentuple phyBpiflpif3pif4pif5 （phyBpifq） mutant and various multiple pif-mutant combinations. The data （1） reaffirm that phyB is the predominant, if not exclusive, photoreceptor imposing the inhibition of hypocotyl elongation in deetiolating seedlings in response to pro- longed continuous R irradiation and （2） show that the PIF quartet （PIF1, PIF3, PIF4, and PIF5） retain and exert a dual capacity to modulate hypocotyl elongation under these conditions, by concomitantly promoting cell elongation through intrinsic transcriptional-regulatory activity, and reducing phyB-inhibitory capacity through feedback-loop-induced phyB degrada- tion. In shade-exposed seedlings, immunoblot analysis shows that the shade-imposed reduction in Pfr levels induces increases in the abundance of PIF3, and mutant analysis indicates that PIF3 acts, in conjunction with PIF4 and PIF5, to promote the known shade-induced acceleration of hypocotyl elongation. Conversely, although
文摘Cinnamyl alcohol dehydrogenase （CAD） is a key enzyme involved in the last step of monolignol biosynthesis. The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize. Trans- genic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alter- ations in cell wall composition. Cell walls of CAD-RNAi stems contain a lignin polymer with a slight reduction in the S-to-G ratio without affecting the total lignin content. In addition, these cell walls accumulate higher levels of cellulose and ara- binoxylans. In contrast, cell walls of CAD-RNAi midribs present a reduction in the total lignin content and of cell wall polysaccharides. In vitro degradability assays showed that, although to a different extent, the changes induced by the repression of CAD activity produced midribs and stems more degradable than wild-type plants. CAD-RNAi plants grown in the field presented a wild-type phenotype and produced higher amounts of dry biomass. Cellulosic bioethanol assays revealed that CAD-RNAi biomass produced higher levels of ethanol compared to wild-type, making CAD a good target to improve both the nutritional and energetic values of maize lignocellulosic biomass.
基金This work has been funded under the EU seventh Framework Programme by the FruitBreedomics project No.265582:Integrated Approach for increasing breeding efficiency in fruit tree crops(http://www.fruitbreedomics.com/).
文摘Despite the availability of whole genome sequences of apple and peach,there has been a considerable gap between genomics and breeding.To bridge the gap,the European Union funded the FruitBreedomics project(March 2011 to August 2015)involving 28 research institutes and private companies.Three complementary approaches were pursued:(i)tool and software development,(ii)deciphering genetic control of main horticultural traits taking into account allelic diversity and(iii)developing plant materials,tools and methodologies for breeders.Decisive breakthroughs were made including the making available of ready-to-go DNA diagnostic tests for Marker Assisted Breeding,development of new,dense SNP arrays in apple and peach,new phenotypic methods for some complex traits,software for gene/QTL discovery on breeding germplasm via Pedigree Based Analysis(PBA).This resulted in the discovery of highly predictive molecular markers for traits of horticultural interest via PBA and via Genome Wide Association Studies(GWAS)on several European genebank collections.FruitBreedomics also developed pre-breeding plant materials in which multiple sources of resistance were pyramided and software that can support breeders in their selection activities.Through FruitBreedomics,significant progresses were made in the field of apple and peach breeding,genetics,genomics and bioinformatics of which advantage will be made by breeders,germplasm curators and scientists.A major part of the data collected during the project has been stored in the FruitBreedomics database and has been made available to the public.This review covers the scientific discoveries made in this major endeavour,and perspective in the apple and peach breeding and genomics in Europe and beyond.
文摘Deposition of the H2A.Z histone variant by the SWR1 complex （SWRI-C） in regulatory regions of specific loci modulates transcription. Characterization of mutations in Arabidopsis thaliana homologs of yeast SWRI-C has revealed a role for H2A.Z exchange in a variety of developmental processes. Nevertheless, the exact composition of plant SWRI-C and how it is recruited to target genes remains to be established. Here we show that SWC4, the Arabidopsis homolog of yeast SANT domain protein Swc4/Eaf2, is a DNA-binding protein that interacts with SWR1-C subunits. We demonstrate that the swc4-1 knockout mutant is embryo- lethal, while SWC4 RNAi knockdown lines display pleiotropic phenotypic alterations in vegetative and repro- ductive traits, including acceleration of flowering time, indicating that SWC4 controls post-embryonic processes. Transcriptomic analyses and genome-wide profiling of H2A.Z indicate that SWC4 represses tran- scription of a number of genes, including the floral integrator FT and key transcription factors, mainly by modulating H2A.Z deposition. Interestingly, SWC4 silencing does not affect H2A.Z deposition at the FLC locus nor expression of this gene, a master regulator of flowering previously shown to be controlled by SWR1-C. Importantly, we find that SWC4 recognizes specific AT-rich DNA elements in the chromatin regions of target genes and that SWC4 silencing impairs SWRI-C binding at FT. Collectively, our data suggest that SWC4 regulates plant growth and development by aiding SWR1-C recruitment and modulating H2A.Z deposition.
文摘Plant isoprenoids are formed from precursors synthesized by the mevalonate （MVA） pathway in the cytosol or by the methyl-D-erythritol 4-phosphate （MEP） pathway in plastids. Although some exchange of precursors occurs, cytosolic sesquiterpenes are assumed to derive mainly from MVA, while plastidial monoterpenes are produced preferentially from MEP precursors. Additional complexity arises in the first step of the MEP pathway, which is typically catalyzed by two divergent 1-deoxy-D-xylulose 5-phosphate synthase isoforms （DXS1, DXS2）. In tomato （Solanum lycopersicum）, the SIDXS1 gene is ubiquitously expressed with highest levels during fruit ripening, whereas SIDXS2 transcripts are abundant in only few tissues, including young leaves, petals, and isolated trichomes. Specific down-regulation of SIDXS2 expression was performed by RNA interference in transgenic plants to investigate feedback mechanisms. SIDXS2 down-regulation led to a decrease in the monoterpene β-phellandrene and an increase in two sesquiterpenes in trichomes. Moreover, incorporation of MVA-derived precursors into residual monoterpenes and into sesquiterpenes was elevated as determined by comparison of ^13C to ^12C natural isotope ratios. A compensatory up-regulation of SIDXS1 was not observed. Down-regulated lines also exhibited increased trichome density and showed less damage by leaf-feeding Spodoptera littoralis caterpillars. The results reveal novel, non-redundant roles of DXS2 in modulating isoprenoid metabolism and a pronounced plasticity in isoprenoid precursor allocation.
