Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Ann Bot ; 131(4): 667-684, 2023 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-36594263

RESUMO

BACKGROUND AND AIMS: The Canary Islands have strong floristic affinities with the Mediterranean Basin. One of the most characteristic and diverse vegetation belts of the archipelago is the thermophilous woodland (between 200 and 900 m.a.s.l.). This thermophilous plant community consists of many non-endemic species shared with the Mediterranean Floristic Region together with Canarian endemic species. Consequently, phytogeographic studies have historically proposed the hypothesis of an origin of the Canarian thermophilous species following the establishment of the summer-dry mediterranean climate in the Mediterranean Basin around 2.8 million years ago. METHODS: Time-calibrated phylogenies for 39 plant groups including Canarian thermophilous species were primarily analysed to infer colonization times. In particular, we used 26 previously published phylogenies together with 13 new time-calibrated phylogenies (including newly generated plastid and nuclear DNA sequence data) to assess whether the time interval between stem and crown ages of Canarian thermophilous lineages postdates 2.8 Ma. For lineages postdating this time threshold, we additionally conducted ancestral area reconstructions to infer the potential source area for colonization. KEY RESULTS: A total of 43 Canarian thermophilous lineages were identified from 39 plant groups. Both mediterranean (16) and pre-mediterranean (9) plant lineages were found. However, we failed to determine the temporal origin for 18 lineages because a stem-crown time interval overlaps with the 2.8-Ma threshold. The spatial origin of thermophilous lineages was also heterogeneous, including ancestral areas from the Mediterranean Basin (nine) and other regions (six). CONCLUSIONS: Our findings reveal an unexpectedly heterogeneous origin of the Canarian thermophilous species in terms of colonization times and mainland source areas. A substantial proportion of the lineages arrived in the Canaries before the summer-dry climate was established in the Mediterranean Basin. The complex temporal and geographic origin of Canarian thermophilous species challenges the view of the Canary Islands (and Madeira) as a subregion within the Mediterranean Floristic Region.


Assuntos
Clima , Filogenia , Espanha , Região do Mediterrâneo
2.
Entropy (Basel) ; 24(7)2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35885073

RESUMO

Sensors have become a key element for the development of the Information Society [...].

3.
Entropy (Basel) ; 24(3)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35327847

RESUMO

In this paper, a method to classify behavioural patterns of cattle on farms is presented. Animals were equipped with low-cost 3-D accelerometers and GPS sensors, embedded in a commercial device attached to the neck. Accelerometer signals were sampled at 10 Hz, and data from each axis was independently processed to extract 108 features in the time and frequency domains. A total of 238 activity patterns, corresponding to four different classes (grazing, ruminating, laying and steady standing), with duration ranging from few seconds to several minutes, were recorded on video and matched to accelerometer raw data to train a random forest machine learning classifier. GPS location was sampled every 5 min, to reduce battery consumption, and analysed via the k-medoids unsupervised machine learning algorithm to track location and spatial scatter of herds. Results indicate good accuracy for classification from accelerometer records, with best accuracy (0.93) for grazing. The complementary application of both methods to monitor activities of interest, such as sustainable pasture consumption in small and mid-size farms, and to detect anomalous events is also explored. Results encourage replicating the experiment in other farms, to consolidate the proposed strategy.

4.
Breed Sci ; 68(4): 481-487, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30369823

RESUMO

Carnations carrying a recessive I gene show accumulation of the yellow pigment chalcononaringenin 2'-glucoside (Ch2'G) in their flowers, whereas those with a dominant I gene do accumulation the red pigment, anthocyanin. Although this metabolic alternative at the I gene could explain yellow and red flower phenotypes, it does not explain the development of orange flower phenotypes which result from the simultaneous accumulation of both Ch2'G and anthocyanin. The carnation whole genome sequencing project recently revealed that two chalcone isomerase genes are present, one that is consistent with the I gene (Dca60979) and another (Dca60978) that had not been characterized. Here, we demonstrate that Dca60979 shows a high level of gene expression and strong enzyme activity in plants with a red flower phenotype; however, functional Dca60979 transcripts are not detected in plants with an orange flower phenotype because of a dTdic1 insertion event. Dca60978 was expressed at a low level and showed a low level of enzyme activity in plants, which could catalyze a part of chalcone to naringenin to advance anthocyanin synthesis but the other part remained to be catalyzed chalcone to Ch2'G by chalcone 2'-glucosyltransferase, resulting in accumulation of anthocyanin and Ch2'G simultaneously to give orange color.

5.
Breed Sci ; 68(1): 139-143, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29681756

RESUMO

In a previous study, two genes responsible for white flower phenotypes in carnation were identified. These genes encoded enzymes involved in anthocyanin synthesis, namely, flavanone 3-hydroxylase (F3H) and dihydroflavonol 4-reductase (DFR), and showed reduced expression in the white flower phenotypes. Here, we identify another candidate gene for white phenotype in carnation flowers using an RNA-seq analysis followed by RT-PCR. This candidate gene encodes a transcriptional regulatory factor of the basic helix-loop-helix (bHLH) type. In the cultivar examined here, both F3H and DFR genes produced active enzyme proteins; however, expression of DFR and of genes for enzymes involved in the downstream anthocyanin synthetic pathway from DFR was repressed in the absence of bHLH expression. Occasionally, flowers of the white flowered cultivar used here have red speckles and stripes on the white petals. We found that expression of bHLH occurred in these red petal segments and induced expression of DFR and the following downstream enzymes. Our results indicate that a member of the bHLH superfamily is another gene involved in anthocyanin synthesis in addition to structural genes encoding enzymes.

6.
Ecol Evol ; 14(7): e11624, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38966248

RESUMO

Astydamia latifolia is the only species of the genus Astydamia, which forms an early-diverging lineage of Apiaceae, subfamily Apioideae. This species is subendemic to the Canary Islands and one of the most representative species of the coastal environments of this archipelago. Astydamia displays diplochory, that is, diaspores with two long-distance dispersal (LDD) syndromes. In particular, A. latifolia has both anemochorous and thalassochorous fruit traits (corky and winged mericarps). Although we expect this species to have a high dispersal capacity, there is no genetic study addressing it. The divergence time of this species from its sister taxon is also unknown. In this study, we aimed (i) to unveil the phylogenetic relationships and divergence times of A. latifolia; (ii) to reconstruct its phylogeographic structure across the Canary Islands; and (iii) to estimate the number of inter-island colonization events. To these ends, we first sequenced the internal transcribed spacer (ITS) region for A. latifolia, reconstructed the phylogenetic relationships of Astydamia and Apiaceae relatives and estimated divergence times. Then, two plastid DNA regions (psaI-aacD and psbK-trnS) were sequenced for 158 individuals (from 36 Canarian population and one NW African population) to reconstruct a haplotype network. The recently developed method Phylogeographic Analysis of Island Colonization Events (PAICE) was used to estimate the number of inter-island colonization events. Results show that A. latifolia is a phylogenetically isolated lineage that diverged from the most closely related genus (Molopospermum) in the Eocene-Miocene. It displays a low plastid DNA diversity (only four haplotypes detected), which is accompanied by a high degree of haplotype sharing between islands and highly linear rarefaction curves of colonization obtained in PAICE. These findings suggest a high colonization ability for this species, most likely related to the availability of two LDD syndromes.

7.
Materials (Basel) ; 16(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37374423

RESUMO

Materials such as wood, textiles, or plastics that are part of the exhibition system in museums are known to emit pollutants such as organic acids. Scientific and technical objects that include these materials in their composition can themselves be a potential source of emissions, which, together with inappropriate humidity and temperature conditions, can lead to corrosion of the metallic parts. In this work, we have studied the corrosivity of different locations in two venues of the Spanish National Museum of Science and Technology (MUNCYT). Coupons of the most representative metals from the collection were placed in different showcases and rooms for 9 months. The corrosion of the coupons has been evaluated in terms of the rate of mass gain, colour changes and characterisation of the corrosion products. The results were correlated to the relative humidity and concentration of gaseous pollutants to determine which metals are most susceptible to corrosion. The results show that metal artefacts exposed in showcases have a higher risk of corrosion than those exposed directly in the room, and that some pollutants are emitted by the artefacts. The corrosivity of the museum environment is low for copper, brass, and aluminium in most locations; however, some placements present a higher aggressivity for steel and lead, due to the high humidity and the presence of organic acids.

8.
Porcine Health Manag ; 9(1): 16, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37403176

RESUMO

BACKGROUND: Statistical Process Control (SPC) is a powerful statistical tool that can be used in animal production to evaluate the evolution of production parameters overtime in response to the implementation of a specific strategy. The aim of this study was to evaluate the effect of supplementing growing-finishing pigs with isoquinoline alkaloids (IQ) on growth performance parameters by using the SPC method. IQ are natural secondary plant metabolites which have been extensively investigated in food animals due to their efficacy in supporting growth performance and the overall health status. Performance parameters and medication usage were collected from 1,283,880 growing-finishing pigs fed the same basal diet, 147,727 of which were supplemented with IQ from day 70 of life until slaughter. RESULTS: Supplementation with IQ improved feed conversion ratio, while feed intake and daily gain were maintained. CONCLUSION: SPC methods are useful statistical tools to evaluate the effect of using a new feed additive in the feed of pigs on growth performance at a commercial level. Additionally, IQ supplementation improved growth performance and it can be considered as a good strategy to reduce feed conversion in growing-finishing pigs.

9.
Rev Esp Geriatr Gerontol ; 58(3): 125-133, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37031072

RESUMO

INTRODUCTION: BNT162b2 (BioNTech and Pfizer) is a nucleoside-modified mRNA vaccine that provides protection against SARS-CoV-2 infection and is generally well tolerated. However, data about its efficacy, immunogenicity and safety in people of old age or with underlying chronic conditions are scarce. PURPOSE: To describe BNT162b2 (BioNTech and Pfizer) COVID-19 vaccine immunogenicity, effectiveness and reactogenicity after complete vaccination (two doses), and immunogenicity and reactogenicity after one booster, in elders residing in nursing homes (NH) and healthy NH workers in real-life conditions. METHODS: Observational, ambispective, multicenter study. Older adults and health workers were recruited from three nursing homes of a private hospital corporation located in three Spanish cities. The primary vaccination was carried out between January and March 2021. The follow-up was 13 months. Humoral immunity, adverse events, SARS-CoV-2 infections, hospitalizations and deaths were evaluated. Cellular immunity was assessed in a participant subset. RESULTS: A total of 181 residents (mean age 84.1 years; 89.9% females, Charlson index ≥2: 45%) and 148 members of staff (mean age 45.2 years; 70.2% females) were surveyed (n:329). After primary vaccination of 327 participants, vaccine response in both groups was similar; ≈70% of participants, regardless of the group, had an antibody titer above the cut-off considered currently protective (260BAU/ml). This proportion increased significantly to ≈ 98% after the booster (p<0.0001 in both groups). Immunogenicity was largely determined by a prior history of COVID-19 infection. Twenty residents and 3 workers were tested for cellular immunity. There was evidence of cellular immunity after primary vaccination and after booster. During the study, one resident was hospitalized for SARS-CoV-2. No SARS-CoV-2-related deaths were reported and most adverse events were mild. CONCLUSIONS: Our results suggest that the BNT162b2 mRNA COVID-19 vaccine is immunogenic, effective and safe in elderly NH residents with underlying chronic conditions.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Idoso , Feminino , Humanos , Idoso de 80 Anos ou mais , Masculino , Vacinas contra COVID-19/efeitos adversos , Vacina BNT162 , COVID-19/prevenção & controle , SARS-CoV-2 , Casas de Saúde , Hospitais Privados
10.
Mol Ecol Resour ; 23(5): 1034-1049, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36799013

RESUMO

Environmental DNA-based diversity studies have increased in popularity with the development of high throughput sequencing technologies. This permits the potential simultaneous retrieval of vast amounts of molecular data from many different organisms and species, thus contributing to a wide range of biological disciplines. Environmental DNA protocols designed for protists often focused on the highly conserved small subunit of the ribosome gene, that does not permit species-level assignments. On the other hand, eDNA protocols aiming at species-level assignments allow a fine level ecological resolution and reproducible results. These protocols are currently applied to organisms living in marine and shallow lotic freshwater ecosystems, often in a bioindication purpose. Therefore, in this study, we present a species-level eDNA protocol designed to explore diversity of Arcellinida (Amoebozoa: Tubulinea) testate amoebae taxa that is based on mitochondrial cytochrome oxidase subunit I (COI). These organisms are widespread in lentic water bodies and soil ecosystems. We applied this protocol to 42 samples from peatlands, estuaries and soil environments, recovering all the infraorders in Glutinoconcha (with COI data), except for Hyalospheniformes. Our results revealed an unsuspected diversity in morphologically homogeneous groups such as Cylindrothecina, Excentrostoma or Sphaerothecina. With this protocol we expect to revolutionize the design of modern distributional Arcellinida surveys. Our approach involves a rapid and cost-effective analysis of testate amoeba diversity living in contrasted ecosystems. Therefore, the order Arcellinida has the potential to be established as a model group for a wide range of theoretical and applied studies.


Assuntos
Amebozoários , DNA Ambiental , Lobosea , Ecossistema , Filogenia , Amebozoários/genética , Lobosea/genética , Solo
11.
Pharmaceutics ; 13(3)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802226

RESUMO

The success on the design of new oral nanocarriers greatly depends on the identification of the best physicochemical properties that would allow their diffusion across the mucus layer that protects the intestinal epithelium. In this context, particle tracking (PT) has arisen in the pharmaceutical field as an excellent tool to evaluate the diffusion of individual particles across the intestinal mucus. In PT, the trajectories of individual particles are characterized by the mean square displacement (MSD), which is used to calculate the coefficient of diffusion (D) and the anomalous diffusion parameter (α) as MSD=4Dτα. Unfortunately, there is no stablished criteria to evaluate the goodness-of-fit of the experimental data to the mathematical model. This work shows that the commonly used R2 parameter may lead to an overestimation of the diffusion capacity of oral nanocarriers. We propose a screening approach based on a combination of R2 with further statistical parameters. We have analyzed the effect of this approach to study the intestinal mucodiffusion of lipid oral nanocarriers, compared to the conventional screening approach. Last, we have developed software able to perform the whole PT analysis in a time-saving, user-friendly, and rational fashion.

12.
Sci Rep ; 10(1): 15256, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938985

RESUMO

Although yellow and orange petal colors are derived from carotenoids in many plant species, this has not yet been demonstrated for the order Caryophyllales, which includes carnations. Here, we identified a carnation cultivar with pale yellow flowers that accumulated carotenoids in petals. Additionally, some xanthophyll compounds were esterified, as is the case for yellow flowers in other plant species. Ultrastructural analysis showed that chromoplasts with numerous plastoglobules, in which flower-specific carotenoids accumulate, were present in the pale yellow petals. RNA-seq and RT-qPCR analyses indicated that the expression levels of genes for carotenoid biosynthesis and esterification in pale yellow and pink petals (that accumulate small amounts of carotenoids) were similar or lower than in green petals (that accumulate substantial amounts of carotenoids) and white petals (that accumulate extremely low levels of carotenoids). Pale yellow and pink petals had a considerably lower level of expression of genes for carotenoid degradation than white petals, suggesting that reduced degradation activity caused accumulation of carotenoids. Our results indicate that some carnation cultivars can synthesize and accumulate esterified carotenoids. By manipulating the rate of biosynthesis and esterification of carotenoids in these cultivars, it should be feasible to produce novel carnation cultivars with vivid yellow flowers.


Assuntos
Vias Biossintéticas , Carotenoides/metabolismo , Dianthus/crescimento & desenvolvimento , Plastídeos/metabolismo , Carotenoides/química , Dianthus/genética , Dianthus/metabolismo , Esterificação , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Plastídeos/genética , Análise de Sequência de RNA
13.
J Clin Invest ; 130(10): 5576-5590, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663195

RESUMO

During hemolysis, macrophages in the liver phagocytose damaged erythrocytes to prevent the toxic effects of cell-free hemoglobin and heme. It remains unclear how this homeostatic process modulates phagocyte functions in inflammatory diseases. Using a genetic mouse model of spherocytosis and single-cell RNA sequencing, we found that erythrophagocytosis skewed liver macrophages into an antiinflammatory phenotype that we defined as MarcohiHmoxhiMHC class IIlo erythrophagocytes. This phenotype transformation profoundly mitigated disease expression in a model of an anti-CD40-induced hyperinflammatory syndrome with necrotic hepatitis and in a nonalcoholic steatohepatitis model, representing 2 macrophage-driven sterile inflammatory diseases. We reproduced the antiinflammatory erythrophagocyte transformation in vitro by heme exposure of mouse and human macrophages, yielding a distinctive transcriptional signature that segregated heme-polarized from M1- and M2-polarized cells. Mapping transposase-accessible chromatin in single cells by sequencing defined the transcription factor NFE2L2/NRF2 as a critical driver of erythrophagocytes, and Nfe2l2/Nrf2 deficiency restored heme-suppressed inflammation. Our findings point to a pathway that regulates macrophage functions to link erythrocyte homeostasis with innate immunity.


Assuntos
Hemólise/fisiologia , Fígado/citologia , Fígado/fisiologia , Macrófagos/citologia , Macrófagos/fisiologia , Fagócitos/citologia , Fagócitos/fisiologia , Animais , Modelos Animais de Doenças , Feminino , Heme/metabolismo , Humanos , Técnicas In Vitro , Inflamação/prevenção & controle , Macrófagos/classificação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Fator 2 Relacionado a NF-E2/deficiência , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Fagócitos/classificação , Fagocitose/fisiologia , Fenótipo , RNA-Seq , Análise de Célula Única , Esferocitose Hereditária/genética , Esferocitose Hereditária/patologia , Esferocitose Hereditária/fisiopatologia
14.
Plants (Basel) ; 8(7)2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31311180

RESUMO

The rooting of stem cuttings is a highly efficient procedure for the vegetative propagation of ornamental plants. In cultivated carnations, an increased auxin level in the stem cutting base produced by active auxin transport from the leaves triggers adventitious root (AR) formation from the cambium. To provide additional insight into the physiological and genetic basis of this complex trait, we studied AR formation in a collection of 159 F1 lines derived from a cross between two hybrid cultivars (2003 R 8 and 2101-02 MFR) showing contrasting rooting performances. In three different experiments, time-series for several stem and root architectural traits were quantified in detail in a subset of these double-cross hybrid lines displaying extreme rooting phenotypes and their parental genotypes. Our results indicate that the water content and area of the AR system directly contributed to the shoot water content and shoot growth. Moreover, morphometric data and rooting quality parameters were found to be associated with some stress-related metabolites such as 1-aminocyclopropane-1-carboxylic acid (ACC), the ethylene precursor, and the conjugated auxin indol-3-acetic acid-aspartic acid (IAA-Asp).

16.
Crop Prot ; 26(7): 1049-1054, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32287715

RESUMO

Carnation mottle virus (CarMV), Carnation etched ring virus (CERV), Carnation vein mottle virus (CVMV), Carnation ringspot virus (CRSV), Carnation Italian ringspot virus (CIRV) and Carnation latent virus (CLV) are the most important viruses affecting carnation crops. All except CERV are RNA viruses. Viral RNA or DNA accumulation on root, stem, leaf, sepal, petal, stamen, pistil and ovary tissues of infected carnation or Saponaria vaccaria plants was analysed by non-isotopic molecular hybridisation. High-titres of CarMV, CRSV, CIRV, and CLV accumulated in all plant tissues whereas CERV and CVMV were irregularly distributed over the plant. High-titres of all viruses accumulated in leaf, petal, stamen, pistil, and ovary tissues, so leaves or petals are a good tissue for routine diagnosis. Six chemicals were evaluated for inactivation of all carnation viruses in infected extracts. Commercial bleach at 7% (v/v) or NaOH at 0.5% (w/v) was found to inactivate all viruses after 60 s treatment in a systemic S. vaccaria bioassay.

17.
Gigascience ; 5: 29, 2016 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-27346392

RESUMO

BACKGROUND: The Mediterranean olive tree (Olea europaea subsp. europaea) was one of the first trees to be domesticated and is currently of major agricultural importance in the Mediterranean region as the source of olive oil. The molecular bases underlying the phenotypic differences among domesticated cultivars, or between domesticated olive trees and their wild relatives, remain poorly understood. Both wild and cultivated olive trees have 46 chromosomes (2n). FINDINGS: A total of 543 Gb of raw DNA sequence from whole genome shotgun sequencing, and a fosmid library containing 155,000 clones from a 1,000+ year-old olive tree (cv. Farga) were generated by Illumina sequencing using different combinations of mate-pair and pair-end libraries. Assembly gave a final genome with a scaffold N50 of 443 kb, and a total length of 1.31 Gb, which represents 95 % of the estimated genome length (1.38 Gb). In addition, the associated fungus Aureobasidium pullulans was partially sequenced. Genome annotation, assisted by RNA sequencing from leaf, root, and fruit tissues at various stages, resulted in 56,349 unique protein coding genes, suggesting recent genomic expansion. Genome completeness, as estimated using the CEGMA pipeline, reached 98.79 %. CONCLUSIONS: The assembled draft genome of O. europaea will provide a valuable resource for the study of the evolution and domestication processes of this important tree, and allow determination of the genetic bases of key phenotypic traits. Moreover, it will enhance breeding programs and the formation of new varieties.


Assuntos
Genoma de Planta , Olea/genética , Análise de Sequência de DNA/métodos , Mapeamento Cromossômico , Mapeamento de Sequências Contíguas , Biblioteca Gênica , Tamanho do Genoma , Região do Mediterrâneo , Anotação de Sequência Molecular
18.
Data Brief ; 5: 805-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26693515

RESUMO

Optimization instances relate to the input and output data stemming from optimization problems in general. Typically, an optimization problem consists of an objective function to be optimized (either minimized or maximized) and a set of constraints. Thus, objective and constraints are jointly a set of equations in the optimization model. Such equations are a combination of decision variables and known parameters, which are usually related to a set domain. When this combination is a linear combination, we are facing a classical Linear Programming (LP) problem. An optimization instance is related to an optimization model. We refer to that model as the Symbolic Model Specification (SMS) containing all the sets, variables, and parameters symbols and relations. Thus, a whole instance is composed by the SMS, the elements in each set, the data values for all the parameters, and, eventually, the optimal decisions resulting from the optimization solution. This data article contains several optimization instances from a real-world optimization problem relating to investment planning on energy efficient technologies at the building level.

19.
PLoS One ; 10(7): e0133123, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26230608

RESUMO

Carnation is one of the most important species on the worldwide market of cut flowers. Commercial carnation cultivars are vegetatively propagated from terminal stem cuttings that undergo a rooting and acclimation process. For some of the new cultivars that are being developed by ornamental breeders, poor adventitious root (AR) formation limits its commercial scaling-up, due to a significant increase in the production costs. We have initiated a genetical-genomics approach to determine the molecular basis of the differences found between carnation cultivars during adventitious rooting. The detailed characterization of AR formation in several carnation cultivars differing in their rooting losses has been performed (i) during commercial production at a breeders' rooting station and (ii) on a defined media in a controlled environment. Our study reveals the phenotypic signatures that distinguishes the bad-rooting cultivars and provides the appropriate set-up for the molecular identification of the genes involved in AR development in this species.


Assuntos
Dianthus/crescimento & desenvolvimento , Dianthus/genética , Dianthus/fisiologia , Genes de Plantas , Fenótipo , Melhoramento Vegetal , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/crescimento & desenvolvimento
20.
Physiol Plant ; 114(2): 303-312, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11903978

RESUMO

The origin and transport of the IAA responsible for rooting was studied in carnation (Dianthus caryophyllus L.) cuttings obtained from secondary shoots of the mother plants. The presence of mature leaves in the cuttings was essential for rooting. Removal of the apex and/or the youngest leaves did not reduce the rooting percentage as long as mature leaves remained attached. Removal of mature leaves inhibited rooting for a 24-day period during which the basal leaves grew and reached maturity. After this period rooting progressed as in intact cuttings. Auxin (NAA + IBA) applied to the stem base of defoliated cuttings was about 60% as effective as mature leaves in stimulating rooting. Application of NPA to the basal internode resulted in full inhibition of rooting. The view, deduced from these results, that auxin from mature leaves is the main factor controlling the rooting process was reinforced by the fact that mature leaves contained IAA and exported labelled IAA to the stem. The distribution of radioactivity after application of (5-3H)-IAA to mature leaves showed that auxin movement in the stem was basipetal and sensitive to NPA inhibition. The features of this transport were studied by applying 3H-IAA to the apical cut surface of stem sections excised from cuttings. The intensity of the transport was lower in the oldest node than in the basal internode, probably due to the presence of vascular traces of leaves. Irrespective of the localization of the sections and the carnation cultivar used, basipetal IAA transport was severely reduced when the temperature was lowered from 25 to 4 degrees C. The polar nature of the IAA transport in the sections was confirmed by the inhibition produced by NPA. Local application of IAA to different tissues of the sections revealed that polar auxin transport was associated with the vascular cylinder, the transport in the pith and cortex being low and apolar. The present results strongly support the conclusion that IAA originating from the leaves and transported in the stem through the polar auxin transport pathway was decisive in controlling adventitious rooting.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA