RESUMO
Ethylene-responsive factors (ERFs) have diverse functions in the regulation of various plant developmental processes. Here, we demonstrate the dual role of an Arabidopsis ERF gene, AtERF19, in regulating reproductive meristem activity and flower organ size through the regulation of genes involved in CLAVATA-WUSCHEL (CLV-WUS) and auxin signaling, respectively. We found that AtERF19 stimulated the formation of flower primordia and controlled the number of flowers produced by activating WUS and was negatively regulated by CLV3. 35S::AtERF19 expression resulted in significantly more flowers, whereas 35S::AtERF19 + SRDX dominant-negative mutants produced fewer flowers. In addition, AtERF19 also functioned to control flower organ size by promoting the division/expansion of the cells through activating Small Auxin Up RNA Gene 32 (SAUR32), which positively regulated MYB21/24 in the auxin signaling pathway. 35S::AtERF19 and 35S::SAUR32 resulted in similarly larger flowers, whereas 35S::AtERF19 + SRDX and 35S::SAUR32-RNAi mutants produced smaller flowers than the wild type. The functions of AtERF19 were confirmed by the production of similarly more and larger flowers in 35S::AtERF19 transgenic tobacco (Nicotiana benthamiana) and in transgenic Arabidopsis which ectopically expressed the orchid gene (Nicotiana benthamiana) PaERF19 than in wild-type plants. The finding that AtERF19 regulates genes involved in both CLV-WUS and auxin signaling during flower development significantly expands the current knowledge of the multifunctional evolution of ERF genes in plants. The results presented in this work indicate a dual role for the transcription factor AtERF19 in controlling the number of flowers produced and flower organ size through the regulation of genes involved in CLV-WUS and auxin signaling, respectively. Our findings expand the knowledge of the roles of ERF genes in the regulation of reproductive development.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Meristema , Tamanho do Órgão/genética , Flores , Ácidos Indolacéticos , Regulação da Expressão Gênica de Plantas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
RESEARCH QUESTION: What differences exist in the phenotypes of pre-eclampsia, perinatal outcomes and neonatal echocardiography between pregnancies conceived naturally and through IVF? DESIGN: Six hundred and ten women diagnosed with pre-eclampsia between January 2002 and December 2022 were included in this study. This research was conducted within the IVF and Maternal-Fetal Medicine Department of Kaohsiung Chang Gung Memorial Hospital, Taiwan. Participants were divided into two groups: those who achieved pregnancy through IVF, and those who conceived naturally. The phenotypes of pre-eclampsia and perinatal outcomes were assessed using a propensity-matched sample (nâ¯=â¯218), along with neonatal echocardiography. RESULTS: After conducting propensity score matching, the natural conception group had a higher prevalence of early-onset pre-eclampsia (53.9% versus 37.7%, Pâ¯=â¯0.04) and exhibited more severe features of pre-eclampsia (89.1% versus 69.8%, Pâ¯=â¯0.01) compared with the IVF group. Regarding perinatal outcomes, neonates in the IVF group had higher placental weights compared with the natural conception group (580 versus 480 g, Pâ¯=â¯0.031). The prevalence of abnormal findings on neonatal echocardiography was similar between the groups. Multivariate analysis showed that greater gestational age at delivery reduced the likelihood of abnormal findings on echocardiography [adjusted risk ratio (aRR) 0.950, Pâ¯=â¯0.001], while pregestational diabetes mellitus increased the likelihood of abnormal findings (aRR 1.451, Pâ¯=â¯0.044). Septal defects were the most common type of defect, occurring in 16.1% of infants. CONCLUSION: The impact of IVF conception on the severity of pre-eclampsia is not as expected. Neonatal echocardiography revealed a higher prevalence of abnormalities in offspring of women with pre-eclampsia compared with the general population. However, these issues were not linked to the method of conception, suggesting the existence of undisclosed factors that could influence the clinical features and perinatal outcomes of pre-eclampsia.
Assuntos
Ecocardiografia , Fertilização in vitro , Pré-Eclâmpsia , Resultado da Gravidez , Humanos , Feminino , Gravidez , Pré-Eclâmpsia/epidemiologia , Adulto , Recém-Nascido , Resultado da Gravidez/epidemiologia , Fenótipo , Taiwan/epidemiologia , FertilizaçãoRESUMO
A 36-year-old woman, gravida 3, para 1 (previous cesarean section), with one medical abortion, and no history of systemic diseases presented an unremarkable medical history during prenatal visits. The final prenatal ultrasound at 38 weeks of gestation showed a vertex presentation, a weight of 2600 g, a normal amniotic fluid level, and the placenta located on the posterior wall of the uterus. Fetal cardiotocography conducted before delivery reported a reactive heart rate without decelerations. The Doppler wave analysis of the fetal umbilical artery was normal (the ratio of peak-systolic flow velocity to the end-diastolic flow velocity was 2.5) without the absence or reversal of end-diastolic velocity. The total score of the fetal biophysical profile by ultrasound was 8. The night before the scheduled cesarean section, she experienced heightened anxiety and was unable to sleep, noting "crazy" fetal movements throughout the night. During the cesarean section, it was discovered that the umbilical cord was wrapped around the newborn's legs, resembling ankle shackles. The fetal weight was 2740 g, and Apgar scores were 9 at the first minute and 10 at the fifth minute. The motility of the neonatal legs was normal without cyanosis or neurological adverse outcomes.
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Thermal decomposition of CH(3)OH diluted in Ar has been studied by monitoring H atoms behind reflected shock waves of 100 ppm CH(3)OH + Ar. The total decomposition rate k(1) for CH(3)OH + M â products obtained in this study is expressed as, ln(k(1)/cm(3) molecule(-1) s(-1)) = -(14.81 ± 1.22) - (38.86 ± 1.82) × 10(3)/T, over 1359-1644 K. The present result on k(1) is indicated to be substantially smaller than the extrapolation of the most of the previous experimental data but consistent with the published theoretical results [Faraday Discuss. 2002, 119, 191-205 and J. Phys. Chem. A 2007, 111, 3932-3950]. Oxidation of CH(3)OH has been studied also by monitoring H atoms behind shock waves of (0.35-100) ppm CH(3)OH + (100-400) ppm O(2) + Ar. For the low concentration CH(3)OH (below 10 ppm) + O(2) mixtures, the initial concentration of CH(3)OH is evaluated by comparing evolutions of H atoms in the same concentration of CH(3)OH with addition of 300 ppm H(2) diluted in Ar. The branching fraction for CH(3)OH + Ar â (1)CH(2) + H(2)O + Ar has been quantitatively evaluated from this comparative measurements with using recent experimental result on the yield of H atoms in the reaction of (1,3)CH(2) + O(2) [J. Phys. Chem. A 2012, 116, 9245-9254]; i.e., the branching fraction for the above reaction is evaluated as, φ(1a) = 0.20 ± 0.04 at T = 1880-2050 K, in the 1.3 and 3.5 ppm CH(3)OH + 100 ppm O(2) samples. An extended reaction mechanism for the pyrolysis and oxidation of CH(3)OH is constructed based on the results of the present study combined with the oxidation mechanism of natural gas [GRI-Mech 3.0]; evolution of H atoms can be predicted very well with this new reaction scheme over a wide concentration range for the pyrolysis (0.36-100 ppm CH(3)OH), and oxidation (0.36-100 ppm CH(3)OH + 100/400 ppm O(2)) of methanol.
Assuntos
Metanol/química , Temperatura , Cinética , OxirreduçãoRESUMO
The ectopic expression of a MADS box gene FOREVER YOUNG FLOWER (FYF) caused a significant delay of senescence and a deficiency of abscission in flowers of transgenic Arabidopsis. The defect in floral abscission was found to be due to a deficiency in the timing of cell separation of the abscission zone cells. Down-regulation of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) may contribute to the delay of the floral abscission in 35S:FYF flowers. FYF was found to be highly expressed in young flowers prior to pollination and was significantly decreased after pollination, a pattern that correlated with its function. Ethylene insensitivity in senescence/abscission and the down-regulation of ETHYLENE RESPONSE DNA-BINDING FACTOR 1 (EDF1) and EDF2, downstream genes in the ethylene response, in 35S:FYF Arabidopsis suggested a role for FYF in regulating senescence/abscission by suppressing the ethylene response. This role was further supported by the fact that 35S:FYF enhanced the delay of flower senescence/abscission in ethylene response 1 (etr1), ethylene-insensitive 2 (ein2) and constitutive triple response 1 (ctr1) mutants, which have defects in upstream genes of the ethylene signaling pathway. The presence of a repressor domain in the C-terminus of FYF and the enhancement of the delay of senescence/abscission in FYF+SRDX (containing a suppression motif) transgenic plants suggested that FYF acts as a repressor. Indeed, in FYF-DR+VP16 transgenic dominant-negative mutant plants, in which FYF was converted to a potent activator by fusion to a VP16-AD motif, the senescence/abscission of the flower organs was significantly promoted, and the expression of BOP2, IDA and EDF1/2 was up-regulated. Our data suggest a role for FYF in controlling floral senescence/abscission by repressing ethylene responses and regulating the expression of BOP2 and IDA in Arabidopsis.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Senescência Celular , Flores/fisiologia , Arabidopsis/anatomia & histologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , DNA Complementar/genética , Regulação para Baixo , Etilenos/farmacologia , Flores/anatomia & histologia , Flores/efeitos dos fármacos , Flores/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Modelos Biológicos , Mutagênese Insercional , Fenótipo , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/anatomia & histologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , RNA de Plantas/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para CimaRESUMO
Gynostemium and ovule development in orchid are unique developmental processes in the plant kingdom. Characterization of C- and D-class MADS-box genes could help reveal the molecular mechanisms underlying gynostemium and ovule development in orchids. In this study, we isolated and characterized a C- and a D-class gene, PeMADS1 and PeMADS7, respectively, from Phalaenopsis equestris. These two genes showed parallel spatial and temporal expression profiles, which suggests their cooperation in gynostemium and ovule development. Furthermore, only PeMADS1 was ectopically expressed in the petals of the gylp (gynostemium-like petal) mutant, whose petals were transformed into gynostemium-like structures. Protein-protein interaction analyses revealed that neither PeMADS1 and PeMADS7 could form a homodimer or a heterodimer. An E-class protein was needed to bridge the interaction between these two proteins. A complementation test revealed that PeMADS1 could rescue the phenotype of the AG mutant. Overexpression of PeMADS7 in Arabidopsis caused typical phenotypes of the D-class gene family. Together, these results indicated that both C-class PeMADS1 and D-class PeMADS7 play important roles in orchid gynostemium and ovule development.
Assuntos
Proteínas de Domínio MADS/genética , Orchidaceae/genética , Óvulo Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/genética , Sequência de Aminoácidos , DNA de Plantas/genética , DNA de Plantas/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Teste de Complementação Genética , Proteínas de Domínio MADS/metabolismo , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Orchidaceae/anatomia & histologia , Orchidaceae/crescimento & desenvolvimento , Óvulo Vegetal/genética , Óvulo Vegetal/ultraestrutura , Fenótipo , Filogenia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/anatomia & histologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Polinização , Mapeamento de Interação de ProteínasRESUMO
Thermal decomposition of CH(2)I(2) [sequential C-I bond fission processes, CH(2)I(2) + Ar â CH(2)I + I + Ar (1a) and CH(2)I + Ar â (3)CH(2) + I + Ar (1b)], and the reactions of (3)CH(2) + H(2) â CH(3) + H (2) and (1)CH(2) + H(2) â CH(3) + H (3) have been studied by using atomic resonance absorption spectrometry (ARAS) of I and H atoms behind reflected shock waves. Highly diluted CH(2)I(2) (0.1-0.4 ppm) with/without excess H(2) (300 ppm) in Ar has been used so that the effect of the secondary reactions can be minimized. From the quantitative measurement of I atoms in the 0.1 ppm CH(2)I(2) + Ar mixture over 1550-2010 K, it is confirmed that two-step sequential C-I bond fission processes of CH(2)I(2), (1a) and (1b), dominate over other product channels. The decomposition step (1b) is confirmed to be the rate determining process to produce (3)CH(2) and the least-squares analysis of the measured rate gives, ln(k(1b)/cm(3) molecule(-1) s(-1)) = -(17.28 ± 0.79) - (30.17 ± 1.40) × 10(3)/T. By utilizing this result, we examine reactions 2 and 3 by monitoring evolution of H atoms in the 0.2-0.4 ppm CH(2)I(2) + 300 ppm H(2) mixtures over 1850-2040 K. By using a theoretical result on k(2) (Lu, K. W.; Matsui, H.; Huang, C.-L.; Raghunath, P.; Wang, N.-S.; Lin, M. C. J. Phys. Chem. A 2010, 114, 5493), we determine the rate for (3) as k(3)/cm(3) molecule(-1) s(-1) = (1.27 ± 0.36) × 10(-10). The upper limit of k(3) (k(3max)) is also evaluated by assuming k(2) = 0, i.e., k(3max)/cm(3) molecule(-1) s(-1) = (2.26 ± 0.59) × 10(-10). The present experimental results on k(3) and k(3max) is found to agree very well with the previous frequency modulation spectroscopy study (Friedrichs, G.; Wagner, H. G. Z. Phys. Chem. 2001, 215, 1601); i.e., the importance of the contribution of (1)CH(2) in the reaction of CH(2) with H(2) at elevated temperature range is reconfirmed.
RESUMO
The reaction CH(2) + O(2) â products has been studied by using atomic resonance absorption spectrometry (ARAS) of H and O((3)P) atoms behind reflected shock waves over 1850-2050 K and 2.1-1.7 atm. Measurements of [H] and [O] are conducted using mixtures of highly diluted CH(2)I(2) (0.2 and 0.4 ppm) with excess O(2) (100 and 262 ppm) in Ar; comparative measurement of [H] in the 0.2 and 0.4 ppm CH(2)I(2) + 300 ppm H(2) mixture has been conducted simultaneously to confirm the initial concentration of CH(2). The apparent reaction rate of CH(2) + O(2) (k(2)'), including the contributions of (3)CH(2) + O(2) â products (2) and (1)CH(2) + O(2) â products (3), has been measured from the evolutions of [H] and [O] and summarized as k(2)'/cm(3) molecule(-1) s(-1) = (1.90 ± 0.31) × 10(-11). The contribution of (1)CH(2) + O(2) reaction on the measured k(2)' has been evaluated as 0.15 ± 0.04, with an assumption that k(3) is independent of temperature and given by the result measured at room temperature [Langford, A. O.; Petek, H.; Moore, C. B. J. Chem. Phys. 1983, 78, 6650-6659]. The net rate for the (3)CH(2) + O(2) reaction is given as k(2)/cm(3) molecule(-1) s(-1) = (1.69 ± 0.31) × 10(-11). The result on k(2) in this study is found to be consistent with the extrapolation of the previous work at lower temperature range of 295-600 K. [Vinckler, C.; Debruyn, W. J. Phys. Chem. 1979, 83, 2057-2062]; these results can be summarized as k(2)/cm(3)molecule(-1) s(-1) = 2.74 × 10(-11) exp(-874/T), (T = 295-2050 K). The apparent production yields of H and O atoms for the reaction channels (1,3)CH(2) + O(2) â H + products (2a, 3a) and (1,3)CH(2) + O(2) â O((3)P) + products (2b, 3b) have been evaluated as φ(2a)' = 0.59 ± 0.06 and φ(2b)' = 0.23 ± 0.06, respectively. The contributions of (1)CH(2) + O(2) reaction on measured φ(2a)' and φ(2b)' are indicated to be minor; the net branching fractions for the (3)CH(2)+O(2) reaction are estimated as φ(2a) = 0.58 ± 0.06 and φ(2b) = 0.25 ± 0.06. No obvious temperature dependence is indicated in the measured rate constant nor in the branching fractions of H and O atoms. The mechanism of the reaction of CH(2) with O(2) is discussed based on the result of the present study together with those of the previous theoretical/experimental studies.
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OBJECTIVE: The present study aimed to investigate the seroprevalence and risk factors for toxoplasmosis among pregnant women in southern Taiwan and to determine the clinical benefits of screening for the same. MATERIALS AND METHODS: The current study included 458 pregnant women who received prenatal care from the first trimester at the Kaohsiung and Chiayi Chang Gung Memorial Hospitals during the time period from 2014 to 2015. Serological tests performed to detect the presence of Toxoplasma IgG and IgM antibodies. Amniocentesis was scheduled and real-time polymerase chain reaction (PCR) was employed to detect Toxoplasma DNA. Moreover, the maternal characteristics and risk factors, perinatal outcomes related to the seropositivity for Toxoplasma infection were analyzed. RESULTS: Among the pregnant patients included in the current study, 39/458 (8.5%) were IgG+ and 2/458 (0.6%) were IgM+. The present study analyzed the maternal characteristics and risk factors, perinatal outcome pertaining to the IgG seropositive group by means of the multiple logistic regression analysis revealed a female predominance (10.8%), compared to the males (6.4%), (adjusted OR = 0.48 (95%, 0.24-0.98), P = 0.043∗). The number cases with gestational age above 37 weeks at the time of delivery was significantly lower, compared to the cases below 37 weeks (adjusted OR = 0.32 (0.12-0.94), P = 0.038∗). Among one case with low avidity cannot exclude recent infection, the amniocentesis did not show any evidence of vertical transmission. CONCLUSION: The scenario may not warrant general screening and the results will not influence the clinical decisions. Although the present study failed to identify the maternal risk factors related to Toxoplasma infection, the results imply that health education is essential, owing to the slightly higher rate of preterm delivery in the IgG seropositive group.
Assuntos
Toxoplasma , Toxoplasmose , Anticorpos Antiprotozoários , Feminino , Humanos , Imunoglobulina G , Imunoglobulina M , Lactente , Recém-Nascido , Masculino , Gravidez , Diagnóstico Pré-Natal , Estudos Soroepidemiológicos , Taiwan/epidemiologia , Toxoplasma/genética , Toxoplasmose/diagnóstico , Toxoplasmose/epidemiologiaRESUMO
The orchid floral organs represent novel and effective structures for attracting pollination vectors. In addition, to avoid inbreeding, the androecium and gynoecium are united in a single structure termed the gynostemium. Identification of C-class MADS-box genes regulating reproductive organ development could help determine the level of homology with the current ABC model of floral organ identity in orchids. In this study, we isolated and characterized two C-class AGAMOUS-like genes, denoted CeMADS1 and CeMADS2, from Cymbidium ensifolium. These two genes showed distinct spatial and temporal expression profiles, which suggests their functional diversification during gynostemium development. Furthermore, the expression of CeMADS1 but not CeMADS2 was eliminated in the multitepal mutant whose gynostemium is replaced by a newly emerged flower, and this ecotopic flower continues to produce sepals and petals centripetally. Protein interaction relationships among CeMADS1, CeMADS2 and E-class PeMADS8 proteins were assessed by yeast two-hybrid analysis. Both CeMADS1 and CeMADS2 formed homodimers and heterodimers with each other and the E-class PeMADS protein. Furthermore, transgenic Arabidopsis plants overexpressing CeMADS1 or CeMADS2 showed limited growth of primary inflorescence. Thus, CeMADS1 may have a pivotal C function in reproductive organ development in C. ensifolium.
Assuntos
Flores/crescimento & desenvolvimento , Flores/genética , Genes Duplicados/genética , Genes de Plantas/genética , Proteínas de Domínio MADS/genética , Orchidaceae/crescimento & desenvolvimento , Orchidaceae/genética , Sequência de Aminoácidos , Arabidopsis/genética , Northern Blotting , Southern Blotting , Flores/citologia , Flores/ultraestrutura , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/química , Proteínas de Domínio MADS/metabolismo , Dados de Sequência Molecular , Orchidaceae/citologia , Orchidaceae/ultraestrutura , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
Scientific evidences in the literature have shown that plants treated exogenously with micromole concentration of hydrogen peroxide (H(2)O(2)) acquire abiotic stress tolerance potential, without substantial disturbances in the endogenous H(2)O(2) pool. In this study, we enhanced the endogenous H(2)O(2) content of tobacco (Nicotiana tabaccum L. cv. SR1) plants by the constitutive expression of a glucose oxidase (GO; EC 1.1.3.4) gene of Aspergillus niger and studied their cold tolerance level. Stable integration and expression of GO gene in the transgenic (T(0)-T(2)) tobacco lines were ascertained by molecular and biochemical tests. Production of functionally competent GO in transgenic plants was confirmed by the elevated levels of H(2)O(2) in the transformed tissues. When three homozygous transgenic lines were exposed to different chilling temperatures for 12 h, the electrolyte conductivity was significantly lower in GO-expressing tobacco plants than the control plants; in particular, chilling protection was more prominent at -1 degree C. In addition, most transgenic lines recovered within a week when returned to normal culture conditions after -1 degree C-12 h cold stress. However, control plants displayed symptoms of chilling injuries such as necrosis of shoot tip, shoots and leaves, consequently plant death. The protective effect realized in the transgenic plants was comparable to cold-acclimatized wild tobacco. The chilling tolerance of transgenic lines was found associated, at least in part, with elevated levels of total antioxidant content, CAT and APX activities. Based on our findings, we predict that the transgenic expression of GO may be deployed to improve cold tolerance potential of higher plants.
Assuntos
Aspergillus/enzimologia , Temperatura Baixa , Glucose Oxidase/metabolismo , Nicotiana/genética , Antioxidantes/análise , Regulação da Expressão Gênica de Plantas , Genes Fúngicos , Vetores Genéticos , Glucose Oxidase/genética , Peróxido de Hidrogênio/análise , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Estresse Fisiológico , Transformação GenéticaRESUMO
BACKGROUND: Lilium callosum is native to Taiwan, but little is known about it since it has been considered extinct since 1915. After the rediscovery of this rare species after a fire in 2011 in Tunghsiao Township, intensive work has been conducted to count the number in the wild population, to develop a conservation strategy, and to understand its reproductive characteristics and even economic potential. RESULTS: To conserve the germplasm of this population, three scales from a wild L. callosum plant were collected to establish a mass propagation system. Flowers from two regenerated plants were crossed by hand-pollination, the ovules were rescued and cultured in vitro, and 10 offspring were obtained. The karyotype was determined to be 2n = 2x = 24 = 2m + 2m(sat) + 2sm + 8st + 10t. The phylogenetic analysis using ITS sequences revealed that the sample of L. callosum from Taiwan was not grouped with the other accessions of L. callosum from other regions. The native habitat is classified as grass-dominated vegetation at the early successional stage and a subtropical monsoon-type climate. To clarify the causes of population scarcity in the native environment, reproductive characteristics of regenerated plants were investigated. CONCLUSIONS: Based on the information from this study, it is possible that factors intrinsic to L. callosum could combine to limit pollination and seed formation. The L. callosum pollen only germinated at a temperature that was higher than the native environment, the plants are self-incompatibile, there was a and scarce population, scattered flowering time and dichogamy. Through the culture of these wild harvested parts, the diversity of the germplasm has been broadened and is now available to preserve this rare and valuable species for the future.
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The ectopic expression of FOREVER YOUNG FLOWER (FYF), a MADS box gene in Arabidopsis, caused significant delay of senescence and a deficiency of abscission in flowers of transgenic Arabidopsis. It was proposed that the function of the FYF gene was related to the regulation of senescence and abscission. This hypothesis was further supported by one line of evidence reported in this study. The evidence is the similar delay of flower senescence and abscission observed in transgenic Arabidopsis ectopically expressing OnFYF, an FYF homolog from the Oncidium orchid, a monocot. This data suggested that the function of FYF homologs in regulating flower senescence and abscission was highly conserved in both dicot and monocot plants.
Assuntos
Arabidopsis/fisiologia , Flores/fisiologia , Proteínas de Domínio MADS/metabolismo , Orchidaceae/genética , Proteínas de Plantas/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologiaRESUMO
In this study, we isolated and characterized the function of a GLOBOSA/PISTILLATA-like gene, PeMADS6, from a native Phalaenopsis species, P. equestris. Southern blot analysis showed PeMADS6 as a single copy in the Phalaenopsis genome. Results of the determination of temporal and spatial expression showed that PeMADS6 was expressed and thus participated in the development of the sepals, petals, labellum and column in Phalaenopsis. Further confirmation of the expression pattern of PeMADS6 was carried out with in situ hybridization. Repressed expression of PeMADS6 in the orchid ovary was found to be pollination regulated, which suggests that the gene may have an inhibitory effect on the development of the ovary or ovule. In addition, auxin acted as the candidate signal to regulate the repression of PeMADS6 expression in the ovary. Furthermore, the flowers of transgenic Arabidopsis plants ectopically overexpressing PeMADS6 showed the morphology of petaloid sepals, with a 3- to 4-fold increase in flower longevity. Concomitantly, delayed fruit maturation was also observed in the transgenic Arabidopsis, which is consistent with the inhibitory effect of PeMADS6 on the development of the ovary. Thus, as a B-function gene, PeMADS6, not only specifies floral organ identity but has functions in flower longevity and ovary development in orchids.