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1.
Biochim Biophys Acta Bioenerg ; : 148078, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31476286

RESUMO

We describe a molecular mechanism tuning the functional properties of chlorophyll a (Chl-a) molecules in photosynthetic antenna proteins. Light-harvesting complexes from photosystem II in higher plants - specifically LHCII purified with α- or ß-dodecyl-maltoside, along with CP29 - were probed by low-temperature absorption and resonance Raman spectroscopies. We show that hydrogen bonding to the conjugated keto carbonyl group of protein-bound Chl-a tunes the energy of its Soret and Qy absorption transitions, inducing red-shifts that are proportional to the strength of the hydrogen bond involved. Chls-a with non-H-bonded keto C131 groups exhibit the blue-most absorption bands, while both transitions are progressively red-shifted with increasing hydrogen-bonding strength - by up 382 & 605 cm-1 in the Qy and Soret band, respectively. These hydrogen bonds thus tune the site energy of Chl-a in light-harvesting proteins, determining (at least in part) the cascade of energy transfer events in these complexes.

2.
Eur J Surg Oncol ; 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31471089

RESUMO

BACKGROUND: The surgical and oncological outcome of extra-levator abdominoperineal excision (ELAPE) procedure remains unclear in low rectal cancer. METHODS: A total of 194 cases of rectal cancer patients underwent ELAPE or conventional abdominoperineal excision (APE) procedure were analyzed in four hospitals' databases from January 2010 to December 2015. Clinicopathological data, overall survival (OS), disease free survival (DFS) and local recurrence free survival (LRFS) of patients were compared between two groups. RESULTS: The operation time spent in perineal phase was significantly shorter in the ELAPE group than that in conventional APE procedure (P < 0.001). There were more specimens with excellent or good quality in ELAPE group compared to conventional APE group (P = 0.033). Patients whom underwent ELAPE procedures showed significantly better OS, DFS and LRFS than those underwent conventional APE procedures. Patients with preoperative stage cT3∼T4 (P = 0.033, P = 0.008, P = 0,033), cN+ (P = 0.002, P < 0.001, P = 0.006) and pathological stage III-IV (P = 0.023, P = 0.008, P = 0.016) were associated with significant benefits from ELAPE procedure in terms of OS, DFS and LRFS. DFS differed significantly between two groups of patients whom got preoperative chemoradiation therapy (P = 0.009) or postoperative chemotherapy (P = 0.029). For patients of pathological stage IIII-IV without preoperative chemoradiation, ELAPE procedures resulted in statistically better OS (P = 0.018) and DFS (P = 0.030). ELAPE procedure was an independent risk factor of OS, DFS and LRFS in multivariate analysis. CONCLUSION: Low rectal cancer patients might benefit from ELAPE procedure on both surgical and oncological outcomes, especially in patients with relatively advanced tumors, inspite of the effects of pre-operative radio- and chemotherapy.

3.
Inj Prev ; 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31473596

RESUMO

OBJECTIVE: Pedestrian injuries are among the most common cause of death and serious injury to children. A range of risk factors, including individual differences and traffic environment factors, has been investigated as predictors of children's pedestrian behaviours. There is little evidence examining how risk factors might interact with each other to influence children's risk, however. The present study examined the independent and joint influences of individual differences (sex and sensation seeking) and traffic environment factors (vehicle speeds and inter-vehicle distances) on children's pedestrian safety. METHODS: A total of 300 children aged 10-13 years were recruited to complete a sensation-seeking scale, and 120 of those were selected for further evaluation based on having high or low sensation-seeking scores in each gender, with 30 children in each group. Children's pedestrian crossing behaviours were evaluated in a virtual reality traffic environment. RESULTS: Children low in sensation seeking missed more opportunities to cross and had longer start gaps to enter the roadway compared with those high in sensation seeking, and these effects were more substantial when vehicles were spread further apart but travelling slowly. Interaction effects between inter-vehicle distance and vehicle speed were also detected, with children engaging in riskier crossings when the car was moving more quickly and the vehicles were spread further than when the vehicles were moving quickly but were closer together. No sex differences or interactions emerged. CONCLUSION: Both sensation seeking and traffic environment factors impact children's behaviour in traffic, and there are interactions between traffic speeds and inter-vehicle distances that impact crossing behaviour.

4.
BMC Pediatr ; 19(1): 312, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484496

RESUMO

BACKGROUND: Earlier age of menarche has been associated with an increased risk of chronic diseases during adulthood, but whether early menarche has intergenerational effect is not clear. METHODS: In this population-based cross-sectional study, we recruited children from 26 primary schools using cluster random probability sampling in Shanghai, China, in 2014. We used multiple linear regression models to estimate the adjusted associations of maternal age of menarche (MAM) with offspring body mass index (BMI). We also used the mediation analysis to examine the contribution of maternal BMI and gestational diabetes to offspring BMI. RESULTS: A total of 17,571 children aged 6-13 years were enrolled, of whom 16,373 had their weight and height measured. Earlier MAM was associated with higher child BMI in boys (- 0.05 z-score per year older MAM, 95% CI - 0.08 to - 0.02) and in girls (- 0.05 z-score per year older MAM, 95% CI - 0.07 to - 0.02). Maternal BMI positively mediated the association of MAM with offspring BMI in both sexes, with mediation effects of 37.7 and 19.4% for boys and girls, respectively. CONCLUSION: Early maternal menarche was associated with greater offspring BMI. This study provides evidence for the intergenerational effect in the development of BMI in offspring.

5.
Acta Pharmacol Sin ; 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484993

RESUMO

TMEM16A Ca2+-activated chloride channel (CaCC) plays an essential role in vascular homeostasis. In this study we investigated the molecular mechanisms underlying downregulation of TMEM16A CaCC activity during hypertension. In cultured basilar artery smooth muscle cells (BASMCs) isolated from 2k2c renohypertesive rats, treatment with angiotensin II (0.125-1 µM) dose-dependently increased endophilin A2 levels and decreased TMEM16A expression. Similar phenomenon was observed in basilar artery isolated from 2k2c rats. We then used whole-cell recording to examine whether endophilin A2 could regulate TMEM16A CaCC activity in BASMCs and found that knockdown of endophilin A2 significantly enhanced CaCC activity, whereas overexpression of endophilin A2 produced the opposite effect. Overexpression of endophilin A2 did not affect the TMEM16A mRNA level, but markedly decreased TMEM16A protein level in BASMCs by inducing ubiquitination and autophagy of TMEM16A. Ubiquitin-binding receptor p62 (SQSTM1) could bind to ubiquitinated TMEM16A and resulted in a process of TMEM16A proteolysis in autophagosome/lysosome. These data provide new insights into the regulation of TMEM16A CaCC activity by endophilin A2 in BASMCs, which partly explains the mechanism of angiotensin-II-induced TMEM16A inhibition during hypertension-induced vascular remodeling.

6.
Mikrochim Acta ; 186(9): 663, 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31473835

RESUMO

The enzyme histone acetyltransferase (HAT) catalyzes the acetylation of a substrate peptide, and acetyl coenzyme A is converted to coenzyme A (CoA). A photoelectrochemical method is described for the determination of the HAT activity by using exfoliated MoS2 nanosheets, phos-tag-biotin, and ß-galactosidase (ß-Gal) based signal amplification. The MoS2 nanosheets are employed as the photoactive material, graphene nanosheets as electron transfer promoter, gold nanoparticles as recognition and capture reagent for CoA, and phos-tag-biotin as the reagent to link CoA and ß-Gal. The enzyme ß-Gal catalyzes the hydrolysis of substrate O-galactosyl-4-aminophenol to generate free 4-aminophenol which is a photoelectrochemical electron donor. The photocurrent increases with the activity of HAT. Under optimal conditions, the response is linear in the 0.3 to 100 nM activity range, and the detection limit is 0.14 nM (at S/N = 3). The assay was applied to HAT inhibitor screening, specifically for the inhibitors C646 and anacardic acid. The IC50 values are 0.28 and 39 µM, respectively. The method is deemed to be a promising tool for epigenetic research and HAT-targeted cancer drug discovery. Graphical abstract Histone acetyltransferase was detected using a sensitive photoelectrochemical method using MoS2 nanosheets as photoactive material.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31488721

RESUMO

In the development of photoelectrochemical cells for water splitting or CO2 reduction, a major challenge is O2 evolution at photoelectrodes that, in behavior, mimic photosystem II. At an appropriate semiconductor electrode, a water oxidation catalyst must be integrated with a visible light absorber in a stable half-cell configuration. Here, we describe an electrode consisting of a light absorber, an intermediate electron donor layer, and a water oxidation catalyst for sustained light driven water oxidation catalysis. In assembling the electrode on nanoparticle SnO2/TiO2 electrodes, a Ru(II) polypyridyl complex was used as the light absorber, NiO was deposited as an overlayer, and a Ru(II) 2,2'-bipyridine-6,6'-dicarboxylate complex as the water oxidation catalyst. In the final electrode, addition of the NiO overlayer enhanced performance toward water oxidation with the final electrode operating with a 1.1 mA/cm2 photocurrent density for 2 h without decomposition under one sun illumination in a pH 4.65 solution. We attribute the enhanced performance to the role of NiO as an electron transfer mediator between the light absorber and the catalyst.

8.
J Cell Physiol ; 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31489631

RESUMO

New York esophageal squamous cell carcinoma 1 (NY-ESO-1) is aberrantly expressed in multiple myeloma (MM) patients, however, its role remains largely unknown. The present study aimed to investigate the effect of NY-ESO-1 knockdown on MM impact and provide evidence for targeting treatment of MM. Human MM U266 cells were infected with lentivirus-based small hairpin RNA-targeting NY-ESO-1 (LV-shNY-ESO-1). Cellular proliferation, colony-forming, migration, and invasion assays were employed. The expressions of cell cycle and epithelial-mesenchymal transition (EMT)-related molecules, MM growth, and mouse osteolytic lesions were evaluated. The results showed that the LV-shNY-ESO-1-U266 cells had a lower expression of NY-ESO-1 and a higher expressions of p21 and E-cadherin, and a weaker abilities of colony formation, drug-resistant to adriamycin, migration, and invasion than those of the control cells. Importantly, the knockdown of NY-ESO-1 inhibited significantly the U266 cell-induced MM growth and osteolytic lesions along with increasing the expressions of E-cadherin, p21, and p53 in mice challenged with LV-shNY-ESO-1-U266 cells. Collectively, our findings demonstrate that knockdown of NY-ESO-1 suppressed the U266 cell-induced MM growth and osteolytic lesions by inhibition of the MMs cell cycle and EMT. The NY-ESO-1 knockdown may be considered for future clinical trials in MM.

9.
Mol Ecol Resour ; 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31482680

RESUMO

The rice stem borer, Chilo suppressalis, is one of the most damaging insect pests to rice production worldwide. Although C. suppressalis has been the focus of numerous studies examining cold tolerance and diapause, plant-insect interactions, pesticide target and resistance, and the development of RNAi-mediated pest management, the absence of a high-quality genome has limited deeper insights. To address this limitation, we generated a draft C. suppressalis genome constructed from both Illumina and PacBio sequences. The assembled genome size was 824.35 Mb with a contig N50 of 307 kb and a scaffold N50 of 1.75 Mb. Hi-C scaffolding assigned 99.2% of the bases to one of 29 chromosomes. Based on universal single-copy orthologs (BUSCO), the draft genome assembly was estimated to be 97% complete and is predicted to encompass 15,653 protein-coding genes. Cold tolerance is an extreme survival strategy found in animals. However, little is known regarding the genetic basis of the winter ecology of C. suppressalis. Here, we focused our orthologous analysis on those gene families associated with animal cold tolerance. Our finding provided first genomic evidence revealing specific cold tolerant strategies in C. suppressalis, including those involved in glucose-originated glycerol biosynthesis, triacylglycerol-originated glycerol biosynthesis, fatty acid synthesis and trehalose transport intermediated cold tolerance. The high-quality C. suppressalis genome provides a valuable resource for research in a broad range of areas in molecular ecology, and subsequently benefits developing modern pest control strategies.

11.
Chem Res Toxicol ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31468958

RESUMO

Elemicin is a constituent of natural aromatic phenylpropanoids present in many herbs and spices. However, its potential to cause toxicity remains unclear. To examine the potential toxicity and associated mechanism, elemicin was administered to mice for three weeks and serum metabolites examined. Enlarged livers were observed in elemicin-treated mice, which was accompanied by lower ratios of unsaturated- and saturated-lysophosphatidylcholines in plasma, and inhibition of stearoyl-CoA desaturase 1 (Scd1) mRNA expression in liver. Administration of the unsaturated fatty acid oleic acid reduced the toxicity of 1'-hydroxylelemicin, the primary oxidative metabolite of elemicin, while treatment with the SCD1 inhibitor A939572 potentiated its toxicity. Furthermore, the in vitro use of recombinant human CYPs and chemical inhibition of CYPs in human liver microsomes revealed that CYP1A1 and CYP1A2 were the primary CYPs responsible for elemicin bioactivation. Notably, the CYP1A2 inhibitor α-naphthoflavone could attenuate the susceptibility of mice to elemicin-induced hepatomegaly. This study revealed that metabolic activation of elemicin leads to SCD1inhibition in liver, suggesting that upregulation of SCD1 may serve as potential intervention strategy for elemicin-induced toxicity.

12.
J Orthop Surg Res ; 14(1): 264, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31451116

RESUMO

BACKGROUND: To investigate the incidence of scoliosis and trunk shift in patients with LDH (lumbar disc herniation) and analyze the differences in spinopelvic alignment among patients with or without trunk shift and non-symptom controls. MATERIALS AND METHODS: All included subjects had standard upright antero-posterior and lateral radiographs of the whole spine taken. Evidence of disc herniation was confirmed by computed tomography or magnetic resonance imaging. The parameters measured included trunk shift and Cobb angle, TK (thoracic kyphosis), TLK (thoraco-lumbar junction kyphosis), LL (lumbar lordosis), PI (pelvic incidence), SS (sacral slope), PT (pelvic tilt) and SVA (sagittal vertical axis). RESULTS: Sixty-eight patients with LDH and 61 controls were included. There were significantly more male patients with trunk shift than the patients without trunk shift. Forty-two patients had curve magnitudes ranging from 5 to 38°. The trunk shift ranged from 0.5 to 7.3 cm. A total of 54.76% of patients had a disc herniation on the concave side of the main curve. Fifty percent of patients showed a trunk shift towards the opposite side of disc herniation. There were significant differences in spinopelvic parameters among groups. Significant correlations were also observed between several spinopelvic parameters in the three groups. However, the degrees of correlations among the spinopelvic parameters differed among the three groups. CONCLUSION: Spinal sagittal morphology in LDH patients with trunk shift exhibits a more anterior shift of the C7 plumb line, less LL, and a more horizontal sacrum. Correlation analysis indicated a disharmonious spinopelvic interaction and a change in the compensatory model in patients with LDH.

13.
Soft Matter ; 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31465079

RESUMO

Injectable hydrogels are adapted to irregularities in the desired location by injection as a liquid and gelation in situ. However, traditional slow-gelling injectable hydrogels may result in loss of cargo (cells/drugs) as well as diffusion at the target site, and extremely rapid gelation may lead to undesired premature coagulation. These practical problems can be solved by using self-healing hydrogels. Herein, through the reduction of disulfide bonds in BSA protein by using a reducing agent, the disulfide bonds between the individual BSA protein molecules are re-matched to form a network structure, thereby forming a protein hydrogel. This hydrogel shows an efficient and rapid self-healing property, and the broken protein hydrogel can be fast repaired within 1-2 minutes in response to H2O2 stimulation, and the repair efficiency reached up to 100%. The hydrogel can be extruded using only a pinhole syringe, and cytotoxicity experiments have demonstrated excellent biocompatibility of the protein hydrogel. This non-toxic, injectable, fast self-healing protein hydrogel is expected to be widely used in biomedical, tissue engineering, injectable gel, 3D bioprinting, and other applications.

14.
Sci Rep ; 9(1): 11950, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31420567

RESUMO

Castor bean (Ricinus communis L., Euphorbiaceae) is a critical biodiesel crop and its seed derivatives have important industrial applications. Due to lack of a high-density genetic map, the breeding and genetic improvement of castor bean has been largely restricted. In this study, based on a recombinant inbred line (RIL) population consisting of 200 individuals, we generated 8,896 high-quality genomic SNP markers and constructed a high-resolution genetic map with 10 linkage groups (LGs), spanning 1,852.33 centiMorgan (cM). Based on the genetic map, 996 scaffolds from the draft reference genome were anchored onto 10 pseudo-chromosomes, covering 84.43% of the castor bean genome. Furthermore, the quality of the pseudo-chromosome scale assembly genome was confirmed via genome collinearity analysis within the castor bean genome as well as between castor bean and cassava. Our results provide new evidence that the phylogenetic position of castor bean is relatively solitary from other taxa in the Euphorbiaceae family. Based on the genetic map, we identified 16 QTLs that control seed size and weight (covering 851 candidate genes). The findings will be helpful for further research into potential new mechanisms controlling seed size and weight in castor bean. The genetic map and improved pseudo-chromosome scale genome provide crucial foundations for marker-assisted selection (MAS) of QTL governing important agronomic traits, as well as the accelerated molecular breeding of castor bean in a cost-effective pattern.

15.
J Colloid Interface Sci ; 555: 94-103, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31377648

RESUMO

Small plasmonic Au nanoparticles (NPs)-decorated with TiO2 nanosheets were fabricated to improve the photocatalytic performance. The Au/TiO2 nanosheets with Au NPs of different sizes ranging from ∼3 nm to 28 nm were prepared by using hydrothermally obtained TiO2 nanosheets as substrate via urea and light reduction method. During synthesis, the obtained Au NPs through urea reduction treatment in different calcination temperatures possessed smaller size (∼3-13 nm) than those of the light reduction method (∼28 nm). The introduced Au NPs were tightly loaded on the surface of TiO2 nanosheets through in situ growth reduction process of chloroauric acid. The emergence of smaller Au NPs promoted the photocatalytic performance over Au/TiO2 nanosheets. The as-prepared Au/TiO2 nanosheets with small Au NP sizes of ∼3-5 nm showed the highest photocatalytic rate of hydrogen production (∼230 µmol·h-1) under xenon lamp illumination, exceeding more than twice that of Au/TiO2 nanosheets with loading of larger Au NPs (∼28 nm). The favorable constituents and combination of Au/TiO2 nanosheets provided large surface adsorptive sites for reactant adsorption, introduced plasmonic effects and formed Schottky barrier junction via surface plasmon resonance. The Schottky barrier height was lower due to the presence of smaller Au NPs, thereby enhancing the charge separation through the Schottky transfer hub to neighboring TiO2 nanosheets. The synergistic effect between the plasmonic hot carrier-driven Au NPs and TiO2 nanosheets was discussed. The photocatalytic mechanism was also proposed for the fabrication of visible light-restricted photocatalysts with smaller Au NPs.

16.
Nano Lett ; 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31414817

RESUMO

The physical confinement of cell microenvironment could enhance the invasive capability and drug resistance of cancer cells. However, due to the lack of in vitro experimental platform to mimic both stiffness and confinement of the tumor microenvironment, the underlying mechanism remains elusive. Here, we developed a hydrogel-based microchannel platform with independently tunable channel stiffness and width in a physiological range. We found that the migration speed of the cancer cell is influenced by the synergistic effect of channel stiffness and width. In addition, the mesenchymal-amoeboid transition has a strong correlation with the channel stiffness. Besides, with a developed computational model, the role of nuclear stiffness on cancer migration speed and thus the mesenchymal-amoeboid transition in microchannels was also revealed. This platform is capable of mimicking the native physical microenvironment during metastasis, providing a powerful tool for high-throughput screening applications and investigating the interaction between cancer migration and biophysical microenvironment.

17.
Sci Total Environ ; 695: 133880, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31425992

RESUMO

The long-term variations of ozone are the combined results of climate change and air quality management. As Guangzhou is under the influence of both subtropical monsoon climate and rapid economic development, the ozone trend in recent years is uncertain. This paper presents the trend analysis of maximum daily average 8 h (MDA8) ozone and daily meteorological observations in Guangzhou from 2008 to 2018, using the Kolmogorov-Zurbenko (KZ) filter method. The observations were conducted at two sites in suburban Guangzhou, thus the datasets were processed in two periods. The first period (P1) is from 2008 to 2013, and the second period (P2) is from 2014 to 2018. Results show that the KZ filter method separates the short-term, seasonal, and long-term components efficiently, leaving a covariance term of 7.3% (5.4%) for P1 (P2). Through linear regression of long-term components, the trends were inferred as -0.06 ±â€¯0.04 ppb year-1 (R2 = 0.00, p < 0.05) for P1, and 0.51 ±â€¯0.08 ppb year-1 (R2 = 0.11, p < 0.05) for P2. It is found that the solar radiation has the strongest impact on ozone. With inclusion of temperature, relative humidity, and wind speed, these four meteorological factors held 71% (76%) variability in baseline ozone (sum of seasonal and long-term ozone) for P1 (P2). After applying the KZ filter method, the results reveal that the variance contribution of emission to long-term ozone variation is larger than that of meteorology in P1, while smaller in P2. Furthermore, 59% of the emission-induced ozone change in P2 could be explained by nitrogen dioxide variation, and their inverse correlation suggests that Guangzhou is mainly under volatile organic compounds-limited regime, despite continuous nitrogen oxides reduction.

18.
Science ; 365(6453): 578-582, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31395780

RESUMO

Dielectric capacitors with ultrahigh power densities are fundamental energy storage components in electrical and electronic systems. However, a long-standing challenge is improving their energy densities. We report dielectrics with ultrahigh energy densities designed with polymorphic nanodomains. Guided by phase-field simulations, we conceived and synthesized lead-free BiFeO3-BaTiO3-SrTiO3 solid-solution films to realize the coexistence of rhombohedral and tetragonal nanodomains embedded in a cubic matrix. We obtained minimized hysteresis while maintaining high polarization and achieved a high energy density of 112 joules per cubic centimeter with a high energy efficiency of ~80%. This approach should be generalizable for designing high-performance dielectrics and other functional materials that benefit from nanoscale domain structure manipulation.

19.
Oncogene ; 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31409901

RESUMO

Clinical applications of antiangiogenic agents profoundly affect tumor cell behaviors via the resultant hypoxia. To date, how the hypoxia regulates tumor cells remains unclear. Here, we show that hypoxia promotes the growth of human breast tumorigenic cells that repopulate tumors [tumor-repopulating cells (TRCs)] in vitro and in vivo. This stimulating effect is ascribed to hypoxia-induced reactive oxygen species (ROS) that activates Akt and NF-κB, dependent on the attenuated tricarboxylic acid (TCA) cycle. We find that fumarate is accumulated in the TCA cycle of hypoxic TRCs, leading to glutathione succination, NADPH/NADP+ decrease, and an increase in ROS levels. Mechanistically, hypoxia-increased HIF-1α transcriptionally downregulates the expression of mitochondrial phosphoenolpyruvate carboxykinase (PCK2), leading to TCA cycle attenuation and fumarate accumulation. These findings reveal that hypoxia-reprogrammed TCA cycle promotes human breast TRCs growth via a HIF-1α-downregulated PCK2 pathway, implying a need for a combination of an antiangiogenic therapy with an antioxidant modulator.

20.
DNA Cell Biol ; 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31411493

RESUMO

The phosphatidylethanolamine-binding protein (PEBP) gene family exists in all eukaryote kingdoms, with three subfamilies: FT (FLOWERING LOCUS T)-like, TFL1 (TERMINAL FLOWER 1)-like, and MFT (MOTHER OF FT AND TFL1)-like. FT genes promote flowering, TFL1 genes act as a repressor of the floral transition, and MFT genes have functions in flowering promotion and regulating seed germination. We identified and characterized orthologs of the Arabidopsis FT/TFL1 gene family in petunia to elucidate their expression patterns and evolution. Thirteen FT/TFL1-like genes were isolated from petunia, with the five FT-like genes mainly expressed in leaves. The circadian rhythms of five FT-like genes and PhCO (petunia CONSTANS ortholog) were figured out. The expression of PhFT1 was contrary to that of PhFT2, PhFT3, PhFT4, and PhFT5. PhCO had a circadian clock different from Arabidopsis CO, but coincided with PhFT1; it decreased in daytime and accumulated at night. Two of the FT-like genes with differential circadian rhythm and higher expression levels, PhFT1 and PhFT4, were used to transform Arabidopsis. Eventually, overexpressing PhFT1 strongly delayed flowering, whereas overexpression of PhFT4 produced extremely early-flowering phenotype. Different from previous reports, PhTFL1a, PhTFL1b, and PhTFL1c were relatively highly expressed in roots. Taken together, this study demonstrates that petunia FT-like genes, like FT, are able to respond to photoperiod. The expression pattern of FT/TFL1 gene family in petunia contributes to a new insight into the functional evolution of this gene family.

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