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1.
BMC Plant Biol ; 19(1): 301, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291885

RESUMO

BACKGROUND: Nothapodytes nimmoniana, a plant of pivotal medicinal significance is a source of potent anticancer monoterpene indole alkaloid (MIA) camptothecin (CPT). This compound owes its potency due to topoisomerase-I inhibitory activity. However, biosynthetic and regulatory aspects of CPT biosynthesis so far remain elusive. Production of CPT is also constrained due to unavailability of suitable in vitro experimental system. Contextually, there are two routes for the biosynthesis of MIAs: the mevalonate (MVA) pathway operating in cytosol and the methylerythritol phosphate (MEP) pathway in the plastids. Determination of relative precursor flux through either of these pathways may provide a new vista for manipulating the enhanced CPT production. RESULTS: In present study, specific enzyme inhibitors of MVA (lovastatin) and MEP pathways (fosmidomycin) were used to perturb the metabolic flux in N. nimmoniana. Interaction of both these pathways was investigated at transcriptional level by using qRT-PCR and at metabolite level by evaluating secologanin, tryptamine and CPT contents. In fosmidomycin treated plants, highly significant reduction was observed in both secologanin and CPT accumulation in the range 40-57% and 64-71.5% respectively, while 4.61-7.69% increase was observed in tryptamine content as compared to control. Lovastatin treatment showed reduction in CPT (7-11%) and secologanin (7.5%) accumulation while tryptamine registered slight increase (3.84%) in comparison to control. These inhibitor mediated changes were reflected at transcriptional level via altering expression levels of deoxy-xylulose-5-phosphate reductoisomerase (DXR) and hydroxymethylglutaryl-CoA reductase (HMG). Further, mRNA expression of four more genes downstream to DXR and HMG of MEP and MVA pathways respectively were also investigated. Expression analysis also included secologanin synthase (SLS) and strictosidine synthase (STR) of seco-iridoid pathway. Present investigation also entailed development of an efficient in vitro multiplication system as a precursor to pathway flux studies. Further, a robust Agrobacterium-mediated transformed hairy root protocol was also developed for its amenability for up-scaling as a future prospect. CONCLUSIONS: Metabolic and transcriptional changes reveal differential efficacy of cytosolic and plastidial inhibitors in context to pathway flux perturbations on seco-iridoid end-product camptothecin. MEP pathway plausibly is the major precursor contributor towards CPT production. These empirical findings allude towards developing suitable biotechnological interventions for enhanced CPT production.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Camptotecina/biossíntese , Magnoliopsida/genética , Vias Biossintéticas , Regulação da Expressão Gênica de Plantas , Magnoliopsida/metabolismo , Plantas Medicinais
2.
Comput Biol Chem ; 80: 498-511, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176140

RESUMO

Magnesium (Mg) is an important micronutrient for various physiological processes in plants. In this study, putative Magnesium Transporter (MGT) genes have been identified in Solanum lycopersicum, Solanum tuberosum, Brachypodium distachyon, Fagaria vesca, Brassica juncea and were classified into 5 distinct groups based on their sequence homology. MGT genes are very diverse and possess very low sequence identity within its family. However, the Gly-Met-Asn (GMN) signature motif is present in most of the genes which are believed to be essential for Mg2+ recognition. In S. lycopersicum, different physiological root growth pattern was observed in both Mg excess and deficient conditions. Quantitative RT-PCR gene expression study shows that most of the SlMGT genes were upregulated in response to Mg deficient condition.


Assuntos
Proteínas de Transporte de Cátions/genética , Genoma , Magnoliopsida/genética , Proteínas de Plantas/genética , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Magnésio/metabolismo , Magnoliopsida/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Conformação Proteica em alfa-Hélice , Reação em Cadeia da Polimerase em Tempo Real , Sementes/genética , Homologia de Sequência , Estresse Fisiológico/genética , Regulação para Cima
3.
Chemosphere ; 233: 300-308, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31176131

RESUMO

The extensive use of poly- and perfluoroalkyl substances (PFAS) has led to perfluoroalkyl acids (PFAAs) contamination in various environmental matrices. To remove PFAAs from contaminated water, this study investigated plant uptake of PFAAs by a native wetland plant species in the US, Juncus effusus. The results showed that J. effusus translocated selected PFAAs, including perfluoropentanoic acid (PFPA), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS). During the 21-day experimental period, the uptake of PFAAs increased with increasing PFAAs exposure concentration and time. PFOS was largely accumulated in the roots with limited upward translocation. PFAAs with shorter carbon chain length were taken up by J. effusus roots and tended to accumulate in plant shoots. The highest removal efficiency (11.4%) of spiked PFAAs by J. effusus was achieved when it was exposed to PFAAs at around 4.6 mg/L for 21 days. The exposure to PFAAs stimulated the antioxidative defense system in J. effusus shoots but inhibited the superoxide dismutase (SOD) and catalase (CAT) activities and damaged the antioxidative defense system in J. effusus roots. These results warrant further studies to evaluate J. effusus's long-term performance in a PFAAs contaminated environment.


Assuntos
Fluorcarbonetos/farmacocinética , Fluorcarbonetos/toxicidade , Magnoliopsida/efeitos dos fármacos , Magnoliopsida/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Catalase/metabolismo , Fluorcarbonetos/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Áreas Alagadas
4.
Int J Mol Sci ; 20(10)2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31137463

RESUMO

Jasmonic acid (JA) and its precursors and dervatives, referred as jasmonates (JAs) are important molecules in the regulation of many physiological processes in plant growth and development, and especially the mediation of plant responses to biotic and abiotic stresses. JAs biosynthesis, perception, transport, signal transduction and action have been extensively investigated. In this review, we will discuss the initiation of JA signaling with a focus on environmental signal perception and transduction, JA biosynthesis and metabolism, transport of signaling molecules (local transmission, vascular bundle transmission, and airborne transportation), and biological function (JA signal receptors, regulated transcription factors, and biological processes involved).


Assuntos
Ciclopentanos/metabolismo , Magnoliopsida/metabolismo , Oxilipinas/metabolismo , Transdução de Sinais , Magnoliopsida/fisiologia , Estresse Fisiológico
5.
Int J Mol Sci ; 20(9)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052234

RESUMO

The goal of this study was to establish an efficient protocol for the large-scale propagation of Mertensia maritima (L.) Gray, and evaluate the carotenoid, fatty acid, and tocopherol contents in the leaves of in vitro regenerated shoots. Surface-disinfected node and shoot tip explants were placed on semisolid Murashige and Skoog (MS) medium with 0-16 µM N6-benzyladenine (BA), kinetin, (KN), and thidiazuron (TDZ) alone, or in combination with, 1 or 2 µM α-naphthaleneacetic acid (NAA). Of the three different cytokinins employed, TDZ elicited the best results for axillary shoot proliferation. A maximum frequency of shoot initiation above 84%, with a mean of 8.9 and 4.8 shoots per node and shoot tip, respectively, was achieved on the culture medium supplemented with 4 µM TDZ. A combination of TDZ + NAA significantly increased the percentage of multiple shoot formation and number of shoots per explant. The best shoot induction response occurred on MS medium with 4 µM TDZ and 1 µM NAA. On this medium, the node (93.8%) and shoot tip (95.9%) explants produced an average of 17.7 and 8.6 shoots, respectively. The highest root induction frequency (97.4%) and number of roots per shoot (25.4), as well as the greatest root length (4.2 cm), were obtained on half-strength MS medium supplemented with 4 µM indole-3-butyric acid (IBA). The presence of six carotenoids and α-tocopherol in the leaf tissues of M. maritima was confirmed by HPLC. Gas chromatography-mass spectrometry analysis confirmed the presence of 10 fatty acids, including γ-linolenic acid and stearidonic acid in the leaf tissues of M. maritima. All-E-lutein (18.49 µg g-1 fresh weight, FW), α-tocopherol (3.82 µg g-1 FW) and α-linolenic acid (30.37%) were found to be the significant compounds in M. maritima. For the first time, a successful protocol has been established for the mass propagation of M. maritima with promising prospects for harnessing its bioactive reserves.


Assuntos
Magnoliopsida/crescimento & desenvolvimento , Compostos Fitoquímicos/metabolismo , Técnicas de Embriogênese Somática de Plantas/métodos , Carotenoides/análise , Carotenoides/metabolismo , Magnoliopsida/química , Magnoliopsida/metabolismo , Compostos Fitoquímicos/análise , Tocoferóis/análise , Tocoferóis/metabolismo
6.
Sci Total Environ ; 677: 447-455, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31059887

RESUMO

Atmospheric N pollution may shift nutrient limitations in aquatic autotrophs from N to P or cause an intensification of P limitation in formerly pristine areas. Small changes in nutrient supply in oligotrophic lakes and rivers could lead to large changes in relative plant growth and yield with possible knock on effects on ecosystem carbon cycling through changes in the decomposition rate of their tissue. Previous biogeographical studies have shown inconsistent responses of plant nutrient tissue content and stoichiometry (functional traits) to external nutrient availability. Here we used a single species, Juncus bulbosus, to test the interplay between plant tissue nutrient (content and stoichiometry) and external environmental factors (local and catchment scale). We developed a comparative approach applicable globally to assess the thresholds for nutrient limitation in aquatic plants in the wild. Phosphorus in Juncus bulbosus tissue was negatively related to sediment organic matter (Fe root plaque limiting P uptake) and catchment vegetation cover (less P leaching to lakes). Our comparative approach revealed that the lack of increase in N plant tissue along the strong gradient in external N concentration may be explained by P limitation and strict plant tissue N:P ratio. Our comparative approach further showed that the nutrient content and stoichiometry of Juncus bulbosus was similar to other submerged aquatic plants growing in nutrient poor aquatic ecosystems. In southern Norway, mass development of Juncus bulbosus may be primarily triggered by changes in P availability, rather than CO2 or inorganic N, as previously thought, although co-limitations are also possible. If so, the mass development of Juncus bulbosus in oligotrophic aquatic ecosystems could be an early indicator of increasing P fluxes through these ecosystems which are less limited by N due to high atmospheric N deposition.


Assuntos
Poluentes Atmosféricos/análise , Meio Ambiente , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/metabolismo , Nitrogênio/análise , Fósforo/metabolismo , Carbono/análise , Carbono/metabolismo , Lagos , Nitrogênio/metabolismo , Noruega , Nutrientes/metabolismo , Fósforo/análise
7.
Aquat Toxicol ; 211: 57-65, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30952066

RESUMO

Three submerged macrophytes, Ceratophyllum demersum (CD), Myriophyllum spicatum (MS) and Myriophyllum aquaticum (MA), were treated with various concentrations of ammonia for different lengths of time. Ammonium ions (NH4+) in the medium severely inhibited plant growth and led to a reduction in total chlorophyll (chl a and b) in CD and MS. The addition of ammonia significantly decreased the soluble protein content and increased the free amino acid content of CD and MS in treatments with high concentrations of NH4+, but MA showed no significant physiological response. The antioxidant enzyme system of MA was activated, which in turn reduced the peroxidation level in the plant and maintained the plant's normal physiological activities when the ammonia nitrogen in the culture fluid increased. The study continued to use higher concentrations (25, 50, 100, 200 and 400 mg/L) of ammonium nitrogen to treat and observe the peroxidation level and corresponding enzyme production for this species of MA in vivo to explore its resistance mechanism. The experiments show that MA can normally live for a period of time in a high-ammonia environment of up to 100 mg/L. The results of the present study will assist in studies of the detoxification of high ammonium ion contents in submersed macrophytes and the selection of plants suitable for macrophyte recovery.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Compostos de Amônio/toxicidade , Magnoliopsida/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Antioxidantes/metabolismo , Clorofila/metabolismo , Relação Dose-Resposta a Droga , Magnoliopsida/metabolismo , Saxifragales/efeitos dos fármacos , Saxifragales/metabolismo , Especificidade da Espécie
8.
Nat Commun ; 10(1): 1892, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015442

RESUMO

The dimeric lindenane sesquiterpenoids are mainly isolated from the plants of Chloranthaceae family. Structurally, they have a crowded molecular scaffold decorated with more than 11 stereogenic centers. Here we report divergent syntheses of eight dimeric lindenane sesquiterpenoids, shizukaols A, C, D, I, chlorajaponilide C, multistalide B, sarcandrolide J and sarglabolide I. In particular, we present a unified dimerization strategy utilizing a base-mediated thermal [4 + 2] cycloaddition between a common furyl diene, generated in situ, and various types of dienophiles. Accordingly, all the three types of lindenane [4 + 2] dimers with versatile biological activities are accessible, which would stimulate future probing of their pharmaceutical potential.


Assuntos
Técnicas de Química Sintética , Magnoliopsida/química , Sesquiterpenos/síntese química , China , Reação de Cicloadição , Dimerização , Magnoliopsida/metabolismo , Estrutura Molecular , Extratos Vegetais/química , Sesquiterpenos/isolamento & purificação
9.
Molecules ; 24(7)2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30934961

RESUMO

The leaves and twigs of the desiccation-tolerant medicinal shrub Myrothamnus flabellifolia are harvested for use in traditional and commercial teas and cosmetics due to their phenolic properties. The antioxidant and pharmacological value of this plant has been widely confirmed; however, previous studies typically based their findings on material collected from a single region. The existence of phenolic variability between plants from different geographical regions experiencing different rainfall regimes has thus not been sufficiently evaluated. Furthermore, the anthocyanins present in this plant have not been assessed. The present study thus used an untargeted liquid chromatography-tandem-mass spectrometry approach to profile phenolics in M. flabellifolia material collected from three climatically distinct (high, moderate, and low rainfall) regions representing the western, southern, and eastern extent of the species range in southern Africa. Forty-one putative phenolic compounds, primarily flavonoids, were detected, nine of which are anthocyanins. Several of these compounds are previously unknown from M. flabellifolia. Using multivariate statistics, samples from different regions could be distinguished by their phenolic profiles, supporting the existence of regional phenolic variability. This study indicates that significant phenolic variability exists across the range of M. flabellifolia, which should inform both commercial and traditional cultivation and harvesting strategies.


Assuntos
Magnoliopsida/química , Metaboloma , Metabolômica , Fenóis/análise , Cosméticos/análise , Ecossistema , Geografia , Magnoliopsida/metabolismo , Metabolômica/métodos , Extratos Vegetais/análise , Extratos Vegetais/química , Chá/química
10.
Planta ; 250(1): 245-261, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30993402

RESUMO

MAIN CONCLUSION: The plastid phosphate translocators evolved in algae but diversified into several groups, which adopted different physiological functions by extensive gene duplications and losses in Streptophyta. The plastid phosphate translocators (pPT) are a family of transporters involved in the exchange of metabolites and inorganic phosphate between stroma and cytosol. Based on their substrate specificities, they were divided into four subfamilies named TPT, PPT, GPT and XPT. To analyse the occurrence of these transporters in different algae and land plant species, we identified 652 pPT genes in 101 sequenced genomes for phylogenetic analysis. The first three subfamilies are found in all species and evolved before the split of red and green algae while the XPTs were derived from the duplication of a GPT gene at the base of Streptophyta. The analysis of the intron-exon structures of the pPTs corroborated these findings. While the number and positions of introns are conserved within each subfamily, they differ between the subfamilies suggesting an insertion of the introns shortly after the three subfamilies evolved. During angiosperm evolution, the subfamilies further split into different groups (TPT1-2, PPT1-3, GPT1-6). Angiosperm species differ significantly in the total number of pPTs, with many species having only a few, while several plants, especially crops, have a higher number, pointing to the importance of these transporters for improved source-sink strength and yield. The differences in the number of pPTs can be explained by several small-scale gene duplications and losses in plant families or single species, but also by whole genome duplications, for example, in grasses. This work could be the basis for a comprehensive analysis of the molecular and physiological functions of this important family of transporters.


Assuntos
Genoma de Planta/genética , Fosfatos/metabolismo , Proteínas de Plantas/genética , Plantas/genética , Mapeamento Cromossômico , Evolução Molecular , Éxons/genética , Duplicação Gênica , Íntrons/genética , Magnoliopsida/genética , Magnoliopsida/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Plastídeos/metabolismo
11.
Eur J Med Chem ; 169: 185-199, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30877973

RESUMO

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common age-related neurodegenerative disorders, affecting several millions of aged people globally. Among these disorders, AD is more severe, affecting about 7% of individuals aged 65 and above. AD is primarily a dementia-related disorder from progressive cognitive deterioration and memory impairment, while PD is primarily a movement disorder illness having three major kinesia or movement disorder symptoms, bradykinesia (slowness of movements), hypokinesia (reduction of movement amplitude), and akinesia (absence of normal unconscious movements) along with muscle rigidity and tremor at rest. AD is characterized by deposition of extracellular beta-amyloid (Aß) proteins and intracellular neurofibrillary tangles (NFT), composed of hyperphosphorylated tau proteins in the neurons located particularly in hippocampus and cerebral cortex regions of brain, resulting the neuronal loss, while PD is characterized by deposition of intraneuronal aggregates of mostly composed of alpha-synuclein gene as Lewy bodies (LB) in the striatal region, known as substantia nigra pars compacta (SNpc) of brain, leading to the death of dopaminergic neurons. These are known as pathological hallmarks of these diseases. However, in some overlapping cases, known as Alzheimer with Parkinson disease or vice versa, alpha-synuclein deposition in AD and tau deposition in PD patients are found. Oxidative stress-induced glial cells activation, neuroinflammation and mitochondrial dysfunction lead to various molecular events in brain neurons causing neuronal cell death in these neurodegenerative disorders. Currently used drugs for treatment of AD and PD only reduce the symptoms of these diseases, but unable to stop the process of neurodegeneration. Therefore, innovation of new synthetic drugs or discovery of natural drugs for the treatment of AD and PD, is a challenging task of basic science and clinical medicine. Plant iridoids such as catalpol and its 10-O-trans-p-coumaroyl derivative, geniposide, harpagoside, and loganin, and seco-iridoids, oleuropein and its aglycone and oleocanthal have been found to exhibit significant neuroprotective effect and the property of slowing down the process of neurogedeneration in AD and PD. These plant metabolites have been shown to ameliorate AD by increasing the expression of insulin degrading enzyme (IDE), neprilysin (NEP), PPAR-γ, and α-secretase, and decreasing the expression of ß-secretase (BACE-1) to reduce the levels of Aß oligomers (AßO) deposition in brain neurons. These plant metabolites reduced the expression of GSK-3ß and its receptor gene, PTEN to reduce hyperphosphorylation of tau proteins and neurofibrillary tangles (NFTs) formation. These metabolites improved the expressions of neuroprotective proteins, Bcl-2 via activations of growth-related protein-1 receptor (GLP-1R), PKC, MEK, MAPK/PI3K, and AMPK, and suppressed the expressions of pro-apoptotic proteins, Bax and caspase-3. Furthermore, these plant metabolites improved the lysosomal autophagy process by increasing the expression levels of Beclin-1, LC3II and cathepsin B genes for clearance of Aß and NFT, and increased the expression of transporter proteins, P-glycoprotein (P-gp) and low density lipoprotein receptor-related protein-1 (LRP-1) for the clearance of Aß load from brain across the blood-brain barrier (BBB) as well as increased the expression of PPAR-γ and ApoE proteins for clearance of Aß in ApoE mediated pathway from brain. Moreover, these plant metabolites reduced the cognitive impairment by increasing the expression of synaptic proteins, BDNF, PSD-95, SNAP-25, SYP and GAP-43 for improvement of learning and memory functions in AD. While among these iridoids, catalpol, 10-O-trans-p-coumaroylcatalpol, geniposide and harpagoside, in PD improved the expressions of GDNF and Bcl-2 proteins and TH-positive neurons by increasing the levels of antioxidant enzymes, SOD and GSH-PX and down-regulating insulin/IGF signalling via activation of MEK protein. Moreover, catalpol and its p-coumaroyl derivative in mutant nematode C. elegans model, up-regulated the expression of DAF-16, a FOXO family transcription factor and SKN-1 genes for improvement of lifespan and resistance against oxidative- and other stresses of mutated worms. Furthermore, geniposide increased the expression of autophagy-related LAMP-2A-protein for clearance of LB from dopaminergic neurons in PD brain via improving lysosomal autophagy process. The present review summarizes the neuroprotective activities and molecular mechanisms of these iridoids and secoiridoids, in prevention and/or treatment of both AD and PD. This review will be helpful to find out the research gap on these plant metabolites in this field to use them as potential drugs against these disorders.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Iridoides/uso terapêutico , Magnoliopsida/química , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Animais , Humanos , Iridoides/química , Iridoides/metabolismo , Magnoliopsida/metabolismo , Estrutura Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-30857159

RESUMO

The influence of pyrolysis temperature on cadmium (Cd) removal capacity and mechanisms by maize straw biochars (MSB) and Platanus leaves biochars (PLB) pyrolyzed at 300, 400, 500 and 600 °C was investigated. The results showed that the biochars pyrolyzed at 500 °C had the highest adsorption capacity for Cd, and the maximum adsorption at pH 5.0 was 35.46 mg/g and 25.45 mg/g for MSB and PLB, respectively. The increase in adsorption efficiency with increasing temperature indicated that the adsorption of Cd onto the biochars was endothermic. Based on the balance analysis between cations (Ca2+ and Mg2+) released and Cd adsorbed onto biochar in combination with SEM-EDX, FTIR, and XRD analysis, it was concluded that cation exchange, complexation with surface functional groups, precipitation with minerals (CdCO3), and coordination with π electrons were the dominant mechanisms responsible for Cd adsorption by MSB. With the pyrolysis temperature increasing from 300 to 600 °C, the contribution of cation exchange (Ca2+ and Mg2+) on Cd removal by MSB decreased from 37.4% to 11.7%, while the contribution of precipitation with Otavite (CdCO3) and Cd2+-π electrons interaction increased. For PLB, the insoluble Cd minerals were not detected by XRD, and the contribution of cation exchange had no significant difference for PLB pyrolyzed at 300, 400, 500 and 600 °C.


Assuntos
Cádmio/isolamento & purificação , Carvão Vegetal , Magnoliopsida/metabolismo , Folhas de Planta/metabolismo , Pirólise , Zea mays/metabolismo , Adsorção , Temperatura Alta , Microscopia Eletrônica de Varredura , Minerais/química , Sementes/química , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
13.
Biochim Biophys Acta Bioenerg ; 1860(5): 383-390, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30890407

RESUMO

The regulation of photosystem I (PSI) redox state under fluctuating light was investigated for four species using P700 measurement and electrochromic shift analysis. Species included the angiosperms Camellia japonica, Bletilla striata and Arabidopsis thaliana and the fern Cyrtomium fortunei. For the first seconds after transition from low to high light, all species showed relatively low levels of the proton gradient (ΔpH) across the thylakoid membranes. At this moment, PSI was highly oxidized in C. japonica and C. fortunei but was over-reduced in B. striata and A. thaliana. In B. striata and A. thaliana, the redox state of PSI was largely dependent on ΔpH. In contrast, the rapid oxidation of P700 in C. japonica was relatively independent of ΔpH, but was mainly dependent on the outflow of electrons to O2 via the water-water cycle. In the fern C. fortunei, PSI redox state was rapidly regulated by the fast photo-reduction of O2 rather than the ΔpH. These results indicate that mechanisms regulating PSI redox state under fluctuating light differ greatly between species. We propose that the water-water cycle is an important mechanism regulating the PSI redox state in angiosperms.


Assuntos
Dryopteridaceae/metabolismo , Luz , Magnoliopsida/metabolismo , Complexo de Proteína do Fotossistema I/metabolismo , Força Próton-Motriz , Água/metabolismo , Oxirredução , Oxigênio/metabolismo
14.
Plant Sci ; 280: 206-218, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30823999

RESUMO

The function of euAP1 and euFUL in AP1/FUL lineage have been well characterized in core eudicots, and they play common and distinct roles in plant development. However, the evolution and function of FUL-like genes is poorly understood in basal eudicots. In this study, we identified three FUL-like genes PlacFL1/2/3 from London plane (Platanus acerifolia). Sequence alignment and phylogenetic analysis indicated that PlacFL1/2/3 are AP1/FUL orthologs and encoded proteins containing FUL motif and paleoAP1 motif. Quantitative real-time PCR (qRT-PCR) analysis showed that PlacFL1/2/3 were expressed in both vegetative and reproductive tissues, but with distinct spatiotemporal patterns. In contrast to PlacFL1 and PlacFL3, PlacFL2 exhibited higher expression levels and broader expression regions, and that the expression of PlacFL2 gene showed a decreasing and increasing tendency in subpetiolar buds during dormancy induction and breaking, respectively. Overexpression of PlacFLs in Arabidopsis and PlacFL3 in tobacco resulted in early flowering, as well as early termination of inflorescence meristems for transgenic Arabidopsis plants. The expression changes of flowering time and flower meristem identity genes in transgenic Arabidopsis lines with different PlacFLs suggested that PlacFL2 and PlacFL3 may regulate different downstream genes to perform divergent functions. Yeast two-hybrid analysis indicated that PlacFLs interacted strongly with PlacSEP proteins, and PlacFL3 instead of PlacFL1 and PlacFL2 could also form a homodimer and interact with D-class proteins. Our results suggest that PlacFLs may play conserved functions in regulating flowering and flower development, and PlacFL2 might also be involved in dormancy regulation. The research helps us to understand the functional evolution of FUL-like genes in basal eudicots, especially in perennial woody species.


Assuntos
Flores/metabolismo , Magnoliopsida/metabolismo , Proteínas de Plantas/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Magnoliopsida/genética , Proteínas de Plantas/genética , Ligação Proteica
15.
Plant Cell Physiol ; 60(5): 1136-1145, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30816950

RESUMO

Land plants have evolved a series of photoreceptors to precisely perceive environmental information. Among these, phytochromes are the sole photoreceptors for red light (R) and far-red light (FR), and play pivotal roles in modulating various developmental processes. Most extant land plants possess multiple phytochromes that probably evolved from a single phytochrome in the common ancestor of land plants. However, the ancestral phytochrome signaling mechanism remains unknown due to a paucity of knowledge regarding phytochrome functions in basal land plants. It has recently been reported that Mpphy, a single phytochrome in the liverwort Marchantia polymorpha, regulates typical photoreversible responses collectively classified as low fluence response (LFR). Here, we show that Mpphy also regulates the gametangiophore formation analogous to the mode of action of the far-red high irradiance response (FR-HIR) in angiosperms. Our phenotypic analyses using mutant plants obtained by CRISPR/Cas9-based genome editing revealed that MpFHY1, an ortholog of FAR-RED ELONGATED HYPOCOTYL1, as well as Mpphy is critical for the FR-HIR signaling in M. polymorpha. In addition, knockout of MpPIF, a single PHYTOCHROME INTERACTING FACTOR gene in M. polymorpha, completely abolished the FR-HIR-dependent gametangiophore formation, while overexpression of MpPIF accelerated the response. FR-HIR-dependent transcriptional regulation was also disrupted in the Mppif mutant. Our findings suggest that plants had already acquired the FR-HIR signaling mediated by phytochrome and PIF at a very early stage during the course of land plant evolution, and that a single phytochrome in the common ancestor of land plants could mediate both LFR and FR-HIR.


Assuntos
Marchantia/metabolismo , Fitocromo/metabolismo , Arabidopsis/metabolismo , Magnoliopsida/metabolismo , Proteínas de Plantas/metabolismo , Transdução de Sinais
16.
Comput Biol Chem ; 80: 1-9, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30851618

RESUMO

The Arabidopsis ECERIFERUM1 (CER1) protein is a decarbonylase that converts fatty acid metabolites into alkanes. Alkanes are components of waxes in the plant cuticle, a waterproof barrier serving to protect land plants from both biotic and abiotic stimuli. CER1 enzymes can be used to produce alternative and sustainable hydrocarbons in eukaryotic systems. In this report we identified 193 CER1 and 128 CER3 sequences from 56 land plants respectively. CER1 and CER3 proteins have high amino acid similarity and both are involved in alkane synthesis in Arabidopsis. The common homologues of CER1 and CER3 genes were identified in three species of chlorophytes, which may be one of the earliest plant taxa that possess CER1 and CER3 genes. To facilitate potential applications, the 3-dimensional structure and conserved motifs of CER1 proteins were also characterized. CER1 and CER3 proteins are structurally similar, but CER1 proteins have more conserved histidine-containing motifs common to fatty acid hydroxylases and stearoyl-CoA desaturases. There was no significant loss or gain of protein motifs after ancient and recent duplications, suggesting that varied properties of CER1 proteins may be associated with less-conserved regions. Among 56 land plants, the codon-based assessments of selection modes revealed that neither entire proteins nor individual amino acids of CER1 proteins were significantly subjected to positive selection, indicating that CER1 proteins are highly conserved throughout evolution.


Assuntos
Aldeído Liases/genética , Alcanos/metabolismo , Evolução Molecular , Genes de Plantas , Magnoliopsida/genética , Proteínas de Plantas/genética , Aldeído Liases/química , Motivos de Aminoácidos , Clorófitas/genética , Clorófitas/metabolismo , Magnoliopsida/metabolismo , Filogenia , Proteínas de Plantas/química , Domínios Proteicos , Alinhamento de Sequência , Software
17.
J Basic Microbiol ; 59(5): 504-510, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30811614

RESUMO

We examined the dynamic of periphytic diatom colonization and litter decompositional pattern in an intermittent stream of South India. Litter bags containing 5 g of fresh fallen leaves (belongs to five different species of angiosperms) were fixed in the five stream pools and they were collected after 7, 14, 21, and 28 days of incubation. This experiment showed the diversity, richness, and abundance of diatoms developed on leaf litter. In total, 131 µl-1 cells of diatoms under four species in three families were collected from decomposing leaves in benthic area of stream pools. During experiment, 142 µl-1 cells representing 11 taxa in 10 families were observed in litter bags. The colonization of epiphytic diatom was rapid in early stage of litter decomposition. The higher number of colonization made by Asterionella and Stenopterobia found in litter bags of all experimental weeks. These findings suggest that the rapid microbial colonization (ephiphytic algae) was occurred in the early stage of litter decomposition in an intermittent tropical stream and a comprehensive ecological investigation in perennial natural streams in India is needed.


Assuntos
Diatomáceas/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Rios , Biodegradação Ambiental , Biodiversidade , Diatomáceas/classificação , Diatomáceas/genética , Índia , Magnoliopsida/metabolismo , Fatores de Tempo
18.
Bioresour Technol ; 280: 213-221, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30771575

RESUMO

Metal-organic framework (MOF) assisted hydrothermal pretreatment and co-catalysis strategy based on UiO-66 MOF is developed for the first time. The Planetree exfoliating bark was pretreated with or without UiO-66 assisted hydrothermal method at a temperature ranging from 160 to 240 °C for 1-3 h residence. With the rise of pretreatment severity, the total reducing sugar (TRS) was increased till reached maximum, 180 mg g-1, in the presence of UiO-66. The fitting models validate the optimal hydrothermal condition was at 180 °C and 1 h, which was characterized with high TRS and very low yield of furfural and HMF. The TRS from enzymatic hydrolysis reaches maximum, 391 mg g-1, in the presence of MOF co-catalysis and the maximum ethanol yield achieved was 73%. Altered morphology, higher surface area and porosity are noticed after MOF assisted hydrothermal pretreatment. This study insights the MOFs' application in lignocellulose biomass processing.


Assuntos
Etanol/metabolismo , Magnoliopsida/metabolismo , Estruturas Metalorgânicas/farmacologia , Zircônio/farmacologia , Biomassa , Furaldeído/metabolismo , Hidrólise , Lignina/metabolismo , Casca de Planta/metabolismo
19.
Genome Biol Evol ; 11(3): 798-813, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30753430

RESUMO

Nuclear-encoded pentatricopeptide repeat (PPR) proteins are site-specific factors for C-to-U RNA editing in plant organelles coevolving with their targets. Losing an editing target by C-to-T conversion allows for eventual loss of its editing factor, as recently confirmed for editing factors CLB19, CRR28, and RARE1 targeting ancient chloroplast editing sites in flowering plants. Here, we report on alternative evolutionary pathways for DOT4 addressing rpoC1eU488SL, a chloroplast editing site in the RNA polymerase ß' subunit mRNA. Upon loss of rpoC1eU488SL by C-to-T conversion, DOT4 got lost multiple times independently in angiosperm evolution with intermediate states of DOT4 orthologs in various stages of degeneration. Surprisingly, we now also observe degeneration and loss of DOT4 despite retention of a C in the editing position (in Carica, Coffea, Vicia, and Spirodela). We find that the cytidine remains unedited, proving that DOT4 was not replaced by another editing factor. Yet another pathway of DOT4 evolution is observed among the Poaceae. Although the rpoC1eU488SL edit has been lost through C-to-T conversion, DOT4 orthologs not only remain conserved but also have their array of PPRs extended by six additional repeats. Here, the loss of the ancient target has likely allowed DOT4 to adapt for a new function. We suggest rps3 antisense transcripts as previously demonstrated in barley (Hordeum vulgare) arising from promotor sequences newly emerging in the rpl16 intron of Poaceae as a new candidate target for the extended PPR stretch of DOT4. Altogether, DOT4 and its target show more flexible pathways for evolution than the previously explored editing factors CLB19, CRR28, and RARE1. Certain plant clades (e.g., Amaranthus, Vaccinium, Carica, the Poaceae, Fabales, and Caryophyllales) show pronounced dynamics in the evolution of editing sites and corresponding factors.


Assuntos
Proteínas de Arabidopsis/genética , Coevolução Biológica , Proteínas de Cloroplastos/genética , Evolução Molecular , Magnoliopsida/genética , Edição de RNA , Proteínas de Ligação a RNA/genética , Cloroplastos/metabolismo , Magnoliopsida/metabolismo
20.
Nat Commun ; 10(1): 627, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733503

RESUMO

Small RNAs are key regulators in plant growth and development. One subclass, phased siRNAs (phasiRNAs) require a trigger microRNA for their biogenesis. In grasses, two pathways yield abundant phasiRNAs during anther development; miR2275 triggers one class, 24-nt phasiRNAs, coincident with meiosis, while a second class of 21-nt phasiRNAs are present in premeiotic anthers. Here we report that the 24-nt phasiRNA pathway is widely present in flowering plants, indicating that 24-nt reproductive phasiRNAs likely originated with the evolutionary emergence of anthers. Deep comparative genomic analyses demonstrated that this miR2275/24-nt phasiRNA pathway is widely present in eudicots plants, however, it is absent in legumes and in the model plant Arabidopsis, demonstrating a dynamic evolutionary history of this pathway. In Solanaceae species, 24-nt phasiRNAs were observed, but the miR2275 trigger is missing and some loci displaying 12-nt phasing. Both the miR2275-triggered and Solanaceae 24-nt phasiRNAs are enriched in meiotic stages, implicating these phasiRNAs in anther and/or pollen development, a spatiotemporal pattern consistent in all angiosperm lineages that deploy them.


Assuntos
Magnoliopsida/genética , Magnoliopsida/metabolismo , RNA de Plantas/metabolismo , RNA Interferente Pequeno/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA de Plantas/genética , RNA Interferente Pequeno/genética , Solanaceae/genética , Solanaceae/metabolismo
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