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1.
New Phytol ; 243(3): 1262-1275, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38849316

RESUMEN

The plant hormone ethylene is of vital importance in the regulation of plant development and stress responses. Recent studies revealed that 1-aminocyclopropane-1-carboxylic acid (ACC) plays a role beyond its function as an ethylene precursor. However, the absence of reliable methods to quantify ACC and its conjugates malonyl-ACC (MACC), glutamyl-ACC (GACC), and jasmonyl-ACC (JA-ACC) hinders related research. Combining synthetic and analytical chemistry, we present the first, validated methodology to rapidly extract and quantify ACC and its conjugates using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Its relevance was confirmed by application to Arabidopsis mutants with altered ACC metabolism and wild-type plants under stress. Pharmacological and genetic suppression of ACC synthesis resulted in decreased ACC and MACC content, whereas induction led to elevated levels. Salt, wounding, and submergence stress enhanced ACC and MACC production. GACC and JA-ACC were undetectable in vivo; however, GACC was identified in vitro, underscoring the broad applicability of the method. This method provides an efficient tool to study individual functions of ACC and its conjugates, paving the road toward exploration of novel avenues in ACC and ethylene metabolism, and revisiting ethylene literature in view of the recent discovery of an ethylene-independent role of ACC.


Asunto(s)
Aminoácidos Cíclicos , Arabidopsis , Etilenos , Espectrometría de Masas en Tándem , Arabidopsis/metabolismo , Arabidopsis/genética , Etilenos/metabolismo , Etilenos/biosíntesis , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión , Aminoácidos Cíclicos/metabolismo , Vías Biosintéticas , Estrés Fisiológico , Reproducibilidad de los Resultados , Mutación/genética , Cromatografía Líquida con Espectrometría de Masas
2.
Molecules ; 29(3)2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38338444

RESUMEN

The urea cycle has been found to be closely associated with certain types of cancers and other diseases such as cardiovascular disease and chronic kidney disease. An analytical method for the precise quantification of urea cycle amino acids (arginine, ornithine, citrulline, and argininosuccinate) by off-line two-dimensional liquid chromatography (2D-LC) combined with fluorescence-based detection was developed. Before analysis, the amino acids were derivatised with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) to obtain NBD-amino acids. The first dimension involved the reversed-phase separation, in which NBD derivatives of urea cycle amino acids were completely separated from each other and mostly separated from the 18 NBD-proteinogenic amino acids. The samples were eluted with stepwise gradient using 0.02% trifluoroacetic acid in water-acetonitrile as the mobile phase. In the second dimension, an amino column was used for the separation of NBD-ornithine, -citrulline, and -argininosuccinate, while a sulfonic acid column was used to separate NBD-arginine. The developed 2D-LC system was used to analyse human plasma samples. The fractions of NBD-urea cycle amino acids obtained in the first dimension were collected manually and introduced into the second dimension. By choosing appropriate mobile phases for the second dimension, each NBD-urea cycle amino acid eluted in the first dimension was well separated from the other proteinogenic amino acids and interference from endogenous substance. This could not be achieved in the first dimension. The urea cycle amino acids in human plasma sample were quantified, and the method was well validated. The calibration curves for each NBD-urea cycle amino acid showed good linearity from 3 (ASA) or 15 (Orn, Cit, and Arg) to 600 nM, with correlation coefficients higher than 0.9969. The intraday and interday precisions were less than 7.9% and 15%, respectively. The 2D-LC system is expected to be useful for understanding the involvement of the urea cycle in disease progression.


Asunto(s)
Citrulina , Urea , Humanos , Cromatografía Líquida de Alta Presión/métodos , Ornitina , Aminoácidos Cíclicos , Arginina/metabolismo
3.
Phys Chem Chem Phys ; 25(23): 15635-15646, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37166113

RESUMEN

The photoionisation and photofragmentation of the two cyclic dipetides cyclo(alanyl-glycine) cGA and cyclo(glycyl-glycine) cGG, have been studied combining experiments and simulations. State selected fragments from the ionized molecules are detected using photo-electron photo-ion coincidence (PEPICO) measurements and specific fragmentation paths are identified and characterized via the use of ion-neutral coincidence maps. The simulations, performed using Quantum Chemistry methods, allow us to infer the fragmentation mechanisms of the ionized and excited molecules. We show that ring opening is followed by emission of the neutral fragments CO and HNCO. In the case of cGG the emission of neutral CO leads to a metastable structure that breaks producing small cationic fragments. The studied cyclic dipeptides evolve under ionizing radiation generating different small aziridin moieties and oxazolidinones. These two species are key reactants to elongate producing peptide chains. The corresponding mechanisms have been computed and show that the reaction requires very low energy and may occur in the presence of ionizing radiation.


Asunto(s)
Dicetopiperazinas , Péptidos , Dipéptidos/química , Glicilglicina , Aminoácidos Cíclicos
4.
Curr Opin Plant Biol ; 65: 102116, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34653952

RESUMEN

In seed plants, 1-amino-cyclopropane-1-carboxylic acid (ACC) is the well-known precursor of the plant hormone ethylene. In nonseed plants, the current view is that ACC is produced but is inefficiently converted to ethylene. Distinct responses to ACC that are uncoupled from ethylene biosynthesis have been discovered in diverse aspects of growth and development in liverworts and angiosperms, indicating that ACC itself can function as a signal. Evolutionarily, ACC may have served as a signal before acquiring its role as the ethylene precursor in seed plants. These findings pave the way for unraveling a potentially conserved ACC signaling pathway in plants and have ramifications for the use of ACC as a substitute for ethylene treatment in seed plants.


Asunto(s)
Aminoácidos Cíclicos , Etilenos , Aminoácidos Cíclicos/metabolismo , Ácidos Carboxílicos , Etilenos/metabolismo , Plantas/metabolismo , Transducción de Señal
5.
Physiol Plant ; 173(4): 2291-2297, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34609746

RESUMEN

The plant hormone ethylene plays vital roles in plant development, including pollen tube (PT) growth. Many studies have used the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), as a tool to trigger ethylene signaling. Several studies have suggested that ACC can act as a signal molecule independently of ethylene, inducing responses that are distinct from those induced by ethylene. In this study, we confirmed that ethylene receptor function is essential for promoting PT growth in tomato, but interestingly, we discovered that ACC itself can act as a signal that also promotes PT growth. Exogenous ACC stimulated PT growth even when ethylene perception was inhibited either chemically by treating with 1-methylcyclopropene (1-MCP) or genetically by using the ethylene-insensitive Never Ripe (NR) mutant. Treatment with aminoethoxyvinylglycine, which reduces endogenous ACC levels, led to a reduction of PT growth, even in the NR mutants. Furthermore, GUS activity driven by an EIN3 Binding Site promoter (EBS:GUS transgene) was triggered by ACC in the presence of 1-MCP. Taken together, these results suggest that ACC signaling can bypass the ethylene receptor step to stimulate PT growth and EBS driven gene expression.


Asunto(s)
Solanum lycopersicum , Aminoácidos Cíclicos/farmacología , Etilenos , Solanum lycopersicum/genética , Tubo Polínico
6.
Plant J ; 107(6): 1819-1836, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34296474

RESUMEN

Leaf senescence is a pivotal step in the last stage of the plant life cycle and is influenced by various external and endogenous cues. A series of reports have indicated the involvement of the WRKY transcription factors in regulating leaf senescence, but the molecular mechanisms and signaling pathways remain largely unclear. Here we provide evidence demonstrating that WRKY71 acts as a positive regulator of leaf senescence in Arabidopsis. WRKY71-1D, an overexpressor of WRKY71, exhibited early leaf senescence, while wrky71-1, the WRKY71 loss-of-function mutant, displayed delayed leaf senescence. Accordingly, a set of senescence-associated genes (SAGs) were substantially elevated in WRKY71-1D but markedly decreased in wrky71-1. Chromatin immunoprecipitation assays indicated that WRKY71 can bind directly to the promoters of SAG13 and SAG201. Transcriptome analysis suggested that WRKY71 might mediate multiple cues to accelerate leaf senescence, such as abiotic stresses, dark and ethylene. WRKY71 was ethylene inducible, and treatment with the ethylene precursor 1-amino-cyclopropane-1-carboxylic acid enhanced leaf senescence in WRKY71-1D but caused only a marginal delay in leaf senescence in wrky71-1. In vitro and in vivo assays demonstrated that WRKY71 can directly regulate ETHYLENE INSENSITIVE2 (EIN2) and ORESARA1 (ORE1), genes of the ethylene signaling pathway. Consistently, leaf senescence of WRKY71-1D was obviously retarded in the ein2-5 and nac2-1 mutants. Moreover, WRKY71 was also proved to interact with ACS2 in vitro and in vivo. Treatment with AgNO3 and aminoethoxyvinylglycine and acs2-1 could greatly arrest the leaf senescence of WRKY71-1D. In conclusion, our data revealed that WRKY71 mediates ethylene signaling and synthesis to hasten leaf senescence in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Liasas de Carbono-Azufre/genética , Etilenos/metabolismo , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/fisiología , Senescencia de la Planta/fisiología , Factores de Transcripción/genética , Oxidorreductasas de Alcohol/genética , Aminoácidos Cíclicos/farmacología , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Inmunoprecipitación de Cromatina , Senescencia de la Planta/genética , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Receptores de Superficie Celular/genética , Transactivadores , Factores de Transcripción/metabolismo
7.
Chemistry ; 27(43): 11216-11220, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34028101

RESUMEN

N-terminal thiourea-modified l-Leu-based peptide {(3,5-diCF3 Ph)NHC(=S)-(l-Leu-l-Leu-Ac5 c)2 -OMe} with five-membered ring α,α-disubstituted α-amino acids (Ac5 c) catalyzed a highly enantioselective 1,4-addition reaction between ß-nitrostyrene and dimethyl malonate. The enantioselective reaction required only 0.5 mol % chiral peptide-catalyst in the presence of i Pr2 EtN (2.5 equiv.), and gave a 1,4-adduct with 93 % ee of an 85 % yield. As Michael acceptors, various ß-nitrostyrene derivatives such as methyl, p-fluoro, p-bromo, and p-methoxy substituents on the phenyl group, 2-furyl, 2-thiophenyl, and naphthyl ß-nitroethylenes could be applied. Furthermore, various alkyl malonates and cyclic ß-keto-esters could be used as Michael donors. It became clear that the length of the peptide chain, a right-handed helical structure, amide N-Hs, and the N-terminal thiourea moiety play crucial roles in asymmetric induction.


Asunto(s)
Aminoácidos Cíclicos , Tiourea , Catálisis , Péptidos , Estereoisomerismo
8.
Plant Cell Physiol ; 62(5): 858-871, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33768225

RESUMEN

Ethylene is a gaseous phytohormone involved in various physiological processes, including fruit ripening, senescence, root hair development and stress responses. Recent genomics studies have suggested that most homologous genes of ethylene biosynthesis and signaling are conserved from algae to angiosperms, whereas the function and biosynthesis of ethylene remain unknown in basal plants. Here, we examined the physiological effects of ethylene, an ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC) and an inhibitor of ethylene perception, silver thiosulfate (STS), in a basal land plant, Marchantia polymorpha. M. polymorpha plants biosynthesized ethylene, and treatment with high concentrations of ACC slightly promoted ethylene production. ACC remarkably suppressed the growth of thalli (vegetative organs) and rhizoids (root-hair-like cells), whereas exogenous ethylene slightly promoted thallus growth. STS suppressed thallus growth and induced ectopic rhizoid formation on the dorsal surface of thalli. Thus, ACC and ethylene have different effects on the vegetative growth of M. polymorpha. We generated single and double mutants of ACC synthase-like (ACSL) genes, MpACSL1 and MpACSL2. The mutants did not show obvious defects in thallus growth, ACC content and ethylene production, indicating that MpACSL genes are not essential for the vegetative growth and biosynthesis of ACC and ethylene. Gene expression analysis suggested the involvement of MpACSL1 and MpACSL2 in stress responses. Collectively, our results imply ethylene-independent function of ACC and the absence of ACC-mediated ethylene biosynthesis in M. polymorpha.


Asunto(s)
Aminoácidos Cíclicos/metabolismo , Etilenos/metabolismo , Marchantia/metabolismo , Aminoácidos Cíclicos/farmacología , Etilenos/biosíntesis , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Marchantia/efectos de los fármacos , Marchantia/genética , Marchantia/crecimiento & desarrollo , Mutación , Compuestos Organofosforados/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tiosulfatos/farmacología
9.
Methods Mol Biol ; 2213: 123-129, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33270198

RESUMEN

The gaseous hormone ethylene regulates a diverse range of plant development and stress responses. Ethylene biosynthesis is tightly regulated by the transcriptional and posttranscriptional regulation of ethylene biosynthetic enzymes. ACC synthase (ACS) is the rate-limiting enzyme that controls the speed of ethylene biosynthesis in plant tissues, thus serving as a primary target for biotic and abiotic stresses to modulate ethylene production. Despite the critical role of ACS in ethylene biosynthesis, only a few regulatory components regulating ACS stability or ACS transcript levels have been identified and characterized. Here we show a genetic approach for identifying novel regulatory components in ethylene biosynthesis by screening EMS-mutagenized Arabidopsis seeds.


Asunto(s)
Metanosulfonato de Etilo/química , Etilenos/biosíntesis , Pruebas Genéticas/métodos , Aminoácidos Cíclicos/metabolismo , Bioensayo , Citocininas/farmacología , Genes Supresores , Mutación/genética , Fenotipo , Semillas/efectos de los fármacos , Esterilización
10.
Plant Physiol Biochem ; 156: 345-356, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33002713

RESUMEN

Although ethylene (ET) is an important participant in plant responses to salt stress, its role in the early period of acclimation, especially in the case of photosynthesis has not been revealed in detail. In this study, the effects of tolerable (100 mM) or lethal (250 mM) NaCl concentrations were investigated in hydroponically grown tomato (Solanum lycopersicum L. cv. Ailsa Craig) plants of different ET status, in wild type (WT) plants, in WT plants pre-treated with the ET generator 1-aminocyclopropane-1-carboxylic acid (ACC) and in ET insensitive, Never ripe (Nr/Nr) mutants for 1-, 6- and 24 h. In the leaves ACC treatment reduced the osmotic effect of salt stress, while Nr mutation enhanced not only osmotic but ionic component of salt stress at 100 mM NaCl. ET insensitivity caused greater decline in stomatal conductance and photosynthetic CO2 assimilation rate than in the controls under tolerable salt stress, but both ACC treatment and Nr mutation helped to maintain positive carbon assimilation under lethal salt stress after 24 h. Nr mutant leaves showed highly enhanced regulated non-photochemical quenching (NPQ) and therefore lower quantum yield of photosystem II (PSII), due to more intensive cyclic electron flow around photosystem I (CEF-PSI), which was further increased under high salinity. Exogenous ACC treatment lowered CEF-PSI and enhanced PSII photochemistry after 6 h of lethal salt stress. Controlling PSI photoinhibition, ET is suggested to be an important regulator of CEF-PSI and photoprotection under salt stress. Furthermore, the altered ET status could cause contrasting effects under different stress severity.


Asunto(s)
Aminoácidos Cíclicos/farmacología , Etilenos/metabolismo , Fotosíntesis , Estrés Salino , Solanum lycopersicum/fisiología , Ácidos Carboxílicos , Complejo de Proteína del Fotosistema II/metabolismo , Hojas de la Planta/metabolismo
11.
Nat Plants ; 6(11): 1335-1344, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33106638

RESUMEN

The plant hormone ethylene has many roles in growth and development1. In seed plants, the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) is converted into ethylene by ACC oxidase (ACO), and treatment with ACC induces ethylene responses2. However, non-seed plants lack ACO homologues3-8, which led us to examine the relationship between ACC and ethylene in the liverwort Marchantia polymorpha. Here, we demonstrate that ACC and ethylene can induce divergent growth responses in Marchantia. Ethylene increases plant and gemma size, induces more gemma cups and promotes gemmae dormancy. As predicted, Mpctr1-knockout mutants display constitutive ethylene responses, whereas Mpein3-knockout mutants exhibit ethylene insensitivity. Compared with the wild type, Mpctr1 gemmae have more and larger epidermal cells, whereas Mpein3 gemmae have fewer and smaller epidermal cells, suggesting that ethylene promotes cell division and growth in developing gemmae. By contrast, ACC treatment inhibits gemma growth and development by suppressing cell division, even in the Mpein3-knockout alleles. Knockout mutants of one or both ACC SYNTHASE (ACS) gene homologues produce negligible levels of ACC, have more and larger gemma cups, and have more-expanded thallus branches. Mpacs2 and Mpacs1 Mpacs2 gemmae also display a high frequency of abnormal apical notches (meristems) that are not observed in ethylene mutants. These findings reveal that ethylene and ACC have distinct functions, and suggest that ACC is a signalling molecule in Marchantia. ACC may be an evolutionarily conserved signal that predates its efficient conversion to ethylene in higher plants.


Asunto(s)
Aminoácidos Cíclicos/metabolismo , Etilenos/metabolismo , Marchantia/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Técnicas de Inactivación de Genes
12.
Int J Mol Sci ; 21(17)2020 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-32872315

RESUMEN

The toxic metal cadmium (Cd) is a major soil pollutant. Knowledge on the acute Cd-induced stress response is required to better understand the triggers and sequence of events that precede plant acclimation. Therefore, we aimed to identify the pressure points of Cd stress using a short-term exposure set-up ranging from 0 h to 24 h. Acute responses related to glutathione (GSH), hydrogen peroxide (H2O2), 1-aminocyclopropane-1-carboxylic acid (ACC), ethylene and the oxidative challenge were studied at metabolite and/or transcript level in roots and leaves of Arabidopsis thaliana either exposed or not to 5 µM Cd. Cadmium rapidly induced root GSH depletion, which might serve as an alert response and modulator of H2O2 signalling. Concomitantly, a stimulation of root ACC levels was observed. Leaf responses were delayed and did not involve GSH depletion. After 24 h, a defined oxidative challenge became apparent, which was most pronounced in the leaves and concerted with a strong induction of leaf ACC synthesis. We suggest that root GSH depletion is required for a proper alert response rather than being a merely adverse effect. Furthermore, we propose that roots serve as command centre via a.o. root-derived ACC/ethylene to engage the leaves in a proper stress response.


Asunto(s)
Aclimatación , Arabidopsis/fisiología , Cadmio/toxicidad , Contaminantes del Suelo/toxicidad , Aminoácidos Cíclicos/metabolismo , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Etilenos/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glutatión/metabolismo , Peróxido de Hidrógeno/metabolismo , Estrés Oxidativo , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo
13.
Mol Biotechnol ; 62(11-12): 557-562, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32949367

RESUMEN

The study of senescence preservative on cut flowers helps boost the commercial value of flowers. Senescence in cut flower is associated with an increase of ethylene production, and is significantly influenced by ethylene pathway. This study was conducted to investigate whether S-adenosyl-L-methionine (SAM) and aminocyclopropane-1-carboxylic acid (ACC) involved in the ethylene synthesis process are correlated with the lysosome. The alterations of lysosome which was treated with the ethylene precursors ACC and SAM in HeLa cell using the confocal laser scanning microscope were investigated. According to the experimental results, the activity of lysosomes increased concentration dependently by ACC treatment, however, no change was observed by SAM treatment. In addition, Liquid chromatography-mass spectrometry (LC/MS) analysis was performed to confirm the effect of lysosomal enzyme (LE) extracted from egg white on ACC reduction, but no change was observed. On the contrary, to confirm the effect of ACC on lysosomes, lysosomes were extracted from HeLa cells treated with 5 mM ACC and confirmed by FE-SEM. The results showed that the size of lysosomes treated with ACC is larger than that of the control, which was treated with distilled water. The lysosomes in the control group were distributed in various ranges from 0 to 800 nm, but those treated with 5 mM ACC were in the range of 400 nm to 800 nm or more. Therefore, lysosomes had no effect on ACC, the precursor of ethylene, the aging hormone of cut flowers, however, ACC had effect on lysosomes.


Asunto(s)
Aminoácidos Cíclicos/farmacología , Lisosomas/ultraestructura , S-Adenosilmetionina/farmacología , Cromatografía Liquida , Células HeLa , Humanos , Lisosomas/efectos de los fármacos , Espectrometría de Masas , Microscopía Confocal , Tamaño de la Partícula
14.
Nat Commun ; 11(1): 4304, 2020 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-32855412

RESUMEN

Ribosome-mediated polymerization of backbone-extended monomers into polypeptides is challenging due to their poor compatibility with the translation apparatus, which evolved to use α-L-amino acids. Moreover, mechanisms to acylate (or charge) these monomers to transfer RNAs (tRNAs) to make aminoacyl-tRNA substrates is a bottleneck. Here, we rationally design non-canonical amino acid analogs with extended carbon chains (γ-, δ-, ε-, and ζ-) or cyclic structures (cyclobutane, cyclopentane, and cyclohexane) to improve tRNA charging. We then demonstrate site-specific incorporation of these non-canonical, backbone-extended monomers at the N- and C- terminus of peptides using wild-type and engineered ribosomes. This work expands the scope of ribosome-mediated polymerization, setting the stage for new medicines and materials.


Asunto(s)
Aminoácidos Cíclicos/metabolismo , Biosíntesis de Péptidos , Ribosomas/metabolismo , Aminoacilación de ARN de Transferencia , Ingeniería Genética , Mutación , Polimerizacion , ARN de Transferencia/metabolismo , Ribosomas/genética
15.
Nat Commun ; 11(1): 4082, 2020 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-32796832

RESUMEN

The phytohormone ethylene has numerous effects on plant growth and development. Its immediate precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), is a non-proteinogenic amino acid produced by ACC SYNTHASE (ACS). ACC is often used to induce ethylene responses. Here, we demonstrate that ACC exhibits ethylene-independent signaling in Arabidopsis thaliana reproduction. By analyzing an acs octuple mutant with reduced seed set, we find that ACC signaling in ovular sporophytic tissue is involved in pollen tube attraction, and promotes secretion of the pollen tube chemoattractant LURE1.2. ACC activates Ca2+-containing ion currents via GLUTAMATE RECEPTOR-LIKE (GLR) channels in root protoplasts. In COS-7 cells expressing moss PpGLR1, ACC induces the highest cytosolic Ca2+ elevation compared to all twenty proteinogenic amino acids. In ovules, ACC stimulates transient Ca2+ elevation, and Ca2+ influx in octuple mutant ovules rescues LURE1.2 secretion. These findings uncover a novel ACC function and provide insights for unraveling new physiological implications of ACC in plants.


Asunto(s)
Arabidopsis/metabolismo , Etilenos/metabolismo , Óvulo Vegetal/metabolismo , Tubo Polínico/metabolismo , Aminoácidos Cíclicos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Calcio/metabolismo , Regulación de la Expresión Génica de las Plantas , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Liasas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo
16.
Chem Commun (Camb) ; 56(42): 5597-5600, 2020 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-32400780

RESUMEN

We demonstrate in vitro incorporation of cyclic ß-amino acids into peptides by the ribosome through genetic code reprogramming. Further, we show that incorporation efficiency can be increased through the addition of elongation factor P.


Asunto(s)
Aminoácidos Cíclicos/química , Péptidos/síntesis química , Biosíntesis de Proteínas , Ribosomas/química , Aminoácidos Cíclicos/genética , Código Genético , Estructura Molecular , ARN de Transferencia/química
17.
Plant Mol Biol ; 102(3): 271-285, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31838617

RESUMEN

KEY MESSAGE: H2 prolonged the vase life and improved the vase quality of cut roses through repressing endogenous ethylene production and alleviating ethylene signal transduction during the entire senescing period. Recently, the application of hydrogen gas (H2) was shown to improve postharvest quality and longevity in perishable horticultural products, but the specific regulation mechanism remains obscure. Here, endogenous ethylene production and the expression of genes in ethylene biosynthesis and signalling pathway were investigated to explore the crosstalk between H2 and ethylene during the senescence of cut roses. Our results revealed that addition of exogenous ethylene by ethephon accelerated the senescence of cut roses, in which 100 mg L-1 ethephon displayed the most obvious senescent phenotype. While the applied different concentrations (1%, 10%, 50% and 100%) of hydrogen-rich water (HRW) conducted different affects in alleviating the senescence of cut roses, and 1% HRW displayed the best ornamental quality and the longest vase life by reducing ethylene production, supported by the decrease of 1-aminocyclopropene-1-carboxylate (ACC) accumulation, ACC synthase (ACS) and ACC oxidase (ACO) activities, and Rh-ACS3 and Rh-ACO1 expressions in ethylene biosynthesis. In addition, HRW increased the transcripts of ethylene receptor genes Rh-ETR1 at blooming period from day 4 to day 6 and suppressed Rh-ETR3 at senescence phase at day 8 after harvest. Furthermore, the relevant affection of HRW on Rh-ETR1 and Rh-ETR3 expressions still existed when the ethylene production was compromised by adequate addition of exogenous ethylene in HRW-treated cut rose petals, and HRW directly repressed the protein level of Rh-ETR3 in a transient expression assay. Overall, the results suggested that H2 is involved in neutralizing ethylene-mediated postharvest in cut flowers.


Asunto(s)
Etilenos/antagonistas & inhibidores , Etilenos/biosíntesis , Flores/efectos de los fármacos , Hidrógeno/farmacología , Rosa/efectos de los fármacos , Rosa/metabolismo , Aminoácidos Cíclicos/metabolismo , Flores/enzimología , Flores/genética , Flores/crecimiento & desarrollo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Hidrógeno/metabolismo , Liasas/genética , Liasas/metabolismo , Compuestos Organofosforados , Fenotipo , Reguladores del Crecimiento de las Plantas , Proteínas de Plantas/genética , Receptores de Superficie Celular/genética , Rosa/enzimología , Rosa/genética , Transducción de Señal
18.
Plant Mol Biol ; 102(1-2): 143-158, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31782079

RESUMEN

KEY MESSAGE: Zinc finger protein transcription factor ZFP5 positively regulates root hair elongation in response to Pi and potassium deficiency by mainly activating the expression of EIN2 in Arabidopsis. Phosphate (Pi) and potassium (K+) are major plant nutrients required for plant growth and development, and plants respond to low-nutrient conditions via metabolic and morphology changes. The C2H2 transcription factor ZFP5 is a key regulator of trichome and root hair development in Arabidopsis. However, its role in regulating root hair development under nutrient deprivations remains unknown. Here, we show that Pi and potassium deficiency could not restore the short root hair phenotype of zfp5 mutant and ZFP5 RNAi lines to wild type level. The deprivation of either of these nutrients also induced the expression of ZFP5 and the activity of an ethylene reporter, pEBS:GUS. The significant reduction of root hair length in ein2-1 and ein3-1 as compared to wild-type under Pi and potassium deficiency supports the involvement of ethylene in root hair elongation. Furthermore, the application of 1-aminocyclopropane-1-carboxylic acid (ACC) significantly enhanced the expression level of ZFP5 while the application of 2-aminoethoxyvinyl glycine (AVG) had the opposite effect when either Pi or potassium was deprived. Further experiments reveal that ZFP5 mainly regulates transcription of ETHYLENE INSENSITIVE 2 (EIN2) to control deficiency-mediated root hair development through ethylene signaling. Generally, these results suggest that ZFP5 regulates root hair elongation by interacting with ethylene signaling mainly through regulates the expression of EIN2 in response to Pi and potassium deficiency in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Fosfatos/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Deficiencia de Potasio/metabolismo , Transducción de Señal , Aminoácidos Cíclicos/farmacología , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Etilenos/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glicina/análogos & derivados , Glicina/farmacología , Desnutrición/tratamiento farmacológico , Mutación , Fenotipo , Raíces de Plantas/efectos de los fármacos , Deficiencia de Potasio/tratamiento farmacológico , Interferencia de ARN , Receptores de Superficie Celular/metabolismo , Factores de Transcripción
19.
Biomolecules ; 9(12)2019 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-31835421

RESUMEN

We have recently discovered that brassinosteroids (BRs) can inhibit the growth of etiolated pea seedlings dose-dependently in a similar manner to the 'triple response' induced by ethylene. We demonstrate here that the growth inhibition of etiolated pea shoots strongly correlates with increases in ethylene production, which also responds dose-dependently to applied BRs. We assessed the biological activities of two natural BRs on pea seedlings, which are excellent material as they grow rapidly, and respond both linearly and uni-phasically to applied BRs. We then compared the BRs' inhibitory effects on growth, and induction of ethylene and ACC (1-aminocyclopropane-1-carboxylic acid) production, to those of representatives of other phytohormone classes (cytokinins, auxins, and gibberellins). Auxin induced ca. 50-fold weaker responses in etiolated pea seedlings than brassinolide, and the other phytohormones induced much weaker (or opposite) responses. Following the optimization of conditions for determining ethylene production after BR treatment, we found a positive correlation between BR bioactivity and ethylene production. Finally, we optimized conditions for pea growth responses and developed a new, highly sensitive, and convenient bioassay for BR activity.


Asunto(s)
Brasinoesteroides/farmacología , Etilenos/metabolismo , Pisum sativum/efectos de los fármacos , Aminoácidos Cíclicos/metabolismo , Bioensayo/métodos , Inhibidores de Crecimiento/farmacología , Ácidos Indolacéticos/farmacología , Pisum sativum/crecimiento & desarrollo , Pisum sativum/metabolismo , Reguladores del Crecimiento de las Plantas/farmacocinética , Reguladores del Crecimiento de las Plantas/farmacología , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Plantones/metabolismo
20.
Cells ; 8(9)2019 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-31492030

RESUMEN

L-Ascorbate (Asc) plays important roles in cell growth and plant development, and its de novo biosynthesis was catalyzed by the first rate-limiting enzyme VTC1. However, the function and regulatory mechanism of VTC1 involved in cell development is obscure in Gossypium hirsutum. Herein, the Asc content and AsA/DHA ratio were accumulated and closely linked with fiber development. The GhVTC1 encoded a typical VTC1 protein with functional conserved domains and expressed preferentially during fiber fast elongation stages. Functional complementary analysis of GhVTC1 in the loss-of-function Arabidopsis vtc1-1 mutants indicated that GhVTC1 is genetically functional to rescue the defects of mutants to normal or wild type (WT). The significant shortened primary root in vtc1-1 mutants was promoted to the regular length of WT by the ectopic expression of GhVTC1 in the mutants. Additionally, GhVTC1 expression was induced by ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), and the GhVTC1 promoter showed high activity and included two ethylene-responsive elements (ERE). Moreover, the 5'-truncted promoters containing the ERE exhibited increased activity by ACC treatment. Our results firstly report the cotton GhVTC1 function in promoting cell elongation at the cellular level, and serve as a foundation for further understanding the regulatory mechanism of Asc-mediated cell growth via the ethylene signaling pathway.


Asunto(s)
Ácido Ascórbico/biosíntesis , Fibra de Algodón , Etilenos/metabolismo , Gossypium/genética , Nucleotidiltransferasas/metabolismo , Proteínas de Plantas/metabolismo , Aminoácidos Cíclicos/metabolismo , Gossypium/metabolismo , Nucleotidiltransferasas/química , Nucleotidiltransferasas/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Elementos de Respuesta
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