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1.
BMC Genomics ; 25(1): 578, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38858635

RESUMEN

BACKGROUND: Rose myrtle (Rhodomyrtus tomentosa (Ait.) Hassk), is an evergreen shrub species belonging to the family Myrtaceae, which is enriched with bioactive volatiles (α-pinene and ß-caryophyllene) with medicinal and industrial applications. However, the mechanism underlying the volatile accumulation in the rose myrtle is still unclear. RESULTS: Here, we present a chromosome-level genomic assembly of rose myrtle (genome size = 466 Mb, scaffold N50 = 43.7 Mb) with 35,554 protein-coding genes predicted. Through comparative genomic analysis, we found that gene expansion and duplication had a potential contribution to the accumulation of volatile substances. We proposed that the action of positive selection was significantly involved in volatile accumulation. We identified 43 TPS genes in R. tomentosa. Further transcriptomic and TPS gene family analyses demonstrated that the distinct gene subgroups of TPS may contribute greatly to the biosynthesis and accumulation of different volatiles in the Myrtle family of shrubs and trees. The results suggested that the diversity of TPS-a subgroups led to the accumulation of special sesquiterpenes in different plants of the Myrtaceae family. CONCLUSIONS: The high quality chromosome-level rose myrtle genome and the comparative analysis of TPS gene family open new avenues for obtaining a higher commercial value of essential oils in medical plants.


Asunto(s)
Cromosomas de las Plantas , Evolución Molecular , Genoma de Planta , Genómica , Myrtaceae , Terpenos , Terpenos/metabolismo , Genómica/métodos , Myrtaceae/genética , Myrtaceae/metabolismo , Cromosomas de las Plantas/genética , Filogenia , Familia de Multigenes
2.
Plant Mol Biol ; 114(3): 57, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38743266

RESUMEN

A high concentration of sodium (Na+) is the primary stressor for plants in high salinity environments. The Salt Overly Sensitive (SOS) pathway is one of the best-studied signal transduction pathways, which confers plants the ability to export too much Na+ out of the cells or translocate the cytoplasmic Na+ into the vacuole. In this study, the Salt Overly Sensitive3 (MpSOS3) gene from Pongamia (Millettia pinnata Syn. Pongamia pinnata), a semi-mangrove, was isolated and characterized. The MpSOS3 protein has canonical EF-hand motifs conserved in other calcium-binding proteins and an N-myristoylation signature sequence. The MpSOS3 gene was significantly induced by salt stress, especially in Pongamia roots. Expression of the wild-type MpSOS3 but not the mutated nonmyristoylated MpSOS3-G2A could rescue the salt-hypersensitive phenotype of the Arabidopsis sos3-1 mutant, which suggested the N-myristoylation signature sequence of MpSOS3 was required for MpSOS3 function in plant salt tolerance. Heterologous expression of MpSOS3 in Arabidopsis accumulated less H2O2, superoxide anion radical (O2-), and malondialdehyde (MDA) than wild-type plants, which enhanced the salt tolerance of transgenic Arabidopsis plants. Under salt stress, MpSOS3 transgenic plants accumulated a lower content of Na+ and a higher content of K+ than wild-type plants, which maintained a better K+/Na+ ratio in transgenic plants. Moreover, no development and growth discrepancies were observed in the MpSOS3 heterologous overexpression plants compared to wild-type plants. Our results demonstrated that the MpSOS3 pathway confers a conservative salt-tolerant role and provided a foundation for further study of the SOS pathway in Pongamia.


Asunto(s)
Arabidopsis , Clonación Molecular , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Plantas Modificadas Genéticamente , Tolerancia a la Sal , Plantas Tolerantes a la Sal , Plantas Tolerantes a la Sal/genética , Plantas Tolerantes a la Sal/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Tolerancia a la Sal/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cloruro de Sodio/farmacología , Secuencia de Aminoácidos , Filogenia , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Estrés Salino/genética , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo
3.
Physiol Plant ; 176(5): e14568, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39377156

RESUMEN

The plant U-box (PUB) proteins, a family of ubiquitin ligases (E3) enzymes, are pivotal in orchestrating many biological processes and facilitating plant responses to environmental stressors. Despite their critical roles, exploring the PUB gene family's characteristics and functional diversity in sweet potato (Ipomoea batatas (L.) Lam.) has been notably limited. There were 81 IbPUB genes identified within the sweet potato genome, and they were categorized into eight distinct groups based on domain architecture, revealing a non-uniform distribution across the 15 chromosomes of I. batatas. The investigation of cis-acting elements has shed light on the potential of PUBs to participate in a wide array of biological processes, particularly emphasizing their role in mediating responses to abiotic stresses. Transcriptome profiles revealed that IbPUB genes displayed a wide range of expression levels among different tissues and were regulated by salt or drought stress. IbPUB52 has emerged as a gene of significant interest due to its induction by salt and drought stresses. Localization studies have confirmed the presence of IbPUB52 in both the nucleus and the cytoplasm, and its ubiquitination activity has been validated through rigorous in vitro and in vivo assays. Intriguingly, the heterogeneous expression of IbPUB52 in Arabidopsis resulted in decreased drought tolerance. The virus-induced gene silencing (VIGS) of IbPUB52 in sweet potatoes led to enhanced resistance to drought. This evidence suggests that IbPUB52 negatively regulates the drought tolerance of plants. The findings of this study are instrumental in advancing our comprehension of the functional dynamics of PUB E3 ubiquitin ligases in sweet potatoes.


Asunto(s)
Sequías , Regulación de la Expresión Génica de las Plantas , Ipomoea batatas , Proteínas de Plantas , Estrés Fisiológico , Ubiquitina-Proteína Ligasas , Ipomoea batatas/genética , Ipomoea batatas/enzimología , Ipomoea batatas/fisiología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estrés Fisiológico/genética , Genoma de Planta/genética , Filogenia
4.
BMC Biol ; 21(1): 122, 2023 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-37226197

RESUMEN

BACKGROUND: The factors that maintain phenotypic and genetic variation within a population have received long-term attention in evolutionary biology. Here the genetic basis and evolution of the geographically widespread variation in twig trichome color (from red to white) in a shrub Melastoma normale was investigated using Pool-seq and evolutionary analyses. RESULTS: The results show that the twig trichome coloration is under selection in different light environments and that a 6-kb region containing an R2R3 MYB transcription factor gene is the major region of divergence between the extreme red and white morphs. This gene has two highly divergent groups of alleles, one of which likely originated from introgression from another species in this genus and has risen to high frequency (> 0.6) within each of the three populations under investigation. In contrast, polymorphisms in other regions of the genome show no sign of differentiation between the two morphs, suggesting that genomic patterns of diversity have been shaped by homogenizing gene flow. Population genetics analysis reveals signals of balancing selection acting on this gene, and it is suggested that spatially varying selection is the most likely mechanism of balancing selection in this case. CONCLUSIONS: This study demonstrate that polymorphisms on a single transcription factor gene largely confer the twig trichome color variation in M. normale, while also explaining how adaptive divergence can occur and be maintained in the face of gene flow.


Asunto(s)
Factores de Transcripción , Tricomas , Factores de Transcripción/genética , Tricomas/genética , Regulación de la Expresión Génica , Alelos , Genómica
5.
Genes Dev ; 30(3): 251-6, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26798133

RESUMEN

H3K9 methylation is usually associated with DNA methylation, and together they symbolize transcriptionally silenced heterochromatin. A number of proteins involved in epigenetic processes have been characterized. However, how the stability of these proteins is regulated at the post-translational level is largely unknown. Here, we show that an Arabidopsis JmjC domain protein, JMJ24, possesses ubiquitin E3 ligase activity. JMJ24 directly targets a DNA methyltransferase, CHROMOMETHYLASE 3 (CMT3), for proteasomal degradation to initiate destabilization of the heterochromatic state of endogenous silenced loci. Our results uncover an additional connection between two conserved epigenetic modifications: histone modification and DNA methylation.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Histona Demetilasas con Dominio de Jumonji/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , ADN-Citosina Metilasas/genética , ADN-Citosina Metilasas/metabolismo , Epigénesis Genética , Metilación , Complejo de la Endopetidasa Proteasomal/genética , Estabilidad Proteica , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación
6.
Appl Environ Microbiol ; 87(12): e0018521, 2021 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-33811023

RESUMEN

Bacteriocins have attracted increasing interest because of their potential as natural preservatives. Recent studies showed that the Bacillus cereus group is a prominent producer of bacteriocins. Using a laboratory-based screening strategy, we identified a strain in the B. cereus group, Bacillus toyonensis XIN-YC13, with antimicrobial activity against B. cereus. A novel, 70-amino-acid-long leaderless bacteriocin, toyoncin, was purified from the culture supernatant of strain XIN-YC13, and its molecular mass was found to be 7,817.1012 Da. Toyoncin shares no similarity with any other known bacteriocins, and its N-terminal amino acid is formylmethionine rather than methionine. Toyoncin shows good pH and heat stability and exhibits specific antimicrobial activity against two important foodborne pathogens, B. cereus and Listeria monocytogenes. Additionally, toyoncin exerts bactericidal activity and induces cell membrane damage. Toyoncin can also inhibit the outgrowth of B. cereus spores. Preservation assays showed that toyoncin effectively suppressed or eradicated B. cereus and L. monocytogenes in pasteurized skim milk. These results suggest that toyoncin can be used as a new biopreservative against B. cereus and L. monocytogenes in the food industry. IMPORTANCE We identified a novel leaderless bacteriocin, toyoncin, produced by B. toyonensis XIN-YC13. Toyoncin shows good pH and heat stability, and it has specific antimicrobial activity against B. cereus and L. monocytogenes (two important foodborne pathogens), likely by destroying their cell membrane integrity. Toyoncin inhibited the outgrowth of B. cereus spores and effectively inhibited or eliminated B. cereus and L. monocytogenes in a milk model system. These results indicate the potential of toyoncin as a food preservative.


Asunto(s)
Bacillus cereus/efectos de los fármacos , Bacillus/metabolismo , Bacteriocinas/farmacología , Agentes de Control Biológico , Conservantes de Alimentos/farmacología , Listeria monocytogenes/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Bacillus cereus/crecimiento & desarrollo , Bacteriocinas/química , Bacteriocinas/genética , Bacteriocinas/aislamiento & purificación , Microbiología de Alimentos , Conservantes de Alimentos/química , Conservantes de Alimentos/aislamiento & purificación , Concentración de Iones de Hidrógeno , Listeria monocytogenes/crecimiento & desarrollo , Leche/microbiología , Familia de Multigenes , Esporas Bacterianas/efectos de los fármacos , Esporas Bacterianas/crecimiento & desarrollo , Temperatura
7.
Int J Mol Sci ; 22(7)2021 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-33801703

RESUMEN

Salt stress is a major increasing threat to global agriculture. Pongamia (Millettia pinnata), a semi-mangrove, is a good model to study the molecular mechanism of plant adaptation to the saline environment. Calcium signaling pathways play critical roles in the model plants such as Arabidopsis in responding to salt stress, but little is known about their function in Pongamia. Here, we have isolated and characterized a salt-responsive MpCML40, a calmodulin-like (CML) gene from Pongamia. MpCML40 protein has 140 amino acids and is homologous with Arabidopsis AtCML40. MpCML40 contains four EF-hand motifs and a bipartite NLS (Nuclear Localization Signal) and localizes both at the plasma membrane and in the nucleus. MpCML40 was highly induced after salt treatment, especially in Pongamia roots. Heterologous expression of MpCML40 in yeast cells improved their salt tolerance. The 35S::MpCML40 transgenic Arabidopsis highly enhanced seed germination rate and root length under salt and osmotic stresses. The transgenic plants had a higher level of proline and a lower level of MDA (malondialdehyde) under normal and stress conditions, which suggested that heterologous expression of MpCML40 contributed to proline accumulation to improve salt tolerance and protect plants from the ROS (reactive oxygen species) destructive effects. Furthermore, we did not observe any measurable discrepancies in the development and growth between the transgenic plants and wild-type plants under normal growth conditions. Our results suggest that MpCML40 is an important positive regulator in response to salt stress and of potential application in producing salt-tolerant crops.


Asunto(s)
Señalización del Calcio , Calmodulina/metabolismo , Millettia/metabolismo , Señales de Localización Nuclear , Proteínas de Plantas/metabolismo , Secuencias de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Calmodulina/genética , Regulación de la Expresión Génica de las Plantas , Malondialdehído/química , Millettia/genética , Sistemas de Lectura Abierta , Ósmosis , Fenotipo , Filogenia , Proteínas de Plantas/genética , Raíces de Plantas , Plantas Modificadas Genéticamente , Prolina/química , Estrés Salino , Tolerancia a la Sal/genética , Plantas Tolerantes a la Sal/metabolismo , Semillas/metabolismo
8.
Int J Mol Sci ; 22(19)2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34639173

RESUMEN

C2H2 zinc finger proteins (ZFPs) play important roles in plant development and response to abiotic stresses, and have been studied extensively. However, there are few studies on ZFPs in mangroves and mangrove associates, which represent a unique plant community with robust stress tolerance. MpZFP1, which is highly induced by salt stress in the mangrove associate Millettia pinnata, was cloned and functionally characterized in this study. MpZFP1 protein contains two zinc finger domains with conserved QALGGH motifs and targets to the nucleus. The heterologous expression of MpZFP1 in Arabidopsis increased the seeds' germination rate, seedling survival rate, and biomass accumulation under salt stress. The transgenic plants also increased the expression of stress-responsive genes, including RD22 and RD29A, and reduced the accumulation of reactive oxygen species (ROS). These results indicate that MpZFP1 is a positive regulator of plant responses to salt stress due to its activation of gene expression and efficient scavenging of ROS.


Asunto(s)
Arabidopsis/fisiología , Dedos de Zinc CYS2-HIS2 , Regulación de la Expresión Génica de las Plantas , Millettia/fisiología , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/fisiología , Tolerancia a la Sal , Arabidopsis/genética , Arabidopsis/metabolismo , Sequías , Millettia/genética , Millettia/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Estrés Fisiológico
9.
New Phytol ; 219(4): 1480-1491, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29862530

RESUMEN

Dispersed H3K27 trimethylation (H3K27me3) of the AGAMOUS (AG) genomic locus is mediated by CURLY LEAF (CLF), a component of the Polycomb Repressive Complex (PRC) 2. Previous reports have shown that the AG second intron, which confers AG tissue-specific expression, harbors sequences targeted by several positive and negative regulators. Using RACE reverse transcription polymerase chain reaction, we found that the AG intron 2 encodes several noncoding RNAs. RNAi experiment showed that incRNA4 is needed for CLF repressive activity. AG-incRNA4RNAi lines showed increased leaf AG mRNA levels associated with a decrease of H3K27me3 levels; these plants displayed AG overexpression phenotypes. Genetic and biochemical analyses demonstrated that the AG-incRNA4 can associate with CLF to repress AG expression in leaf tissues through H3K27me3-mediated repression and to autoregulate its own expression level. The mechanism of AG-incRNA4-mediated repression may be relevant to investigations on tissue-specific expression of Arabidopsis MADS-box genes.


Asunto(s)
Proteína AGAMOUS de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/metabolismo , Intrones/genética , Hojas de la Planta/genética , ARN no Traducido/genética , Transcripción Genética , Proteína AGAMOUS de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Co-Represoras/metabolismo , Flores/genética , Glucuronidasa/metabolismo , Histonas/metabolismo , Proteínas de Homeodominio/genética , Especificidad de Órganos/genética , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN no Traducido/metabolismo , Plantones/genética
10.
Bioconjug Chem ; 29(6): 2039-2049, 2018 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-29771500

RESUMEN

Chemical drug design based on the biochemical characteristics of cancer cells has become an important strategy for discovery of targeted therapies for personalized cancer medicine. Herein, cancer targeting RGD peptide has been covalently conjugated to selenadiazole derivative (RGD-SeD) to improve its cancer selectivity. The RGD decoration significantly enhances the anticancer efficacy of RGD-SeD in αVß3 integrin-overexpressing HepG2 liver cancer cells but not in normal liver cells. Cellular uptake assay and fluorescent imaging confirmed the selectivity of RGD-SeD to integrin-overexpressing cancer cells. RGD-SeD strongly sensitizes HepG2 cells to clinically used X-ray radiotherapy through ROS overproduction, which triggers DNA damage-mediated apoptosis and G2/M cell cycle arrest. This X-ray-responsive DNA damage activates p53 signaling pathways by phosphorylation of ATM/ATR and γ-H2A.X. Furthermore, in a HepG2 nude mice xenograft model, the combined treatment of RGD-SeD and X-ray demonstrates potent in vivo antitumor efficacy via induction of apoptotic cell death but shows no toxicity on the functions of major organs. In summary, this study provides a strategy to design a selenium-based cancer targeting radiosensitizer for precise cancer therapy.


Asunto(s)
Neoplasias Hepáticas/radioterapia , Oligopéptidos/química , Oligopéptidos/uso terapéutico , Compuestos de Organoselenio/química , Compuestos de Organoselenio/uso terapéutico , Fármacos Sensibilizantes a Radiaciones/química , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Animales , Daño del ADN/efectos de los fármacos , Daño del ADN/efectos de la radiación , Sistemas de Liberación de Medicamentos , Diseño de Fármacos , Femenino , Células Hep G2 , Humanos , Integrina alfaVbeta3/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Ratones Endogámicos BALB C , Ratones Desnudos , Oligopéptidos/administración & dosificación , Oligopéptidos/farmacología , Compuestos de Organoselenio/administración & dosificación , Compuestos de Organoselenio/farmacología , Fármacos Sensibilizantes a Radiaciones/administración & dosificación , Fármacos Sensibilizantes a Radiaciones/farmacología , Especies Reactivas de Oxígeno/metabolismo
11.
Plant Cell ; 27(7): 2016-31, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26163577

RESUMEN

MYC2 is an important regulator for jasmonic acid (JA) signaling, but little is known about its posttranslational regulation. Here, we show that the MYC2 C-terminal region interacted with the PLANT U-BOX PROTEIN10 (PUB10) armadillo repeats in vitro. MYC2 was efficiently polyubiquitinated by PUB10 with UBC8 as an E2 enzyme and the conserved C249 in PUB10 was required for activity. The inactive PUB10(C249A) mutant protein retained its ability to heterodimerize with PUB10, thus blocking PUB10 E3 activity as a dominant-negative mutant. Both MYC2 and PUB10 were nucleus localized and coimmunoprecipitation experiments confirmed their interaction in vivo. Although unstable in the wild type, MYC2 stability was enhanced in pub10, suggesting destabilization by PUB10. Moreover, MYC2 half-life was shortened or prolonged by induced expression of PUB10 or the dominant-negative PUB10(C249A) mutant, respectively. Root growth of pub10 seedlings phenocopied 35S:MYC2 seedlings and was hypersensitive to methyl jasmonate, whereas 35S:PUB10 and jin1-9 (myc2) seedlings were hyposensitive. In addition, the root phenotype conferred by MYC2 overexpression in double transgenic plants was reversed or enhanced by induced expression of PUB10 or PUB10(C249A), respectively. Similar results were obtained with three other JA-regulated genes, TAT, JR2, and PDF1.2. Collectively, our results show that MYC2 is targeted by PUB10 for degradation during JA responses.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Ciclopentanos/farmacología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genotipo , Glucuronidasa/metabolismo , Semivida , Datos de Secuencia Molecular , Mutación/genética , Oxilipinas/farmacología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética , Plantas Modificadas Genéticamente , Poliubiquitina/metabolismo , Unión Proteica/efectos de los fármacos , Estabilidad Proteica/efectos de los fármacos , Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligasas/química , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/efectos de los fármacos
12.
Plant Physiol ; 171(1): 424-36, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26945048

RESUMEN

CURLY LEAF (CLF), a histone methyltransferase of Polycomb Repressive Complex 2 (PRC2) for trimethylation of histone H3 Lys 27 (H3K27me3), has been thought as a negative regulator controlling mainly postgermination growth in Arabidopsis (Arabidopsis thaliana). Approximately 14% to 29% of genic regions are decorated by H3K27me3 in the Arabidopsis genome; however, transcriptional repression activities of PRC2 on a majority of these regions remain unclear. Here, by analysis of transcriptome profiles, we found that approximately 11.6% genes in the Arabidopsis genome were repressed by CLF in various organs. Unexpectedly, approximately 54% of these genes were preferentially repressed in siliques. Further analyses of 118 transcriptome datasets uncovered a group of genes that was preferentially expressed and repressed by CLF in embryos at the mature-green stage. This observation suggests that CLF mediates a large-scale H3K27me3 programming/reprogramming event during embryonic development. Plants of clf-28 produced bigger and heavier seeds with higher oil content, larger oil bodies, and altered long-chain fatty acid composition compared with wild type. Around 46% of CLF-repressed genes were associated with H3K27me3 marks; moreover, we verified histone modification and transcriptional repression by CLF on regulatory genes. Our results suggest that CLF silences specific gene expression modules. Genes operating within a module have various molecular functions, but they cooperate to regulate a similar physiological function during embryo development.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Homeodominio/genética , Lípidos/biosíntesis , Semillas/crecimiento & desarrollo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Tamaño de la Célula , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/metabolismo , Lisina/metabolismo , Metilación , Complejo Represivo Polycomb 2 , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Semillas/genética , Semillas/metabolismo
13.
Plant J ; 83(5): 770-82, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26119694

RESUMEN

Transposable elements (TEs) and repetitive sequences are ubiquitously present in eukaryotic genomes which are in general epigenetically silenced by DNA methylation and/or histone 3 lysine 9 methylation (H3K9me). RNA-directed DNA methylation (RdDM) is the major pathway that initiates de novo DNA methylation in Arabidopsis and sets up a self-reinforcing silencing loop between DNA methylation and H3K9me. However, a key issue is the requirement of a basal level transcript from the target loci to initiate the RNA-based silencing. How the heterochromatic silenced loci are transcribed remains largely unknown. Here, we show that JMJ24, a JmjC domain-containing protein counteracts H3K9me to promote basal level transcription of endogenous silenced loci in Arabidopsis. JMJ24 functionally resembles the fission yeast JmjC protein Epe1. The transcript promoted by JMJ24 is, at least in part, processed to small RNA to initiate the RdDM. Genome-wide transcriptome profiling indicates that transcript levels of TEs are more likely regulated by JMJ24, compared with protein-coding genes. Our data suggest that JMJ24 plays a conserved role in promoting basal level transcription of endogenous silenced loci to reinforce the silencing. We also provide evidence of a physical association between JMJ24 and RNA-dependent RNA polymerase 2 (RDR2), which represents an evolved property of the RNA silencing pathway.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Histona Demetilasas con Dominio de Jumonji/metabolismo , ARN Polimerasa Dependiente del ARN/metabolismo , Transcripción Genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Metilación de ADN , Silenciador del Gen , Histona Demetilasas con Dominio de Jumonji/genética , Lisina/metabolismo , Metilación , Mutación , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Filogenia , Plantas Modificadas Genéticamente , ARN Polimerasa Dependiente del ARN/genética , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/metabolismo , Secuencias Repetidas Terminales
14.
Plant Cell Physiol ; 56(8): 1667-78, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26076969

RESUMEN

Transcriptional gene silencing (TGS) is often associated with promoter methylation in both animals and plants. However, the function of DNA methylation in the intragenic region remains unclear. Here, we confirmed that promoter methylation of FLOWERING LOCUS T (FT) led to gene silencing; in contrast, we found that intragenic methylation triggered by RNA-directed DNA methylation (RdDM) promoted FT expression. DNA methylation of the FT gene body blocked FLC repressor binding to the CArG boxes. However, when the boxes were not directly targeted by inverted-repeat RNAs (IRs), FLC binding blocked spreading of DNA methylation to theses sequences. Notwithstanding the FLC binding, FT was still activated under this condition. The DNA methylation was accompanied by elevated H3K9 methylation levels on the FT gene body. More importantly, the FT diurnal and organ-specific expression pattern was preserved in the activated plants. Our data demonstrate that the same type of epigenetic modification can lead to an opposite genetic outcome depending on the location of the modification on the gene locus. Moreover, we highlight a novel strategy to activate gene expression without changing its spatio-temporal regulatory patterns.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Intrones/genética , Secuencias Invertidas Repetidas/genética , Proteínas de Dominio MADS/genética , Metilación de ADN , Epigénesis Genética , Silenciador del Gen , Genes Reporteros , Código de Histonas , Fenotipo , Regiones Promotoras Genéticas/genética , ARN de Planta/genética , Transgenes
15.
Plant Cell ; 24(11): 4333-45, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23136377

RESUMEN

Long intergenic noncoding RNAs (lincRNAs) transcribed from intergenic regions of yeast and animal genomes play important roles in key biological processes. Yet, plant lincRNAs remain poorly characterized and how lincRNA biogenesis is regulated is unclear. Using a reproducibility-based bioinformatics strategy to analyze 200 Arabidopsis thaliana transcriptome data sets, we identified 13,230 intergenic transcripts of which 6480 can be classified as lincRNAs. Expression of 2708 lincRNAs was detected by RNA sequencing experiments. Transcriptome profiling by custom microarrays revealed that the majority of these lincRNAs are expressed at a level between those of mRNAs and precursors of miRNAs. A subset of lincRNA genes shows organ-specific expression, whereas others are responsive to biotic and/or abiotic stresses. Further analysis of transcriptome data in 11 mutants uncovered SERRATE, CAP BINDING PROTEIN20 (CBP20), and CBP80 as regulators of lincRNA expression and biogenesis. RT-PCR experiments confirmed these three proteins are also needed for splicing of a small group of intron-containing lincRNAs.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Unión al Calcio/genética , Regulación de la Expresión Génica de las Plantas , Péptidos y Proteínas de Señalización Intercelular/genética , Proteínas de la Membrana/genética , ARN Largo no Codificante/genética , Proteínas de Unión al ARN/genética , Arabidopsis/metabolismo , Biología Computacional , Flores/genética , Flores/metabolismo , Perfilación de la Expresión Génica , Biblioteca de Genes , Intrones , Mutación , Análisis de Secuencia por Matrices de Oligonucleótidos , Especificidad de Órganos , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Empalme del ARN , ARN Largo no Codificante/metabolismo , ARN de Planta/genética , ARN de Planta/metabolismo , Análisis de Secuencia de ARN , Proteínas Serrate-Jagged , Estrés Fisiológico , Transcriptoma
16.
Plant Cell Physiol ; 55(4): 823-33, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24492259

RESUMEN

Transcriptional gene silencing (TGS) of transgenes by promoter-related RNAs has been known for more than a decade. However, the effectiveness and efficiency of silencing of endogenes by single-stranded and inverted repeat (IR) RNA/silencers remain unclear. Here, we demonstrated that a single-stranded antisense (AS) silencer targeting the promoter region can efficiently silence four Arabidopsis endogenes, with comparable efficiency to an IR silencer. In the case of Too Many Mouths (TMM), single-stranded silencers generated mainly 24 nt small RNAs (smRNAs), whereas IR silencers produced a higher proportion of 21-23 nt smRNAs. Heavy CG, CHG and CHH methylations were detected on the TMM promoter in silenced plant lines. We also demonstrated that the silencing and DNA methylation of the TMM promoter was dependent on the presence of the silencer. Chromatin immunoprecipitation (ChIP) assays showed that DNA methylation was accompanied by formation of repressive chromatin structures. Our results suggest that single-stranded silencer transcripts are converted to double-stranded RNA to enter the RdRM (RNA-directed DNA methylation) pathway for TGS of endogenes.


Asunto(s)
Arabidopsis/genética , Silenciador del Gen , Genes de Plantas , Regiones Promotoras Genéticas , ARN de Planta/genética , Transcripción Genética , Proteínas de Arabidopsis/genética , Cruzamientos Genéticos , Metilación de ADN/genética , ADN Bacteriano/genética , Histonas/metabolismo , Secuencias Invertidas Repetidas/genética , Mutagénesis Insercional/genética , Mutación/genética , Penetrancia , Fenotipo , Procesamiento Proteico-Postraduccional , ARN de Planta/metabolismo , Transformación Genética
17.
Plant Physiol Biochem ; 211: 108721, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38739961

RESUMEN

Pongamia (Millettia pinnata Syn. Pongamia pinnata), a mangrove associate plant, exhibits good stress tolerance, making it a treasure of genetic resources for crop improvement. NAC proteins are plant-specific transcription factors, which have been elucidated to participate in the regulation and tolerance of abiotic stresses (such as salt and drought). Here, we identified a salt-induced gene from Pongamia, MpNAC1, which encodes an NAC factor sharing five highly conserved domains with other NACs and exhibits close homology to AtNAC19/AtNAC55/AtNAC72 in Arabidopsis. MpNAC1 showed nuclear localization and transcriptional activator activity. MpNAC1-overexpressing Arabidopsis exhibited significantly stronger salt and drought tolerance compared with wild-type plants. The expression levels of stress-responsive genes were activated in transgenic Arabidopsis. Furthermore, the heterologous expression of MpNAC1 also enhanced the salt and drought tolerance of transgenic rice. The major agronomic traits, such as plant height and tiller number, panicle length, grain size, and yield, were similar between the transgenic lines and wild type under normal field growth conditions. RNA-Seq analysis revealed that MpNAC1 significantly up-regulated stress-responsive genes and activated the biosynthesis of secondary metabolites such as flavonoids, resulting in increased stress tolerance. Taken together, the MpNAC1 increased salt and drought stress tolerance in transgenic plants and did not retard the plant growth and development under normal growth conditions, suggesting the potential of MpNAC1 in breeding stress-resilient crops.


Asunto(s)
Arabidopsis , Sequías , Regulación de la Expresión Génica de las Plantas , Oryza , Proteínas de Plantas , Plantas Modificadas Genéticamente , Tolerancia a la Sal , Factores de Transcripción , Arabidopsis/genética , Oryza/genética , Oryza/fisiología , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Tolerancia a la Sal/genética , Millettia/genética , Millettia/metabolismo , Estrés Fisiológico/genética
18.
Carbohydr Polym ; 329: 121768, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38286543

RESUMEN

In the current study, the effects of extrusion using a haake rheometer with a twin-roll mixer, with and without FA addition, on the structures and in vitro digestibility of starches from different sources were investigated. After extruding for 15 min at 90 °C with a moisture content of 40 %, no matter FA was added or not, lager Ap molecules were preferentially debranched, while Am with longer CL were depolymerized simultaneously, resulting to reduced averaged molecular size of Ap and shortened Am chains. Of all starches, regardless of their botanical backgrounds, although synergic effects were found between extrusion and FA addition on reducing their relative crystallinity and the ordered structures, distinctly different effects on the in vitro digestibility of these starches have also been observed especially regarding the digestion of starch branches with DP > 10 Particularly, the Am chains with DP 10-1000 was remaining undigested when FA was added. This study provides important information concerning how to adjust starch digestibility into a healthy range through altering the starch structures using extrusion technique with the addition of phytochemicals or not.


Asunto(s)
Ácidos Cumáricos , Almidón , Almidón/química , Digestión
19.
RSC Adv ; 14(16): 11482-11512, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38595725

RESUMEN

Over the past decade, transition metal (TM)-based electrodes have shown intriguing physicochemical properties and widespread applications, especially in the field of supercapacitor energy storage owing to their diverse configurations, composition, porosity, and redox reactions. As one of the most intriguing research interests, the design of porous architectures in TM-based electrode materials has been demonstrated to facilitate ion/electron transport, modulate their electronic structure, diminish strain relaxation, and realize synergistic effects of multi-metals. Herein, the recent advances in porous TM-based electrodes are summarized, focusing on their typical synthesis strategies, including template-mediated assembly, thermal decomposition strategy, chemical deposition strategy, and host-guest hybridization strategy. Simultaneously, the corresponding conversion mechanism of each synthesis strategy are reviewed, and the merits and demerits of each strategy in building porous architectures are also discussed. Subsequently, TM-based electrode materials are categorized into TM oxides, TM hydroxides, TM sulfides, TM phosphides, TM carbides, and other TM species with a detailed review of their crystalline phase, electronic structure, and microstructure evolution to tune their electrochemical energy storage capacity. Finally, the challenges and prospects of porous TM-based electrode materials are presented to guide the future development in this field.

20.
J Ethnopharmacol ; 330: 118199, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-38631486

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Nocardiosis is an uncommon infectious disease that bears certain similarities to tuberculosis, with a continuous increase in its incidence and a poor prognosis. In traditional Chinese medicine, the leaves of Cajanus cajan (L.) Millsp. are employed to treat wounds, malaria, coughs, and abdominal pain. AIM OF THE STUDY: In this study, we investigated the effects and mechanisms of longistylin A (LGA), a natural stilbene isolated from C. cajan, as a potential antibiotic against nocardiosis. MATERIALS AND METHODS: LGA was isolated from the leaves of C. cajan and assessed using a minimum bactericidal concentration (MBC) determination against Nocardia seriolae. Multi-omics analysis encompassing genes, proteins, and metabolites was conducted to investigate the impact of LGA treatment on N. seriolae. Additionally, quantitative analysis of 40 cytokinins in N. seriolae mycelium was performed to assess the specific effects of LGA treatment on cytokinin levels. Cryo-scanning electron microscopy was utilized to examine morphological changes induced by LGA treatment, particularly in the presence of exogenous trans-zeatin-O-glucoside (tZOG). The therapeutic effect of LGA was investigated by feeding N. seriolae-infected largemouth bass. RESULTS: LGA exhibited significant efficacy against N. seriolae, with MBC value of 2.56 µg/mL. Multi-omics analysis revealed that LGA disrupted glycerophospholipid metabolism and hormone biosynthesis by notably reducing the expression of glycerol-3-phosphate dehydrogenase and calmodulin-like protein. Treatment with LGA markedly disrupted 12 distinct cytokinins in N. seriolae mycelium. Additionally, the addition of exogenous tZOG counteracted the inhibitory effects of LGA on filamentous growth, resulting in mycelial elongation and branching. Furthermore, LGA treatment improved the survival rate of largemouth bass infected with N. seriolae. CONCLUSIONS: We found for the first time that LGA from C. cajan exhibited significant efficacy against N. seriolae by interfering with glycerophospholipid metabolism and cytokinin biosynthesis.


Asunto(s)
Antibacterianos , Cajanus , Citocininas , Glicerofosfolípidos , Nocardia , Nocardia/metabolismo , Nocardia/efectos de los fármacos , Citocininas/farmacología , Citocininas/biosíntesis , Citocininas/metabolismo , Glicerofosfolípidos/metabolismo , Glicerofosfolípidos/biosíntesis , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Hojas de la Planta
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