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1.
Plant Cell ; 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34469582

RESUMO

Verticillium wilt is a severe plant disease that causes massive losses in multiple crops. Increasing the plant resistance to Verticillium wilt is a critical challenge worldwide. Here, we report that the hemibiotrophic Verticillium dahliae (V. dahliae)-secreted Asp f2-like protein VDAL causes leaf wilting when applied to cotton leaves in vitro but enhances the resistance to V. dahliae when overexpressed in Arabidopsis or cotton without affecting the plant growth and development. VDAL protein interacts with Arabidopsis E3 ligases PUB25 and PUB26 (PUBs) and is ubiquitinated by PUBs in vitro. However, VDAL is not degraded by PUB25 or PUB26 in planta. Besides, the pub25 pub26 double mutant shows higher resistance to V. dahliae than the wild type. PUBs interact with the transcription factor MYB6 in a yeast two-hybrid screen. MYB6 promotes plant resistance to Verticillium wilt while PUBs ubiquitinate MYB6 and mediate its degradation. VDAL competes with MYB6 for binding to PUBs, and the role of VDAL in increasing Verticillium wilt resistance depends on MYB6. Taken together, these results suggest that plants evolute a strategy to utilize the invaded effector protein VDAL to resist the V. dahliae infection without causing a hypersensitive response (HR); alternatively, hemibiotrophic pathogens may use some effectors to keep plant cells alive during its infection in order to take nutrients from host cells. This study provides the molecular mechanism for plants increasing disease resistance when overexpressing some effector proteins without inducing HR, and may promote searching for more genes from pathogenic fungi or bacteria to engineer plant disease resistance.

2.
Nat Commun ; 12(1): 4713, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354054

RESUMO

Maize (Zea mays L.) is a cold-sensitive species that often faces chilling stress, which adversely affects growth and reproduction. However, the genetic basis of low-temperature adaptation in maize remains unclear. Here, we demonstrate that natural variation in the type-A Response Regulator 1 (ZmRR1) gene leads to differences in chilling tolerance among maize inbred lines. Association analysis reveals that InDel-35 of ZmRR1, encoding a protein harboring a mitogen-activated protein kinase (MPK) phosphorylation residue, is strongly associated with chilling tolerance. ZmMPK8, a negative regulator of chilling tolerance, interacts with and phosphorylates ZmRR1 at Ser15. The deletion of a 45-bp region of ZmRR1 harboring Ser15 inhibits its degradation via the 26 S proteasome pathway by preventing its phosphorylation by ZmMPK8. Transcriptome analysis indicates that ZmRR1 positively regulates the expression of ZmDREB1 and Cellulose synthase (CesA) genes to enhance chilling tolerance. Our findings thus provide a potential genetic resource for improving chilling tolerance in maize.


Assuntos
Zea mays/genética , Zea mays/fisiologia , Alelos , Temperatura Baixa , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Técnicas In Vitro , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Biológicos , Fosforilação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Estresse Fisiológico/genética
3.
New Phytol ; 230(6): 2355-2370, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33666235

RESUMO

The farmland of the world's main corn-producing area is increasingly affected by salt stress. Therefore, the breeding of salt-tolerant cultivars is necessary for the long-term sustainability of global corn production. Previous studies have shown that natural maize varieties display a large diversity of salt tolerance, yet the genetic variants underlying such diversity remain poorly discovered and applied, especially those mediating the tolerance to salt-induced osmotic stress (SIOS). Here we report a metabolomics-driven understanding and genetic improvement of maize SIOS tolerance. Using a LC-MS-based untargeted metabolomics approach, we profiled the metabolomes of 266 maize inbred lines under control and salt conditions, and then identified 37 metabolite biomarkers of SIOS tolerance (METO1-37). Follow-up metabolic GWAS (mGWAS) and genotype-to-phenotype modeling identified 10 candidate genes significantly associating with the SIOS tolerance and METO abundances. Furthermore, we validated that a citrate synthase, a glucosyltransferase and a cytochrome P450 underlie the genotype-METO-SIOS tolerance associations, and showed that their favorable alleles additively improve the SIOS tolerance of elite maize inbred lines. Our study provides a novel insight into the natural variation of maize SIOS tolerance, which boosts the genetic improvement of maize salt tolerance, and demonstrates a metabolomics-based approach for mining crop genes associated with this complex agronomic trait.


Assuntos
Melhoramento Vegetal , Zea mays , Metabolômica , Pressão Osmótica , Fenótipo , Zea mays/genética
4.
EMBO J ; 39(13): e103630, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32449547

RESUMO

Light and temperature are two core environmental factors that coordinately regulate plant growth and survival throughout their entire life cycle. However, the mechanisms integrating light and temperature signaling pathways in plants remain poorly understood. Here, we report that CBF1, an AP2/ERF-family transcription factor essential for plant cold acclimation, promotes hypocotyl growth under ambient temperatures in Arabidopsis. We show that CBF1 increases the protein abundance of PIF4 and PIF5, two phytochrome-interacting bHLH-family transcription factors that play pivotal roles in modulating plant growth and development, by directly binding to their promoters to induce their gene expression, and by inhibiting their interaction with phyB in the light. Moreover, our data demonstrate that CBF1 promotes PIF4/PIF5 protein accumulation and hypocotyl growth at both 22°C and 17°C, but not at 4°C, with a more prominent role at 17°C than at 22°C. Together, our study reveals that CBF1 integrates light and temperature control of hypocotyl growth by promoting PIF4 and PIF5 protein abundance in the light, thus providing insights into the integration mechanisms of light and temperature signaling pathways in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Hipocótilo/crescimento & desenvolvimento , Temperatura , Transativadores/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipocótilo/genética , Transativadores/genética
5.
Plant Cell ; 32(7): 2196-2215, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32371543

RESUMO

Phytochromes are red (R) and far-red (FR) light photoreceptors in plants, and PHYTOCHROME-INTERACTING FACTORS (PIFs) are a group of basic helix-loop-helix family transcription factors that play central roles in repressing photomorphogenesis. Here, we report that MYB30, an R2R3-MYB family transcription factor, acts as a negative regulator of photomorphogenesis in Arabidopsis (Arabidopsis thaliana). We show that MYB30 preferentially interacts with the Pfr (active) forms of the phytochrome A (phyA) and phytochrome B (phyB) holoproteins and that MYB30 levels are induced by phyA and phyB in the light. It was previously shown that phytochromes induce rapid phosphorylation and degradation of PIFs upon R light exposure. Our current data indicate that MYB30 promotes PIF4 and PIF5 protein reaccumulation under prolonged R light irradiation by directly binding to their promoters to induce their expression and by inhibiting the interaction of PIF4 and PIF5 with the Pfr form of phyB. In addition, our data indicate that MYB30 interacts with PIFs and that they act additively to repress photomorphogenesis. In summary, our study demonstrates that MYB30 negatively regulates Arabidopsis photomorphogenic development by acting to promote PIF4 and PIF5 protein accumulation under prolonged R light irradiation, thus providing new insights into the complicated but delicate control of PIFs in the responses of plants to their dynamic light environment.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica de Plantas , Luz , Fitocromo A/metabolismo , Fitocromo B/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Plântula/fisiologia , Fatores de Transcrição/genética
6.
Mol Plant ; 13(3): 414-430, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32059872

RESUMO

PHYTOCHROME-INTERACTING FACTORS (PIFs) are a group of basic helix-loop-helix transcription factors that can physically interact with photoreceptors, including phytochromes and cryptochromes. It was previously demonstrated that PIFs accumulated in darkness and repressed seedling photomorphogenesis, and that PIFs linked different photosensory and hormonal pathways to control plant growth and development. In this study, we show that PIFs positively regulate the ABA signaling pathway during the seedling stage specifically in darkness. We found that PIFs positively regulate ABI5 transcript and protein levels in darkness in response to exogenous ABA treatment by binding directly to the G-box motifs in the ABI5 promoter. Consistently, PIFs and the G-box motifs in the ABI5 promoter determine ABI5 expression in darkness, and overexpression of ABI5 could rescue the ABA-insensitive phenotypes of pifq mutants in the dark. Moreover, we discovered that PIFs can physically interact with the ABA receptors PYL8 and PYL9, and that this interaction is not regulated by ABA. Further analyses showed that PYL8 and PYL9 promote PIF4 protein accumulation in the dark and enhance PIF4 binding to the ABI5 promoter, but negatively regulate PIF4-mediated ABI5 activation. Taken together, our data demonstrate that PIFs interact with ABA receptors to orchestrate ABA signaling in darkness by controlling ABI5 expression, providing new insights into the pivotal roles of PIFs as signal integrators in regulating plant growth and development.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Escuridão , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Sequência de Bases , Fatores de Transcrição de Zíper de Leucina Básica/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos da radiação , RNA Mensageiro/genética , Transdução de Sinais/efeitos da radiação
7.
Exp Ther Med ; 19(2): 999-1005, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32010262

RESUMO

The aim of the present study was to determine the role of long intergenic non-protein coding RNA 858 (LINC00858) in retinoblastoma (RB) and investigate the underlying molecular mechanisms. RB tissues and paracancerous tissues of 27 RB cases were obtained. RB cell lines (SO-RB50, Y79, HXO-RB44 and WERI-Rb1) and a normal retinal epithelial cell line (ARPE-19) were cultured for in vitro experiments. Batches of SO-RB50 and Y79 cells were assigned to groups transfected with small interfering RNA targeting LINC00858 (si-LINC00858 group), microRNA (miR)-3182 mimics or inhibitor, or the respective controls. A Cell Counting Kit-8 and Transwell assays were performed to assess the effect of the transfections on the proliferation, migration and invasion of SO-RB50 and Y79 cells. A luciferase reporter assay was performed using SO-RB50 cells to demonstrate the direct binding of LINC00858 and miR-3182. Reverse transcription-quantitative PCR was employed to detect LINC00858 and miR-3182 expression. Pearson correlation analysis was used to assess the correlation between the expression of LINC00858 and miR-3182. The results indicated that RB tissues and cells exhibited aberrantly elevated LINC00858 expression (P<0.05). Compared with those in the control-transfected group, SO-RB50 and Y79 cells of the si-LINC00858 group had a lower cell proliferation, as well as a lower number of migrated and invaded cells (all P<0.05). miR-3182 was proven to be a target gene of LINC00858, to be abnormally downregulated in RB tissues and cells (P<0.05) and to be negatively correlated with LINC00858 expression. Compared with those in the si-LINC00858 + inhibitor-negative control group, SO-RB50 and Y79 cells of the si-LINC00858 + miR-3182 inhibitor group exhibited a significantly higher relative proliferation, migration and invasion (all P<0.05). In conclusion, LINC00858 promoted RB cell proliferation, migration and invasion, at least partially by inhibiting miR-3182.

8.
Plant Physiol ; 181(1): 249-261, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31331996

RESUMO

DNA methylation and histone modification are important epigenetic marks that coregulate gene expression and genome stability. To identify factors involved in chromatin silencing, we carried out a forward genetic screen for mutants that release the silenced Pro-35S:LUCIFERASE (35SP-LUC) in Arabidopsis (Arabidopsis thaliana). We identified an epigenetic regulator, METHIONINE SYNTHASE1 (ATMS1), which catalyzes the synthesis of methionine (Met) in the one-carbon metabolism pathway. The ATMS1 mutation releases the silenced 35SP-LUC and the majority of endogenous genes and transposons. The effect of ATMS1 on chromatin silencing is related to decreased levels of DNA methylation (CG, CHG, and CHH) and histone-3 lysine-9 dimethylation. The ATMS1 mutation caused a significant decrease in the ratio of S-adenosylmethionine to S-adenosylhomocysteine. Exogenous application of Met rescued the phenotype of atms1-1 ATMS1 plays a predominant role in DNA and histone methylations among the three Met synthetase homologs. These results suggest that ATMS1 is required for DNA and histone methylations through its function in the one-carbon metabolism pathway, indicating the complex interplay between metabolism and epigenetic regulation.


Assuntos
5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Epigênese Genética , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , 5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Metilação de DNA , Inativação Gênica , Lisina/metabolismo , Metionina/metabolismo
9.
Proc Natl Acad Sci U S A ; 116(21): 10576-10585, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31064880

RESUMO

Epigenetic markers, such as histone acetylation and DNA methylation, determine chromatin organization. In eukaryotic cells, metabolites from organelles or the cytosol affect epigenetic modifications. However, the relationships between metabolites and epigenetic modifications are not well understood in plants. We found that peroxisomal acyl-CoA oxidase 4 (ACX4), an enzyme in the fatty acid ß-oxidation pathway, is required for suppressing the silencing of some endogenous loci, as well as Pro35S:NPTII in the ProRD29A:LUC/C24 transgenic line. The acx4 mutation reduces nuclear histone acetylation and increases DNA methylation at the NOS terminator of Pro35S:NPTII and at some endogenous genomic loci, which are also targeted by the demethylation enzyme REPRESSOR OF SILENCING 1 (ROS1). Furthermore, mutations in multifunctional protein 2 (MFP2) and 3-ketoacyl-CoA thiolase-2 (KAT2/PED1/PKT3), two enzymes in the last two steps of the ß-oxidation pathway, lead to similar patterns of DNA hypermethylation as in acx4 Thus, metabolites from fatty acid ß-oxidation in peroxisomes are closely linked to nuclear epigenetic modifications, which may affect diverse cellular processes in plants.


Assuntos
Arabidopsis/metabolismo , Metilação de DNA , Epigênese Genética , Ácidos Graxos/metabolismo , Peroxissomos/metabolismo , ATP Citrato (pro-S)-Liase/metabolismo , Acetilação , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Histonas/metabolismo , Oxirredução , Plantas Geneticamente Modificadas , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo
10.
Int Ophthalmol ; 39(10): 2223-2235, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30607864

RESUMO

OBJECTIVE: To understand the involvement of the mGluR5-mediated JNK signaling pathway in rats with diabetic retinopathy (DR). METHODS: This study established rat models of diabetes mellitus (DM), which were divided into Normal, DM, DM + CHPG (mGluR5 agonist CHPG), and DM + MTEP (mGluR5 antagonist MTEP) groups. The blood glucose and weight of rats were recorded. EB staining was used for observation of blood-retinal barrier (BRB) damage. Neural retina function was measured by pattern electroretinogram (ERG). PAS and NG2 immunohistochemistry were conducted to evaluate the retinal vascular morphology. The TUNEL assay and active caspase-3 immunohistochemistry were performed to detect retinal cell apoptosis. Additionally, the expression levels of superoxide dismutase (SOD) and methylenedioxyamphetamine (MDA) were measured. Moreover, expression levels of mGluR5 and JNK pathway-related proteins were detected by western blot. RESULTS: When compared with control rats, rats in the DM group showed decreased amplitude and latency of the peak times in the ERG test; further, DM group rats presented increases in blood glucose, BRB permeability, a retinal capillary area density, retinal cell apoptosis with an increased number of active caspase-3-positive cells, MDA level, mGluR5 levels, and the ratio of p-JNK/JNK, and they showed reductions in body weight and SOD activity, as well as in the number of pericytes and in the pericyte coverage (all P < 0.05). However, rats in DM + CHPG group had stronger negative effects than those in DM group (all P < 0.05). Rats from DM + MTEP group showed an opposite trend compared with the DM rats (all P < 0.05). CONCLUSION: The level of mGluR5 in DR rats was upregulated, whereas inhibition of mGluR5 alleviated retinal pathological damage and decreased cell apoptosis to improve DR via suppression of the JNK signaling pathway, which provided a scientific theoretical basis for the clinical treatment of DR.


Assuntos
Retinopatia Diabética/fisiopatologia , Sistema de Sinalização das MAP Quinases/fisiologia , Receptor de Glutamato Metabotrópico 5/fisiologia , Animais , Glicemia/metabolismo , Barreira Hematorretiniana/patologia , Diabetes Mellitus Experimental , Retinopatia Diabética/metabolismo , Eletrorretinografia , Masculino , Ratos , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5/metabolismo , Retina/fisiopatologia , Vasos Retinianos/patologia
11.
Proc Natl Acad Sci U S A ; 115(50): E11864-E11873, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30478060

RESUMO

Phytochrome A (phyA) is the only plant photoreceptor that perceives far-red light and then mediates various responses to this signal. Phosphorylation and dephosphorylation of oat phyA have been extensively studied, and it was shown that phosphorylation of a serine residue in the hinge region of oat phyA could regulate the interaction of phyA with its signal transducers. However, little is known about the role of the hinge region of Arabidopsis phyA. Here, we report that three sites in the hinge region of Arabidopsis phyA (i.e., S590, T593, and S602) are essential in regulating phyA function. Mutating all three of these sites to either alanines or aspartic acids impaired phyA function, changed the interactions of mutant phyA with FHY1 and FHL, and delayed the degradation of mutant phyA upon light exposure. Moreover, the in vivo formation of a phosphorylated phyA form was greatly affected by these mutations, while our data indicated that the abundance of this phosphorylated phyA form correlated well with the extent of phyA function, thus suggesting a pivotal role of the phosphorylated phyA in inducing the far-red light response. Taking these data together, our study reveals the important role of the hinge region of Arabidopsis phyA in regulating phyA phosphorylation and function, thus linking specific residues in the hinge region to the regulatory mechanisms of phyA phosphorylation.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fitocromo A/química , Fitocromo A/metabolismo , Transporte Ativo do Núcleo Celular , Substituição de Aminoácidos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Ciclo Celular/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Luz , Mutagênese Sítio-Dirigida , Fosforilação , Fitocromo/metabolismo , Fitocromo A/genética , Plantas Geneticamente Modificadas , Proteólise , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Transcriptoma , Ubiquitina-Proteína Ligases/metabolismo
12.
Plant Physiol ; 177(2): 652-670, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29572390

RESUMO

DNA and histone methylation coregulate heterochromatin formation and gene silencing in animals and plants. To identify factors involved in maintaining gene silencing, we conducted a forward genetic screen for mutants that release the silenced transgene Pro35S::NEOMYCIN PHOSPHOTRANSFERASE II in the transgenic Arabidopsis (Arabidopsis thaliana) line L119 We identified MAT4/SAMS3/MTO3/AT3G17390, which encodes methionine (Met) adenosyltransferase 4 (MAT4)/S-adenosyl-Met synthetase 3 that catalyzes the synthesis of S-adenosyl-Met (SAM) in the one-carbon metabolism cycle. mat4 mostly decreases CHG and CHH DNA methylation and histone H3K9me2 and reactivates certain silenced transposons. The exogenous addition of SAM partially rescues the epigenetic defects of mat4 SAM content and DNA methylation were reduced more in mat4 than in three other mat mutants. MAT4 knockout mutations generated by CRISPR/Cas9 were lethal, indicating that MAT4 is an essential gene in Arabidopsis. MAT1, 2, and 4 proteins exhibited nearly equal activity in an in vitro assay, whereas MAT3 exhibited higher activity. The native MAT4 promoter driving MAT1, 2, and 3 cDNA complemented the mat4 mutant. However, most mat4 transgenic lines carrying native MAT1, 2, and 3 promoters driving MAT4 cDNA did not complement the mat4 mutant because of their lower expression in seedlings. Genetic analyses indicated that the mat1mat4 double mutant is dwarfed and the mat2mat4 double mutant was nonviable, while mat1mat2 showed normal growth and fertility. These results indicate that MAT4 plays a predominant role in SAM production, plant growth, and development. Our findings provide direct evidence of the cooperative actions between metabolism and epigenetic regulation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Metilação de DNA , Histonas/metabolismo , Metionina Adenosiltransferase/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Heterocromatina/genética , Histonas/genética , Metionina Adenosiltransferase/genética , Metilação , Mutação , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , S-Adenosilmetionina/metabolismo , Plântula/genética , Plântula/crescimento & desenvolvimento , Transgenes
13.
Mol Plant ; 10(4): 545-559, 2017 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-28089951

RESUMO

Cold stress is a major environmental factor that adversely affects plant growth and development. The C-repeat binding factor/DRE binding factor 1 (CBF/DREB1) transcriptional regulatory cascade has been shown to play important roles in plant response to cold. Here we demonstrate that two key components of brassinosteroid (BR) signaling modulate freezing tolerance of Arabidopsis plants. The loss-of-function mutant of the GSK3-like kinases involved in BR signaling, bin2-3 bil1 bil2, showed increased freezing tolerance, whereas overexpression of BIN2 resulted in hypersensitivity to freezing stress under both non-acclimated and acclimated conditions. By contrast, gain-of-function mutants of the transcription factors BZR1 and BES1 displayed enhanced freezing tolerance, and consistently cold treatment could induce the accumulation of dephosphorylated BZR1. Biochemical and genetic analyses showed that BZR1 acts upstream of CBF1 and CBF2 to directly regulate their expression. Moreover, we found that BZR1 also regulated other COR genes uncoupled with CBFs, such as WKRY6, PYL6, SOC1, JMT, and SAG21, to modulate plant response to cold stress. Consistently, wrky6 mutants showed decreased freezing tolerance. Taken together, our results indicate that BZR1 positively modulates plant freezing tolerance through CBF-dependent and CBF-independent pathways.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Congelamento , Proteínas Nucleares/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas Nucleares/genética , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Plant Physiol ; 171(2): 1192-208, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27208288

RESUMO

DNA polymerase δ plays crucial roles in DNA repair and replication as well as maintaining genomic stability. However, the function of POLD2, the second small subunit of DNA polymerase δ, has not been characterized yet in Arabidopsis (Arabidopsis thaliana). During a genetic screen for release of transcriptional gene silencing, we identified a mutation in POLD2. Whole-genome bisulfite sequencing indicated that POLD2 is not involved in the regulation of DNA methylation. POLD2 genetically interacts with Ataxia Telangiectasia-mutated and Rad3-related and DNA polymerase α The pold2-1 mutant exhibits genomic instability with a high frequency of homologous recombination. It also exhibits hypersensitivity to DNA-damaging reagents and short telomere length. Whole-genome chromatin immunoprecipitation sequencing and RNA sequencing analyses suggest that pold2-1 changes H3K27me3 and H3K4me3 modifications, and these changes are correlated with the gene expression levels. Our study suggests that POLD2 is required for maintaining genome integrity and properly establishing the epigenetic markers during DNA replication to modulate gene expression.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , DNA Polimerase III/metabolismo , Epigênese Genética , Instabilidade Genômica , Subunidades Proteicas/metabolismo , Arabidopsis/citologia , Ciclo Celular/genética , Clonagem Molecular , Metilação de DNA/genética , Reparo do DNA/genética , Replicação do DNA/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Histonas/metabolismo , Recombinação Homóloga/genética , Mutação/genética , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Telômero/metabolismo
15.
Nat Commun ; 6: 8630, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26482222

RESUMO

Clade A protein phosphatase 2Cs (PP2Cs) are abscisic acid (ABA) co-receptors that block ABA signalling by inhibiting the downstream protein kinases. ABA signalling is activated after PP2Cs are inhibited by ABA-bound PYR/PYL/RCAR ABA receptors (PYLs) in Arabidopsis. However, whether these PP2Cs are regulated by other factors remains unknown. Here, we report that ABI1 (ABA-INSENSITIVE 1) can interact with the U-box E3 ligases PUB12 and PUB13, but is ubiquitinated only when it interacts with ABA receptors in an in vitro assay. A mutant form of ABI1-1 that is unable to interact with PYLs is more stable than the wild-type protein. Both ABI1 degradation and all tested ABA responses are reduced in pub12 pub13 mutants compared with the wild type. Introducing the abi1-3 loss-of-function mutation into pub12 pub13 mutant recovers the ABA-insensitive phenotypes of the pub12 pub13 mutant. We thus uncover an important regulatory mechanism for regulating ABI1 levels by PUB12 and PUB13.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Fosfoproteínas Fosfatases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Mutação , Fosfoproteínas Fosfatases/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética
16.
BMC Bioinformatics ; 14: 95, 2013 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-23496817

RESUMO

BACKGROUND: Chloroplast is an essential organelle in plants which contains independent genome. Chloroplast genomes have been widely used for plant phylogenetic inference recently. The number of complete chloroplast genomes increases rapidly with the development of various genome sequencing projects. However, no comprehensive platform or tool has been developed for the comparative and phylogenetic analysis of chloroplast genomes. Thus, we constructed a comprehensive platform for the comparative and phylogenetic analysis of complete chloroplast genomes which was named as chloroplast genome analysis platform (CGAP). RESULTS: CGAP is an interactive web-based platform which was designed for the comparative analysis of complete chloroplast genomes. CGAP integrated genome collection, visualization, content comparison, phylogeny analysis and annotation functions together. CGAP implemented four web servers including creating complete and regional genome maps of high quality, comparing genome features, constructing phylogenetic trees using complete genome sequences, and annotating draft chloroplast genomes submitted by users. CONCLUSIONS: Both CGAP and source code are available at http://www.herbbol.org:8000/chloroplast. CGAP will facilitate the collection, visualization, comparison and annotation of complete chloroplast genomes. Users can customize the comparative and phylogenetic analysis using their own unpublished chloroplast genomes.


Assuntos
Genoma de Cloroplastos , Software , Internet , Anotação de Sequência Molecular , Filogenia
17.
Mol Biol Evol ; 30(5): 1032-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23389766

RESUMO

Phylogenetic analysis based on alignment method meets huge challenges when dealing with whole-genome sequences, for example, recombination, shuffling, and rearrangement of sequences. Thus, various alignment-free methods for phylogeny construction have been proposed. However, most of these methods have not been implemented as tools or web servers. Researchers cannot use these methods easily with their data sets. To facilitate the usage of various alignment-free methods, we implemented most of the popular alignment-free methods and constructed a user-friendly web server for alignment-free genome phylogeny (AGP). AGP integrated the phylogenetic tree construction, visualization, and comparison functions together. Both AGP and all source code of the methods are available at http://www.herbbol.org:8000/agp (last accessed February 26, 2013). AGP will facilitate research in the field of whole-genome phylogeny and comparison.


Assuntos
Genoma/genética , Internet , Filogenia , Software , Algoritmos , Análise de Sequência de DNA/métodos
18.
J Acoust Soc Am ; 131(4): 2859-65, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22501064

RESUMO

Research into acoustic recognition systems for insects has focused on species identification rather than individual identification. In this paper, the feasibility of applying pattern recognition techniques to construct an acoustic system capable of automatic individual recognition for insects is investigated analytically and experimentally across two species of Orthoptera. Mel-frequency cepstral coefficients serve as the acoustic feature, and α-Gaussian mixture models were selected as the classification models. The performance of the proposed acoustic system is promising and displays high accuracy. The results suggest that the acoustic feature and classifier method developed here have potential for individual animal recognition and can be applied to other species of interest.


Assuntos
Ortópteros/fisiologia , Reconhecimento Automatizado de Padrão/métodos , Vocalização Animal/fisiologia , Acústica , Animais , Estudos de Viabilidade , Masculino , Espectrografia do Som
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