RÉSUMÉ
Anthocyanin is a type of plant secondary metabolite beneficial to human health. The anthocyanin content of vegetable and fruit crops signifies their nutritional quality. However, the molecular mechanism of anthocyanin accumulation, especially tissue-specific accumulation, in Caitai, as well as in other Brassica rapa varieties, remains elusive. In the present study, taking advantage of three kinds of Caitai cultivars with diverse colour traits between leaves and stems, we conducted a comparative transcriptome analysis and identified the molecular pathway of anthocyanin biosynthesis in Caitai leaves and stems, respectively. Our further investigations demonstrate that bHLH42, which is robustly induced by MeJA, closely correlates with tissue-specific accumulation of anthocyanins in Caitai; bHLH42 upregulates the expression of flavonoid/anthocyanin biosynthetic pathway genes to activate anthocyanin biosynthesis pathway, importantly, overexpression of bHLH42 significantly improves the anthocyanin content of Caitai. Our analysis convincingly suggests that bHLH42 induced by jasmonic acid signalling plays a crucial role in tissue-specific accumulation of anthocyanins in Caitai.
Sujet(s)
Acétates , Anthocyanes , Facteurs de transcription à motif basique hélice-boucle-hélice , Cyclopentanes , Flavonoïdes , Régulation de l'expression des gènes végétaux , Oxylipines , Protéines végétales , Anthocyanes/métabolisme , Cyclopentanes/métabolisme , Oxylipines/métabolisme , Flavonoïdes/métabolisme , Acétates/métabolisme , Acétates/pharmacologie , Protéines végétales/métabolisme , Protéines végétales/génétique , Facteurs de transcription à motif basique hélice-boucle-hélice/métabolisme , Facteurs de transcription à motif basique hélice-boucle-hélice/génétique , Feuilles de plante/métabolisme , Feuilles de plante/génétique , Facteur de croissance végétal/métabolismeRÉSUMÉ
Corynebacterium glutamicum, a microorganism classified as generally recognized as safe for use in the industrial production of food raw materials and additives, has encountered challenges in achieving widespread adoption and popularization as microbial cell factories. These obstacles arise from the intricate nature of manipulating metabolic flux through conventional methods, such as gene knockout and enzyme overexpression. To address this challenge, we developed a CRISPR/dCpf1-based bifunctional regulation system to bidirectionally regulate the expression of multiple genes in C. glutamicum. Specifically, through fusing various transcription factors to the C-terminus of dCpf1, the resulting dCpf1-SoxS exhibited both CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) capabilities in C. glutamicum by altering the binding sites of crRNAs. The bifunctional regulation system was used to fine-tune metabolic flux from shikimic acid (SA) and l-serine biosynthesis, resulting in 27-fold and 10-fold increases in SA and l-serine production, respectively, compared to the original strain. These findings highlight the potential of the CRISPR/dCpf1-based bifunctional regulation system in effectively enhancing the yield of target products in C. glutamicum.
Sujet(s)
Clustered regularly interspaced short palindromic repeats , Corynebacterium glutamicum , Corynebacterium glutamicum/génétique , Corynebacterium glutamicum/métabolisme , Sérine/métabolisme , Génie métabolique/méthodesRÉSUMÉ
Plasmodiophora brassicae (P. brassicae) is a soil-born pathogen worldwide and can infect most cruciferous plants, which causes great yield decline and economic losses. It is not well known how microbial diversity and community composition change during P. brassicae infecting plant roots. Here, we employed a resistant and a susceptible pakchoi cultivar with and without inoculation with P. brassicae to analyze bacterial and fungal diversity using 16S rRNA V3-V4 and ITS_V1 regions, respectively. 16S rRNA V3-V4 and ITS_V1 regions were amplified and sequenced separately. Results revealed that both fungal and bacterial diversity increased, and composition was changed in the rhizosphere soil of the susceptible pakchoi compared with the resistant cultivar. In the four groups of R_mock, S_mock, R_10d, and S_10d, the most relatively abundant bacterium and fungus was Proteobacteria, accounting for 61.92%, 58.17%, 48.64%, and 50.00%, respectively, and Ascomycota, accounting for 75.11%, 63.69%, 72.10%, and 90.31%, respectively. A total of 9488 and 11,914 bacteria were observed uniquely in the rhizosphere soil of resistant and susceptible pakchoi, respectively, while only 80 and 103 fungi were observed uniquely in the correlated soil. LefSe analysis showed that 107 and 49 differentially abundant taxa were observed in bacteria and fungi. Overall, we concluded that different pakchoi cultivars affect microbial diversity and community composition, and microorganisms prefer to gather around the rhizosphere of susceptible pakchoi. These findings provide a new insight into plant-microorganism interactions.
Sujet(s)
Microbiote , Mycobiome , Plasmodiophorida , Microbiote/génétique , Plasmodiophorida/génétique , ARN ribosomique 16S/génétique , Rhizosphère , Champignons/génétique , Microbiologie du sol , Bactéries/génétique , Sol , Racines de plante/microbiologieRÉSUMÉ
Downy mildew caused by the obligate parasite Hyaloperonospora brassicae is a devastating disease for Brassica species. Infection of Hyaloperonospora brassicae often leads to yellow spots on leaves, which significantly impacts quality and yield of pakchoi. In the present study, we conducted a comparative transcriptome between the resistant and susceptible pakchoi cultivars in response to Hyaloperonospora brassicae infection. A total of 1073 disease-resistance-related differentially expressed genes were identified using a Venn diagram. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that these genes were mainly involved in plant-pathogen interaction, plant hormone signal transduction, and other photosynthesis-related metabolic processes. Analysis of the phytohormone content revealed that salicylic acid increased significantly in the resistant material after inoculation with Hyaloperonospora brassicae, whereas the contents of jasmonic acid, abscisic acid, and 1-aminocyclopropane-1-carboxylic acid decreased. Exogenous salicylic acid treatment also significantly upregulated Hyaloperonospora brassicae-induced genes, which further confirmed a crucial role of salicylic acid during pakchoi defense against Hyaloperonospora brassicae. Based on these findings, we suggest that the salicylic-acid-mediated signal transduction contributes to the resistance of pakchoi to downy mildew, and PAL1, ICS1, NPR1, PR1, PR5, WRKY70, WRKY33, CML43, CNGC9, and CDPK15 were involved in this responsive process. Our findings evidently contribute to revealing the molecular mechanism of pakchoi defense against Hyaloperonospora brassicae.
Sujet(s)
Oomycetes , Peronospora , Humains , Transcriptome , Maladies des plantes/génétique , Oomycetes/génétique , Analyse de profil d'expression de gènes , Résistance à la maladie/génétique , Acide salicylique/pharmacologie , Acide salicylique/métabolisme , Prédisposition aux maladiesRÉSUMÉ
Hypocotyl length is a critical determinant for the efficiency of mechanical harvesting in pakchoi production, but the knowledge on the molecular regulation of hypocotyl growth is very limited. Here, we report a spontaneous mutant of pakchoi, lhy7.1, and identified its characteristics. We found that it has an elongated hypocotyl phenotype compared to the wild type caused by the longitudinal growth of hypocotyl cells. Different light quality treatments, transcriptome, and proteomic analyses were performed to reveal the molecular mechanisms of hypocotyl elongation. The data showed that the hypocotyl length of lhy7.1 was significantly longer than that of WT under red, blue, and white lights but there was no significant difference under dark conditions. Furthermore, we used transcriptome and label-free proteome analyses to investigate differences in gene and protein expression levels between lhy7.1 and WT. At the transcript level, 4568 differentially expressed genes (DEGs) were identified, which were mainly enriched in "plant hormone signal transduction", "photosynthesis", "photosynthesis-antenna proteins", and "carbon fixation in photosynthetic organisms" pathways. At the protein level, 1007 differentially expressed proteins (DEPs) were identified and were mainly enriched in photosynthesis-related pathways. The comprehensive transcriptome and proteome analyses revealed a regulatory network of hypocotyl elongation involving plant hormone signal transduction and photosynthesis-related pathways. The findings of this study help elucidate the regulatory mechanisms of hypocotyl elongation in lhy7.1.
Sujet(s)
Hypocotyle , Protéome , Protéome/génétique , Hypocotyle/génétique , Facteur de croissance végétal , Protéomique , TranscriptomeRÉSUMÉ
BACKGROUND: Maintaining osmotic equilibrium plays an important role in the survival of cold-water fishes. Heat stress has been proven to reduce the activity of Na+/K+-ATPase in the gill tissue, leading to destruction of the osmotic equilibrium. However, the mechanism of megatemperature affecting gill osmoregulation has not been fully elucidated. RESULTS: In this study, Siberian sturgeon (Acipenser baerii) was used to analyze histopathological change, plasma ion level, and transcriptome of gill tissue subjected to 20â, 24âand 28â. The results showed that ROS level and damage were increased in gill tissue with the increasing of heat stress temperature. Plasma Cl- level at 28â was distinctly lower than that at 20â and 24â, while no significant difference was found in Na+ and K+ ion levels among different groups. Transcriptome analysis displayed that osmoregulation-, DNA-repair- and apoptosis-related terms or pathways were enriched in GO and KEGG analysis. Moreover, 194 osmoregulation-related genes were identified. Amongst, the expression of genes limiting ion outflow, occluding (OCLN), and ion absorption, solute carrier family 4, member 2 (AE2) solute carrier family 9, member 3 (NHE3) chloride channel 2 (CLC-2) were increased, while Na+/K+-ATPase alpha (NKA-a) expression was decreased after heat stress. CONCLUSIONS: This study reveals for the first time that the effect of heat stress on damage and osmotic regulation in gill tissue of cold-water fishes. Heat stress increases the permeability of fish's gill tissue, and induces the gill tissue to keep ion balance through active ion absorption and passive ion outflow. Our study will contribute to research of global-warming-caused effects on cold-water fishes.
Sujet(s)
Analyse de profil d'expression de gènes , Branchies , Animaux , Branchies/métabolisme , Température , Eau/métabolisme , Sodium/métabolisme , Adenosine triphosphatases/métabolisme , Poissons/métabolismeRÉSUMÉ
BACKGROUND: The straw mushroom (Volvariella volvacea) is one of the important vegetables that is popular for its delicious taste. However, the straw mushroom is sensitive to low temperature, resulting in economic loss during transportation and storage. We obtained a novel straw mushroom strain, named VH3, via ultraviolet mutagenesis. RESULTS: Our study revealed that VH3 exhibited high cold resistance compared to an ordinary straw mushroom cultivar, V23. We found that the electrolyte leakages of VH3 were always significantly lower than that of V23 treated with 4 °C for 0 h, 2 h,4 h, 8 h, 16 h, and 24 h. Before cold treatment (0 h), there were no difference of MDA contents, SOD activities, and CAT activities between VH3 and V23. At the late stage (8 h, 26 h, and 24 h) of cold treatment, the MDA contents of VH3 were lower while both the SOD and CAT activities were higher than those of V23. To investigate the potential mechanisms of VH3 cold resistance, we performed transcriptome sequencing to detect the transcriptome profiling of VH3 and V23 after 0 h and 4 h cold treatment. Transcriptome sequencing revealed that 111 differentially expressed genes (DEG) between V23 (0 h) and VH3 (0 h) (V23-0_vs_VH3-0), consisting 50 up-regulated and 61 down-regulated DEGs. A total of 117 DEGs were obtained between V23 (4 h) and VH3(4 h) (V23-4_vs_VH3-4), containing 94 up-regulated and 23 down-regulated DEGs. Among these DEGs, VVO_00021 and VVO_00017 were up-regulated while VVO_00003, VVO_00004, VVO_00010, and VVO_00030 were down-regulated in V23-0_vs_VH3-0 and VH3-4_vs_V23-4. KEGG and GO analysis revealed that the 6 DEGs were annotated to pathways related to cold stress. Besides, the GA3 content was also decreased in VH3. CONCLUSIONS: Collectively, our study first revealed that the increased cold resistance of VH3 might be caused by the expression change of VVO_00003, VVO_00004, VVO_00017, VVO_00021, and VVO_00030, and decreased GA3.
Sujet(s)
Acclimatation/génétique , Agaricales/génétique , Basse température , Agaricales/physiologie , Agaricales/effets des radiations , Réponse au choc froid/génétique , Analyse de profil d'expression de gènes , Régulation de l'expression des gènes fongiques , Gènes fongiques/génétique , Mutagenèse/effets des radiations , Rayons ultravioletsRÉSUMÉ
The complete mitochondrial genome (mitogenome) of Eoscarta assimilis (Uhler, 1896) was sequenced in the current paper. The total length of the mitogenome is 17,231 bp and it consists of 37 genes including 22 transfer RNA (tRNAs), 13 protein-coding (PCGs) and 2 ribosomal RNA (rRNAs). The 13 PCGs initiated with the start codon ATN, but ND4 started with TTG. All of the PCGs ended with TAA, apart from COX3 which terminated by incomplete TAG. A ML tree based on sequences of 15 complete mitogenomes (13 Cercopidae and 2 outgroup) suggests that E. assimilis is more closely related to the genus Callitettix. The phylogenetic analysis supports the monophyly of the family Cercopidae and the genus Cosmoscarta, and the paraphyly of the subfamily Callitettixinae. This mitogenome information for E. assimilis could facilitate future evolutionary studies to related insects.
RÉSUMÉ
Clubroot is one of the most serious diseases affecting Brassicaceae plants worldwide. However, there is no effective control method for clubroot. Salicylic acid (SA) is a plant hormone that plays a critical role in plant defense. In our study, we found the disease severity of a clubroot-sensitive cultivar of pakchoi, Xinxiaqing, was reduced with 0.6mM exogenous SA after the infection of P. brassicae. To investigate the mechanism of SA-reduced disease severity against clubroot, then we analyzed the plant growth, alteration of antioxidant enzyme system, and related gene expression of Xinxiaqing. Results showed that the clubroot incidence rate and disease index were decreased after being treated with 0.6 mM exogenous SA. Furthermore, plant growth, reactive oxygen species (ROS) contents, and membrane lipid peroxidation were changed. The activities of antioxidant enzymes, including superoxide dismutase (SOD), ascorbic acid-peroxidase (APX), catalase (CAT), and glutathione reductase (GR), were increased. Additionally, the production rates of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2·-) were also inhibited. The expression levels of genes, encoding SOD, APX, CAT, and GR, were increased. By summering all results, we conclude that 0.6 mM SA contributes to the reduction of disease severity to clubroot by increasing the activities of antioxidant enzymes, abilities of osmotic regulation, and ROS scavenging to reduce the clubroot-induced damage in pakchoi.
Sujet(s)
Brassica/effets des médicaments et des substances chimiques , Maladies des plantes/prévention et contrôle , Plasmodiophorida/effets des médicaments et des substances chimiques , Acide salicylique/pharmacologie , Indice de gravité de la maladie , Anti-infectieux/pharmacologie , Antioxydants/métabolisme , Brassica/croissance et développement , Brassica/parasitologie , Catalase/métabolisme , Gènes de plante , Maladies des plantes/parasitologie , Plasmodiophorida/physiologie , Superoxide dismutase/métabolismeRÉSUMÉ
A series of hybrids of MEK inhibitor and nitric oxide donor have been designed and synthesized. Compound 18h [4-(3-((3-(2-fluoro-3-((N-methylsulfamoyl)amino)benzyl)-4-methyl-2-oxo-2H-chromen-7-yl)oxy) propoxy)-3-(phenylsulfonyl)-1,2,5-oxadiazole 2-oxide] was proven to be more potent than the clinical compound RO5126766 in MDA-MB-231 cells. Compound 18h can significantly reduce the levels of pMEK and pERK, induce cell apoptosis in MDA-MB-231 cells, and release NO in cells efficiently, suggesting that these hybrids, while displaying the properties of both MEK inhibitors and NO donors have a mechanism of action different from that of MEK inhibitors and NO donors. Thus, we are able to report a series of multitarget hybrids with better antitumor potency than a known MEK inhibitor and NO donor.
Sujet(s)
Antinéoplasiques/pharmacologie , Coumarines/pharmacologie , Mitogen-Activated Protein Kinase Kinases/antagonistes et inhibiteurs , Inhibiteurs de protéines kinases/pharmacologie , Antinéoplasiques/synthèse chimique , Antinéoplasiques/composition chimique , Apoptose/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Coumarines/synthèse chimique , Coumarines/composition chimique , Relation dose-effet des médicaments , Tests de criblage d'agents antitumoraux , Cellules HCT116 , Humains , Mitogen-Activated Protein Kinase Kinases/métabolisme , Simulation de docking moléculaire , Structure moléculaire , Monoxyde d'azote/antagonistes et inhibiteurs , Monoxyde d'azote/biosynthèse , Inhibiteurs de protéines kinases/synthèse chimique , Inhibiteurs de protéines kinases/composition chimique , Relation structure-activité , Cellules cancéreuses en cultureRÉSUMÉ
A series of tripeptidic proteasome inhibitors with furylketone as C-terminus were designed and synthesized. Biochemical evaluations against ß1, ß2 and ß5 subunits revealed that they acted selectively on ß5 subunit with IC50s against chymotrypsin-like (CT-L) activity in micromolar range. LC-MS/MS analysis of the ligand-20S proteasome mixture showed that the most potent compound 11m (IC50 = 0.18 µM) made no covalent modification on 20S proteasome. However, it was identified acting in a slowly reversible manner in wash-out assay and the reversibility was much lower than that of MG132, suggesting the possibility of these tripeptidic furylketones forming reversible covalent bonds with 20S proteasome. Several compounds were selected for anti-proliferative assay towards multiple cancer cell lines, and compound 11m displayed comparable potency to positive control (MG132) in all cell lines tested. Furthermore, the pharmacokinetic (PK) data in rats indicated 11m behaved similarly (Cmax, 2007 µg/L; AUC0-t, 680 µg/L·h; Vss, 0.66 L/kg) to the clinical used agent carfilzomib. All these data suggest 11m is a good lead compound to be developed to novel anti-tumor agent.
Sujet(s)
Antinéoplasiques/pharmacologie , Conception de médicament , Furanes/pharmacologie , Cétones/pharmacologie , Proteasome endopeptidase complex/métabolisme , Inhibiteurs du protéasome/pharmacologie , Animaux , Antinéoplasiques/synthèse chimique , Antinéoplasiques/composition chimique , Prolifération cellulaire/effets des médicaments et des substances chimiques , Relation dose-effet des médicaments , Tests de criblage d'agents antitumoraux , Furanes/synthèse chimique , Furanes/composition chimique , Cellules HCT116 , Humains , Cétones/synthèse chimique , Cétones/composition chimique , Mâle , Souris , Souris de lignée BALB C , Souris nude , Structure moléculaire , Tumeurs expérimentales/traitement médicamenteux , Tumeurs expérimentales/métabolisme , Tumeurs expérimentales/anatomopathologie , Inhibiteurs du protéasome/synthèse chimique , Inhibiteurs du protéasome/composition chimique , Rats , Rat Sprague-Dawley , Relation structure-activitéRÉSUMÉ
SnRK2 (sucrose non-fermenting 1-related protein kinases 2) protein kinase family involves in several abiotic stress response in plants. Although the regulatory mechanism of SnRK2 have been well demonstrated in Arabidopsis thaliana, their functions in rice are still largely unknown. Here, we report a SnRK2 family gene, OsSAPK8, can be strongly induced by abiotic stresses, including low-temperature, drought and high salt stress. The ossapk8 mutants showed lower tolerance to low-temperature, high salinity and drought stresses at the vegetative stages. Moreover, the expressions of marker genes for those abiotic stresses, e.g. OsDREB1, OsDREB2, OsNCED and OsRAB21, were downregulated in the ossapk8 mutants. We further confirmed that the yield was reduced in ossapk8 mutant lines compared with the wild type. Our results provide evidence for OsSAPK8 acting as a positive regulator in cold, drought, and salt stress responses.
Sujet(s)
Régulation de l'expression des gènes végétaux/physiologie , Oryza/physiologie , Protéines végétales/génétique , Protein kinases/génétique , Stress physiologique/génétique , Basse température , Sécheresses , Oryza/génétique , Protéines végétales/métabolisme , Protein kinases/métabolisme , Stress salin/génétiqueRÉSUMÉ
The biotrophic protist Plasmodiophora brassicae causes serious damage to Brassicaceae crops grown worldwide. However, the molecular mechanism of the Brassica rapa response remains has not been determined. Long noncoding RNA and mRNA expression profiles in response to Plasmodiophora brassicae infection were investigated using RNA-seq on the Chinese cabbage inbred line C22 infected with P. brassicae. Approximately 5,193 mRNAs were significantly differentially expressed, among which 1,345 were upregulated and 3,848 were downregulated. The GO enrichment analysis shows that most of these mRNAs are related to the defense response. Meanwhile, 114 significantly differentially expressed lncRNAs were identified, including 31 upregulated and 83 downregulated. Furthermore, a total of 2,344 interaction relationships were detected between 1,725 mRNAs and 103 lncRNAs with a correlation coefficient greater than 0.8. We also found 15 P. brassicaerelated mRNAs and 16 lncRNA interactions within the correlation network. The functional annotation showed that 15 mRNAs belong to defense response proteins (66.67%), protein phosphorylation (13.33%), root hair cell differentiation (13.33%) and regulation of salicylic acid biosynthetic process (6.67%). KEGG annotation showed that the vast majority of these genes are involved in the biosynthesis of secondary metabolism pathways and plant-pathogen interactions. These results provide a new perspective on lncRNA-mRNA network function and help to elucidate the molecular mechanism of P. brassicae infection.
Sujet(s)
Brassica/microbiologie , Maladies des plantes/génétique , Plasmodiophorida/physiologie , ARN long non codant/métabolisme , ARN messager/métabolisme , ARN des plantes/métabolisme , Brassica/génétique , Analyse de profil d'expression de gènes , Régulation de l'expression des gènes végétaux , Maladies des plantes/immunologie , Maladies des plantes/microbiologie , Analyse de séquence d'ARNRÉSUMÉ
We report in this work the discovery of novel allosteric MEK inhibitors by pharmacophore modeling and virtual screening. Two out of 13 virtual hit compounds were identified as MEK kinase inhibitors using a MEK1 binding assay. Structural derivations on the hit compound M100 (IC50â¯=â¯27.2⯱â¯4.5⯵M in RAF-MEK cascading assay) by substituent transformation and bioisosterism replacement have led to the synthesis of a small library of carbazoles. The enzymatic studies revealed the preliminary structure-activity relationships and the derivative 22k (IC50â¯=â¯12.8⯱â¯0.5⯵M) showed the most potent inhibitory effect against Raf-MEK cascading. Compound 7 was discovered as toxic as M100 to tumor cells whereas safer to HEK293â¯cells (IC50â¯>â¯100⯵M) than M100 (IC50â¯=â¯8.9⯱â¯2.0⯵M). It suggests that carbazole is a good scaffold for the design of novel MEK inhibitors for therapeutic uses. More importantly, the developed pharmacophore model can serve as a reliable criterion in novel MEK inhibitor discovery.
Sujet(s)
Antinéoplasiques/pharmacologie , Carbazoles/pharmacologie , Découverte de médicament , MAP Kinase Kinase Kinases/antagonistes et inhibiteurs , Inhibiteurs de protéines kinases/pharmacologie , Régulation allostérique/effets des médicaments et des substances chimiques , Antinéoplasiques/synthèse chimique , Antinéoplasiques/composition chimique , Carbazoles/synthèse chimique , Carbazoles/composition chimique , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Relation dose-effet des médicaments , Évaluation préclinique de médicament , Tests de criblage d'agents antitumoraux , Cellules HEK293 , Humains , MAP Kinase Kinase Kinases/métabolisme , Modèles moléculaires , Structure moléculaire , Inhibiteurs de protéines kinases/synthèse chimique , Inhibiteurs de protéines kinases/composition chimique , Relation structure-activitéRÉSUMÉ
In this report, we designed and synthesized a series of cobalt(II)-Schiff base complexes (CoSBC) with competent MEK1 (mitogen-activated protein kinase kinase-1) inhibitory activity. Based on our previous report, the CoSBC exhibited high binding affinity with MEK1 protein. To further explore metal complexes as MEK1 inhibitors, a series of transition metals and ligands were employed to build a library of various metal Schiff base complexes. The MEK inhibition assays revealed that only CoSBC exhibited obvious inhibitory activity, complex 2b showed the best inhibition both in BRaf (B-rapidly accelerated fibrosarcoma)/MEK1 and MEK1/ERK2 (extracellular signal-regulated kinases-2) cascading (IC50 is 1.988⯱â¯0.14⯵M and 1.589⯱â¯0.054⯵M respectively). In addition, homogeneous time-resolved fluorescence test method was used to prove that CoSBC as ATP-noncompetitive MEK1 inhibitor. MEK kinase selectivity assay indicated that CoSBC can selectively inhibit MEK1/2 kinases rather than other MAPKs (mitogen-activated protein kinases) family kinases. Moreover, the interaction mode of 2b with MEK1 protein has been demonstrated by computer aided drug design.
Sujet(s)
Complexes de coordination/composition chimique , MAP Kinase Kinase 1/antagonistes et inhibiteurs , Inhibiteurs de protéines kinases/composition chimique , Bases de Schiff/composition chimique , Sites de fixation , Complexes de coordination/métabolisme , Cuivre/composition chimique , Conception de médicament , Humains , MAP Kinase Kinase 1/métabolisme , Simulation de docking moléculaire , Structure moléculaire , Liaison aux protéines , Inhibiteurs de protéines kinases/métabolisme , Bases de Schiff/métabolisme , Relation structure-activitéRÉSUMÉ
Auxin is an important plant hormone that is essential for growth and development due to its effects on organogenesis, morphogenesis, tropisms, and apical dominance. The functional diversity of auxin highlights the importance of its biosynthesis, transport, and associated responses. In this study, we show that a NAC transcription factor, ANAC092 (also named AtNAC2 and ORESARA1), known to positively regulate leaf senescence and contribute to abiotic stress responses, also affects primary root development. Plants overexpressing ANAC092 had altered root meristem lengths and shorter primary roots compared with the wild-type control. Additionally, expression of the proANAC092::GUS was strongly induced by indole-3-acetic acid. Quantitative real-time RT-PCR (qRT-PCR) analysis revealed that the YUCCA2, PIN, and ARF expression levels were downregulated in ANAC092-overexpressing plants. Moreover, yeast one-hybrid and chromatin immunoprecipitation assays confirmed that ANAC092 binds to the promoters of AUXIN RESPONSE FACTOR 8 (ARF8) and PIN-FORMED 4 (PIN4). Furthermore, a dual-luciferase assay indicated that ANAC092 decreases ARF8 and PIN4 promoter activities. We also applied a CRISPR/Cas9 system to mutate ANAC092. The roots of three of the analyzed mutants were longer than normal. Collectively, our findings indicate that ANAC092 negatively affects root development by controlling the auxin pathway.
Sujet(s)
Protéines d'Arabidopsis/métabolisme , Arabidopsis/métabolisme , Arabidopsis/génétique , Protéines d'Arabidopsis/génétique , Clustered regularly interspaced short palindromic repeats , Régulation de l'expression des gènes végétaux/génétique , Régulation de l'expression des gènes végétaux/physiologie , Acides indolacétiques/métabolisme , Méristème , Racines de plante/génétique , Racines de plante/métabolisme , Régions promotrices (génétique)/génétiqueRÉSUMÉ
Plant development and adaptation to environmental stresses are intimately associated with programmed cell death (PCD). Although some of the mechanisms regulating PCD [e.g., accumulation of reactive oxygen species (ROS)] are common among responses to different abiotic stresses, the pathways mediating salt-induced PCD remain largely uncharacterized. Here we report that overexpression of OsNAC2, which encodes a plant-specific transcription factor, promotes salt-induced cell death accompanied by the loss of plasma membrane integrity, nuclear DNA fragmentation, and changes to caspase-like activity. In OsNAC2-knockdown lines, cell death was markedly decreased in response to severe salt stress. Additionally, OsNAC2 expression was enhanced in rice seedlings exposed to a high NaCl concentration. Moreover, the results of quantitative real-time PCR, chromatin immunoprecipitation, dual-luciferase, and yeast one-hybrid assays indicated that OsNAC2 targeted genes that encoded an ROS scavenger (OsCOX11) and a caspase-like protease (OsAP37). Furthermore, K+ -efflux channels (OsGORK and OsSKOR) were clearly activated by OsNAC2. Overall, our results suggested that OsNAC2 accelerates NaCl-induced PCD and provide new insights into the mechanisms that affect ROS accumulation, plant caspase-like activity, and K+ efflux.
Sujet(s)
Mort cellulaire/effets des médicaments et des substances chimiques , Oryza/génétique , Protéines végétales/physiologie , Facteurs de transcription/physiologie , Membrane cellulaire/métabolisme , Immunoprécipitation de la chromatine , Piégeurs de radicaux libres/métabolisme , Régulation de l'expression des gènes végétaux/génétique , Techniques de knock-down de gènes , Gènes de plante/génétique , Gènes de plante/physiologie , Oryza/métabolisme , Oryza/physiologie , Peptide hydrolases/métabolisme , Protéines végétales/génétique , Protéines végétales/métabolisme , Végétaux génétiquement modifiés , Régions promotrices (génétique)/génétique , Espèces réactives de l'oxygène/métabolisme , Réaction de polymérisation en chaine en temps réel , Stress salin , Facteurs de transcription/génétique , Facteurs de transcription/métabolisme , Techniques de double hybrideRÉSUMÉ
It is well known that abscisic acid (ABA)-induced leaf senescence and premature leaf senescence negatively affect the yield of rice (Oryza sativa). However, the molecular mechanism underlying this relationship, especially the upstream transcriptional network that modulates ABA level during leaf senescence, remains largely unknown. Here, we demonstrate a rice NAC transcription factor, OsNAC2, that participates in ABA-induced leaf senescence. Overexpression of OsNAC2 dramatically accelerated leaf senescence, whereas its knockdown lines showed a delay in leaf senescence. Chromatin immunoprecipitation-quantitative PCR, dual-luciferase, and yeast one-hybrid assays demonstrated that OsNAC2 directly activates expression of chlorophyll degradation genes, OsSGR and OsNYC3 Moreover, ectopic expression of OsNAC2 leads to an increase in ABA levels via directly up-regulating expression of ABA biosynthetic genes (OsNCED3 and OsZEP1) as well as down-regulating the ABA catabolic gene (OsABA8ox1). Interestingly, OsNAC2 is upregulated by a lower level of ABA but downregulated by a higher level of ABA, indicating a feedback repression of OsNAC2 by ABA. Additionally, reduced OsNAC2 expression leads to about 10% increase in the grain yield of RNAi lines. The novel ABA-NAC-SAGs regulatory module might provide a new insight into the molecular action of ABA to enhance leaf senescence and elucidates the transcriptional network of ABA production during leaf senescence in rice.
Sujet(s)
Acide abscissique/biosynthèse , Oryza/croissance et développement , Oryza/métabolisme , Feuilles de plante/croissance et développement , Protéines végétales/métabolisme , Facteurs de transcription/métabolisme , Acide abscissique/pharmacologie , Chlorophylle/métabolisme , Régulation négative/génétique , Régulation de l'expression des gènes végétaux , Gènes de plante , Modèles biologiques , Mutation/génétique , Oryza/génétique , Phénotype , Feuilles de plante/génétique , Végétaux génétiquement modifiés , Régions promotrices (génétique)/génétique , Liaison aux protéines/effets des médicaments et des substances chimiques , Caractère quantitatif héréditaire , Interférence par ARN , Nicotiana/génétique , Régulation positive/génétiqueRÉSUMÉ
Plants can perceive environmental changes and respond to external stressors. Here, we show that OsNAC2, a member of the NAC transcription factor family, was strongly induced by ABA and osmotic stressors such as drought and high salt. With reduced yields under drought conditions at the flowering stage, OsNAC2 overexpression lines had lower resistance to high salt and drought conditions. RNAi plants showed enhanced tolerance to high salinity and drought stress at both the vegetative and flowering stages. Furthermore, RNAi plants had improved yields after drought stress. A microarray assay indicated that many ABA-dependent stress-related genes were down-regulated in OsNAC2 overexpression lines. We further confirmed that OsNAC2 directly binds the promoters of LATE EMBRYOGENESIS ABUNDANT 3 (OsLEA3) and Stress-Activated Protein Kinases 1 (OsSAPK1), two marker genes in the abiotic stress and ABA response pathways, respectively. Our results suggest that in rice OsNAC2 regulates both abiotic stress responses and ABA-mediated responses, and acts at the junction between the ABA and abiotic stress pathways.
RÉSUMÉ
This corrects the article DOI: 10.1038/srep40641.