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1.
BMC Genomics ; 25(1): 320, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38549066

RESUMO

BACKGROUND: Stigma exsertion is an essential agricultural trait that can promote cross-pollination to improve hybrid seed production efficiency. However, the molecular mechanism controlling stigma exsertion remains unknown. RESULTS: In this study, the Nicotiana tabacum cv. K326 and its two homonuclear-heteroplasmic lines, MSK326 (male-sterile) and MSK326SE (male-sterile and stigma exserted), were used to investigate the mechanism of tobacco stigma exsertion. A comparison of the flowers between the three lines showed that the stigma exsertion of MSK326SE was mainly due to corolla shortening. Therefore, the corollas of the three lines were sampled and presented for RNA-seq analysis, which found 338 candidate genes that may cause corolla shortening. These genes were equally expressed in K326 and MSK326, but differentially expressed in MSK326SE. Among these 338 genes, 15 were involved in hormone synthesis or signal transduction pathways. Consistently, the content of auxin, dihydrozeatin, gibberellin, and jasmonic acid was significantly decreased in the MSK326SE corolla, whereas abscisic acid levels were significantly increased. Additionally, seven genes involved in cell division, cell cycle, or cell expansion were identified. Protein-protein interaction network analysis identified 45 nodes and 79 protein interactions, and the largest module contained 20 nodes and 52 protein interactions, mainly involved in the hormone signal transduction and pathogen defensive pathways. Furthermore, a putative hub gene coding a serine/threonine-protein kinase was identified for the network. CONCLUSIONS: Our results suggest that hormones may play a key role in regulating tobacco stigma exsertion induced by corolla shortening.


Assuntos
Nicotiana , Transcriptoma , Nicotiana/genética , Revelação , Ácidos Indolacéticos/metabolismo , Hormônios/metabolismo , Flores/metabolismo
2.
BMC Plant Biol ; 24(1): 326, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658809

RESUMO

BACKGROUND: Salt stress severely inhibits plant growth, and the WRKY family transcription factors play important roles in salt stress resistance. In this study, we aimed to characterize the role of tobacco (Nicotiana tabacum) NtWRKY65 transcription factor gene in salinity tolerance. RESULTS: This study characterized the role of tobacco (Nicotiana tabacum) NtWRKY65 transcription factor gene in salinity tolerance using four NtWRKY65 overexpression lines. NtWRKY65 is localized to the nucleus, has transactivation activity, and is upregulated by NaCl treatment. Salinity treatment resulted in the overexpressing transgenic tobacco lines generating significantly longer roots, with larger leaf area, higher fresh weight, and greater chlorophyll content than those of wild type (WT) plants. Moreover, the overexpressing lines showed elevated antioxidant enzyme activity, reduced malondialdehyde content, and leaf electrolyte leakage. In addition, the Na+ content significantly decreased, and the K+/Na+ ratio was increased in the NtWRKY65 overexpression lines compared to those in the WT. These results suggest that NtWRKY65 overexpression enhances salinity tolerance in transgenic plants. RNA-Seq analysis of the NtWRKY65 overexpressing and WT plants revealed that NtWRKY65 might regulate the expression of genes involved in the salt stress response, including cell wall component metabolism, osmotic stress response, cellular oxidant detoxification, protein phosphorylation, and the auxin signaling pathway. These results were consistent with the morphological and physiological data. These findings indicate that NtWRKY65 overexpression confers enhanced salinity tolerance. CONCLUSIONS: Our results indicated that NtWRKY65 is a critical regulator of salinity tolerance in tobacco plants.


Assuntos
Regulação da Expressão Gênica de Plantas , Nicotiana , Proteínas de Plantas , Plantas Geneticamente Modificadas , Tolerância ao Sal , Fatores de Transcrição , Nicotiana/genética , Nicotiana/fisiologia , Tolerância ao Sal/genética , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
Blood ; 137(26): 3616-3628, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33763699

RESUMO

Continuous lenalidomide-dexamethasone (Rd)-based regimens are among the standards of care in transplant-ineligible newly diagnosed multiple myeloma (NDMM) patients. The oral proteasome inhibitor ixazomib is suitable for continuous dosing, with predictable, manageable toxicities. In the double-blind, placebo-controlled TOURMALINE-MM2 trial, transplant-ineligible NDMM patients were randomized to ixazomib 4 mg (n = 351) or placebo (n = 354) plus Rd. After 18 cycles, dexamethasone was discontinued and treatment was continued using reduced-dose ixazomib (3 mg) and lenalidomide (10 mg) until progression/toxicity. The primary endpoint was progression-free survival (PFS). Median PFS was 35.3 vs 21.8 months with ixazomib-Rd vs placebo-Rd, respectively (hazard ratio [HR], 0.830; 95% confidence interval, 0.676-1.018; P = .073; median follow-up, 53.3 and 55.8 months). Complete (26% vs 14%; odds ratio [OR], 2.10; P < .001) and ≥ very good partial response (63% vs 48%; OR, 1.87; P < .001) rates were higher with ixazomib-Rd vs placebo-Rd. In a prespecified high-risk cytogenetics subgroup, median PFS was 23.8 vs 18.0 months (HR, 0.690; P = .019). Overall, treatment-emergent adverse events (TEAEs) were mostly grade 1/2. With ixazomib-Rd vs placebo-Rd, 88% vs 81% of patients experienced grade ≥3 TEAEs, 66% vs 62% serious TEAEs, and 35% vs 27% TEAEs resulting in regimen discontinuation; 8% vs 6% died on study. Addition of ixazomib to Rd was tolerable with no new safety signals and led to a clinically meaningful PFS benefit of 13.5 months. Ixazomib-Rd is a feasible option for certain patients who can benefit from an all-oral triplet combination. This trial was registered at www.clinicaltrials.gov as #NCT01850524.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Mieloma Múltiplo , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Compostos de Boro/administração & dosagem , Compostos de Boro/efeitos adversos , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Intervalo Livre de Doença , Método Duplo-Cego , Feminino , Seguimentos , Glicina/administração & dosagem , Glicina/efeitos adversos , Glicina/análogos & derivados , Humanos , Lenalidomida/administração & dosagem , Lenalidomida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/mortalidade , Taxa de Sobrevida
4.
BMC Plant Biol ; 21(1): 32, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413114

RESUMO

BACKGROUND: Carotenoids play important roles in photosynthesis, hormone signaling, and secondary metabolism. Phytoene synthase (PSY) catalyzes the first step of the carotenoid biosynthetic pathway. In this study, we aimed to characterize the PSY genes in tobacco and analyze their function. RESULTS: In this study, we identified three groups of PSY genes, namely PSY1, PSY2, and PSY3, in four Nicotiana species; phylogenetic analysis indicated that these genes shared a high similarity with those in tomato but not with those in monocots such as rice and maize. The expression levels of PSY1 and PSY2 were observed to be highest in leaves compared to other tissues, and they could be elevated by treatment with certain phytohormones and exposure to strong light. No PSY3 expression was detected under these conditions. We constructed virus-induced PSY1 and PSY2 silencing in tobacco and found that the newly emerged leaves in these plants were characterized by severe bleaching and markedly decreased carotenoid and chlorophyll content. Thylakoid membrane protein complex levels in the gene-silenced plants were also less than those in the control plants. The chlorophyll fluorescence parameters such as Fv/Fm, ΦPSII, qP, and NPQ, which reflect photosynthetic system activities, of the gene-silenced plants were also significantly decreased. We further performed RNA-Seq and metabonomics analysis between gene-silenced tobacco and control plants. RNA-Seq results showed that abiotic stress, isoprenoid compounds, and amino acid catabolic processes were upregulated, whereas the biosynthesis of cell wall components was downregulated. Metabolic analysis results were consistent with the RNA-Seq. We also found the downstream genes in carotenoid biosynthesis pathways were upregulated, and putative transcription factors that regulate carotenoid biosynthesis were identified. CONCLUSIONS: Our results suggest that PSY can regulate carotenoid contents not only by controlling the first biosynthesis step but also by exerting effects on the expression of downstream genes, which would thereby affect photosynthetic activity. Meanwhile, PSY may affect other processes such as amino acid catabolism and cell wall organization. The information we report here may aid further research on PSY genes and carotenoid biosynthesis.


Assuntos
Carotenoides/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Geranil-Geranildifosfato Geranil-Geraniltransferase/genética , Geranil-Geranildifosfato Geranil-Geraniltransferase/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Variação Genética , Genótipo , Filogenia
5.
Invest New Drugs ; 36(3): 407-415, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-28932928

RESUMO

This two-part, phase I study evaluated the mass balance, excretion, pharmacokinetics (PK), and safety of ixazomib in patients with advanced solid tumors. In Part A of the study, patients received a single 4.1 mg oral solution dose of [14C]-ixazomib containing ~500 nCi total radioactivity (TRA), followed by non-radiolabeled ixazomib (4 mg capsule) on days 14 and 21 of the 35-day PK cycle. Patients were confined to the clinic for the first 168 h post dose and returned for 24 h overnight clinic visits on days 14, 21, 28, and 35. Blood, urine, and fecal samples were collected during Part A to assess the mass balance (by accelerator mass spectrometry), excretion, and PK of ixazomib. During Part B of the study, patients received non-radiolabeled ixazomib (4 mg capsules) on days 1, 8, and 15 of 28-day cycles. After oral administration, ixazomib was rapidly absorbed with a median plasma Tmax of 0.5 h and represented 70% of total drug-related material in plasma. The mean total recovery of administered TRA was 83.9%; 62.1% in urine and 21.8% in feces. Only 3.23% of the administered dose was recovered in urine as unchanged drug up to 168 h post dose, suggesting that most of the TRA in urine was attributable to metabolites. All patients experienced a treatment-emergent adverse event, which most commonly involved the gastrointestinal system. These findings suggest that ixazomib is extensively metabolized, with urine representing the predominant route of excretion of drug-related material.Trial ID: ClinicalTrials.gov # NCT01953783.


Assuntos
Compostos de Boro/farmacocinética , Compostos de Boro/uso terapêutico , Radioisótopos de Carbono/farmacocinética , Glicina/análogos & derivados , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Inibidores de Proteassoma/farmacocinética , Inibidores de Proteassoma/uso terapêutico , Administração Oral , Idoso , Compostos de Boro/administração & dosagem , Compostos de Boro/sangue , Radioisótopos de Carbono/administração & dosagem , Radioisótopos de Carbono/sangue , Fezes , Feminino , Glicina/administração & dosagem , Glicina/sangue , Glicina/farmacocinética , Glicina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Inibidores de Proteassoma/administração & dosagem , Inibidores de Proteassoma/sangue , Radioatividade , Resultado do Tratamento , Urina
6.
Br J Haematol ; 174(5): 748-59, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27196567

RESUMO

Renal impairment (RI) is a major complication of multiple myeloma (MM). This study aimed to characterize the single-dose pharmacokinetics (PK) of the oral proteasome inhibitor, ixazomib, in cancer patients with normal renal function [creatinine clearance (CrCl) ≥90 ml/min; n = 20), severe RI (CrCl <30 ml/min; n = 14), or end-stage renal disease requiring haemodialysis (ESRD; n = 7). PK and adverse events (AEs) were assessed after a single 3 mg dose of ixazomib. Ixazomib was highly bound to plasma proteins (~99%) in all renal function groups. Unbound and total systemic exposures of ixazomib were 38% and 39% higher, respectively, in severe RI/ESRD patients versus patients with normal renal function. Total ixazomib concentrations were similar in pre- and post-dialyser samples collected from ESRD patients; therefore, ixazomib can be administered without regard to haemodialysis timing. Except for anaemia, the incidence of the most common AEs was generally similar across groups, but grade 3 and 4 AEs were more frequent in the severe RI/ESRD groups versus the normal group (79%/57% vs. 45%), as were serious AEs (43%/43% vs. 15%). The PK and safety results support a reduced ixazomib dose of 3 mg in patients with severe RI/ESRD.


Assuntos
Compostos de Boro/farmacocinética , Glicina/análogos & derivados , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteases/farmacocinética , Insuficiência Renal/terapia , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/etiologia , Proteínas Sanguíneas/metabolismo , Compostos de Boro/administração & dosagem , Compostos de Boro/metabolismo , Cálculos da Dosagem de Medicamento , Feminino , Glicina/administração & dosagem , Glicina/metabolismo , Glicina/farmacocinética , Humanos , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/complicações , Inibidores de Proteases/administração & dosagem , Diálise Renal
7.
Front Sports Act Living ; 6: 1383665, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725472

RESUMO

Introduction: In being an important lifestyle factor, the physical activity influences people's health status, including life expectancy. Specific forms of physical activity are exercises related to hand-to-hand combat in the broadest sense, often overlapping and containing similar elements associated with combat sports (for Western culture) and martial arts (for Far Eastern culture). There are many types of forms of practising hand-to-hand combat exercises, which can be seen as opposing or in some ways complementary, e.g.: "traditional"-e.g., karate or kung fu, practised for hundreds or even thousands of years, usually adhering to moral codes of conduct, and drawing ideas from philosophy, religion vs. "modern"-e.g., American pro wrestling or mixed martial arts-MMA, suggesting a combination of various traditional forms of martial arts. In terms of shaping a healthy lifestyle with mental health elements based on the implementation of hand-to-hand combat exercises, an analysis of these fundamental insights into physical activity is warranted. This study aims to investigate the development direction of the hand-to-hand exercises in Western culture, opposing the "traditional" and "modern" forms. Discussion: In this study, INNOAGON theory responds to the overuse of the term "science of martial arts". It is currently being used to promote extreme aggression and violence as an acceptable means of achieving success, and this model is expressively permeating other spheres of social interaction. In INNOAGON's understanding, hand-to-hand combat should be associated with the ancient thought of "doing good" (ancient Greece) or "wisdom" (Far Eastern cultures) including aesthetic and philosophical aspects. This links to numerous psychosocial benefits, self-esteem, discipline, body-mind coordination including breath control and relaxation, respect for others. The modern form of hand-to-hand combat, framed in these discussions as MMA or American pro wrestling, historically refers to the gladiatorial fights held during the Roman Games. The holding of fights in so-called "cages" refers to the arena in which Roman slave fights were held, and the athletes performing there are often referred to as modern-day "gladiators". Conclusion: Proper education, including education in the area of physical culture, leading to the development of a society turned towards values broader than just fun or self-satisfaction should be the basis for the development of the next generations. It actually remains to decide which path of social change we will choose: in the case of INNOAGON a positive one, and in the case of modern gladiator a destructive one. Only a proper education combined with a broad programme of social role modelling, social facilitation-the foundations of which are laid by INNOAGON-including promotion on the Internet and social media can provide the right counterbalance to the pathology increasingly penetrating our lives, leading to the promotion of aggression and threats to physical and mental health.

8.
Sci Total Environ ; 930: 172695, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38663613

RESUMO

General control non-derepressible-2 (GCN2) is widely expressed in eukaryotes and responds to biotic and abiotic stressors. However, the precise function and mechanism of action of GCN2 in response to cadmium (Cd) stress in Nicotiana tabacum L. (tobacco) remains unclear. We investigated the role of NtGCN2 in Cd tolerance and explored the mechanism by which NtGCN2 responds to Cd stress in tobacco by exposing NtGCN2 transgenic tobacco lines to different concentrations of CdCl2. NtGCN2 was activated under 50 µmol·L-1 CdCl2 stress and enhanced the Cd tolerance and photosynthetic capacities of tobacco by increasing chlorophyll content and antioxidant capacity by upregulating NtSOD, NtPOD, and NtCAT expression and corresponding enzyme activities and decreasing malondialdehyde and O2·- contents. NtGCN2 enhanced the osmoregulatory capacity of tobacco by elevating proline (Pro) and soluble sugar contents and maintaining low levels of relative conductivity. Finally, NtGCN2 enhanced Cd tolerance in tobacco by reducing Cd uptake and translocation, promoting Cd efflux, and regulating Cd subcellular distribution. In conclusion, NtGCN2 improves the tolerance of tobacco to Cd through a series of mechanisms, namely, increasing antioxidant, photosynthetic, and osmoregulation capacities and regulating Cd uptake, translocation, efflux, and subcellular distribution. This study provides a scientific basis for further exploration of the role of NtGCN2 in plant responses to Cd stress and enhancement of the Cd stress signaling network in tobacco.


Assuntos
Cádmio , Resistência a Medicamentos , Nicotiana , Proteínas de Plantas , Cádmio/toxicidade , Cádmio/metabolismo , Nicotiana/fisiologia , Nicotiana/metabolismo , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Clorofila/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/metabolismo , Resistência a Medicamentos/genética , Oxirredutases/genética , Oxirredutases/metabolismo , Ativação Enzimática/genética , Osmorregulação/genética , Espaço Intracelular/metabolismo
9.
Sci Total Environ ; 933: 173065, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38723969

RESUMO

Arbuscular mycorrhizal fungi (AMF) increase the ability of plants to obtain nitrogen (N) from the soil, and thus can affect emissions of nitrous oxide (N2O), a long-lived potent greenhouse gas. However, the mechanisms underlying the effects of AMF on N2O emissions are still poorly understood, particularly in agroecosystems with different forms of N fertilizer inputs. Utilizing a mesocosm experiment in field, we examined the effects of AMF on N2O emissions via their influence on maize root traits and denitrifying microorganisms under ammonia and nitrate fertilizer input using 15N isotope tracer. Here we show that the presence of AMF alone or both maize roots and AMF increased maize biomass and their 15N uptake, root length, root surface area, and root volume, but led to a reduction in N2O emissions under both N input forms. Random forest model showed that root length and surface area were the most important predictors of N2O emissions. Additionally, the presence of AMF reduced the (nirK + nirS)/nosZ ratio by increasing the relative abundance of nirS-Bradyrhizobium and Rubrivivax with ammonia input, but reducing nosZ-Azospirillum, Cupriavidus and Rhodopseudomonas under both fertilizer input. Further, N2O emissions were significantly and positively correlated with the nosZ-type Azospirillum, Cupriavidus and Rhodopseudomonas, but negatively correlated with the nirS-type Bradyrhizobium and Rubrivivax. These results indicate that AMF reduce N2O emissions by increasing root length to explore N nutrients and altering the community composition of denitrifiers, suggesting that effective management of N fertilizer forms interacting with the rhizosphere microbiome may help mitigate N2O emissions under future N input scenarios.


Assuntos
Desnitrificação , Micorrizas , Óxido Nitroso , Raízes de Plantas , Microbiologia do Solo , Solo , Micorrizas/fisiologia , Óxido Nitroso/análise , Raízes de Plantas/microbiologia , Solo/química , Zea mays , Fertilizantes , Poluentes Atmosféricos/análise
10.
J Hazard Mater ; 465: 133462, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38215520

RESUMO

The DELAY OF GERMINATION1-LIKE (DOGL) genes play an essential role in diverse biological processes in plants. However, their exact involvement in the response to cadmium (Cd) stress via the ABA pathway remains unclear. Here, we focused on NtDOGL4, a tobacco DOGL gene whose expression is highly induced upon exposure to Cd. Overexpression of NtDOGL4 in tobacco resulted in elevated endogenous ABA levels, reduced Cd accumulation, and increased tolerance to Cd. Moreover, NtDOGL4 overexpression led to decreased accumulation of reactive oxygen species (ROS) and improved ROS scavenging capacity under Cd stress. Further analyses revealed the direct binding of the transcription factor ABSCISIC ACID-INSENSITIVE 5 (ABI5) to the NtDOGL4 promoter, positively regulating its expression in tobacco. Notably, NtDOGL4 overexpression promoted suberin formation and deposition, while suppressing the expression of Cd transporter genes in tobacco roots, as evidenced by histochemical staining, suberin fraction determination, and qRT-PCR assays. Collectively, our results demonstrate that NtDOGL4 overexpression reduces Cd accumulation, thereby improving Cd stress tolerance through the modulation of antioxidant system, transcription of Cd transporters, and suberin deposition. Notably, the NtABI5-NtDOGL4 module functions as a positive regulator in tobacco's Cd tolerance, underscoring its potential as a molecular target for developing low-Cd crops to ensure environmental safety.


Assuntos
Ácido Abscísico , Cádmio , Espécies Reativas de Oxigênio/metabolismo , Cádmio/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/metabolismo
11.
Plant Sci ; 326: 111528, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36332767

RESUMO

Stigma exsertion is an essential outcrossing trait that can improve hybrid seed production efficiencies. In this study, the morphological and physiological mechanisms of cytoplasmic inheritance stigma exsertion trait expression in a tobacco line (MSK326SE) which generated from a stigma exsertion tobacco mutant through continuous backcross were investigated. Compared with its homonuclear-heteroplasmic lines (MSK326 and K326 with inserted stigmas), the exserted stigma phenotype of MSK326SE was mainly caused by corolla shortening, while was stable under different environmental temperature. The different responses of mainly endogenous hormones and expression of cell division- and expansion-related genes caused the differences in cell division and expansion in different flower organs, which further determined the lengths of the corolla. Furthermore, the significant decrease of MSK326SE corolla epidermal cell size caused corolla shortening and finally resulting in stigma exsertion. Exogenous JA could shorten the corolla and more effective increased stigma exsertion degree of MSK326SE, suggesting a potential relationship between stigma exsertion and high JA levels during early bud development. The hybrid seed production efficiency could be improved in tobacco. Our results provide a basis for elucidating the cytoplasmic inheritance stigma exsertion trait expression in tobacco while helping to improve hybrid seed production efficiency.


Assuntos
Flores , Nicotiana , Nicotiana/genética , Flores/genética , Fenótipo , Sementes/genética , Herança Extracromossômica
12.
Microbiol Res ; 270: 127349, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36870194

RESUMO

Some agronomic practices not only promote the development of crop roots and increase overall plant performance but also affect colonisation by rhizosphere microorganisms. However, the composition and temporal dynamics of the tobacco rhizosphere microbiota under different root-promoting practices are poorly understood. Here, we characterised the tobacco rhizosphere microbiota at the knee-high, vigorous growing, and maturity stages under the application of potassium fulvic acid (PFA), γ-Polyglutamic acid (PGA), soymilk root irrigation (SRI), and conventional fertilization (CK) and its correlation with root characteristics and soil nutrients. The results showed that three root-promoting practices notably improved the dry and fresh root weights. Total nitrogen and phosphorus, available phosphorus and potassium, and organic matter contents in the rhizosphere markedly increased at the vigorous growing stage. The rhizosphere microbiota was changed through root-promoting practices. However, with tobacco growth, the change of rhizosphere microbiota showed a pattern of slow first and then fast and the microbiota of different treatments gradually approached. SRI reduced plant-pathogenic fungi but increased chemoheterotrophic and phototrophic bacteria, and arbuscular mycorrhizal fungi. PFA and PGA markedly increased arbuscular mycorrhizal and ectomycorrhizal fungi at the knee-high stage, which benefitted tobacco nutrient absorption. The correlation between rhizosphere microorganisms and environmental factors varied at different growth stages. Notably, the rhizosphere microbiota was more sensitive to environmental factors at the vigorous growing stage, and the interactions were more complex than in other stages. Furthermore, a variance partitioning analysis showed that the influence of root-soil interaction on the rhizosphere microbiota increased with tobacco growth. Overall, all three root-promoting practices could improve root characteristics, rhizosphere nutrient, and rhizosphere microbiota to varying degrees and increase the tobacco biomass, among which PGA had the most obvious effect and most suitable for tobacco cultivation. Our findings revealed the role of root-promoting practices in shaping the rhizosphere microbiota during plant growth and elucidated the assembly patterns and environmental drivers of crop rhizosphere microbiota driven by the application of root-promoting practices in agricultural production.


Assuntos
Micorrizas , Nicotiana , Raízes de Plantas/microbiologia , Rizosfera , Solo , Plantas , Microbiologia do Solo , Fósforo
13.
Plant Physiol Biochem ; 201: 107901, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37494824

RESUMO

Heat stress considerably restricts the geographical distribution of crops and affects their growth, development, and productivity. HSP70 plays a critical regulatory role in plant growth response to heat stress. However, the mechanisms of this regulatory remain poorly understood. Here, an HSP70 gene, NtHSP70-8b, which is involved in the heat stress response of tobacco, was cloned and identified. The expression of NtHSP70-8b was induced by exogenous abscisic acid (ABA) treatment and abiotic stress, including heat, drought, and salt. Notably, high NtHSP70-8b expression occurred under heat stress conditions, which was consistent with the ß-glucuronidase histochemical analysis. Moreover, NtHSP70-8b overexpression markedly enhanced heat stress tolerance by changing the stomatal conductance and antioxidant capacity in tobacco leaves. qRT-PCR showed that the expression levels of ABA synthesis and response genes (NtNCED3 and NtAREB), stress defence genes (NtERD10C and NtLEA5), and other HSP genes (NtHSP90 and NtHSP26a) in NtHSP70-8b-overexpressing tobacco were high under heat stress. The interaction of NtHSP70-8b with NtHSP26a was further confirmed by a luciferase complementation imaging assay. In contrast, NtHSP70-8b knockout mutants showed significantly reduced antioxidant capacity compared to the wild type (WT) under heat stress conditions, suggesting that NtHSP70-8b acts as a positive regulator of heat stress in tobacco. Moreover, NtHSP70-8b overexpression increased the 1000-seed weight. Taken together, NtHSP70-8b is involved in the heat stress response, and NtHSP70-8b overexpression contributed to enhanced tolerance to heat stress, which is thus an essential gene with potential application value for developing heat stress-tolerant crops.


Assuntos
Nicotiana , Termotolerância , Nicotiana/metabolismo , Termotolerância/genética , Antioxidantes/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/metabolismo , Secas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo
14.
Plant Physiol Biochem ; 198: 107665, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37018865

RESUMO

Drought stress is a severe threat to plants. Genes that respond to drought stress are essential for plant growth and development. General control nonderepressible 2 (GCN2) encodes a protein kinase that responds to various biotic and abiotic stresses. However, the mechanism of GCN2 in plant drought tolerance remains unclear. In the present study, the promoters of NtGCN2 from Nicotiana tabacum K326, which contained a drought-responsive Cis-acting element MYB that can be activated by drought stress, were cloned. Furthermore, the drought tolerance function of NtGCN2 was investigated using NtGCN2-overexpressed transgenic tobacco plants. NtGCN2-overexpressed transgenic plants were more tolerant to drought stress than wild-type (WT) plants. The transgenic tobacco plants exhibited higher proline and abscisic acid (ABA) contents, antioxidant enzyme activities, leaf relative water content, and expression levels of genes encoding key antioxidant enzymes and proline synthase, but lower levels of malondialdehyde and reactive oxygen species, and reduced stomatal apertures, stomatal densities, and stomatal opening rates compared to WT plants under drought stress. These results indicated that overexpression of NtGCN2 conferred drought tolerance in transgenic tobacco plants. RNA-seq analysis showed that overexpression of NtGCN2 responded to drought stress by regulating the expression of genes related to proline synthesis and catabolism, abscisic acid synthesis and catabolism, antioxidant enzymes, and ion channels in guard cells. These results showed that NtGCN2 might regulate drought tolerance by regulating proline accumulation, reactive oxygen species (ROS) scavenging, and stomatal closure in tobacco and may have the potential for application in the genetic modification of crop drought tolerance.


Assuntos
Antioxidantes , Nicotiana , Nicotiana/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/metabolismo , Resistência à Seca , Ácido Abscísico/metabolismo , Prolina/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Estresse Fisiológico/genética , Secas , Regulação da Expressão Gênica de Plantas
15.
Blood Cancer J ; 13(1): 14, 2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36631458

RESUMO

Some cytogenetic abnormalities (CAs) are associated with poorer prognosis in multiple myeloma (MM); proteasome inhibitors appear to benefit patients with high-risk CAs. We evaluated 2247 MM patients from the TOURMALINE-MM1/-MM2/-MM3/-MM4 trials to assess the PFS benefit of ixazomib plus lenalidomide-dexamethasone (Rd) vs placebo-Rd (TOURMALINE-MM1/-MM2) or ixazomib vs placebo (TOURMALINE-MM3/-MM4) in specific high-risk CAs. After a pooled median follow-up of 25.6 months, the hazard ratio (HR) for PFS with ixazomib- vs placebo-based therapy for high-risk patients was 0.74 (95% confidence interval [CI]: 0.59-0.93; median PFS [mPFS] 17.8 vs 13.2 months), and 0.70 (95% CI: 0.62-0.80; mPFS 26.3 vs 17.6 months) for complementary standard-risk patients. The HR for expanded high-risk patients was 0.75 (95% CI: 0.64-0.87; mPFS 18.1 vs 14.1 months), and 0.71 (95% CI: 0.59-0.85; mPFS 36.1 vs 21.4 months) for complementary standard-risk patients. The HR for PFS with ixazomib- vs placebo-based therapy was 0.68 in patients with t(4;14) (95% CI: 0.48-0.96; mPFS 22.4 vs 13.2 months), and 0.77 for patients with amp1q21 (95% CI: 0.63-0.93; mPFS 18.8 vs 14.5 months). A PFS benefit was demonstrated with ixazomib- vs placebo-based therapy regardless of cytogenetic status, with greatest benefit observed in patients with t(4;14) and amp1q21.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Lenalidomida/uso terapêutico , Dexametasona/efeitos adversos , Compostos de Boro/efeitos adversos , Aberrações Cromossômicas , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
16.
EJHaem ; 4(4): 995-1005, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38024593

RESUMO

Deeper responses are associated with longer survival in multiple myeloma (MM); however, limited data exist on the impact of response kinetics on outcomes. We investigated progression-free survival (PFS) and duration of response (DOR) by response depth and in early (best confirmed response 0-4 months; n = 424) versus late responders (best confirmed response >4 months; n = 281). Newly diagnosed patients enrolled in TOURMALINE-MM2 receiving ixazomib-lenalidomide-dexamethasone (IRd) (n = 351) or placebo-Rd (n = 354) were evaluated post hoc. Deeper responses were associated with longer PFS (complete response [CR] not reached [NR], very good partial response [VGPR] 37.2 months, partial response [PR] 16.4 months) and DOR (CR NR, VGPR 42.6 months, PR 15.4 months). Among patients with a PFS (n = 511) or DOR (n = 484) of ≥6 months who achieved ≥PR, median PFS was prolonged among late versus early responders receiving IRd (59.7 vs. 17.9 months) or placebo-Rd (56.6 vs. 12.4 months), as was median DOR (IRd, NR vs. 20.9 months; placebo-Rd, 58.2 vs. 11.7 months). While the treatment paradigm for newly diagnosed MM is treatment to progression, our findings suggest slowness of response to a proteasome inhibitor-immunomodulatory drug-steroid combination is not a negative predictor of outcome.

17.
Diabetes Metab J ; 46(4): 640-649, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35483673

RESUMO

BACKGROUND: Fatty acid-binding protein 4 (FABP4) has been demonstrated to be a predictor of early diabetic nephropathy. However, little is known about the relationship between FABP4 and diabetic retinopathy (DR). This study explored the value of FABP4 as a biomarker of DR in patients with type 2 diabetes mellitus (T2DM). METHODS: A total of 238 subjects were enrolled, including 20 healthy controls and 218 T2DM patients. Serum FABP4 levels were measured using a sandwich enzyme-linked immunosorbent assay. The grade of DR was determined using fundus fluorescence angiography. Based on the international classification of DR, all T2DM patients were classified into the following three subgroups: non-DR group, non-proliferative diabetic retinopathy (NPDR) group, and proliferative diabetic retinopathy (PDR) group. Multivariate logistic regression analyses were employed to assess the correlation between FABP4 levels and DR severity. RESULTS: FABP4 correlated positively with DR severity (r=0.225, P=0.001). Receiver operating characteristic curve analysis was used to assess the diagnostic potential of FABP4 in identifying DR, with an area under the curve of 0.624 (37% sensitivity, 83.6% specificity) and an optimum cut-off value of 76.4 µg/L. Multivariate logistic regression model including FABP4 as a categorized binary variable using the cut-off value of 76.4 µg/L showed that the concentration of FABP4 above the cut-off value increased the risk of NPDR (odds ratio [OR], 3.231; 95% confidence interval [CI], 1.574 to 6.632; P=0.001) and PDR (OR, 3.689; 95% CI, 1.306 to 10.424; P=0.014). CONCLUSION: FABP4 may be used as a serum biomarker for the diagnosis of DR.


Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Proteínas de Ligação a Ácido Graxo , Biomarcadores/sangue , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/metabolismo , Proteínas de Ligação a Ácido Graxo/sangue , Humanos , Curva ROC
18.
Sci Bull (Beijing) ; 67(8): 836-843, 2022 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-36546236

RESUMO

Forestation is important for sequestering atmospheric carbon, and it is a cost-effective and nature-based solution (NBS) for mitigating global climate change. Here, under the assumption of forestation in the potential plantable lands, we used the forest carbon sequestration (FCS) model and field survey involving 3365 forest plots to assess the carbon sequestration rate (CSR) of Chinese existing and new forestation forests from 2010 to 2060 under three forestation and three climate scenarios. Without considering the influence of extreme events and human disturbance, the estimated average CSR in Chinese forests was 0.358 ± 0.016 Pg C a-1, with partitioning to biomass (0.211 ± 0.016 Pg C a-1) and soil (0.147 ± 0.005 Pg C a-1), respectively. The existing forests account for approximately 93.5% of the CSR, which will peak near 2035, and decreasing trend was present overall after 2035. After 2035, effective tending management is required to maintain the high CSR level, such as selective cutting, thinning, and approximate disturbance. However, new forestation from 2015 in the potential plantable lands would play a minimal role in additional CSR increases. In China, the CSR is generally higher in the Northeast, Southwest, and Central-South, and lower in the Northwest. Considering the potential losses through deforestation and logging, it is realistically estimated that CSR in Chinese forests would remain in the range of 0.161-0.358 Pg C a-1 from 2010 to 2060. Overall, forests have the potential to offset 14.1% of the national anthropogenic carbon emissions in China over the period of 2010-2060, significantly contributing to the carbon neutrality target of 2060 with the implementation of effective management strategies for existing forests and expansion of forestation.


Assuntos
Sequestro de Carbono , Florestas , Biomassa , Carbono/análise , China
19.
Front Plant Sci ; 11: 568489, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193495

RESUMO

Drought and heat stresses are two major environmental stress factors that severely threaten crop growth and productivity. Plant delay of germination 1-like (DOG1L) family genes play important roles in various developmental processes and stress responses. In our previous study, a tobacco DOG1L gene (NtDOG1L-T) was found to regulate seedling growth and drought response. Unfortunately, the role of DOG1L genes in heat stress response is yet to be studied. Here, we present data supporting the role of DOG1L genes in heat stress and possible underlying molecular mechanisms. Transcript levels of NtDOG1L-T were rapidly induced by heat or abscisic acid (ABA) treatment. Furthermore, NtDOG1L-T promoter activity was markedly activated by ABA or heat stress, as revealed by histochemical staining in transgenic tobacco seedlings. Overexpression of NtDOG1L-T in transgenic lines improved heat stress tolerance. The NtDOG1L-T-transgenic plants exhibited lower levels of reactive oxygen species (ROS) and lipid peroxidation but higher antioxidant enzyme activities in response to heat stress. Furthermore, transcript abundance of some defense-, heat-, and ABA-responsive marker genes was significantly upregulated, as shown by reverse transcription quantitative PCR (qPCR) in these transgenic plants. In conclusion, NtDOG1L-T positively regulates heat stress tolerance possibly by modulation of antioxidant capability and defense-, heat-, and ABA-related gene expression in tobacco. This study may provide valuable resource for the potential exploitation of DOG1Ls in genetic improvement of heat stress tolerance in crops.

20.
Plant Sci ; 287: 110186, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31481202

RESUMO

Drought is one of the major environmental stresses limiting crop growth and production. It is very important to exploit and utilize drought-tolerance genes to improve crop drought-resistance. In this study, we identified two homoeologs of a Nicotiana tabacum (Ntab) DELAY OF GERMINATION (DOG) 1 like gene, named as NtabDOG1L-T and NtabDOG1L-S, respectively. The NtabDOG1L genes were preferentially expressed in roots and their expression levels were induced by polyethylene glycol, high salt, cold, and abscisic acid treatments. Subcellular localization results indicated that NtabDOG1L-T was localized in the nucleus, cytoplasm and cell membrane. Overexpression of NtabDOG1L-T in tobacco resulted in roots growth enhancement in transgenic plants. Furthermore, overexpression of NtabDOG1L-T enhanced drought stress tolerance in transgenic tobacco. The transgenic tobacco lines exhibited lower leaf water loss and electrolyte leakage, lower content of malondialdehyde and reactive oxygen species (ROS), and higher antioxidant enzymes activities after drought treatment when compared with wild type (WT) plants. In addition, the expression levels of several genes encoding key antioxidant enzymes and drought-related proteins were higher in the transgenic plants than in the WT plants under drought stress. Taken together, our results showed that NtabDOG1L functions as a novel regulator that improves plant growth and drought tolerance in tobacco.


Assuntos
Regulação da Expressão Gênica de Plantas , Nicotiana/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Ácido Abscísico/metabolismo , Antioxidantes/metabolismo , Secas , Expressão Gênica , Malondialdeído/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Nicotiana/crescimento & desenvolvimento , Nicotiana/fisiologia
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