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1.
Plant J ; 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39378337

RESUMO

Leaf senescence is a complex developmental process influenced by abscisic acid (ABA) and reactive oxygen species (ROS), both of which increase during senescence. Understanding the regulatory mechanisms of leaf senescence can provide insights into enhancing crop yield and stress tolerance. In this study, we aimed to elucidate the role and mechanisms of rice (Oryza sativa) LONG GRAIN 3 (OsLG3), an APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factor, in orchestrating dark-induced leaf senescence. The transcript levels of OsLG3 gradually increased during dark-induced and natural senescence. Transgenic plants overexpressing OsLG3 exhibited delayed senescence, whereas CRISPR/Cas9-mediated oslg3 mutants exhibited accelerated leaf senescence. OsLG3 overexpression suppressed senescence-induced ABA signaling by downregulating OsABF4 (an ABA-signaling-related gene) and reduced ROS accumulation by enhancing catalase activity through upregulation of OsCATC. In vivo and in vitro binding assays demonstrated that OsLG3 downregulated OsABF4 and upregulated OsCATC by binding directly to their promoter regions. These results demonstrate the critical role of OsLG3 in fine-tuning leaf senescence progression by suppressing ABA-mediated signaling while simultaneously activating ROS-scavenging mechanisms. These findings suggest that OsLG3 could be targeted to enhance crop resilience and longevity.

2.
Plant J ; 117(2): 599-615, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37902786

RESUMO

Chloroplasts are essential organelles in plants that contain chlorophylls and facilitate photosynthesis for growth and development. As photosynthetic efficiency significantly impacts crop productivity, understanding the regulatory mechanisms of chloroplast development has been crucial in increasing grain and biomass production. This study demonstrates the involvement of OsGATA16, an ortholog of Arabidopsis GATA, NITRATE INDUCIBLE, CARBON-METABOLISM INVOLVED (GNC), and GNC-LIKE/CYTOKININ-RESPONSIVE GATA FACTOR 1 (GNL/CGA1), in chlorophyll biosynthesis and chloroplast development in rice (Oryza sativa). The osgata16-1 knockdown mutants produced pale-green leaves, while OsGATA16-overexpressed plants (OsGATA16-OE1) generated dark-green leaves, compared to their parental japonica rice. Reverse transcription and quantitative PCR analysis revealed downregulation of genes related to chloroplast division, chlorophyll biosynthesis, and photosynthesis in the leaves of osgata16-1 and upregulation in those of OsGATA16-OE1. Additionally, in vivo binding assays showed that OsGATA16 directly binds to the promoter regions of OsHEMA, OsCHLH, OsPORA, OsPORB, and OsFtsZ, and upregulates their expression. These findings indicate that OsGATA16 serves as a positive regulator controlling chlorophyll biosynthesis and chloroplast development in rice.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Oryza , Oryza/metabolismo , Cloroplastos/metabolismo , Fotossíntese/genética , Clorofila/metabolismo , Arabidopsis/genética , Folhas de Planta/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/metabolismo
3.
BMC Med ; 22(1): 91, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38433201

RESUMO

BACKGROUND: Epilepsy, characterized by recurrent unprovoked seizures, poses significant challenges to affected individuals globally. While several established risk factors for epilepsy exist, the association with cigarette smoking remains debated. This study aims to conduct systematic review and meta-analysis to elucidate the potential association between smoking and the likelihood of epilepsy. METHODS: The search was performed on March 31st, 2023, using the Medline, Embase, Web of Science, Scopus, and ScienceDirect. We included cohort, cross-sectional, and case-control studies in our meta-analysis, conducting subgroup analyses based on smoking history, sex, and epilepsy type to yield specific insights. RESULTS: We identified 2550 studies, of which 17 studies were finally included in this study. The pooled odds ratio of epilepsy was 1.14 (0.96-1.36) in smokers compared to non-smokers. In current smokers compared to non-smokers, the odds ratio was 1.46 (1.13-1.89), while, in former smokers compared to non-smokers, the odds ratio was 1.14 (0.83-1.56). CONCLUSIONS: While the overall association between smoking and epilepsy did not reach statistical significance, a notable association was found among current smokers. The study emphasizes the importance of smoking cessation as a potential preventive measure against epilepsy, especially given the proconvulsive effects of nicotine. Future research should address limitations and explore specific clinical scenarios to enhance our understanding of the complex relationship between cigarette use and epilepsy. SYSTEMATIC REVIEW REGISTRATION: CRD42022342510.


Assuntos
Epilepsia , Humanos , Estudos Transversais , Epilepsia/epidemiologia , Fumantes , Fatores de Risco , Fumar/efeitos adversos , Fumar/epidemiologia
4.
Plant Cell Environ ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39012205

RESUMO

Flowering time is a crucial adaptive response to seasonal variation in plants and is regulated by environmental cues such as photoperiod and temperature. In this study, we demonstrated the regulatory function of rice CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1-LIKE (OsCIBL1) in flowering time. Overexpression of OsCIB1L promoted flowering, whereas the oscib1l knockout mutation did not alter flowering time independent of photoperiodic conditions. Cryptochromes (CRYs) are blue light photoreceptors that enable plants to sense photoperiodic changes. OsCIBL1 interacted with OsCRY2, a member of the rice CRY family (OsCRY1a, OsCRY1b, and OsCRY2), and bound to the Early heading date 1 (Ehd1) promoter, activating the rice-specific Ehd1-Heading date 3a/RICE FLOWERING LOCUS T 1 pathway for flowering induction. Dual-luciferase reporter assays showed that the OsCIBL1-OsCRY2 complex required blue light to induce Ehd1 transcription. Natural alleles resulting from nonsynonymous single nucleotide polymorphisms in OsCIB1L and OsCRY2 may contribute to the adaptive expansion of rice cultivation areas. These results expand our understanding of the molecular mechanisms controlling rice flowering and highlight the importance of blue light-responsive genes in the geographic distribution of rice.

5.
BMC Geriatr ; 24(1): 867, 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39448893

RESUMO

BACKGROUND: The unprecedented pandemic situation of COVID-19 has had a negative impact on the mental health of many people, especially among the "old-old" older adults who are aged 75 or older. Therefore, the aim of this study is to investigate the changes in depression among "old-old" older adults before and after the onset of COVID-19, and the extent to which depression affects suicidal ideations. METHOD: The 12th to 16th Korea Welfare Panel Study(KoWePS) conducted from 2017 to 2021 was used for analysis. For this study, 771 older individuals with complete data to estimate the degree of change of depression were selected as the final analysis subjects. RESULT: A Growth Mixture Modeling(GMM) analysis was conducted, resulting in the classification of two groups: an increasing group and a decreasing group. The study findings showed that "old-old" older individuals with high levels of depression, specifically those in the decreasing group, may be more susceptible to suicidal ideation. Despite this steep change slope, the decreasing group still exhibited a higher level of depression in 2021 compared to the increasing group. As per characteristics, the decreasing group, which showed a higher prevalence of suicidal ideation, had a higher proportion of women and individuals with lower levels of education, those living alone, and a lower household income compared to the increasing group. CONCLUSION: It is important to note that although the study emphasized the need to prioritize intervention for the decreasing group with consistently high levels of depression, the majority of individuals belong to the increasing group, which exhibited a gradual increase in depression levels over time. Therefore, intervention plans should be developed concurrently for both groups. Also, it is crucial to implement proactive efforts targeting groups with understandings of these characteristics when establishing preventative measures for depression and suicidal ideation among "old-old" older adults.


Assuntos
COVID-19 , Depressão , Ideação Suicida , Humanos , COVID-19/psicologia , COVID-19/epidemiologia , Idoso , Feminino , Masculino , República da Coreia/epidemiologia , Depressão/psicologia , Depressão/epidemiologia , Idoso de 80 Anos ou mais
6.
Plant J ; 109(6): 1386-1396, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34919778

RESUMO

Extracellular ATP (eATP) is known to act as a danger signal in both plants and animals. In plants, eATP is recognized by the plasma membrane (PM)-localized receptor P2K1 (LecRK-I.9). Among the first measurable responses to eATP addition is a rapid rise in cytoplasmic free calcium levels ([Ca2+ ]cyt ), which requires P2K1. However, the specific transporter/channel proteins that mediate this rise in [Ca2+ ]cyt are unknown. Through a forward genetic screen, we identified an Arabidopsis ethylmethanesulfonate (EMS) mutant impaired in the [Ca2+ ]cyt response to eATP. Positional cloning revealed that the mutation resided in the cngc6 gene, which encodes cyclic nucleotide-gated ion channel 6 (CNGC6). Mutation of the CNGC6 gene led to a notable decrease in the PM inward Ca2+ current in response to eATP. eATP-induced mitogen-activated protein kinase activation and gene expression were also significantly lower in cngc6 mutant plants. In addition, cngc6 mutant plants were also more susceptible to the bacterial pathogen Pseudomonas syringae. Taken together, our results indicate that CNGC6 plays a crucial role in mediating eATP-induced [Ca2+ ]cyt signaling, as well as plant immunity.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Canais de Cátion Regulados por Nucleotídeos Cíclicos , Trifosfato de Adenosina/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cálcio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Nucleotídeos Cíclicos , Imunidade Vegetal/genética
7.
Aging Ment Health ; 26(1): 26-32, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33251834

RESUMO

OBJECTIVES: Older adults are closely connected to their neighborhoods and they spend more time there than younger adults. Because their mobility is often impeded by diminished health and functioning, access to neighborhood health and social services is essential for their well-being. This article examines whether geographic proximity to these types of neighborhood resources is associated with depression among older adults in South Korea. METHODS: Data are from A Profile of Older Adults: 2015 which sampled 1,455 community-dwelling individuals ages 60 and older in South Korea. The Patient Health Questionnaire-9 (PHQ-9) was used to assess depression, the outcome. We measured geographic proximity to neighborhood destinations, which included the time it takes the respondent to go to the grocery store, hospital, government office, senior center, social service center, and bus stop. We conducted latent profile analyses (LPA) with a distal outcome using the BCH method to determine whether geographic proximity to neighborhood resources is associated with depression. RESULTS: The LPA identified three distinct subgroups of geographic proximity to neighborhood resources: High Access (10%), Moderate Access (41%), and Low Access (49%). Low Access (b = 3.71, p < .001) and Moderate Access (b = 3.00, p < .001) groups had higher levels of depression compared to those in the High Access group. DISCUSSION: Our findings suggest that access to essential services in one's neighborhood is associated with lower levels of depression, which supports existing evidence that age-friendly community initiatives are important to older adults' psychological well-being.


Assuntos
Depressão , Características de Residência , Idoso , Depressão/epidemiologia , Serviços de Saúde , Humanos , Vida Independente , República da Coreia/epidemiologia
8.
Br J Neurosurg ; : 1-5, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35016576

RESUMO

OBJECTIVE: Anterior approach cervical surgery is widely used for accessing C3 lesions. When operating with an anterior approach, the surgical field is obstructed by mandible. Neck extension is popular method to secure better surgical field but risk devastating neurological damage. To overcome this limited surgical field without neck extension, we adopted nasotracheal intubation and evaluated its efficiency. METHODS: We retrospectively analyzed 16 patients who underwent anterior cervical discectomy or corpectomy of C3 lesions via nasotracheal intubation. We enrolled an additional 29 patients who underwent anterior cervical discectomy or corpectomy of C3 lesions via orotracheal intubation as a control group. All patients had been diagnosed with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament. We measured the mandibular-cervical angle, which is the angle between the lower mandibular line and anterior vertebral line. RESULTS: The mandibular-cervical angle was increased by 7.3 with nasotracheal intubation compared to orotracheal intubation. CONCLUSIONS: Nasotracheal intubation is an effective surgical option for securing the surgical field without neck extension in anterior cervical surgery including C3 lesions.

9.
Plant Physiol ; 183(3): 1364-1375, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32345768

RESUMO

In animals, extracellular ATP is a well-studied signaling molecule that is recognized by plasma membrane-localized P2-type purinergic receptors. However, in contrast, much less is known about purinergic signaling in plants. P2 receptors play critical roles in a variety of animal biological processes, including immune system regulation. The first plant purinergic receptor, Arabidopsis (Arabidopsis thaliana) P2K1 (L-type lectin receptor kinase-I.9), was shown to contribute to plant defense against bacterial, oomycete, and fungal pathogens. Here, we demonstrate the isolation of a second purinergic receptor, P2K2, by complementation of an Arabidopsis p2k1 mutant. P2K2 (LecRK-I.5) has 74% amino acid similarity to P2K1. The P2K2 extracellular lectin domain binds to ATP with higher affinity than P2K1 (dissociation constant [K d] = 44.47 ± 15.73 nm). Interestingly, p2k2 and p2k1 p2k2 mutant plants showed increased susceptibility to the pathogen Pseudomonas syringae, with the double mutant showing a stronger phenotype. In vitro and in planta studies demonstrate that P2K2 and P2K1 interact and cross-phosphorylate upon extracellular ATP treatment. Thus, similar to animals, plants possess multiple purinergic receptors.


Assuntos
Trifosfato de Adenosina/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/imunologia , Espaço Extracelular/metabolismo , Imunidade Inata , Lectinas/metabolismo , Imunidade Vegetal , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Cálcio/metabolismo , Membrana Celular/metabolismo , Citosol/metabolismo , Resistência à Doença , Mutação/genética , Fosforilação , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Ligação Proteica , Domínios Proteicos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Pseudomonas syringae/fisiologia , Transdução de Sinais
10.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200157

RESUMO

The purpose of this study was to investigate whether polymorphisms in five microRNAs (miRNAs), miR-604A>G, miR-608C>G, 631I/D, miR-938G>A, and miR-1302-3C>T, are associated with the risk of idiopathic recurrent pregnancy loss (RPL). Blood samples were collected from 388 patients with idiopathic RPL (at least two consecutive spontaneous abortions) and 227 control participants. We found the miR-604 AG and AG + GG genotypes of miR-604, the miR-938 GA and GA + AA genotypes of miR-938, and the miR-1302-3CT and CT + TT genotypes of miR-1302-3 are less frequent than the wild-type (WT) genotypes, miR-604AA, miR-938GG, and miR-1302-3CC, respectively, in RPL patients. Using allele-combination multifactor dimensionality reduction (MDR) analysis, we found that eight haplotypes conferred by the miR-604/miR-608/miR-631/miR-938/miR-1302-3 allele combination, A-C-I-G-T, A-C-I-A-C, G-C-I-G-C, G-C-I-G-T, G-G-I-G-C, G-G-I-G-T, G-G-I-A-C, G-G-D-G-C, three from the miR-604/miR-631/miR-938/miR-1302-3 allele combination, A-I-G-T, G-I-G-C, G-I-A-T, one from the miR-604/miR-631/miR-1302-3 allele combination, G-I-C, and two from the miR-604/miR-1302-3 allele combination, G-C and G-T, were less frequent in RPL patients, suggesting protective effects (all p < 0.05). We also identified the miR-604A>G and miR-938G>A polymorphisms within the seed sequence of the mature miRNAs and aligned the seed sequences with the 3'UTR of putative target genes, methylenetetrahydrofolate reductase (MTHFR) and gonadotropin-releasing hormone receptor (GnRHR), respectively. We further found that the binding affinities between miR-604/miR-938 and the 3'UTR of their respective target genes (MTHFR, GnRHR) were significantly different for the common (miR-604A, miR-938G) and variant alleles (miR-604G, miR-938A). These results reveal a significant association between the miR-604A>G and miR-938G>A polymorphisms and idiopathic RPL and suggest that miRNAs can affect RPL in Korean women.


Assuntos
Aborto Habitual/patologia , Predisposição Genética para Doença , MicroRNAs/genética , Polimorfismo de Nucleotídeo Único , Regiões 3' não Traduzidas , Aborto Habitual/etiologia , Adulto , Estudos de Casos e Controles , Implantação do Embrião , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Gravidez
11.
Hepatology ; 66(3): 855-868, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28439950

RESUMO

Sorafenib is the only approved targeted drug for hepatocellular carcinoma (HCC), but its effect on patients' survival gain is limited and varies over a wide range depending on pathogenetic conditions. Thus, enhancing the efficacy of sorafenib and finding a reliable predictive biomarker are crucial to achieve efficient control of HCCs. In this study, we utilized a systems approach by combining transcriptome analysis of the mRNA changes in HCC cell lines in response to sorafenib with network analysis to investigate the action and resistance mechanism of sorafenib. Gene list functional enrichment analysis and gene set enrichment analysis revealed that proteotoxic stress and apoptosis modules are activated in the presence of sorafenib. Further analysis of the endoplasmic reticulum stress network model, combined with in vitro experiments, showed that introducing an additional stress by treating the orally active protein disulfide isomerase (PDI) inhibitor (PACMA 31) can synergistically increase the efficacy of sorafenib in vitro and in vivo, which was confirmed using a mouse xenograft model. We also found that HCC patients with high PDI expression show resistance to sorafenib and poor clinical outcomes, compared to the low-PDI-expression group. CONCLUSION: These results suggest that PDI is a promising therapeutic target for enhancing the efficacy of sorafenib and can also be a biomarker for predicting sorafenib responsiveness. (Hepatology 2017;66:855-868).


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Niacinamida/análogos & derivados , Compostos de Fenilureia/administração & dosagem , Isomerases de Dissulfetos de Proteínas/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Estudos de Coortes , Modelos Animais de Doenças , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Niacinamida/administração & dosagem , Modelos de Riscos Proporcionais , Isomerases de Dissulfetos de Proteínas/metabolismo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Distribuição Aleatória , Sorafenibe , Estatísticas não Paramétricas , Células Tumorais Cultivadas
12.
Adv Exp Med Biol ; 1051: 233-253, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29064066

RESUMO

Adenosine 5'-triphosphate (ATP), a ubiquitously dispersed biomolecule, is not only a major source of biochemical energy for living cells, but also acts as a critical signaling molecule through inter-cellular communication. Recent studies have clearly shown that extracellular ATP is involved in various physiological processes in plants, including root growth, stomata movement, pollen tube development, gravitropism, and abiotic/biotic stress responses. The first plant purinergic receptor for extracellular ATP, DORN1 (the founding member of the P2K family of purinergic receptors), was identified in Arabidopsis thaliana by a forward genetic screen. DORN1 consists of an extracellular lectin domain, transmembrane domain, and serine/threonine kinase, intracellular domain. The predicted structure of the DORN1 extracellular domain revealed putative key ATP binding residues but an apparent lack of sugar binding. In this chapter, we summarize recent studies on the molecular mechanism of plant recognition of extracellular ATP with specific reference to the role of DORN1.


Assuntos
Trifosfato de Adenosina/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Desenvolvimento Vegetal/fisiologia , Proteínas Quinases/metabolismo , Estresse Fisiológico , Trifosfato de Adenosina/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Domínios Proteicos , Proteínas Quinases/genética
13.
J Exp Bot ; 67(6): 1677-87, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26767749

RESUMO

The plant-specific WUSCHEL-related homeobox (WOX) nuclear proteins have important roles in the transcriptional regulation of many developmental processes. Among the rice (Oryza sativa) WOX proteins, a loss of OsWOX3A function in narrow leaf2 (nal2) nal3 double mutants (termed nal2/3) causes pleiotropic effects, such as narrow and curly leaves, opened spikelets, narrow grains, more tillers, and fewer lateral roots, but almost normal plant height. To examine OsWOX3A function in more detail, transgenic rice overexpressing OsWOX3A (OsWOX3A-OX) were generated; unexpectedly, all of them consistently exhibited severe dwarfism with very short and wide leaves, a phenotype that resembles that of gibberellic acid (GA)-deficient or GA-insensitive mutants. Exogenous GA3 treatment fully rescued the developmental defects of OsWOX3A-OX plants, suggesting that constitutive overexpression of OsWOX3A downregulates GA biosynthesis. Quantitative analysis of GA intermediates revealed significantly reduced levels of GA20 and bioactive GA1 in OsWOX3A-OX, possibly due to downregulation of the expression of KAO, which encodes ent-kaurenoic acid oxidase, a GA biosynthetic enzyme. Yeast one-hybrid and electrophoretic mobility shift assays revealed that OsWOX3A directly interacts with the KAO promoter. OsWOX3A expression is drastically and temporarily upregulated by GA3 and downregulated by paclobutrazol, a blocker of GA biosynthesis. These data indicate that OsWOX3A is a GA-responsive gene and functions in the negative feedback regulation of the GA biosynthetic pathway for GA homeostasis to maintain the threshold levels of endogenous GA intermediates throughout development.


Assuntos
Vias Biossintéticas , Retroalimentação Fisiológica , Giberelinas/biossíntese , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Sequência de Bases , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Retroalimentação Fisiológica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Giberelinas/farmacologia , Mutação/genética , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Oryza/efeitos dos fármacos , Oryza/genética , Fenótipo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Triazóis/farmacologia
14.
J Exp Bot ; 66(22): 7045-59, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26276867

RESUMO

Lesion mimic mutants commonly display spontaneous cell death in pre-senescent green leaves under normal conditions, without pathogen attack. Despite molecular and phenotypic characterization of several lesion mimic mutants, the mechanisms of the spontaneous formation of cell death lesions remain largely unknown. Here, the rice lesion mimic mutant spotted leaf3 (spl3) was examined. When grown under a light/dark cycle, the spl3 mutant appeared similar to wild-type at early developmental stages, but lesions gradually appeared in the mature leaves close to heading stage. By contrast, in spl3 mutants grown under continuous light, severe cell death lesions formed in developing leaves, even at the seedling stage. Histochemical analysis showed that hydrogen peroxide accumulated in the mutant, likely causing the cell death phenotype. By map-based cloning and complementation, it was shown that a 1-bp deletion in the first exon of Oryza sativa Mitogen-Activated Protein Kinase Kinase Kinase1 (OsMAPKKK1)/OsEDR1/OsACDR1 causes the spl3 mutant phenotype. The spl3 mutant was found to be insensitive to abscisic acid (ABA), showing normal root growth in ABA-containing media and delayed leaf yellowing during dark-induced and natural senescence. Expression of ABA signalling-associated genes was also less responsive to ABA treatment in the mutant. Furthermore, the spl3 mutant had lower transcript levels and activities of catalases, which scavenge hydrogen peroxide, probably due to impairment of ABA-responsive signalling. Finally, a possible molecular mechanism of lesion formation in the mature leaves of spl3 mutant is discussed.


Assuntos
Ácido Abscísico/metabolismo , Genes de Plantas , MAP Quinase Quinase Quinase 1/genética , Oryza/genética , Proteínas de Plantas/genética , Catalase/biossíntese , Morte Celular , Senescência Celular , Clonagem Molecular , Regulação para Baixo , MAP Quinase Quinase Quinase 1/metabolismo , Mutação , Oryza/enzimologia , Oryza/metabolismo , Fenótipo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
15.
J Exp Bot ; 66(19): 5727-38, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26049159

RESUMO

Although lipo-chitooligosaccharides (LCOs) are important signal molecules for plant-symbiont interactions, a number of reports suggest that LCOs can directly impact plant growth and development, separate from any role in plant symbioses. In order to investigate this more closely, maize and Setaria seedlings were treated with LCO and their growth was evaluated. The data indicate that LCO treatment significantly enhanced root growth. RNA-seq transcriptomic analysis of LCO-treated maize roots identified a number of genes whose expression was significantly affected by the treatment. Among these genes, some LCO-up-regulated genes are likely involved in root growth promotion. Interestingly, some stress-related genes were down-regulated after LCO treatment, which might indicate reallocation of resources from defense responses to plant growth. The promoter activity of several LCO-up-regulated genes using a ß-glucuronidase reporter system was further analysed. The results showed that the promoters were activated by LCO treatment. The data indicate that LCO can directly impact maize root growth and gene expression.


Assuntos
Quitina/análogos & derivados , Poaceae/crescimento & desenvolvimento , Transdução de Sinais , Carbono/química , Quitina/farmacologia , Quitosana , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Oligossacarídeos , Poaceae/química , Poaceae/efeitos dos fármacos , Poaceae/metabolismo , Plântula/química , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Análise de Sequência de RNA , Transdução de Sinais/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Zea mays/química , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
16.
Plant J ; 74(1): 122-33, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23289852

RESUMO

NADPH:protochlorophyllide oxidoreductase (POR) catalyzes photoreduction of protochlorophyllide (Pchlide) to chlorophyllide in chlorophyll (Chl) synthesis, and is required for prolamellar body (PLB) formation in etioplasts. Rice faded green leaf (fgl) mutants develop yellow/white leaf variegation and necrotic lesions during leaf elongation in field-grown plants. Map-based cloning revealed that FGL encodes OsPORB, one of two rice POR isoforms. In fgl, etiolated seedlings contained smaller PLBs in etioplasts, and lower levels of total and photoactive Pchlide. Under constant or high light (HL) conditions, newly emerging green leaves rapidly turned yellow and formed lesions. Increased levels of non-photoactive Pchlide, which acts as a photosensitizer, may cause reactive oxygen accumulation and lesion formation. OsPORA expression is repressed by light and OsPORB expression is regulated in a circadian rhythm in short-day conditions. OsPORA was expressed at high levels in developing leaves and decreased dramatically in fully mature leaves, whereas OsPORB expression was relatively constant throughout leaf development, similar to expression patterns of AtPORA and AtPORB in Arabidopsis. However, OsPORB expression is rapidly upregulated by HL treatment, similar to the fluence rate-dependent regulation of AtPORC. This suggests that OsPORB function is equivalent to both AtPORB and AtPORC functions. Our results demonstrate that OsPORB is essential for maintaining light-dependent Chl synthesis throughout leaf development, especially under HL conditions, whereas OsPORA mainly functions in the early stages of leaf development. Developmentally and physiologically distinct roles of monocot OsPORs are discussed by comparing with those of dicot AtPORs.


Assuntos
Clorofila/biossíntese , Luz , Oryza/enzimologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Proteínas de Plantas/metabolismo , Clonagem Molecular , Mutação da Fase de Leitura , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/efeitos da radiação , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Folhas de Planta/enzimologia , Folhas de Planta/efeitos da radiação , Proteínas de Plantas/genética , Deleção de Sequência
17.
Plant Cell Environ ; 37(1): 101-12, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23668360

RESUMO

Natural variation in heading-date genes enables rice, a short-day (SD) plant, to flower early under long-day (LD) conditions at high latitudes. Through analysis of heading-date quantitative trait loci (QTL) with F7 recombinant inbred lines from the cross of early heading 'H143' and late heading 'Milyang23 (M23)', we found a minor-effect Early Heading3 (EH3) QTL in the Hd16 region on chromosome 3. We found that Early flowering1 (EL1), encoding casein kinase I (CKI), is likely to be responsible for the EH3/Hd16 QTL, because a missense mutation occurred in the highly conserved serine/threonine kinase domain of EL1 in H143. A different missense mutation was found in the EL1 kinase domain in Koshihikari. In vitro kinase assays revealed that EL1/CKI in H143 and Koshihikari are non-functional. In F7:9 heterogeneous inbred family-near isogenic lines (HNILs), HNIL(H143) flowered 13 days earlier than HNIL(M23) in LD, but not in SD, in which EL1 mainly acts as a LD-dependent flowering repressor, down-regulating Ehd1 expression. In the world rice collection, two types of non-functional EL1 variants were found in japonica rice generally cultivated at high latitudes. These results indicate that natural variation in EL1 contributes to early heading for rice adaptation to LD in temperate and cooler regions.


Assuntos
Caseína Quinase I/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Variação Genética , Oryza/genética , Locos de Características Quantitativas/genética , Alelos , Caseína Quinase I/metabolismo , Mapeamento Cromossômico , Regulação para Baixo , Flores/genética , Flores/efeitos da radiação , Geografia , Endogamia , Mutação de Sentido Incorreto , Oryza/fisiologia , Oryza/efeitos da radiação , Fosforilação , Fotoperíodo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único , Temperatura
18.
BMB Rep ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39044456

RESUMO

The vascular system in plants facilitates long-distance transportation of water and nutrients through the xylem and phloem, while also providing mechanical support for vertical growth. Although many genes that regulate vascular development in rice have been identified, the mechanism by which epigenetic regulators control vascular development remains unclear. This study found that Rolled Fine Striped (RFS), a Chromodomain Helicase DNA-binding 3 (CHD3)/Mi-2 subfamily protein, regulates vascular development in rice by affecting the initiation and development of primordia. The rfs mutant was found to affect auxin-related genes, as revealed by RNA sequencing and reverse transcription-quantitative PCR analysis. The transcript levels of OsPIN1 and NAL1 genes were downregulated in rfs mutant, compared to the wild-type plant. The chromatin immunoprecipitation assays showed lower levels of H3K4me3 in the OsPIN1a and NAL1 genes in rfs mutant. Furthermore, exogenous auxin treatment partially rescued the reduced adventitious root vascular development in rfs mutant. Subsequently, exogenous treatments with auxin or an auxin-transport inhibitor revealed that the expression of OsPIN1a and NAL1 is mainly affected by auxin. These results provide strong evidence that RFS plays an important role in vascular development and root formation through the auxin signaling pathway in rice.

19.
Front Plant Sci ; 15: 1372361, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38633461

RESUMO

Plants are remarkable in their ability to adapt to changing environments, with receptor-like kinases (RLKs) playing a pivotal role in perceiving and transmitting environmental cues into cellular responses. Despite extensive research on RLKs from the plant kingdom, the function and activity of many kinases, i.e., their substrates or "clients", remain uncharted. To validate a novel client prediction workflow and learn more about an important RLK, this study focuses on P2K1 (DORN1), which acts as a receptor for extracellular ATP (eATP), playing a crucial role in plant stress resistance and immunity. We designed a Kinase-Client (KiC) assay library of 225 synthetic peptides, incorporating previously identified P2K phosphorylated peptides and novel predictions from a deep-learning phosphorylation site prediction model (MUsite) and a trained hidden Markov model (HMM) based tool, HMMER. Screening the library against purified P2K1 cytosolic domain (CD), we identified 46 putative substrates, including 34 novel clients, 27 of which may be novel peptides, not previously identified experimentally. Gene Ontology (GO) analysis among phosphopeptide candidates revealed proteins associated with important biological processes in metabolism, structure development, and response to stress, as well as molecular functions of kinase activity, catalytic activity, and transferase activity. We offer selection criteria for efficient further in vivo experiments to confirm these discoveries. This approach not only expands our knowledge of P2K1's substrates and functions but also highlights effective prediction algorithms for identifying additional potential substrates. Overall, the results support use of the KiC assay as a valuable tool in unraveling the complexities of plant phosphorylation and provide a foundation for predicting the phosphorylation landscape of plant species based on peptide library results.

20.
Pharmacogenet Genomics ; 23(7): 341-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23736108

RESUMO

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is characterized by the development of airway obstruction in asthmatic individuals following the ingestion of aspirin or other nonsteroidal anti-inflammatory drugs. TAPBP (TAP-binding protein, tapasin) is upregulated by eicosanoids, which act as potent inflammatory molecules in aspirin-related reactions. Thus, functional alterations in the TAPBP gene may contribute toward AERD. OBJECTIVES: We examined the relationship between the single nucleotide polymorphisms on the TAPBP gene and AERD. MATERIALS AND METHODS: A group of asthmatic patients (n=1252) underwent the oral aspirin challenge. Oral aspirin challenge reactions were categorized into two groups as follows: 15% or greater decreases in forced expiratory volume in 1 s or naso-ocular and skin reactions (AERD), or 15% or less decreases in forced expiratory volume in 1 s without naso-ocular and skin reactions (aspirin-tolerant asthma). Five single nucleotide polymorphisms of the TAPBP gene were genotyped. RESULTS: Logistic regression analysis showed that the minor allele frequencies of TAPBP rs2071888 C>G (Thr260Arg) on exon 4 (P>0.05), which was in absolute linkage disequilibrium with rs1059288 T>C on 3'UTR, were significantly higher in the AERD group than in the aspirin-tolerant asthma group, and the P values remained significant after multiple comparisons (Pcorr=0.006, odds ratio: 1.37, 95% confidence interval: 1.11-1.69, additive model; Pcorr=0.009, odds ratio: 1.52, 95% confidence interval: 1.14-2.03, dominant model). Alpha-helical wheel plotting showed that 260Arg had greater hydrophilic helical property than 260Thr. CONCLUSION: TAPBP polymorphisms may play a role in the development of AERD.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Aspirina/efeitos adversos , Asma Induzida por Aspirina/genética , Proteínas de Membrana Transportadoras/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade
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