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1.
Proc Natl Acad Sci U S A ; 119(10): e2116549119, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35235457

RESUMO

Legumes attract symbiotic bacteria and create de novo root organs called nodules. Nodule development consists of bacterial infection of root epidermis and subsequent primordium formation in root cortex, steps that need to be spatiotemporally coordinated. The Lotus japonicus mutant "daphne " has uncoupled symbiotic events in epidermis and cortex, in that it promotes excessive bacterial infection in epidermis but does not produce nodule primordia in cortex. Therefore, daphne should be useful for exploring unknown signals that coordinate these events across tissues. Here, we conducted time-course RNA sequencing using daphne after rhizobial infection. We noticed that IAA carboxyl methyltransferase 1 (IAMT1) , which encodes the enzyme that converts auxin (IAA) into its methyl ester (MeIAA), is transiently induced in wild-type roots at early stages of infection but shows different expression dynamics in daphne. IAMT1 serves an important function in shoot development of Arabidopsis, a nonsymbiotic plant, but the function of IAMT1 in roots has not been reported. Phylogenetic tree analysis suggests a gene duplication of IAMT1 in the legume lineage, and we found that one of the two IAMT1s (named IAMT1a) was induced in roots by epidermal infection. IAMT1a knockdown inhibited nodule development in cortex; however, it had no effect on epidermal infection. The amount of root MeIAA increased with rhizobial infection. Application of MeIAA, but not IAA , significantly induced expression of the symbiotic gene NIN in the absence of rhizobial infection. Our results provide evidence for the role of auxin methylation in an early stage of root nodule development.


Assuntos
Duplicação Gênica , Ácidos Indolacéticos/metabolismo , Lotus/metabolismo , Nódulos Radiculares de Plantas/crescimento & desenvolvimento , Genes de Plantas , Lotus/genética , Lotus/crescimento & desenvolvimento , Metilação , Mutação , Filogenia , Transcriptoma
2.
Jpn J Clin Oncol ; 53(6): 514-521, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36946312

RESUMO

BACKGROUND: This study aimed to investigate the effect of androgen deprivation therapy (ADT) on the survival of intermediate-risk prostate cancer (IR-PCA) patients treated with dose-escalated external beam radiation therapy (DE-EBRT), and to determine the group that will benefit from ADT. METHODS: We analysed 620 IR-PCA patients treated with DE-EBRT at two institutions. Variables were adjusted using the stabilised inverse probability of treatment weighting method (sIPTW) between radiation therapy (RT) and RT plus ADT groups. Biochemical relapse-free survival (bRFS) rate and overall survival (OS) rate were compared using Kaplan-Meier analysis and log-rank test. Cox proportional hazard analysis (CPH) was conducted to detect unfavorable risk factors. RESULTS: This study included 405 patients; with 217 and 188 patients in the RT and RT plus ADT groups, respectively. The prescribed radiation dose was 78 Gy in 39 fractions. The median follow-up time was 82.0 months. After sIPTW-adjustment, 214.3 and 189.7 patients were assigned to the RT and RT plus ADT groups, respectively. The 7-year bRFS and OS were 89.3% and 94.6% in RT group and 92.3% and 91.0% in RT plus ADT group, respectively. Before and after sIPTW adjustment, no statistically significant differences were found in these endpoints between treatment groups. Multivariate CPH for bRFS revealed Gleason score (GS) 4 + 3 as an unfavorable risk factor, and ADT improved biochemical control of them. CONCLUSION: ADT may not always be effective in all Japanese IR-PCA patients treated with DE-EBRT, but it can improve biochemical control in patients with GS 4 + 3.


Assuntos
Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Masculino , Humanos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Antagonistas de Androgênios/uso terapêutico , Estudos Retrospectivos , Recidiva Local de Neoplasia/tratamento farmacológico , Dosagem Radioterapêutica , Antígeno Prostático Específico
3.
Jpn J Clin Oncol ; 52(2): 170-178, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34689189

RESUMO

BACKGROUND: There are few reports from Japan about the outcomes of intensity-modulated radiation therapy for localized prostate cancer. This study was aimed at assessing the efficacy and toxicity of intensity-modulated radiation therapy in patients with intermediate- or high-risk prostate cancer. METHODS: We conducted a review of the data, retrieved from our institutional database, of patients who had received intensity-modulated radiation therapy for localized prostate cancer at a radiation dose of 78 Gy in 39 fractions. Data of 201 patients with intermediate-risk prostate cancer and 311 patients with high-risk prostate cancer were analyzed. RESULTS: The median follow-up period after the completion of intensity-modulated radiation therapy was 100 months (range, 24-154). The rates of cause-specific survival, overall survival, metastasis-free survival and biochemical recurrence-free survival in the intermediate-risk patients were 99, 95, 95 and 94% at 5 years and 99, 91, 90 and 86% at 8 years, respectively; the corresponding rates in the high-risk patients were 100, 97, 91 and 84% at 5 years and 96, 92, 84 and 76% at 8 years, respectively. The crude incidence of late grade 2-3 genitourinary toxicity was 28.1%, and that of late grade 3 genitourinary toxicity was 2.0%. The crude incidence of late grade 2 gastrointestinal toxicity was 5.1%, and there were no cases of late grade 3 gastrointestinal toxicity. CONCLUSIONS: Our data demonstrated that intensity-modulated radiation therapy is effective for patients with localized intermediate-risk or high-risk prostate cancer while having minimal toxicity.


Assuntos
Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Humanos , Masculino , Incidência , Neoplasias da Próstata/radioterapia , Radioterapia de Intensidade Modulada/efeitos adversos , Resultado do Tratamento , Sistema Urogenital
4.
J Plant Res ; 133(1): 109-122, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31828682

RESUMO

Root nodule (RN) symbiosis is a mutualistic interaction observed between nitrogen-fixing soil bacteria and nodulating plants, which are scattered in only four orders of angiosperms called nitrogen-fixing clade. Most of legumes engage in RN symbiosis with rhizobia. Molecular genetic analyses with legumes and non-leguminous nodulating plants revealed that RN symbiosis utilizes early signalling components that are required for symbiosis with arbuscular mycorrhizal (AM) fungi. However detailed evolutionary processes are still largely unknown. Comparative analyses with non-nodulating species phylogenetically related to legumes could be better strategies to study the evolution of RN symbiosis in legumes. Polygala paniculata is a non-leguminous species that belongs to a family different from legumes but that is classified into the same order, Fabales. It has appropriate characteristics for cultivation in laboratories: small body size, high fertility and short lifecycles. Therefore, we further assessed whether this species is suitable as a model species for comparative studies with legumes. We first validated that the plant we obtained in Palau was truly P. paniculata by molecular phylogenetic analysis using rbcL sequences. The estimated genome size of this species was less than those of two model legumes, Lotus japonicus and Medicago truncatula. We determined conditions for cultivation in vitro and for hairy root formation from P. paniculata seedlings. It would facilitate to investigate gene functions in this species. The ability of P. paniculata to interact with AM fungi was confirmed by inoculation with Rhizophagus irregularis, suggesting the presence of early signalling factors that might be involved in RN symbiosis. Unexpectedly, branching of root hairs was observed when inoculated with Mesorhizobium loti broad host range strain NZP2037, indicating that P. paniculata has the biological potential to respond to rhizobia. We propose that P. paniculata is used as a model plant for the evolutionary study of RN symbiosis.


Assuntos
Polygala , Rhizobium , Filogenia , Simbiose
5.
J Plant Res ; 132(5): 641-653, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31313020

RESUMO

Legumes engage in symbiosis with nitrogen-fixing soil bacteria, collectively called rhizobia, under nitrogen-limited conditions. In many legumes, the root invasion of rhizobia is mediated by infection threads (ITs), tubular invaginations of the host cell wall and plasma membrane, developed from infection foci of deformed root hairs. IT formation is regulated by a series of signal transduction in host root. Nodulation signals activate the host transcription factor (TF), CYCLOPS, which directly induces expression of two TF genes, ERF REQUIRED FOR NODULATION1 (ERN1) and NODULE INCEPTION (NIN), essential for IT development. Here, we explored the relationship among these three symbiotic TF genes in the model legume Lotus japonicus and examined how their interplay contributes to IT formation. qRT-PCR analysis showed that NIN expression induced by rhizobial infection was attenuated in ern1-1, and further declined in cyclops-3 ern1-1. ERN1 overexpression led to induction of NIN expression in cyclops-3 ern1-1 in the presence of rhizobia. Thus, in addition to CYCLOPS, ERN1 is able to increase the NIN expression level depending on infection. Furthermore, consistent with this transcriptional hierarchy, ectopic expression of ERN1 as well as NIN suppressed the IT-deficient cyclops-3 phenotype, but ERN1 failed to confer ITs in the nin-2 root. However, the ern1-1 symbiotic epidermal phenotype was not suppressed by the NIN ectopic expression. The cyclops-3 ern1-1 double mutant was less sensitive to rhizobial infection than the single mutants and defective in the symbiotic root hair response at earlier stages. This more severe phenotype of the double mutant suggests a role for ERN1 that independent of the CYCLOPS-mediated transcriptional regulation. We conclude that ERN1 is involved in regulating NIN expression in addition to CYCLOPS, and these TFs coordinately promote the symbiotic root hair response and IT development. Our data help to reveal the extensive role of ERN1 in root nodule symbiosis signaling.


Assuntos
Regulação da Expressão Gênica de Plantas , Lotus/genética , Proteínas de Plantas/genética , Rhizobiaceae/fisiologia , Transdução de Sinais/genética , Lotus/microbiologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Simbiose
6.
Genes Dev ; 25(1): 64-76, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21156810

RESUMO

The Agrobacterium Ti plasmid (T-DNA) 6b proteins interact with many different host proteins implicated in plant cell proliferation. Here, we show that Arabidopsis plants overexpressing 6b display microRNA (miRNA) deficiency by directly targeting SERRATE and AGO1 via a specific loop fragment (residues 40-55). In addition, we report the crystal structures of Agrobacterium tumefaciens AK6b at 2.1 Å, Agrobacterium vitis AB6b at 1.65 Å, and Arabidopsis ADP ribosylation factor (ARF) at 1.8 Å. The 6b structure adopts an ADP-ribosylating toxin fold closely related to cholera toxin. In vitro ADP ribosylation analysis demonstrates that 6b represents a new toxin family, with Tyr 66, Thr 93, and Tyr 153 as the ADP ribosylation catalytic residues in the presence of Arabidopsis ARF and GTP. Our work provides molecular insights, suggesting that 6b regulates plant cell growth by the disturbance of the miRNA pathway through its ADP ribosylation activity.


Assuntos
Arabidopsis/microbiologia , Proteínas de Bactérias/metabolismo , DNA Bacteriano/metabolismo , Fatores de Ribosilação do ADP/química , Agrobacterium tumefaciens/metabolismo , Arabidopsis/citologia , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Proteínas Argonautas , Proteínas de Bactérias/química , Toxinas Bacterianas/química , Toxinas Bacterianas/isolamento & purificação , Toxinas Bacterianas/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proliferação de Células , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Proteínas de Ligação a RNA , Proteínas Serrate-Jagged
7.
Plant J ; 88(2): 306-317, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27322352

RESUMO

Long terminal repeat (LTR) retrotransposons are closely related to retroviruses, and their activities shape eukaryotic genomes. Here, we present a complete Lotus japonicus insertion mutant collection generated by identification of 640 653 new insertion events following de novo activation of the LTR element Lotus retrotransposon 1 (LORE1) (http://lotus.au.dk). Insertion preferences are critical for effective gene targeting, and we exploit our large dataset to analyse LTR element characteristics in this context. We infer the mechanism that generates the consensus palindromes typical of retroviral and LTR retrotransposon insertion sites, identify a short relaxed insertion site motif, and demonstrate selective integration into CHG-hypomethylated genes. These characteristics result in a steep increase in deleterious mutation rate following activation, and allow LORE1 active gene targeting to approach saturation within a population of 134 682 L. japonicus lines. We suggest that saturation mutagenesis using endogenous LTR retrotransposons with germinal activity can be used as a general and cost-efficient strategy for generation of non-transgenic mutant collections for unrestricted use in plant research.


Assuntos
Lotus/genética , Proteínas de Plantas/metabolismo , Retroelementos/genética , Sequências Repetidas Terminais/genética , Metilação de DNA/genética , Mutagênese Insercional , Mutação/genética , Proteínas de Plantas/genética
8.
Proc Natl Acad Sci U S A ; 111(40): 14607-12, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25246578

RESUMO

Autoregulatory negative-feedback loops play important roles in fine-balancing tissue and organ development. Such loops are composed of short-range intercellular signaling pathways via cell-cell communications. On the other hand, leguminous plants use a long-distance negative-feedback system involving root-shoot communication to control the number of root nodules, root lateral organs that harbor symbiotic nitrogen-fixing bacteria known as rhizobia. This feedback system, known as autoregulation of nodulation (AON), consists of two long-distance mobile signals: root-derived and shoot-derived signals. Two Lotus japonicus CLAVATA3/endosperm surrounding region (CLE)-related small peptides, CLE root signal1 (CLE-RS1) and CLE-RS2, function as root-derived signals and are perceived by a shoot-acting AON factor, the hypernodulation aberrant root formation1 (HAR1) receptor protein, an ortholog of Arabidopsis CLAVATA1, which is responsible for shoot apical meristem homeostasis. This peptide-receptor interaction is necessary for systemic suppression of nodulation. How the onset of nodulation activates AON and how optimal nodule numbers are maintained remain unknown, however. Here we show that an RWP-RK-containing transcription factor, nodule inception (NIN), which induces nodule-like structures without rhizobial infection when expressed ectopically, directly targets CLE-RS1 and CLE-RS2. Roots constitutively expressing NIN systemically repress activation of endogenous NIN expression in untransformed roots of the same plant in a HAR1-dependent manner, leading to systemic suppression of nodulation and down-regulation of CLE expression. Our findings provide, to our knowledge, the first molecular evidence of a long-distance autoregulatory negative-feedback loop that homeostatically regulates nodule organ formation.


Assuntos
Proteínas de Plantas/genética , Nodulação/genética , Nódulos Radiculares de Plantas/genética , Transdução de Sinais/genética , Retroalimentação Fisiológica , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Interações Hospedeiro-Patógeno , Lotus/genética , Lotus/microbiologia , Mutação , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Brotos de Planta/genética , Brotos de Planta/microbiologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rhizobium/fisiologia , Nódulos Radiculares de Plantas/microbiologia , Simbiose
10.
PLoS Genet ; 9(3): e1003352, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23555278

RESUMO

The interactions of legumes with symbiotic nitrogen-fixing bacteria cause the formation of specialized lateral root organs called root nodules. It has been postulated that this root nodule symbiosis system has recruited factors that act in early signaling pathways (common SYM genes) partly from the ancestral mycorrhizal symbiosis. However, the origins of factors needed for root nodule organogenesis are largely unknown. NODULE INCEPTION (NIN) is a nodulation-specific gene that encodes a putative transcription factor and acts downstream of the common SYM genes. Here, we identified two Nuclear Factor-Y (NF-Y) subunit genes, LjNF-YA1 and LjNF-YB1, as transcriptional targets of NIN in Lotus japonicus. These genes are expressed in root nodule primordia and their translational products interact in plant cells, indicating that they form an NF-Y complex in root nodule primordia. The knockdown of LjNF-YA1 inhibited root nodule organogenesis, as did the loss of function of NIN. Furthermore, we found that NIN overexpression induced root nodule primordium-like structures that originated from cortical cells in the absence of bacterial symbionts. Thus, NIN is a crucial factor responsible for initiating nodulation-specific symbiotic processes. In addition, ectopic expression of either NIN or the NF-Y subunit genes caused abnormal cell division during lateral root development. This indicated that the Lotus NF-Y subunits can function to stimulate cell division. Thus, transcriptional regulation by NIN, including the activation of the NF-Y subunit genes, induces cortical cell division, which is an initial step in root nodule organogenesis. Unlike the legume-specific NIN protein, NF-Y is a major CCAAT box binding protein complex that is widespread among eukaryotes. We propose that the evolution of root nodules in legume plants was associated with changes in the function of NIN. NIN has acquired functions that allow it to divert pathways involved in the regulation of cell division to root nodule organogenesis.


Assuntos
Fator de Ligação a CCAAT/genética , Proteínas de Plantas , Nódulos Radiculares de Plantas , Simbiose/genética , Evolução Biológica , Fator de Ligação a CCAAT/metabolismo , Fabaceae/genética , Fabaceae/metabolismo , Regulação da Expressão Gênica de Plantas , Lotus/genética , Lotus/crescimento & desenvolvimento , Organogênese , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/crescimento & desenvolvimento , Nódulos Radiculares de Plantas/metabolismo , Nódulos Radiculares de Plantas/microbiologia , Transdução de Sinais , Fatores de Transcrição
11.
Plant Cell Physiol ; 56(2): 368-76, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25416287

RESUMO

Legumes produce root nodules as symbiotic organs where nitrogen-fixing bacteria are accommodated. Lotus japonicus NODULE INCEPTION (NIN) is an essential factor that specifically and positively regulates nodulation processes, and has evolved from a member of the NIN-like proteins, of which Arabidopsis homologs target nitrate-responsive elements (NREs), and activate gene expression in response to nitrate. It is therefore assumed that the NIN-mediated transcriptional network overlaps with those regulated by NLPs, because of their common DNA-binding RWP-RK domains. However, nodulation is inhibited in the presence of nitrate, and involvement of NIN in nitrate responses has remained largely unknown. Here we determined a consensus of NIN-binding nucleotide sequences (NBSs) by in vitro experiments, and revealed that the sequence pattern was very similar to those of NREs. Chromatin immunoprecitiation (ChIP)-PCR analyses showed that NIN targeted NREs in L. japonicus nitrate-inducible gene promoters, including LjNIR1, LjNRT2.1 and LjNRT2.2. Affinities of NIN binding to the NREs were comparable with that to NBS-yB1a, an NBS on the symbiotic LjNF-YB1 promoter, indicating that NREs are potential targets of NIN. However, rhizobial infection did not activate LjNIR1, LjNRT2.1 and LjNRT2.2. NIN ectopic expression interfered with nitrate-dependent activation of these genes. Nitrate treatment followed by NIN activation down-regulated expression of symbiotic NIN target genes. Our results showed that NIN and nitrate antagonistically regulate expression of genes that are activated by nitrate and NIN, respectively. We propose that this antagonistic relationship prevents inappropriate activation of genes in response to nitrate and rhizobial infection.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lotus/genética , Nitratos/farmacologia , Proteínas de Plantas/metabolismo , Sequência de Bases , Sequência Consenso/genética , Genes de Plantas , Lotus/efeitos dos fármacos , Lotus/microbiologia , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacos , Rhizobium/efeitos dos fármacos , Rhizobium/fisiologia , Transcrição Gênica/efeitos dos fármacos
12.
Science ; 385(6706): 288-294, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39024445

RESUMO

Host plants benefit from legume root nodule symbiosis with nitrogen-fixing bacteria under nitrogen-limiting conditions. In this interaction, the hosts must regulate nodule numbers and distribution patterns to control the degree of symbiosis and maintain root growth functions. The host response to symbiotic bacteria occurs discontinuously but repeatedly at the region behind the tip of the growing roots. Here, live-imaging and transcriptome analyses revealed oscillating host gene expression with approximately 6-hour intervals upon bacterial inoculation. Cytokinin response also exhibited a similar oscillation pattern. Cytokinin signaling is crucial to maintaining the periodicity, as observed in cytokinin receptor mutants displaying altered infection foci distribution. This periodic regulation influences the size of the root region responsive to bacteria, as well as the nodulation process progression.


Assuntos
Citocininas , Regulação da Expressão Gênica de Plantas , Interações entre Hospedeiro e Microrganismos , Lotus , Mesorhizobium , Nodulação , Nódulos Radiculares de Plantas , Simbiose , Citocininas/metabolismo , Perfilação da Expressão Gênica , Lotus/genética , Lotus/crescimento & desenvolvimento , Lotus/metabolismo , Mutação , Nódulos Radiculares de Plantas/crescimento & desenvolvimento , Nódulos Radiculares de Plantas/microbiologia , Transdução de Sinais , Mesorhizobium/genética , Mesorhizobium/fisiologia
13.
Br J Radiol ; 97(1153): 142-149, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38263831

RESUMO

OBJECTIVE: This study evaluated the prognostic impact of the quality of dose distribution using dosiomics in patients with prostate cancer, stratified by pretreatment prostate-specific antigen (PSA) levels and Gleason grade (GG) group. METHODS: A total of 721 patients (Japanese Foundation for Cancer Research [JFCR] cohort: N = 489 and Tokyo Radiation Oncology Clinic [TROC] cohort: N = 232) with localized prostate cancer treated by intensity-modulated radiation therapy were enrolled. Two predictive dosiomic features for biochemical recurrence (BCR) were selected and patients were divided into certain groups stratified by pretreatment PSA levels and GG. Freedom from biochemical failure (FFBF) was estimated using the Kaplan-Meier method based on each dosiomic feature and univariate discrimination was evaluated using the log-rank test. As an exploratory analysis, a dosiomics hazard (DH) score was developed and its prognostic power for BCR was examined. RESULTS: The dosiomic feature extracted from planning target volume (PTV) significantly distinguished the high- and low-risk groups in patients with PSA levels >10 ng/mL (7-year FFBF: 86.7% vs 76.1%, P < .01), GG 4 (92.2% vs 76.9%, P < .01), and GG 5 (83.1% vs 77.8%, P = .04). The DH score showed significant association with BCR (hazard score: 2.04; 95% confidence interval: 1.38-3.01; P < .001). CONCLUSION: The quality of planned dose distribution on PTV may affect the prognosis of patients with poor prognostic factors, such as PSA levels >10 ng/mL and higher GGs. ADVANCES IN KNOWLEDGE: The effects of planned dose distribution on prognosis differ depending on the patient's clinical background.


Assuntos
Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Masculino , Humanos , Antígeno Prostático Específico , Estudos Retrospectivos , Análise de Sobrevida
14.
Plant J ; 69(4): 720-30, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22014259

RESUMO

We established a gene tagging population of the model legume Lotus japonicus using an endogenous long terminal repeat (LTR) retrotransposon Lotus Retrotransposon 1 (LORE1). The population was composed of 2450 plant lines, from which a total of 4532 flanking sequence tags of LORE1 were recovered by pyrosequencing. The two-dimensional arrangement of the plant population, together with the use of multiple identifier sequences in the primers used to amplify the flanking regions, made it possible to trace insertions back to the original plant lines. The large-scale detection of new LORE1 insertion sites revealed a preference for genic regions, especially in exons of protein-coding genes, which is an interesting feature to consider in the interaction between host genomes and chromoviruses, to which LORE1 belongs, a class of retrotransposon widely distributed among plants. Forward screening of the symbiotic mutants from the population succeeded to identify five symbiotic mutants of known genes. These data suggest that LORE1 is robust as a genetic tool.


Assuntos
Éxons/genética , Lotus/genética , Mutagênese Insercional/métodos , Retroelementos/genética , Primers do DNA/genética , Marcação de Genes , Mutação , Análise de Sequência de DNA , Simbiose , Sequências Repetidas Terminais/genética
15.
Plant Cell Physiol ; 54(4): 433-47, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23390201

RESUMO

The interaction of legumes with N2-fixing bacteria collectively called rhizobia results in root nodule development. The number of nodules formed is tightly restricted through the systemic negative feedback control by the host called autoregulation of nodulation (AON). Here, we report the characterization and gene identification of TOO MUCH LOVE (TML), a root factor that acts during AON in a model legume Lotus japonicus. In our genetic analyses using another root-regulated hypernodulation mutant, plenty, the tml-1 plenty double mutant showed additive effects on the nodule number, whereas the tml-1 har1-7 double mutant did not, suggesting that TML and PLENTY act in different genetic pathways and that TML and HAR1 act in the same genetic pathway. The systemic suppression of nodule formation by CLE-RS1/RS2 overexpression was not observed in the tml mutant background, indicating that TML acts downstream of CLE-RS1/RS2. The tml-1 Snf2 double mutant developed an excessive number of spontaneous nodules, indicating that TML inhibits nodule organogenesis. Together with the determination of the deleted regions in tml-1/-2/-3, the fine mapping of tml-4 and the next-generation sequencing analysis, we identified a nonsense mutation in the Kelch repeat-containing F-box protein. As the gene knockdown of the candidate drastically increased the number of nodules, we concluded that it should be the causative gene. An expression analysis revealed that TML is a root-specific gene. In addition, the activity of ProTML-GUS was constitutively detected in the root tip and in the nodules/nodule primordia upon rhizobial infection. In conclusion, TML is a root factor acting at the final stage of AON.


Assuntos
Proteínas F-Box/metabolismo , Fabaceae/metabolismo , Fabaceae/microbiologia , Proteínas de Plantas/metabolismo , Rhizobium/fisiologia , Proteínas F-Box/genética , Lotus/metabolismo , Lotus/microbiologia , Proteínas de Plantas/genética , Nodulação/genética , Nodulação/fisiologia , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo , Simbiose/genética , Simbiose/fisiologia
16.
Plant Cell ; 22(11): 3778-90, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21098735

RESUMO

Cytokinesis in plants is achieved by the formation of the cell plate. A pathway that includes mitogen-activated protein (MAP) kinase kinase kinase and MAP kinase kinase (MAPKK) plays a key role in the control of plant cytokinesis. We show here that a MAP kinase, MPK4, is required for the formation of the cell plate in Arabidopsis thaliana. Single mutations in MPK4 caused dwarfism and characteristic defects in cytokinesis, such as immature cell plates, which became much more prominent upon introduction of a mutation in MKK6/ANQ, the MAPKK for cytokinesis, into mpk4. MKK6/ANQ strongly activated MPK4 in protoplasts, and kinase activity of MPK4 was detected in wild-type tissues that contained dividing cells but not in mkk6/anq mutants. Fluorescent protein-fused MPK4 localized to the expanding cell plates in cells of root tips. Expansion of the cell plates in mpk4 root tips appeared to be retarded. The level of MPK11 transcripts was markedly elevated in mpk4 plants, and defects in the mpk4 mpk11 double mutant with respect to growth and cytokinesis were more severe than in the corresponding single mutants. These results indicate that MPK4 is the downstream target of MKK6/ANQ in the regulation of cytokinesis in Arabidopsis and that MPK11 is also involved in cytokinesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/enzimologia , Citocinese/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Animais , Proteínas de Arabidopsis/genética , MAP Quinase Quinase 6/genética , MAP Quinase Quinase 6/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Mutação , Fenótipo , Raízes de Plantas/citologia , Raízes de Plantas/enzimologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais/fisiologia , Distribuição Tecidual
17.
Front Plant Sci ; 13: 995589, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36733592

RESUMO

Legumes develop root nodules in association with compatible rhizobia to overcome nitrogen deficiency. Rhizobia enter the host legume, mainly through infection threads, and induce nodule primordium formation in the root cortex. Multiple transcription factors have been identified to be involved in the regulation of the establishment of root nodule symbiosis, including ERF Required for Nodulation1 (ERN1). ERN1 is involved in a transcription network with CYCLOPS and NODULE INCEPTION (NIN). Mutation of ERN1 often results in misshapen root hair tips, deficient infection thread formation, and immature root nodules. ERN1 directly activates the expression of ENOD11 in Medicago truncatula to assist cell wall remodeling and Epr3 in Lotus japonicus to distinguish rhizobial exopolysaccharide signals. However, aside from these two genes, it remains unclear which genes are regulated by LjERN1 or what role LjERN1 plays during root nodule symbiosis. Thus, we conducted RNA sequencing to compare the gene expression profiles of wild-type L. japonicus and Ljern1-6 mutants. In total, 234 differentially expressed genes were identified as candidate LjERN1 target genes. These genes were found to be associated with cell wall remodeling, signal transduction, phytohormone metabolism, and transcription regulation, suggesting that LjERN1 is involved in multiple processes during the early stages of the establishment of root nodule symbiosis. Many of these candidate genes including RINRK1 showed decreased expression levels in Ljnin-2 mutants based on a search of a public database, suggesting that LjERN1 and LjNIN coordinately regulate gene expression. Our data extend the current understanding of the pleiotropic role of LjERN1 in root nodule symbiosis.

18.
Int J Radiat Oncol Biol Phys ; 112(1): 247-259, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34706278

RESUMO

PURPOSE: Although radiation therapy is one of the most significant treatment modalities for localized prostate cancer, the prognostic factors for biochemical recurrence (BCR) regarding the treatment plan are unclear. We aimed to develop a novel dosiomics-based prediction model for BCR in patients with prostate cancer and clarify the correlations between the dosimetric factors and BCR. METHODS AND MATERIALS: This study included 489 patients with localized prostate cancer (BCR: 96; no-BCR: 393) who received intensity modulated radiation therapy. A total of 2475 dosiomic features were extracted from the dose distributions on the prostate, clinical target volume (CTV), and planning target volume. A prediction model for BCR was trained on a training cohort of 342 patients. The performance of this model was validated using the concordance index (C-index) in a validation cohort of 147 patients. Another model was constructed using clinical variables, dosimetric parameters, and radiomic features for comparisons. Kaplan-Meier curves with log-rank analysis were used to assess the univariate discrimination based on the predictive dosiomic features. RESULTS: The dosiomic feature derived from the CTV was significantly associated with BCR (hazard ratio, 0.73; 95% CI, 0.57-0.93; P = .01). Although the dosiomics model outperformed the dosimetric and radiomics models, it did not outperform the clinical model. The performance significantly improved by combining the clinical variables and dosiomic features (C-index: 0.67; 95% CI, 0.65-0.68; P < .0001). The predictive dosiomic features were used to distinguish high-risk and low-risk patients (P < .05). CONCLUSIONS: The dosiomic feature extracted from the CTV was significantly correlated with BCR in patients with prostate cancer, and the dosiomics model outperformed the model with conventional dose indices. Hence, new metrics for evaluating the quality of a treatment plan are warranted. Moreover, further research should be conducted to determine whether dosiomics can be incorporated in a clinical workflow or clinical trial.


Assuntos
Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Humanos , Masculino , Próstata , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radiometria , Radioterapia de Intensidade Modulada/métodos
19.
Curr Opin Plant Biol ; 59: 102000, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33454544

RESUMO

Legumes and several plant species in the monophyletic nitrogen-fixing clade produce root nodules that function as symbiotic organs and establish mutualistic relationships with nitrogen-fixing bacteria. The modes of nodule organogenesis are distinct from those of lateral root development and also differ among different types of nodules formed in legumes and actinorhizal plants. It is considered that the evolution of new organs occurs through rearrangement of molecular networks interposed by certain neo-functionalized factors. Accumulating evidence has suggested that root nodule organogenesis involves root or lateral root developmental pathways. This review describes the current knowledge about the factors/pathways acquired by the common ancestor of the nitrogen-fixing clade in order to control nodule organogenesis.


Assuntos
Fabaceae , Simbiose , Fabaceae/genética , Nitrogênio , Fixação de Nitrogênio , Nódulos Radiculares de Plantas
20.
Brachytherapy ; 20(1): 29-37, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32814663

RESUMO

PURPOSE: The purpose of this study was to identify the time to achieve a prostate-specific antigen (PSA) nadir of ≤0.2 ng/mL and the related factors to achieve this goal. MATERIALS AND METHODS: We retrospectively reviewed 2218 Japanese prostate cancer patients who received 125I brachytherapy with or without external beam radiotherapy between 2003 and 2013 at one institution. Among them, patients followed up for ≥72 months and without luteinizing hormone-releasing hormone (LH-RH) agonist/antagonist were included (total of 1089 patients). The time to a PSA nadir of ≤0.2 ng/mL (months) was defined as the time between the date of implantation and the first time the lowest PSA value reached ≤0.2 ng/mL. Biochemical recurrence (BCR) was determined using the Phoenix definition. Multivariate linear regression analysis was performed to detect the related factors to achieve this nadir. RESULTS: We assigned 409, 592, and 88 patients to the low-, intermediate-risk, and high-risk groups, respectively. The median followup time was 9.5 years. The median time to achieve a PSA nadir of ≤0.2 ng/mL was 44.0 (95% confidence interval: 42.3-45.7) months. The percentage of patients that achieved the nadir was 89.1%. BCR was noted in 107 (9.8%) patients. In the multivariate analysis of patients without BCR, younger age, larger prostate volume at implantation, higher initial PSA level, and monotherapy were significantly associated with longer time to achieve the PSA nadir. CONCLUSION: The median time to achieve a PSA nadir of ≤0.2 ng/mL was 44.0 months. Some patients, however, may require a lengthy period of time to do so.


Assuntos
Braquiterapia , Neoplasias da Próstata , Braquiterapia/métodos , Seguimentos , Humanos , Masculino , Antígeno Prostático Específico , Neoplasias da Próstata/radioterapia , Estudos Retrospectivos
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