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1.
Plant J ; 118(1): 159-170, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38212943

RESUMEN

Increasing nutrient uptake and use efficiency in plants can contribute to improved crop yields and reduce the demand for fertilizers in crop production. In this study, we characterized a rice mutant, 88n which showed long roots under low nitrogen (N) or phosphorus (P) conditions. Low expression levels of N transporter genes were observed in 88n root, and total N concentration in 88n shoots were decreased, however, C concentrations and shoot dry weight in 88n were comparable to that in WT. Therefore, 88n showed high nitrogen utilization efficiency (NUtE). mRNA accumulation of Pi transporter genes was higher in 88n roots, and Pi concentration and uptake activity were higher in 88n than in WT. Therefore, 88n also showed high phosphorus uptake efficiency (PUpE). Molecular genetic analysis revealed that the causal gene of 88n phenotypes was OsbZIP1, a monocot-specific ortholog of the A. thaliana bZIP transcription factor HY5. Similar to the hy5 mutant, chlorophyll content in roots was decreased and root angle was shallower in 88n than in WT. Finally, we tested the yield of 88n in paddy fields over 3 years because 88n mutant plants showed higher PUpE and NUtE activity and different root architecture at the seedling stage. 88n showed large panicles and increased panicle weight/plant. Taken together, a mutation in OsbZIP1 could contribute to improved crop yields.


Asunto(s)
Arabidopsis , Oryza , Fósforo/metabolismo , Fenotipo , Nitrógeno/metabolismo , Plantones/metabolismo , Arabidopsis/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Oryza/genética , Oryza/metabolismo
2.
Plant Cell Physiol ; 65(4): 671-679, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38226464

RESUMEN

Nutritropism is a positive tropism toward nutrients in plant roots. An NH4+ gradient is a nutritropic stimulus in rice (Oryza sativa L.). When rice roots are exposed to an NH4+ gradient generated around nutrient sources, root tips bend toward and coil around the sources. The molecular mechanisms are largely unknown. Here, we analyzed the transcriptomes of the inside and outside of bending root tips exhibiting nutritropism to reveal nutritropic signal transduction. Tissues facing the nutrient sources (inside) and away (outside) were separately collected by laser microdissection. Principal component analysis revealed distinct transcriptome patterns between the two tissues. Annotations of 153 differentially expressed genes implied that auxin, gibberellin and ethylene signaling were activated differentially between the sides of the root tips under nutritropism. Exogenous application of transport and/or biosynthesis inhibitors of these phytohormones largely inhibited the nutritropism. Thus, signaling and de novo biosynthesis of the three phytohormones are necessary for nutritropism. Expression patterns of IAA genes implied that auxins accumulated more in the inside tissues, meaning that ammonium stimulus is transduced to auxin signaling in nutritropism similar to gravity stimulus in gravitropism. SAUR and expansin genes, which are known to control cell wall modification and to promote cell elongation in shoot gravitropism, were highly expressed in the inside tissues rather than the outside tissues, and our transcriptome data are unexplainable for differential elongation in root nutritropism.


Asunto(s)
Etilenos , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Giberelinas , Ácidos Indolacéticos , Oryza , Transducción de Señal , Oryza/genética , Oryza/metabolismo , Oryza/fisiología , Ácidos Indolacéticos/metabolismo , Giberelinas/metabolismo , Etilenos/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Meristema/genética , Meristema/metabolismo , Transcriptoma , Raíces de Plantas/metabolismo , Raíces de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
Theor Appl Genet ; 137(4): 77, 2024 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-38460027

RESUMEN

KEY MESSAGE: We proposed models to predict the effects of genomic and environmental factors on daily soybean growth and applied them to soybean growth data obtained with unmanned aerial vehicles. Advances in high-throughput phenotyping technology have made it possible to obtain time-series plant growth data in field trials, enabling genotype-by-environment interaction (G × E) modeling of plant growth. Although the reaction norm is an effective method for quantitatively evaluating G × E and has been implemented in genomic prediction models, no reaction norm models have been applied to plant growth data. Here, we propose a novel reaction norm model for plant growth using spline and random forest models, in which daily growth is explained by environmental factors one day prior. The proposed model was applied to soybean canopy area and height to evaluate the influence of drought stress levels. Changes in the canopy area and height of 198 cultivars were measured by remote sensing using unmanned aerial vehicles. Multiple drought stress levels were set as treatments, and their time-series soil moisture was measured. The models were evaluated using three cross-validation schemes. Although accuracy of the proposed models did not surpass that of single-trait genomic prediction, the results suggest that our model can capture G × E, especially the latter growth period for the random forest model. Also, significant variations in the G × E of the canopy height during the early growth period were visualized using the spline model. This result indicates the effectiveness of the proposed models on plant growth data and the possibility of revealing G × E in various growth stages in plant breeding by applying statistical or machine learning models to time-series phenotype data.


Asunto(s)
Sequías , Glycine max , Glycine max/genética , Fitomejoramiento , Genoma , Genómica/métodos
4.
Ann Bot ; 132(3): 455-470, 2023 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-37688538

RESUMEN

BACKGROUND AND AIMS: Air and root zone temperatures are important environmental factors affecting plant growth and yield. Numerous studies have demonstrated that air temperature strongly affects plant growth and development. Despite the extensive literature on air temperature, comprehensive studies on the effects of root zone temperature (RZT) on plant growth, elemental composition, and pigments are limited. In this study, we carefully observed the effects of RZT in red leaf lettuce to understand its effect on lettuce growth and pigment content. METHODS: Lettuce (Lactuca sativa, red leaf cultivar 'Red Fire') was grown hydroponically in a plant factory with artificial light under three RZT treatments (15, 25, or 35 °C) for 13 days. We investigated the comprehensive effects of RZT on the production of red leaf lettuce by metabolome and ionome analyses. KEY RESULTS: The 25 °C RZT treatment achieved maximum shoot and root dry weight. The 35 °C RZT decreased plant growth but significantly increased pigment contents (e.g. anthocyanins, carotenoids). In addition, a RZT heating treatment during plant cultivation that changed from 25 to 35 °C RZT for 8 days before harvest significantly increased shoot dry weight compared with the 35 °C RZT and significantly increased pigments compared with the 25 °C RZT. The 15 °C RZT resulted in significantly less pigment content relative to the 35 °C RZT. The 15 °C RZT also resulted in shoot and root dry weights greater than the 35 °C RZT but less than the 25 °C RZT. CONCLUSIONS: This study demonstrated that plant growth and pigments can be enhanced by adjusting RZT during different stages of plant growth to attain enhanced pigment contents while minimizing yield loss. This suggests that controlling RZT could be a viable method to improve lettuce quality via enhancement of pigment content quality while maintaining acceptable yields.


Asunto(s)
Lactuca , Raíces de Plantas , Temperatura , Hidroponía , Antocianinas/farmacología
5.
Plant Cell Physiol ; 63(9): 1215-1229, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-35791818

RESUMEN

Nitrogen (N) is an important macronutrient for plant growth and development. Currently, N fertilizers are required for the efficient production of modern crops such as rice due to their limited capacity to take up N when present at low concentrations. Wild rice represents a useful genetic resource for improving crop responses to low nutrient stress. Here, we describe the isolation and characterization of an introgression line, KRIL37, that carries a small region of the Oryza rufipogon genome in the Oryza sativa L. cv Koshihikari (KH) background. This line was found to grow better under low N conditions and have similar or lower C/N ratios in aerial portions compared to those in the parental KH cultivar, suggesting that KRIL37 has a higher capacity to take up and assimilate N when present at low concentrations. KRIL37 performance in the field was also better than that of KH cultivated without N and fertilizer (-F). Transcriptome analyses of 3-week-old seedlings based on RNA-sequencing revealed that KH induced a wider suite of genes than the tolerant line KRIL37 in response to low N conditions. Some ammonium transporters and N assimilation genes were found to be induced under low N in KRIL37, but not in KH. Our findings suggest that the superior growth performance of KRIL37 under limited N conditions could be due to the expression of wild alleles influencing N uptake and assimilation. Our study demonstrates the potential to use wild rice genomes to improve modern crops for low nutrient tolerance.


Asunto(s)
Oryza , Productos Agrícolas/genética , Perfilación de la Expresión Génica , Nitrógeno/metabolismo , Oryza/metabolismo , Plantones/genética
6.
Plant J ; 104(2): 351-364, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32652697

RESUMEN

The Elongator complex, which is conserved in eukaryotes, has multiple roles in diverse organisms. In Arabidopsis thaliana, Elongator is shown to be involved in development, hormone action and environmental responses. However, except for Arabidopsis, our knowledge of its function is poor in plants. In this study, we initially carried out a genetic analysis to characterize a rice mutant with narrow and curled leaves, termed curled later1 (cur1). The cur1 mutant displayed a heteroblastic change, whereby the mutant leaf phenotype appeared specifically at a later adult phase of vegetative development. The shoot apical meristem (SAM) was small and the leaf initiation rate was low, suggesting that the activity of the SAM seemed to be partially reduced in cur1. We then revealed that CUR1 encodes a yeast ELP1-like protein, the largest subunit of Elongator. Furthermore, disruption of OsELP3 encoding the catalytic subunit of Elongator resulted in phenotypes similar to those of cur1, including the timing of the appearance of mutant phenotypes. Thus, Elongator activity seems to be specifically required for leaf development at the late vegetative phase. Transcriptome analysis showed that genes involved in protein quality control were highly upregulated in the cur1 shoot apex at the later vegetative phase, suggesting the restoration of impaired proteins probably produced by partial defects in translational control due to the loss of function of Elongator. The differences in the mutant phenotype and gene expression profile between CUR1 and its Arabidopsis ortholog suggest that Elongator has evolved to play a unique role in rice development.


Asunto(s)
Meristema/fisiología , Oryza/fisiología , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Técnicas de Inactivación de Genes , Histona Acetiltransferasas/genética , Complejos Multiproteicos , Mutación , Oryza/crecimiento & desarrollo , Factores de Elongación de Péptidos/genética , Fenotipo , Hojas de la Planta/citología , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Subunidades de Proteína , Proteínas de Saccharomyces cerevisiae/genética
7.
Plant Cell Physiol ; 62(7): 1156-1167, 2021 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-33693871

RESUMEN

Nitrate is an important nutrient and signaling molecule in plants, which modulates the expression of many genes and regulates plant growth. In paddy-grown rice (Oryza sativa), nitrogen is mostly supplied in the form of ammonium but can also be supplied in the form of nitrate. Several nitrogen transporters and nitrate assimilation enzymes have been identified and functionally characterized in rice. However, little is known regarding the nitrate sensing system in rice, and the regulatory mechanisms of nitrate-related genes remain to be elucidated. In recent years, NIN-like proteins (NLPs) have been described as key transcription factors of nitrogen responses in Arabidopsis thaliana, which implies that OsNLP4 is involved in the regulation of nitrate assimilation and nitrogen use efficiency in rice. Here, we show that OsNLP4 can influence plant growth by affecting nitrate reductase (NR) activity. The growth of OsNLP4 knockdown mutants was reduced when nitrate was supplied, but not when ammonium was supplied. The nitrate concentration was significantly reduced in osnlp4 mutants. Furthermore, the concentrations of iron and molybdenum, essential elements for NR activity, were reduced in OsNLP4 knockdown mutants. We propose that, in addition to the regulation of gene expression within the nitrate signaling pathway, OsNLP4 can affect the NR activity and nitrate-dependent growth of rice. Our results support a working model for the role of OsNLP4 in the nitrate signaling pathway.


Asunto(s)
Nitrato-Reductasa/metabolismo , Nitratos/farmacología , Oryza/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Nitratos/metabolismo , Oryza/enzimología , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética
8.
PLoS Genet ; 14(4): e1007365, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29684018

RESUMEN

Rice (Oryza sativa) has long and narrow leaves with parallel veins, similar to other grasses. Relative to Arabidopsis thaliana which has oval-shaped leaves, our understanding of the mechanism of leaf development is insufficient in grasses. In this study, we show that OsWOX4, a member of the WUSCHEL-RELATED HOMEOBOX gene family, plays important roles in early leaf development in rice. Inducible downregulation of OsWOX4 resulted in severe defects in leaf development, such as an arrest of vascular differentiation, a partial defect in the early cell proliferation required for midrib formation, and a failure to maintain cellular activity in general parenchyma cells. In situ analysis showed that knockdown of OsWOX4 reduced the expression of two LONELY GUY genes, which function in the synthesis of active cytokinin, in developing vascular bundles. Consistent with this, cytokinin levels were downregulated by OsWOX4 knockdown. Transcriptome analysis further showed that OsWOX4 regulates multiple genes, including those responsible for cell cycle progression and hormone action, consistent with the effects of OsWOX4 downregulation on leaf phenotypes. Collectively, these results suggest that OsWOX4 acts as a key regulator at an early stage of leaf development. Our previous work revealed that OsWOX4 is involved in the maintenance of shoot apical meristem in rice, whereas AtWOX4 is specifically associated with the maintenance of vascular stem cells in Arabidopsis. Thus, the function of the two orthologous genes seems to be diversified between rice and Arabidopsis.


Asunto(s)
Genes Homeobox , Genes de Plantas , Oryza/crecimiento & desarrollo , Oryza/genética , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Citocininas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Técnicas de Silenciamiento del Gen , Proteínas de Homeodominio/genética , Oryza/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente , Especificidad de la Especie
9.
Plant Cell Physiol ; 61(3): 546-553, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31808938

RESUMEN

Plants take up water and nutrients through roots, and uptake efficiency depends on root behavior. Roots recognize the moisture gradient in the soil and grow toward the direction of high moisture. This phenomenon is called hydrotropism, and it contributes to efficient water uptake. As nutrients in soil are also unevenly distributed, it is beneficial for plants to grow their roots in the direction of increasing nutrient concentrations, but such a phenomenon has not been demonstrated. Here, we describe the directional growth of roots in response to a nutrient gradient. Using our assay system, the gradient of a nitrogen nutrient, NH4+, was sufficient to stimulate positive tropic responses of rice lateral roots. This phenomenon is a tropism of plant roots to nutrients; hence, we propose the name 'nutritropism'. As well as other tropisms, differential cell elongation was observed before the elongation zone during nutritropism, but the pattern promoting cell elongation preferentially on the non-stimulated side was opposite to those in root hydrotropism and gravitropism. Our evaluation of the NH4+ gradient suggested that the root tips responded to a sub-micromolar difference in NH4+ concentration on both sides of the root. Hydrotropism, gravitropism and phototropism were described in plants as the 'power of movement' by Charles and Francis Darwin in 1880, and these three tropisms have attracted the attention of plant scientists for more than 130 years. Our discovery of nutritropism represents the fourth 'power of movement' in plants and provides a novel root behavioral property used by plants to acquire nutrients efficiently.


Asunto(s)
Nutrientes/metabolismo , Oryza/fisiología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Tropismo/fisiología , Compuestos de Amonio/metabolismo , Transporte Biológico , Gravitropismo/fisiología , Nitrógeno/metabolismo , Fototropismo/fisiología , Suelo , Agua
10.
Plant Cell Physiol ; 61(3): 457-469, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31697317

RESUMEN

In plants, reversible histone acetylation and deacetylation play a crucial role in various biological activities, including development and the response to environmental stress. Histone deacetylation, which is generally associated with gene silencing, is catalyzed by multiple histone deacetylases (HDACs). Our understanding of HDAC function in plant development has accumulated from molecular genetic studies in Arabidopsis thaliana. By contrast, how HDACs contribute to the development of rice (Oryza sativa) is poorly understood and no rice mutants of HDAC have been reported. Here we have characterized a new rice mutant showing semi-dwarfism, which we named dwarf with slender leaf1 (dsl1). The mutant showed pleiotropic defects in both vegetative and reproductive developments; e.g. dsl1 produced short and narrow leaves, accompanied by a reduction in the number and size of vascular bundles. The semi-dwarf phenotype was due to suppression of the elongation of some culm (stem) internodes. Interestingly, despite this suppression of the upper internodes, the elongation and generation of lower internodes were slightly enhanced. Inflorescence and spikelet development were also affected by the dsl1 mutation. Some of the observed morphological defects were related to a reduction in cell numbers, in addition to reduced cell division in leaf primordia revealed by in situ hybridization analysis, suggesting the possibility that DSL1 is involved in cell division control. Gene cloning revealed that DSL1 encodes an HDAC belonging to the reduced potassium dependence3/histone deacetylase1 family. Collectively, our study shows that the HDAC DSL1 plays diverse and important roles in development in rice.


Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Oryza/crecimiento & desarrollo , Oryza/metabolismo , División Celular , Clonación Molecular , Genes de Plantas , Histonas/metabolismo , Mutación , Oryza/genética , Fenotipo , Hojas de la Planta/citología , Hojas de la Planta/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Brotes de la Planta/citología , Brotes de la Planta/crecimiento & desarrollo
11.
Plant J ; 96(5): 997-1006, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30194869

RESUMEN

Essential metal absorption for plant growth is mediated predominantly by metal-specific transporters, with expression that responds to the environmental or cellular conditions of specific metals. Differing from metal-specific regulation, we describe a constitutively expressed transcription factor that regulates the transport of several metals in rice. We characterized the rice mutant LOW CADMIUM 5 (LC5), which exhibited reduced growth and accumulation of essential metals (e.g., copper [Cu], zinc [Zn] and manganese [Mn]) in shoots. LC5 was dwarf and developed less tillers than the wild type, but the structure of vasculature was apparently normal. Molecular genetic analysis revealed that the causal gene of LC5 is an ortholog of the transcriptional regulator Arabidopsis thaliana TITANIA (TTA), known as a transcriptional regulator. Expression analyses demonstrated that the OsTTA gene encodes a nucleus-localized protein containing a plant homeodomain-finger (PHD-finger) domain and is expressed ubiquitously in rice plants. RNA sequencing and quantitative PCR analyses revealed that the mRNA accumulation of transporter genes for essential metals, including iron (Fe), Zn, or Mn, were substantially lower in LC5 roots than in the wild type. Unlike known transcription factors of metal transport regulation, OsTTA transcript accumulation was not affected by metal availability. In addition, the growth defect of LC5 was partially rescued by Fe, Zn, or Mn supplementation, respectively. Taken together, OsTTA is a constitutively expressed regulator of multiple metal transporter genes responsible for essential metals delivery to shoots for their normal growth.


Asunto(s)
Proteínas de Transporte de Membrana/genética , Oryza/metabolismo , Dedos de Zinc PHD/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Cadmio/metabolismo , Cobre/metabolismo , Genes de Plantas/genética , Hierro/metabolismo , Manganeso/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Mutación , Oryza/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Zinc/metabolismo
12.
Cytokine ; 118: 80-92, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30017387

RESUMEN

Many tumor cells escape from cancer immunosurveillance and resist treatment with interferons (IFNs). Although the mechanism underlying IFN resistance is mostly attributed to a deficiency of components of the IFN-signaling pathway, some types of tumor cells resist IFN-mediated cell growth arrest despite the presence of an intact JAK/STAT signaling pathway. However, the molecular mechanisms underlying the unresponsiveness to IFNs independent of the defective JAK/STAT pathway remain to be clarified. To elucidate the mechanisms underlying IFNγ resistance, we examined the anti-proliferative effect of IFNγ on mouse tumor cell lines. Mouse squamous cell carcinoma (SCCVII) cells were resistant to IFNγ-mediated cell growth arrest despite the presence of the IFNγ-induced STAT1-dependent signaling pathway, whereas IFNγ inhibited cell growth of B16/F1 cells, a well-known IFNγ-sensitive mouse melanoma cell line, at the G1 phase of the cell cycle. Treatment of SCCVII cells with IFNγ neither downregulated the expression of cyclin D1, cyclin A2, and cyclin E1 nor induced a hypo-phosphorylated, active form of retinoblastoma protein (pRb). Interestingly, the hyper-phosphorylated, inactive form of pRb was exclusively localized in the cytoplasm in SCCVII cells. The IFN-inducible 204 gene (Ifi204), whose gene product, p204, binds to pRb and exerts an anti-proliferative effect, was repressed in SCCVII cells. p204 overexpression in SCCVII significantly inhibited cell growth, and mutation of a pRb-binding LXCXE motif decreased the anti-proliferative effect. These results suggest that silencing of Ifi204/p204 induces resistance to IFNγ-mediated cell growth arrest in SCCVII cells.


Asunto(s)
Proliferación Celular/genética , Inhibidores de Crecimiento/genética , Interferón gamma/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Animales , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Regulación hacia Abajo/genética , Fase G1/genética , Melanoma/genética , Melanoma/patología , Ratones , Fosforilación/genética , Unión Proteica/genética , Proteína de Retinoblastoma/genética , Transducción de Señal/genética
13.
Plant Cell ; 27(4): 1173-84, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25841039

RESUMEN

Axillary shoot formation is a key determinant of plant architecture. Formation of the axillary shoot is regulated by initiation of the axillary meristem or outgrowth of the axillary bud. Here, we show that rice (Oryza sativa) TILLERS ABSENT1 (TAB1; also known as Os WUS), an ortholog of Arabidopsis thaliana WUS, is required to initiate axillary meristem development. We found that formation of the axillary meristem in rice proceeds via a transient state, which we term the premeristem, characterized by the expression of OSH1, a marker of indeterminate cells in the shoot apical meristem. In the tab1-1 (wus-1) mutant, however, formation of the axillary meristem is arrested at various stages of the premeristem zone, and OSH1 expression is highly reduced. TAB1/WUS is expressed in the premeristem zone, where it shows a partially overlapping pattern with OSH1. It is likely, therefore, that TAB1 plays an important role in maintaining the premeristem zone and in promoting the formation of the axillary meristem by promoting OSH1 expression. Temporal expression patterns of WUSCHEL-RELATED HOMEOBOX4 (WOX4) indicate that WOX4 is likely to regulate meristem maintenance instead of TAB1 after establishment of the axillary meristem. Lastly, we show that the prophyll, the first leaf in the secondary axis, is formed from the premeristem zone and not from the axillary meristem.


Asunto(s)
Meristema/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Meristema/genética , Oryza/genética , Proteínas de Plantas/genética , Unión Proteica
14.
Mediators Inflamm ; 2018: 3979606, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30158833

RESUMEN

During chronic inflammation from diseases, such as periodontal disease, the proinflammatory cytokines interferon-gamma (IFNγ) and tumor necrosis factor-α (TNFα) alter bone remodeling. To elucidate the underlying molecular mechanisms, we investigated the effect of IFNγ and TNFα on the proliferation and survival of clonal MC3T3-E1 mouse osteoblasts. We found that although IFNγ or TNFα alone affected cell growth and survival only marginally, costimulation with both synergistically inhibited cell growth and reduced cell viability. The diminished cell viability was due to apoptosis, as indicated by increased TUNEL staining and elevated caspase 3, 8, and 9 activities. Western blot also showed that costimulation with IFNγ and TNFα elicited cytochrome c release and downregulated B cell lymphoma 2 (Bcl-2) expression without affecting Bcl-2-associated X (Bax) protein expression. Furthermore, stable Bcl-2 overexpression significantly alleviated cell death following costimulation. Collectively, these results suggested that IFNγ and TNFα elicited osteoblast apoptosis via cytochrome c release from damaged mitochondria, caspase activation, and Bcl-2 downregulation.


Asunto(s)
Citocromos c/metabolismo , Interferón gamma/farmacología , Mitocondrias/metabolismo , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Etiquetado Corte-Fin in Situ , Ratones , Mitocondrias/efectos de los fármacos , Proteína X Asociada a bcl-2/metabolismo
16.
Plant Physiol ; 171(1): 566-79, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26979330

RESUMEN

Phosphorus (P) is a crucial nutrient for plant growth, but its availability to roots is limited in soil. Arbuscular mycorrhizal (AM) symbiosis is a promising strategy for improving plant P acquisition. However, P fertilizer reduces fungal colonization (P inhibition) and compromises mycorrhizal P uptake, warranting studies on the mechanistic basis of P inhibition. In this study, early morphological changes in P inhibition were identified in rice (Oryza sativa) using fungal cell wall staining and live-cell imaging of plant membranes that were associated with arbuscule life cycles. Arbuscule density decreased, and aberrant hyphal branching was observed in roots at 5 h after P treatment. Although new arbuscule development was severely inhibited, preformed arbuscules remained intact and longevity remained constant. P inhibition was accelerated in the rice pt11-1 mutant, which lacks P uptake from arbuscule branches, suggesting that mature arbuscules are stabilized by the symbiotic P transporter under high P condition. Moreover, P treatment led to increases in the number of vesicles, in which lipid droplets accumulated and then decreased within a few days. The development of new arbuscules resumed within by 2 d. Our data established that P strongly and temporarily inhibits new arbuscule development, but not intraradical accommodation of AM fungi.


Asunto(s)
Micorrizas/crecimiento & desarrollo , Oryza/microbiología , Fósforo/farmacología , Raíces de Plantas/microbiología , Proteínas Fluorescentes Verdes/genética , Micorrizas/efectos de los fármacos , Oryza/efectos de los fármacos , Oryza/fisiología , Fosfatos/farmacología , Fósforo/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Plantones/microbiología , Simbiosis/fisiología
17.
Plant Cell ; 25(1): 229-41, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23371950

RESUMEN

The shoot apical meristem is the ultimate source of the cells that constitute the entire aboveground portion of the plant body. In Arabidopsis thaliana, meristem maintenance is regulated by the negative feedback loop of WUSCHEL-CLAVATA (WUS-CLV). Although CLV-like genes, such as FLORAL ORGAN NUMBER1 (FON1) and FON2, have been shown to be involved in maintenance of the reproductive meristems in rice (Oryza sativa), current understanding of meristem maintenance remains insufficient. In this article, we demonstrate that the FON2-LIKE CLE PROTEIN1 (FCP1) and FCP2 genes encoding proteins with similar CLE domains are involved in negative regulation of meristem maintenance in the vegetative phase. In addition, we found that WUSCHEL-RELATED HOMEOBOX4 (WOX4) promotes the undifferentiated state of the meristem in rice and that WOX4 function is associated with cytokinin action. Consistent with similarities in the shoot apical meristem phenotypes caused by overexpression of FCP1 and downregulation of WOX4, expression of WOX4 was negatively regulated by FCP1 (FCP2). Thus, FCP1/2 and WOX4 are likely to be involved in maintenance of the vegetative meristem in rice.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/genética , Meristema/genética , Oryza/genética , Proteínas de Plantas/genética , Arabidopsis/citología , Arabidopsis/genética , Arabidopsis/fisiología , Regulación hacia Abajo , Flores/citología , Flores/genética , Flores/fisiología , Expresión Génica , Proteínas de Homeodominio/metabolismo , Meristema/citología , Meristema/fisiología , Mutación , Oryza/citología , Oryza/fisiología , Fenotipo , Hojas de la Planta/citología , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Proteínas de Plantas/metabolismo , Brotes de la Planta/citología , Brotes de la Planta/genética , Brotes de la Planta/fisiología , Plantas Modificadas Genéticamente , Estructura Terciaria de Proteína , Interferencia de ARN
18.
Plant Cell ; 24(1): 80-95, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22286138

RESUMEN

The meristem initiates lateral organs in a regular manner, and proper communication between the meristem and the lateral organs ensures the normal development of plants. Here, we show that mutation of the rice (Oryza sativa) gene TONGARI-BOUSHI1 (TOB1) results in pleiotropic phenotypes in spikelets, such as the formation of a cone-shaped organ instead of the lemma or palea, the development of two florets in a spikelet, or premature termination of the floret meristem, in addition to reduced growth of the lemma or palea and elongation of the awn. These phenotypes seem to result from not only failure in growth of the lateral organs, but also defects in maintenance and organization of the meristem. For example, the cone-shaped organ develops as a ring-like primordium from an initial stage, suggesting that regulation of organ initiation in the meristem may be compromised. TOB1 encodes a YABBY protein, which is closely related to FILAMENTOUS FLOWER in Arabidopsis thaliana, and is expressed in the lateral organ primordia without any patterns of polarization. No TOB1 expression is detected in the meristem, so TOB1 may act non-cell autonomously to maintain proper meristem organization and is therefore likely to play an important role in rice spikelet development.


Asunto(s)
Meristema/crecimiento & desarrollo , Meristema/metabolismo , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Meristema/genética , Datos de Secuencia Molecular , Oryza/genética , Proteínas de Plantas/genética
19.
BMC Cancer ; 15: 573, 2015 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-26242181

RESUMEN

BACKGROUND: Tumor-associated macrophages (TAMs) are implicated in the growth, invasion and metastasis of various solid tumors. However, the phenotype of TAMs in premalignant lesions of solid tumors has not been clarified. In the present study, we identify the phenotype of TAMs in leukoplakia, an oral premalignant lesion, by immunohistochemical analysis and investigate the involvement of infiltrated T cells that participate in the polarization of TAMs. METHODS: The subjects included 30 patients with oral leukoplakia and 10 individuals with normal mucosa. Hematoxylin and eosin slides were examined for the histological grades, and immunohistochemical analysis was carried out using antibodies against CD68 (pan-MΦ), CD80 (M1 MΦ), CD163 (M2 MΦ), CD4 (helper T cells: Th), CD8 (cytotoxic T cells), CXCR3, CCR5 (Th1), CCR4 (Th2), signal transducer and activator of transcription (STAT1), phosphorylated STAT1 (pSTAT1) and chemokine CXCL9. The differences in the numbers of positively stained cells among the different histological grades were tested for statistical significance using the Kruskal-Wallis test. Correlations between different types of immune cells were determined using Spearman's rank analysis. RESULTS: An increase in the rate of CD163(+) TAM infiltration was observed in mild and moderate epithelial dysplasia, which positively correlated with the rate of intraepithelial CD4(+) Th cell infiltration. Although CCR4(+) cells rarely infiltrated, CXCR3(+) and CCR5(+) cells were observed in these lesions. Cells positive for STAT1 and chemokine CXCL9, interferon- (IFN)-induced gene products, and pSTAT1 were also observed in the same lesions. Double immunofluorescence staining demonstrated that the cells that were positive for CD163 were also positive for STAT1. CONCLUSIONS: CD163(+) TAMs in oral premalignant lesions coexpress CD163 and STAT1, suggesting that the TAMs in oral premalignant lesions possess an M1 phenotype in a Th1-dominated micromilieu.


Asunto(s)
Antígenos CD/genética , Antígenos de Diferenciación Mielomonocítica/genética , Macrófagos/metabolismo , Macrófagos/patología , Neoplasias de la Boca/genética , Neoplasias de la Boca/patología , Lesiones Precancerosas , Receptores de Superficie Celular/genética , Factor de Transcripción STAT1/genética , Células TH1/metabolismo , Adulto , Anciano , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Biomarcadores , Biopsia , Estudios de Casos y Controles , Femenino , Humanos , Leucopenia/genética , Leucopenia/inmunología , Leucopenia/patología , Macrófagos/inmunología , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/inmunología , Clasificación del Tumor , Unión Proteica , Transporte de Proteínas , Receptores CXCR3/metabolismo , Receptores de Superficie Celular/metabolismo , Factor de Transcripción STAT1/metabolismo , Células TH1/inmunología , Microambiente Tumoral
20.
J Plant Res ; 127(1): 67-71, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24338063

RESUMEN

After the accident of the Fukushima 1 nuclear power plant in March 2011, radioactive cesium was released and paddy field in a wide area of Fukushima Prefecture was contaminated. To reduce radioactive Cs uptake by rice, it is important to understand factors that affect Cs uptake in rice. Here we describe our study in 2011 and 2012 to investigate Cs concentration in two rice cultivars, Koshihikari and Hitomebore, the top two cultivars in Fukushima prefecture, grown under different fertilizer conditions in the contaminated paddy field. Our study demonstrated that high nitrogen and low potassium conditions increase Cs concentrations both in straw and brown rice.


Asunto(s)
Radioisótopos de Cesio/metabolismo , Accidente Nuclear de Fukushima , Oryza/metabolismo , Suelo/química , Agricultura , Biodegradación Ambiental , Isótopos de Cesio/análisis , Isótopos de Cesio/metabolismo , Radioisótopos de Cesio/análisis , Fertilizantes , Japón , Nitrógeno/farmacología , Plantas de Energía Nuclear , Oryza/química , Oryza/efectos de los fármacos , Tallos de la Planta/química , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/metabolismo , Potasio/farmacología , Monitoreo de Radiación , Semillas/química , Semillas/efectos de los fármacos , Semillas/metabolismo , Contaminantes Radiactivos del Suelo/análisis , Contaminantes Radiactivos del Suelo/metabolismo , Especificidad de la Especie
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