Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
Más filtros











Intervalo de año de publicación
1.
BMC Genomics ; 25(1): 797, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39179980

RESUMEN

BACKGROUND: R2R3-MYB transcription factors belong to one of the largest gene subfamilies in plants, and they are involved in diverse biological processes. However, the role of R2R3-MYB transcription factor subfamily genes in the response of rice (Oryza sativa L.) to salt stress has been rarely reported. RESULTS: In this study, we performed a genome-wide characterization and expression identification of rice R2R3-MYB transcription factor subfamily genes. We identified a total of 117 R2R3-MYB genes in rice and characterized their gene structure, chromosomal location, and cis-regulatory elements. According to the phylogenetic relationships and amino acid sequence homologies, the R2R3-MYB genes were divided into four groups. qRT-PCR of the R2R3-MYB genes showed that the expression levels of 10 genes significantly increased after 3 days of 0.8% NaCl treatment. We selected a high expression gene OsMYB2-115 for further analysis. OsMYB2-115 was highly expressed in the roots, stem, leaf, and leaf sheath. OsMYB2-115 was found to be localized in the nucleus, and the yeast hybrid assay showed that OsMYB2-115 has transcriptional activation activity. CONCLUSION: This result provides important information for the functional analyses of rice R2R3-MYB transcription factor subfamily genes related to the salt stress response and reveals that OsMYB2-115 may be an important gene associated with salt tolerance in rice.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Oryza , Filogenia , Proteínas de Plantas , Estrés Salino , Factores de Transcripción , Oryza/genética , Oryza/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Estrés Salino/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genoma de Planta , Familia de Multigenes , Perfilación de la Expresión Génica , Cromosomas de las Plantas/genética
2.
Plant Biotechnol J ; 21(11): 2224-2240, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37432878

RESUMEN

Starch accounts for up to 90% of the dry weight of rice endosperm and is a key determinant of grain quality. Although starch biosynthesis enzymes have been comprehensively studied, transcriptional regulation of starch-synthesis enzyme-coding genes (SECGs) is largely unknown. In this study, we explored the role of a NAC transcription factor, OsNAC24, in regulating starch biosynthesis in rice. OsNAC24 is highly expressed in developing endosperm. The endosperm of osnac24 mutants is normal in appearance as is starch granule morphology, while total starch content, amylose content, chain length distribution of amylopectin and the physicochemical properties of the starch are changed. In addition, the expression of several SECGs was altered in osnac24 mutant plants. OsNAC24 is a transcriptional activator that targets the promoters of six SECGs; OsGBSSI, OsSBEI, OsAGPS2, OsSSI, OsSSIIIa and OsSSIVb. Since both the mRNA and protein abundances of OsGBSSI and OsSBEI were decreased in the mutants, OsNAC24 functions to regulate starch synthesis mainly through OsGBSSI and OsSBEI. Furthermore, OsNAC24 binds to the newly identified motifs TTGACAA, AGAAGA and ACAAGA as well as the core NAC-binding motif CACG. Another NAC family member, OsNAP, interacts with OsNAC24 and coactivates target gene expression. Loss-of-function of OsNAP led to altered expression in all tested SECGs and reduced the starch content. These results demonstrate that the OsNAC24-OsNAP complex plays key roles in fine-tuning starch synthesis in rice endosperm and further suggest that manipulating the OsNAC24-OsNAP complex regulatory network could be a potential strategy for breeding rice cultivars with improved cooking and eating quality.


Asunto(s)
Endospermo , Oryza , Endospermo/genética , Endospermo/metabolismo , Oryza/metabolismo , Fitomejoramiento , Almidón/metabolismo , Amilopectina/metabolismo , Amilosa/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
3.
Theor Appl Genet ; 136(5): 117, 2023 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-37093272

RESUMEN

KEY MESSAGE: Mapping of QTLs for dorsal aleurone thickness (DAT) was performed using chromosome segment substitution lines in rice. Three QTLs, qDAT3.1, qDAT3.2, and qDAT7.1, were detected in multiple environments. As a specified endosperm cell type, the aleurone has an abundance of various nutrients. Increasing the number of aleurone layers is a practicable way of developing highly nutritious cereals. Identifying genes that can increase aleurone thickness is useful for the breeding of aleurone traits to improve the nutritional and health values of rice. Here, we found that iodine staining could efficiently distinguish the aleurone layers, which revealed great variation of the aleurone thickness in rice, especially at the dorsal side of the seed. Therefore, we used a population of chromosome segmental substitution lines (CSSLs) derived from Koshihikari and Nona Bokra for quantitative trait locus (QTL) analysis of the dorsal aleurone thickness (DAT). Three QTLs, qDAT3.1, qDAT3.2, and qDAT7.1, were detected in multiple seasons. Among these, qDAT3.2 colocalizes with Hd6 and Hd16, two QTLs previously identified to regulate the heading date of Koshihikari, explaining the negative correlation between the DAT and days to heading (DTH) in rice. We also provide evidence that early-heading ensures the filling of rice seed under a relatively high temperature to promote aleurone thickening. qDAT7.1, the most stable QTL expressed in different environments, functions independently from heading date. Although Nona Bokra has a lower DAT, its qDAT7.1 allele significantly increased DAT in rice, which was further validated using two near-isogenic lines (NILs). These findings pave the way for further gene cloning of aleurone-related QTLs and may aid the development of highly nutritious rice.


Asunto(s)
Oryza , Sitios de Carácter Cuantitativo , Oryza/genética , Cromosomas de las Plantas , Fitomejoramiento
4.
Front Plant Sci ; 13: 905148, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35651773

RESUMEN

Grain size and the endosperm starch content determine grain yield and quality in rice. Although these yield components have been intensively studied, their regulatory mechanisms are still largely unknown. In this study, we show that loss-of-function of OsNAC129, a member of the NAC transcription factor gene family that has its highest expression in the immature seed, greatly increased grain length, grain weight, apparent amylose content (AAC), and plant height. Overexpression of OsNAC129 had the opposite effect, significantly decreasing grain width, grain weight, AAC, and plant height. Cytological observation of the outer epidermal cells of the lemma using a scanning electron microscope (SEM) revealed that increased grain length in the osnac129 mutant was due to increased cell length compared with wild-type (WT) plants. The expression of OsPGL1 and OsPGL2, two positive grain-size regulators that control cell elongation, was consistently upregulated in osnac129 mutant plants but downregulated in OsNAC129 overexpression plants. Furthermore, we also found that several starch synthase-encoding genes, including OsGBSSI, were upregulated in the osnac129 mutant and downregulated in the overexpression plants compared with WT plants, implying a negative regulatory role for OsNAC129 both in grain size and starch biosynthesis. Additionally, we found that the expression of OsNAC129 was induced exclusively by abscisic acid (ABA) in seedlings, but OsNAC129-overexpressing plants displayed reduced sensitivity to exogenous brassinolide (BR). Therefore, the results of our study demonstrate that OsNAC129 negatively regulates seed development and plant growth, and further suggest that OsNAC129 participates in the BR signaling pathway.

5.
Front Plant Sci ; 13: 1050882, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36714703

RESUMEN

Rice is a major food crop that sustains approximately half of the world population. Recent worldwide improvements in the standard of living have increased the demand for high-quality rice. Accurate identification of quantitative trait loci (QTLs) for rice grain quality traits will facilitate rice quality breeding and improvement. In the present study, we performed high-resolution QTL mapping for rice grain quality traits using a genotyping-by-sequencing approach. An F2 population derived from a cross between an elite japonica variety, Koshihikari, and an indica variety, Nona Bokra, was used to construct a high-density genetic map. A total of 3,830 single nucleotide polymorphism markers were mapped to 12 linkage groups spanning a total length of 2,456.4 cM, with an average genetic distance of 0.82 cM. Seven grain quality traits-the percentage of whole grain, percentage of head rice, percentage of area of head rice, transparency, percentage of chalky rice, percentage of chalkiness area, and degree of chalkiness-of the F2 population were investigated. In total, 15 QTLs with logarithm of the odds (LOD) scores >4 were identified, which mapped to chromosomes 6, 7, and 9. These loci include four QTLs for transparency, four for percentage of chalky rice, four for percentage of chalkiness area, and three for degree of chalkiness, accounting for 0.01%-61.64% of the total phenotypic variation. Of these QTLs, only one overlapped with previously reported QTLs, and the others were novel. By comparing the major QTL regions in the rice genome, several key candidate genes reported to play crucial roles in grain quality traits were identified. These findings will expedite the fine mapping of these QTLs and QTL pyramiding, which will facilitate the genetic improvement of rice grain quality.

6.
Mol Plant ; 12(8): 1123-1142, 2019 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-31075443

RESUMEN

As sessile organisms, plants have evolved numerous strategies to acclimate to changes in environmental temperature. However, the molecular basis of this acclimation remains largely unclear. In this study we identified a tRNAHis guanylyltransferase, AET1, which contributes to the modification of pre-tRNAHis and is required for normal growth under high-temperature conditions in rice. Interestingly, AET1 possibly interacts with both RACK1A and eIF3h in the endoplasmic reticulum. Notably, AET1 can directly bind to OsARF mRNAs including the uORFs of OsARF19 and OsARF23, indicating that AET1 is associated with translation regulation. Furthermore, polysome profiling assays suggest that the translational status remains unaffected in the aet1 mutant, but that the translational efficiency of OsARF19 and OsARF23 is reduced; moreover, OsARF23 protein levels are obviously decreased in the aet1 mutant under high temperature, implying that AET1 regulates auxin signaling in response to high temperature. Our findings provide new insights into the molecular mechanisms whereby AET1 regulates the environmental temperature response in rice by playing a dual role in tRNA modification and translational control.


Asunto(s)
Regulación de la Expresión Génica de las Plantas/fisiología , Oryza/metabolismo , Oryza/fisiología , Regulación de la Expresión Génica de las Plantas/genética , Calor , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo , Oryza/genética , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , Temperatura
7.
Plant Cell ; 30(4): 871-888, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29588389

RESUMEN

Grain number and size are interactive agronomic traits that determine grain yield. However, the molecular mechanisms responsible for coordinating the trade-off between these traits remain elusive. Here, we characterized the rice (Oryza sativa) grain size and number1 (gsn1) mutant, which has larger grains but sparser panicles than the wild type due to disordered localized cell differentiation and proliferation. GSN1 encodes the mitogen-activated protein kinase phosphatase OsMKP1, a dual-specificity phosphatase of unknown function. Reduced expression of GSN1 resulted in larger and fewer grains, whereas increased expression resulted in more grains but reduced grain size. GSN1 directly interacts with and inactivates the mitogen-activated protein kinase OsMPK6 via dephosphorylation. Consistent with this finding, the suppression of mitogen-activated protein kinase genes OsMPK6, OsMKK4, and OsMKKK10 separately resulted in denser panicles and smaller grains, which rescued the mutant gsn1 phenotypes. Therefore, OsMKKK10-OsMKK4-OsMPK6 participates in panicle morphogenesis and acts on a common pathway in rice. We confirmed that GSN1 is a negative regulator of the OsMKKK10-OsMKK4-OsMPK6 cascade that determines panicle architecture. The GSN1-MAPK module coordinates the trade-off between grain number and grain size by integrating localized cell differentiation and proliferation. These findings provide important insights into the developmental plasticity of the panicle and a potential means to improve crop yields.


Asunto(s)
Oryza/genética , Proteínas de Plantas/metabolismo , Grano Comestible/genética , Grano Comestible/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Proteínas Quinasas Activadas por Mitógenos/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Oryza/crecimiento & desarrollo , Fenotipo , Proteínas de Plantas/genética
8.
Mol Plant ; 9(2): 233-244, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26537047

RESUMEN

In flowering plants, photoperiodic flowering is controlled by a complicated network. Light is one of the most important environmental stimuli that control the timing of the transition from vegetative growth to reproductive development. Several photoreceptors, including PHYA, PHYB, CRY2, and FKF1 in Arabidopsis and their homologs (OsPHYA, OsPHYB, OsPHYC, and OsCRY2) in rice, have been identified to be related to flowering. Our previous study suggests that OsHAL3, a flavin mononucleotide-binding protein, may function as a blue-light sensor. Here, we report the identification of OsHAL3 as a positive regulator of flowering in rice. OsHAL3 overexpression lines exhibited an early flowering phenotype, whereas downregulation of OsHAL3 expression by RNA interference delayed flowering under an inductive photoperiod (short-day conditions). The change in flowering time was not accompanied by altered Hd1 expression but rather by reduced accumulation of Hd3a and MADS14 transcripts. OsHAL3 and Hd1 colocalized in the nucleus and physically interacted in vivo under the dark, whereas their interaction was inhibited by white or blue light. Moreover, OsHAL3 directly bound to the promoter of Hd3a, especially before dawn. We conclude that OsHAL3, a novel light-responsive protein, plays an essential role in photoperiodic control of flowering time in rice, which is probably mediated by forming a complex with Hd1. Our findings open up new perspectives on the photoperiodic flowering pathway.


Asunto(s)
Flores/crecimiento & desarrollo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Flores/genética , Flores/metabolismo , Flores/efectos de la radiación , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Luz , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/efectos de la radiación , Proteínas de Plantas/genética , Regiones Promotoras Genéticas/efectos de la radiación , Unión Proteica/efectos de la radiación , Factores de Transcripción/genética
9.
PLoS Genet ; 11(10): e1005617, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26496194

RESUMEN

Natural disasters, including drought and salt stress, seriously threaten food security. In previous work we cloned a key zinc finger transcription factor gene, Drought and Salt Tolerance (DST), a negative regulator of drought and salt tolerance that controls stomatal aperture in rice. However, the exact mechanism by which DST regulates the expression of target genes remains unknown. In the present study, we demonstrated that DST Co-activator 1 (DCA1), a previously unknown CHY zinc finger protein, acts as an interacting co-activator of DST. DST was found to physically interact with itself and to form a heterologous tetramer with DCA1. This transcriptional complex appears to regulate the expression of peroxidase 24 precursor (Prx 24), a gene encoding an H2O2 scavenger that is more highly expressed in guard cells. Downregulation of DCA1 significantly enhanced drought and salt tolerance in rice, and overexpression of DCA1 increased sensitivity to stress treatment. These phenotypes were mainly influenced by DCA1 and negatively regulated stomatal closure through the direct modulation of genes associated with H2O2 homeostasis. Our findings establish a framework for plant drought and salt stress tolerance through the DCA1-DST-Prx24 pathway. Moreover, due to the evolutionary and functional conservation of DCA1 and DST in plants, engineering of this pathway has the potential to improve tolerance to abiotic stress in other important crop species.


Asunto(s)
Adaptación Fisiológica/genética , Peroxidasas/genética , Estrés Fisiológico/genética , Factores de Transcripción/genética , Sequías , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Oryza , Peroxidasas/biosíntesis , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Tolerancia a la Sal/genética , Dedos de Zinc/genética
10.
Nat Genet ; 47(7): 827-33, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25985140

RESUMEN

Global warming threatens many aspects of human life, for example, by reducing crop yields. Breeding heat-tolerant crops using genes conferring thermotolerance is a fundamental way to help deal with this challenge. Here we identify a major quantitative trait locus (QTL) for thermotolerance in African rice (Oryza glaberrima), Thermo-tolerance 1 (TT1), which encodes an α2 subunit of the 26S proteasome involved in the degradation of ubiquitinated proteins. Ubiquitylome analysis indicated that OgTT1 protects cells from heat stress through more efficient elimination of cytotoxic denatured proteins and more effective maintenance of heat-response processes than achieved with OsTT1. Variation in TT1 has been selected for on the basis of climatic temperature and has had an important role in local adaptation during rice evolution. In addition, we found that overexpression of OgTT1 was associated with markedly enhanced thermotolerance in rice, Arabidopsis and Festuca elata. This discovery may lead to an increase in crop security in the face of the ongoing threat of global warming.


Asunto(s)
Oryza/genética , Proteínas de Plantas/genética , Complejo de la Endopetidasa Proteasomal/genética , Adaptación Fisiológica , Alelos , Secuencia de Aminoácidos , Genes de Plantas , Estudios de Asociación Genética , Respuesta al Choque Térmico , Datos de Secuencia Molecular , Oryza/enzimología , Sitios de Carácter Cuantitativo
11.
Biol Trace Elem Res ; 166(2): 173-82, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25693680

RESUMEN

Fluoride compounds are abundant and widely distributed in the environment at a variety of concentrations. Further, fluoride induces toxic effects in target organs such as the liver. In this study, we investigated liver histopathology, DNA damage, apoptosis, and the mRNA and protein expressions of caspase-3 and -9 in the rat livers by administering varying concentrations of fluoride (0, 50, 100, 200 mg/L ) for 120 days. The results showed fluoride-induced morphological changes and significantly increased apoptosis and DNA damage in rats exposed to fluoride, especially in response to higher doses. The immunohistochemical and qRT-PCR results indicated that caspase-3, caspase-9 protein positive expression and mRNA relative expression enhanced with increasing NaF concentration. In summary, our findings suggest that chronic exposure to fluoride causes damages to liver histopathology and leads to liver apoptosis through caspase-mediated pathways.


Asunto(s)
Caspasas/metabolismo , Daño del ADN/efectos de los fármacos , Fluoruros/farmacología , Hígado/efectos de los fármacos , Hígado/metabolismo , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Caspasa 3/genética , Caspasa 3/metabolismo , Caspasa 9/genética , Caspasa 9/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley
12.
Plant J ; 80(6): 1108-17, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25345491

RESUMEN

Young organisms have relatively strong resistance to diseases and adverse conditions. When confronted with adversity, the process of development is delayed in plants. This phenomenon is thought to result from the rebalancing of energy, which helps plants to coordinate the relationship between development and stress tolerance; however, the molecular mechanism underlying this phenomenon remains mysterious. In this study, we found that miR156 integrates environmental signals to ensure timely flowering, thus enabling the completion of breeding. Under stress conditions, miR156 is induced to maintain the plant in the juvenile state for a relatively long period of time, whereas under favorable conditions, miR156 is suppressed to accelerate the developmental transition. Blocking the miR156 signaling pathway in Arabidopsis thaliana with 35S::MIM156 (via target mimicry) increased the sensitivity of the plant to stress treatment, whereas overexpression of miR156 increased stress tolerance. In fact, this mechanism is also conserved in Oryza sativa (rice). We also identified downstream genes of miR156, i.e. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 9 (SPL9) and DIHYDROFLAVONOL-4-REDUCTASE (DFR), which take part in this process by influencing the metabolism of anthocyanin. Our results uncover a molecular mechanism for plant adaptation to the environment through the miR156-SPLs-DFR pathway, which coordinates development and abiotic stress tolerance.


Asunto(s)
Adaptación Fisiológica , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , MicroARNs/genética , Transducción de Señal , Oxidorreductasas de Alcohol/genética , Oxidorreductasas de Alcohol/metabolismo , Antocianinas/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/crecimiento & desarrollo , Flores/fisiología , Regulación del Desarrollo de la Expresión Génica , MicroARNs/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/fisiología , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas/genética , Estrés Fisiológico , Transactivadores/genética , Transactivadores/metabolismo
13.
J. physiol. biochem ; 70(3): 761-768, sept. 2014.
Artículo en Inglés | IBECS | ID: ibc-127320

RESUMEN

The biological effects of fluoride on human health are often extensive, either beneficial or detrimental. Among the various effects of fluoride exposure in different organs, the reproductive tract is particularly susceptible to disruption by fluoride at a sufficient concentration. It has attracted much attention to the effect of sodium fluoride on male fertility, gestational female, and offspring. Herein, we applied a widespread natural compound sodium fluoride (NaF) and investigated the effects of acute NaF exposure on Leydig cells, including their proliferation, apoptosis, and signal pathway changes. Our results demonstrated that high dosage of NaF could inhibit cell proliferation by stress-induced apoptosis, which was confirmed by cellular and molecular evidences. We found that fluoride exposure affected the expression levels of stress response factors, signal transduction components, and apoptosis-related proteins, including caspase-3/caspase-9, B-cell lymphoma 2 (Bcl-2), and Bax. This study suggests that the complex effects of fluoride on Leydig cells are closely related to its dosage


Asunto(s)
Animales , Ratones , Fluoruro de Sodio/farmacocinética , Proliferación Celular , Apoptosis , Células Intersticiales del Testículo , Caspasa 3 , Caspasa 9 , Linfoma de Células B , Fenómenos Fisiológicos Reproductivos
14.
J. physiol. biochem ; 70(3): 857-868, sept. 2014.
Artículo en Inglés | IBECS | ID: ibc-127329

RESUMEN

Long-term excessive sodium fluoride (NaF) intake can cause many bone diseases and nonskeletal fluorosis. The kidneys are the primary organs involved in the excretion and retention of NaF. The objective of the present study was to determine the effects of NaF treatment on renal cell apoptosis, DNA damage, and the protein expression levels of cytosolic cytochrome C (Cyt C) and cleaved caspases 9, 8, and 3 in vivo. Male Sprague-Dawley rats were divided randomly into four groups (control, low fluoride, medium fluoride, and high fluoride) and administered 0, 50, 100, and 200 mg/L of NaF, respectively, via drinking water for 120 days. Histopathological changes in the kidneys were visualized using hematoxylin and eosin staining. Renal cell apoptosis was examined using flow cytometry, and renal cell DNA damage was detected using the comet assay. Cytosolic Cyt C and cleaved caspases 9, 8, and 3 protein expression levels were visualized using immunohistochemistry and Western blotting. The results showed that NaF treatment increased apoptosis and DNA damage. In addition, NaF treatment increased the protein expression levels of cytosolic Cyt C and cleaved caspases 9, 8, and 3. These results indicated that NaF induces apoptosis in the kidney of rats through caspase-mediated pathway, and DNA damage may be involved in this process


Asunto(s)
Animales , Ratas , Fluoruro de Sodio/farmacocinética , Apoptosis , Caspasas/farmacocinética , Daño del ADN , Riñón
15.
J Physiol Biochem ; 70(3): 857-68, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25158646

RESUMEN

Long-term excessive sodium fluoride (NaF) intake can cause many bone diseases and nonskeletal fluorosis. The kidneys are the primary organs involved in the excretion and retention of NaF. The objective of the present study was to determine the effects of NaF treatment on renal cell apoptosis, DNA damage, and the protein expression levels of cytosolic cytochrome C (Cyt C) and cleaved caspases 9, 8, and 3 in vivo. Male Sprague-Dawley rats were divided randomly into four groups (control, low fluoride, medium fluoride, and high fluoride) and administered 0, 50, 100, and 200 mg/L of NaF, respectively, via drinking water for 120 days. Histopathological changes in the kidneys were visualized using hematoxylin and eosin staining. Renal cell apoptosis was examined using flow cytometry, and renal cell DNA damage was detected using the comet assay. Cytosolic Cyt C and cleaved caspases 9, 8, and 3 protein expression levels were visualized using immunohistochemistry and Western blotting. The results showed that NaF treatment increased apoptosis and DNA damage. In addition, NaF treatment increased the protein expression levels of cytosolic Cyt C and cleaved caspases 9, 8, and 3. These results indicated that NaF induces apoptosis in the kidney of rats through caspase-mediated pathway, and DNA damage may be involved in this process.


Asunto(s)
Apoptosis/efectos de los fármacos , Riñón/efectos de los fármacos , Fluoruro de Sodio/toxicidad , Animales , Apoptosis/fisiología , Caspasa 3/metabolismo , Caspasa 8/metabolismo , Caspasa 9/metabolismo , Citocromos c/metabolismo , Daño del ADN , Modelos Animales de Enfermedad , Fluorosis Dental/etiología , Fluorosis Dental/metabolismo , Fluorosis Dental/patología , Humanos , Riñón/metabolismo , Riñón/patología , Masculino , Redes y Vías Metabólicas/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Fluoruro de Sodio/administración & dosificación
16.
J Physiol Biochem ; 70(3): 761-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25074826

RESUMEN

The biological effects of fluoride on human health are often extensive, either beneficial or detrimental. Among the various effects of fluoride exposure in different organs, the reproductive tract is particularly susceptible to disruption by fluoride at a sufficient concentration. It has attracted much attention to the effect of sodium fluoride on male fertility, gestational female, and offspring. Herein, we applied a widespread natural compound sodium fluoride (NaF) and investigated the effects of acute NaF exposure on Leydig cells, including their proliferation, apoptosis, and signal pathway changes. Our results demonstrated that high dosage of NaF could inhibit cell proliferation by stress-induced apoptosis, which was confirmed by cellular and molecular evidences. We found that fluoride exposure affected the expression levels of stress response factors, signal transduction components, and apoptosis-related proteins, including caspase-3/caspase-9, B-cell lymphoma 2 (Bcl-2), and Bax. This study suggests that the complex effects of fluoride on Leydig cells are closely related to its dosage.


Asunto(s)
Células Intersticiales del Testículo/efectos de los fármacos , Fluoruro de Sodio/toxicidad , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Células Intersticiales del Testículo/metabolismo , Células Intersticiales del Testículo/patología , Masculino , Ratones , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal/efectos de los fármacos , Fluoruro de Sodio/administración & dosificación , Proteína X Asociada a bcl-2/metabolismo
17.
Nat Commun ; 5: 3357, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24556665

RESUMEN

Reproductive barriers perform a vital role during speciation. Hybrid weakness, the poorer development of hybrids compared with their parents, hinders gene exchange between different species at the postzygotic stage. Here we show that two incompatible dominant loci (Hwi1 and Hwi2) involving three genes are likely to determine the high temperature-dependent expression of hybrid weakness in interspecific hybrids of rice. Hwi1 comprises two leucine-rich repeat receptor-like kinase (LRR-RLK) genes, 25L1 and 25L2, which are specific to wild rice (Oryza rufipogon) and induce hybrid weakness. Hwi2, a rare allele that is predominantly distributed in indica rice (Oryza sativa), encodes a secreted putative subtilisin-like protease. Functional analysis indicated that pyramiding of Hwi1 and Hwi2 activates the autoimmune response in the basal nodes of hybrids, interrupting root formation and then impairing shoot growth. These findings bring new insights into our understanding of reproductive isolation and may benefit rice breeding.


Asunto(s)
Hibridación Genética/fisiología , Oryza/metabolismo , Oryza/fisiología , Proteínas de Plantas/metabolismo , Cruzamiento , Hibridación Genética/genética , Oryza/genética , Proteínas de Plantas/genética
18.
Methods Mol Biol ; 956: 69-82, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23135845

RESUMEN

Most agronomic traits are governed by quantitative trait loci (QTLs) and exhibit continuous distribution in a segregating population. The hereditary characteristics of these traits are more complicated than those of monogenic traits. Detection and isolation of these QTLs can greatly improve crop production throughout the world. In recent times, significant progress has been made toward understanding the molecular basis underlying quantitative traits. Herein, we describe a QTL-mapping protocol for detecting and cloning a major QTL regulating rice shoot K(+) concentration under salt stress conditions. This QTL-mapping approach combined with the marker-assisted selection technique can be applied for the elucidation of complex traits in rice and other cereal crops.


Asunto(s)
Mapeo Cromosómico , Clonación Molecular , Oryza/genética , Sitios de Carácter Cuantitativo , Tolerancia a la Sal/genética , Cromosomas de las Plantas , Genes de Plantas , Ligamiento Genético , Escala de Lod , Oryza/metabolismo , Mapeo Físico de Cromosoma , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Potasio/metabolismo , Reproducibilidad de los Resultados
19.
Mol Plant ; 6(3): 716-28, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23220941

RESUMEN

Hybrid weakness is an important reproductive barrier that hinders genetic exchange between different species at the post-zygotic stage. However, our understanding of the molecular mechanisms underlying hybrid weakness is limited. In this study, we report discovery of a novel interspecific hybrid weakness in a rice chromosome segment substitution line (CSSL) library derived from a cross between the indica variety Teqing (Oryza sativa) and common wild rice (O. rufipogon). The dominant Hybrid weakness i1 (Hwi1) gene from wild rice is genetically incompatible with Teqing and induced a set of weakness symptoms, including growth suppression, yield decrease, impaired nutrient absorption, and the retardation of crown root initiation. Phytohormone treatment showed that salicylic acid (SA) could restore the height of plants expressing hybrid weakness, while other phytohormones appear to have little effect. Fine mapping indicated that Hwi1 is located in a tandem leucine-rich repeat receptor-like kinase (LRR-RLK) gene cluster. Within the 13.2-kb candidate region on the short arm of chromosome 11, there are two annotated LRR-RLK genes, LOC_Os11g07230 and LOC_Os11g07240. The Teqing allele of LOC_Os11g07230 and the wild rice allele of LOC_Os11g07240 encode predicted functional proteins. Based on the genetic inheritance of hybrid weakness, LOC_Os11g07240 is implicated as the candidate gene for Hwi1. Functional analysis of Hwi1 will expand our knowledge of the regulation of hybrid weakness in rice.


Asunto(s)
Hibridación Genética , Oryza/genética , Oryza/fisiología , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas/genética , Estudios de Asociación Genética , Hibridación Genética/efectos de los fármacos , Endogamia , Iones/metabolismo , Oryza/efectos de los fármacos , Fenotipo , Filogenia , Mapeo Físico de Cromosoma , Reguladores del Crecimiento de las Plantas/farmacología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Sesquiterpenos/metabolismo , Especificidad de la Especie , Factores de Tiempo , Fitoalexinas
20.
Cell Res ; 22(12): 1666-80, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23147796

RESUMEN

Increased crop yields are required to support rapid population growth worldwide. Grain weight is a key component of rice yield, but the underlying molecular mechanisms that control it remain elusive. Here, we report the cloning and characterization of a new quantitative trait locus (QTL) for the control of rice grain length, weight and yield. This locus, GL3.1, encodes a protein phosphatase kelch (PPKL) family - Ser/Thr phosphatase. GL3.1 is a member of the large grain WY3 variety, which is associated with weaker dephosphorylation activity than the small grain FAZ1 variety. GL3.1-WY3 influences protein phosphorylation in the spikelet to accelerate cell division, thereby resulting in longer grains and higher yields. Further studies have shown that GL3.1 directly dephosphorylates its substrate, Cyclin-T1;3, which has only been rarely studied in plants. The downregulation of Cyclin-T1;3 in rice resulted in a shorter grain, which indicates a novel function for Cyclin-T in cell cycle regulation. Our findings suggest a new mechanism for the regulation of grain size and yield that is driven through a novel phosphatase-mediated process that affects the phosphorylation of Cyclin-T1;3 during cell cycle progression, and thus provide new insight into the mechanisms underlying crop seed development. We bred a new variety containing the natural GL3.1 allele that demonstrated increased grain yield, which indicates that GL3.1 is a powerful tool for breeding high-yield crops.


Asunto(s)
Ciclina T/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Sitios de Carácter Cuantitativo , Alelos , División Celular , Clonación Molecular , Ciclina T/genética , Regulación hacia Abajo , Genes de Plantas , Oryza/genética , Oryza/crecimiento & desarrollo , Fosforilación , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Semillas/genética , Semillas/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA