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1.
Mol Biol Rep ; 51(1): 626, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717621

RESUMO

BACKGROUND: Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most devastating diseases of rice leading to huge yield losses in Southeast Asia. The recessive resistance gene xa-45(t) from Oryza glaberrima IRGC102600B, mapped on rice chromosome 8, spans 80 Kb with 9 candidate genes on Nipponbare reference genome IRGSP-1.0. The xa-45(t) gene provides durable resistance against all the ten Xanthomonas pathotypes of Northern India, thus aiding in the expansion of recessive bacterial blight resistance gene pool. Punjab Rice PR127, carrying xa-45(t), was released for wider use in breeding programs. This study aims to precisely locate the target gene among the 9 candidates conferring resistance to bacterial blight disease. METHODS AND RESULTS: Sanger sequencing of all nine candidate genes revealed seven SNPs and an Indel between the susceptible parent Pusa 44 and the resistant introgression line IL274. The genotyping with polymorphic markers identified three recombinant breakpoints for LOC_Os08g42370, and LOC_Os08g42400, 15 recombinants for LOC_Os08g423420 and 26 for LOC_Os08g42440 out of 190 individuals. Relative expression analysis across six time intervals (0, 8, 24, 48, 72, and 96 h) after bacterial blight infection showed over expression of LOC_Os08g42410-specific transcripts in IL274 compared to Pusa 44, with a significant 4.46-fold increase observed at 72 h post-inoculation. CONCLUSIONS: The Indel marker at the locus LOC_Os08g42410 was found co-segregating with the phenotype, suggesting its candidacy towards xa-45(t). The transcript abundance assay provides strong evidence for the involvement of LOC_Os08g42410 in the resistance conferred by the bacterial blight gene xa-45(t).


Assuntos
Mapeamento Cromossômico , Resistência à Doença , Oryza , Doenças das Plantas , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Genes Recessivos , Genótipo , Oryza/genética , Oryza/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único/genética , Xanthomonas/patogenicidade
2.
BMC Pregnancy Childbirth ; 24(1): 498, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048938

RESUMO

BACKGROUND: SARS-CoV-2 infection in pregnant women during the third trimester resulted in overall adverse pregnancy outcomes compared to non-infected controls and a unique humoral and cellular response at delivery. In this study we aimed to assess the impact of SARS-CoV-2 infection on maternal/neonatal peripartum outcomes andimmunological profiles. METHOD: In this study, we recruited 304 SARS-CoV-2 infected pregnant women and 910 SARS-CoV-2 non-infected pregnant women who were admitted for delivery. Peripartum and neonates' outcomes response to SARS-CoV-2 infection were analyzed. Furthermore, we characterized the antibody and cytokines profile in SARS-CoV-2 infected maternal blood (MB) and cord blood (CB). We also assessed routine laboratory tests and liver function tests in MB before labor. Unpaired T test, Mann-Whitney test and Spearman test were used to analyze the data. RESULTS: SARS-CoV-2 infected pregnant women were significantly associated with increased risk of adverse pregnancy outcomes, including preterm labor (13.8% vs. 9.5%, p = 0.033) and meconium-stained amniotic fluid (8.9% vs. 5.5%, p = 0.039). The risk of low birth weight (< 2500 g) (10.5% vs. 6.5%, p = 0.021) and Apgar score < 8 at 1-minute (9.2% vs. 5.8%, p = 0.049) significantly increased in newborns from COVID-19 positive mothers than their counterparts. Our results showed that antibodies were increased in adverse-outcome SARS-CoV-2 infected mothers and their neonates, and abnormal proportion of immune cells were detected in SARS-CoV-2 infected mothers. While the immune response showed no difference between adverse-outcome infected pregnant women and normal-outcome infected pregnant women. Thus, SARS-CoV-2 infection during the third trimester of pregnancy induced a unique humoral and cellular response at delivery. CONCLUSION: SARS-CoV-2 infection closer to delivery could incline to adverse pregnancy outcomes. Therefore, the utmost care is required for SARS-CoV-2 infected pregnant women and their newborns. TRIAL REGISTRATION: The study protocol was approved by the Institutional Review Board of the First Hospital of Jilin University with the approval code number 23K170-001, and informed consent was obtained from all enrolled patients prior to sample collection.


Assuntos
COVID-19 , Complicações Infecciosas na Gravidez , Resultado da Gravidez , Terceiro Trimestre da Gravidez , SARS-CoV-2 , Humanos , Gravidez , Feminino , COVID-19/imunologia , Complicações Infecciosas na Gravidez/imunologia , Terceiro Trimestre da Gravidez/imunologia , Adulto , Recém-Nascido , SARS-CoV-2/imunologia , Sangue Fetal/imunologia , Período Periparto/imunologia , Anticorpos Antivirais/sangue , Citocinas/sangue , Trabalho de Parto Prematuro/imunologia
3.
Biol Reprod ; 108(3): 382-392, 2023 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-36504233

RESUMO

Maternal-fetal immune tolerance is a process that involves complex interactions of the immune system, and myeloid-derived suppressor cells have emerged as one of the novel immunomodulator in the maintenance of maternal-fetal immune tolerance. Myeloid-derived suppressor cells are myeloid progenitor cells with immunosuppressive activities on both innate and adaptive cells through various mechanisms. Emerging evidence demonstrates the accumulation of myeloid-derived suppressor cells during healthy pregnancy to establish maternal-fetal immune tolerance, placentation, and fetal-growth process. By contrast, the absence or decreased myeloid-derived suppressor cells in pregnancy complications like preeclampsia, preterm birth, stillbirth, and recurrent spontaneous abortion have been reported. Here, we have summarized the origin, mechanisms, and functions of myeloid-derived suppressor cells during pregnancy along with the recent advancements in this dynamic field. We also shed light on the immunomodulatory activity of myeloid-derived suppressor cells, which can be a foundation for potential therapeutic manipulation in immunological pregnancy complications.


Assuntos
Aborto Habitual , Células Supressoras Mieloides , Complicações na Gravidez , Nascimento Prematuro , Recém-Nascido , Gravidez , Feminino , Humanos , Placentação , Tolerância Imunológica
4.
Theor Appl Genet ; 136(7): 159, 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37344686

RESUMO

KEY MESSAGE: This work reports the physical mapping of an important gene affecting spike compactness located in a low-recombination region of hexaploid wheat. This work paves the way for the eventual isolation and characterization of the factor involved but also opens up possibilities to use this approach to precisely map other wheat genes located on proximal parts of wheat chromosomes that show highly reduced recombination. Mapping wheat genes, in the centromeric and pericentromeric regions (~ 2/3rd of a given chromosome), poses a formidable challenge due to highly suppressed recombination. Using an example of compact spike locus (C-locus), this study provides an approach to precisely map wheat genes in the pericentromeric and centromeric regions that house ~ 30% of wheat genes. In club-wheat, spike compactness is controlled by the dominant C-locus, but previous efforts have failed to localize it, on a particular arm of chromosome 2D. We integrated radiation hybrid (RH) and high-resolution genetic mapping to locate C-locus on the short arm of chromosome 2D. Flanking markers of the C-locus span a physical distance of 11.0 Mb (231.0-242 Mb interval) and contain only 11 high-confidence annotated genes. This work demonstrates the value of this integrated strategy in mapping dominant genes in the low-recombination regions of the wheat genome. A comparison of the mapping resolutions of the RH and genetic maps using common anchored markers indicated that the RH map provides ~ 9 times better resolution that the genetic map even with much smaller population size. This study provides a broadly applicable approach to fine map wheat genes in regions of suppressed recombination.


Assuntos
Mapeamento de Híbridos Radioativos , Triticum , Triticum/genética , Mapeamento Cromossômico , Recombinação Genética
5.
Plant Cell Physiol ; 63(11): 1607-1623, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36018059

RESUMO

Crop domestication has a tremendous impact on socioeconomic conditions and human civilization. Modern cultivars were domesticated from their wild progenitors thousands of years ago by the selection of natural variation by humans. New cultivars are being developed by crossing two or more compatible individuals. But the limited genetic diversity in the cultivars severely affects the yield and renders the crop susceptible to many biotic and abiotic stresses. Crop wild relatives (CWRs) are the rich reservoir for many valuable agronomic traits. The incorporation of useful genes from CWR is one of the sustainable approaches for enriching the gene pool of cultivated crops. However, CWRs are not suited for urban and intensive cultivation because of several undesirable traits. Researchers have begun to study the domestication traits in the CWRs and modify them using genome-editing tools to make them suitable for extensive cultivation. Growing evidence has shown that modification in these genes is not sufficient to bring the desired change in the neodomesticated crop. However, the other dynamic genetic factors such as microRNAs (miRNAs), transposable elements, cis-regulatory elements and epigenetic changes have reshaped the domesticated crops. The creation of allelic series for many valuable domestication traits through genome editing holds great potential for the accelerated development of neodomesticated crops. The present review describes the current understanding of the genetics of domestication traits that are responsible for the agricultural revolution. The targeted mutagenesis in these domestication genes via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 could be used for the rapid domestication of CWRs.


Assuntos
Domesticação , Edição de Genes , Humanos , Produtos Agrícolas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Agricultura
6.
BMC Plant Biol ; 22(1): 351, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35850632

RESUMO

BACKGROUND: Rice (Oryza sativa L.) is the major source of daily caloric intake for more than 30% of the human population. However, the sustained productivity of this staple food crop is continuously threatened by various pathogens and herbivores. Breeding has been successful in utilizing various mechanisms of defense by gene pyramiding in elite cultivars, but the continuous resurgence of highly resistant races of pathogens and herbivores often overcomes the inherent capacity of host plant immunity. MicroRNAs (miRNAs) are endogenous, short, single-stranded, non-coding RNA molecules that regulate gene expression by sequence-specific cleavage of target mRNA or suppressing target mRNA translation. While miRNAs function as upstream regulators of plant growth, development, and host immunity, their direct effects on growth and development in the context of balancing defenses with agronomic potential have not been extensively discussed and explored as a more viable strategy in breeding for disease and pest resistant cultivars of rice with optimal agronomic potentials. RESULTS: Using the available knowledge in rice and other model plants, this review examines the important roles of miRNAs in regulating host responses to various fungal, bacterial, and viral pathogens, and insect pests, in the context of gains and trade-offs to crop yield. Gains from R-gene-mediated resistance deployed in modern rice cultivars are often undermined by the rapid breakdown of resistance, negative pleiotropic effects, and linkage drags with undesirable traits. In stark contrast, several classes of miRNAs are known to efficiently balance the positive gains from host immunity without significant costs in terms of losses in agronomic potentials (i.e., yield penalty) in rice. Defense-related miRNAs such as Osa-miR156, Osa-miR159, Osa-miR162, Osa-miR396, Osa-530, Osa-miR1432, Osa-miR1871, and Osa-miR1873 are critical in fine-tuning and integrating immune responses with physiological processes that are necessary to the maintenance of grain yield. Recent research has shown that many defense-related miRNAs regulate complex and agronomically important traits. CONCLUSIONS: Identification of novel immune-responsive miRNAs that orchestrate physiological processes critical to the full expression of agronomic potential will facilitate the stacking of optimal combinations of miRNA-encoding genes to develop high-yielding cultivars with durable resistance to disease and insect pests with minimal penalties to yield.


Assuntos
MicroRNAs , Oryza , Mecanismos de Defesa , Regulação da Expressão Gênica de Plantas , Herbivoria , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Oryza/metabolismo , Melhoramento Vegetal , Plantas Geneticamente Modificadas/genética
7.
Mol Biol Rep ; 49(9): 8597-8606, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35764746

RESUMO

BACKGROUND: Brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive pests of rice accounting for 52% of annual yield loss. The breakdown of resistance against known BPH biotypes necessitates the identification and deployment of new genes from diverse sources. The current study aimed at mapping and transfer of a novel BPH resistance gene from the wild species of rice O. rufipogon accession CR100441 to the elite rice cultivar against BPH biotype 4. METHODS AND RESULTS: The phenotypic screening against BPH biotype 4 was conducted using the standard seedbox screening technique (SSST). Inheritance study using damage score caused by BPH infestation at the seedling stage indicated the presence of a single major recessive gene with the segregation ratio of susceptible to resistant plants in 3:1 (210:66, χ2c = 0.17 ≤ χ20.05,1 = 3.84). The genotyping of the mapping population was done using polymorphic microsatellite markers between PR122 and O.rufipogon acc.CR100441 spanning all the 12 chromosomes of rice. A total of 537 SSR markers were used to map a BPH resistance gene (designated as bph42) on the short arm of chromosome 4 between RM16282 and RM6659. QTL analysis identified a peak marker RM16335 contributing 29% of the phenotypic variance at 40.76 LOD. CONCLUSIONS: The identified marker co-segregates with the bph42 and hence could be efficiently used for marker-assisted selection (MAS) for the transfer of resistance into elite rice cultivars. The introgression lines with higher yield and BPH resistance were identified and are under advanced yield trails for further varietal release.


Assuntos
Hemípteros , Oryza , Animais , Mapeamento Cromossômico/métodos , Cruzamentos Genéticos , Genes de Plantas/genética , Hemípteros/genética , Oryza/genética , Doenças das Plantas/genética
8.
Theor Appl Genet ; 133(3): 689-705, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31811315

RESUMO

KEY MESSAGE: A novel recessive bacterial blight resistance locus designated as a xa-45(t) was identified from Oryza glaberrima accession IRGC 102600B, transferred to O. sativa and mapped to the long arm of chromosome 8 using ddRAD sequencing approach. The identified QTL spans 80 kb region on Nipponbare reference genome IRGSP-1.0 and contains 9 candidate genes. An STS marker developed from the locus LOC_Os08g42410 was found co-segregating with the trait and will be useful for marker-assisted transfer of this recessive resistance gene in breeding programs. Bacterial blight, caused by Xanthomonas oryzae pv. oryzae, is one of the major constraints of rice productivity in Southeast Asia. In spite of having 44 bacterial blight resistance genes from cultivated rice and wild species, the durability of resistance is always at stake due to the continually evolving nature of the pathogen and lack of suitable chemical control. Here, we report high-resolution genetic mapping of a novel bacterial blight resistance gene tentatively designated as a xa-45(t) from an introgression line derived from Oryza glaberrima accession IRGC 102600B. This introgression line was crossed with the susceptible rice indica cultivar cv. Pusa 44 to generate F2 and F2:3 populations for inheritance and mapping studies. The inheritance studies revealed the presence of single recessive locus controlling resistance to the Xanthomonas pathotype seven. A high-density linkage map was constructed using double-digest restriction-associated DNA sequencing of 96 F2 populations along with the parents. The QTL mapping identified a major locus on the long arm of rice chromosome 8 with a LOD score of 33.22 between the SNP markers C8.26737175 and C8.26818765. The peak marker, C8.26810477, explains 49.8% of the total phenotypic variance and was positioned at 202.90 cM on the linkage map. This major locus spans 80 kb region on Nipponbare reference genome IRGSP-1.0 and contains 9 candidate genes. A co-segregating STS marker was developed from the LOC_Os08g42410 for efficient transfer of this novel gene to elite cultivars.


Assuntos
Resistência à Doença/genética , Genes de Plantas , Oryza/genética , Doenças das Plantas/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Cruzamentos Genéticos , Genes Recessivos , Introgressão Genética , Ligação Genética , Marcadores Genéticos , Fenótipo , Filogenia , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Xanthomonas/patogenicidade
9.
Mol Biol Rep ; 47(1): 401-422, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31642040

RESUMO

Rice bran oil is good quality edible oil, rich in antioxidants and comprised typically of oleic-linoleic type fatty acids. However, presence of a highly lipolytic enzyme Phospholipase D alpha1 (OsPLDα1) increases free fatty acid content in the oil which further leads to stale flavor and rancidity of the oil, making it unfit for human consumption. In this study, we compared the upstream regions of OsPLDα1 orthologs across 34 accessions representing 5 wild Oryza species and 8 cultivars, to uncover sequence variations and identify cis-elements involved in differential transcription of orthologs. Alignment of the upstream sequences to the Nipponbare OsPLDα1 reference sequence revealed the presence of 39 SNPs. Phylogenetic analysis showed that all the selected cultivars and wild species accessions are closely related to the reference except for three accessions of O. rufipogon (IRGC89224, IRGC104425, and IRGC105902). Furthermore, using exon-specific qRT-PCR, OsPLDα1 expression patterns in immature grains indicated significant differences in transcript abundance between the wild species accessions. In comparison to the control, lowest gene expression was observed in IRGC89224 accession (0.20-fold) followed by IRGC105902 (0.26-fold) and IRGC104425 (0.41-fold) accessions. In-silico analysis of the OsPLDα1 promoter revealed that the copy number variations of CGCGBOXAT, GT1CONSENSUS, IBOXCORE, NODCON2GM, OSE2ROOTNODULE, SURECOREATSULTR11, and SORLIP1AT cis-elements play an important role in the transcriptional activities of orthologous genes. Owing to the presence of ARFAT and SEBF elements only in the IRGC89224 accession, which had the lowest gene expression as well, these putative upstream regulatory sequences have been identified as novel cis-elements which may act as repressors in regulating the OsPLDα1 gene expression. The accessions identified with low OsPLDα1 expressions could be further deployed as potential donors of ideal OsPLDα1 allele for transfer of the desired trait into elite rice cultivars.


Assuntos
Oryza/genética , Fosfolipase D/genética , Alelos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Variações do Número de Cópias de DNA/genética , Regulação da Expressão Gênica de Plantas/genética , Frequência do Gene/genética , Oryza/metabolismo , Fosfolipase D/metabolismo , Filogenia , Proteínas de Plantas/genética , Regiões Promotoras Genéticas/genética , Sequências Reguladoras de Ácido Nucleico/genética , Alinhamento de Sequência/métodos
11.
Genome ; 62(11): 705-714, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31330117

RESUMO

Oryza punctata Kotschy ex Steud. (BB, 2n = 24) is a wild species of rice that has many useful agronomic traits. An interspecific hybrid (AB, 2n = 24) was produced by crossing O. punctata and Oryza sativa variety Punjab Rice 122 (PR122, AA, 2n = 24) to broaden the narrow genetic base of cultivated rice. Cytological analysis of the pollen mother cells (PMCs) of the interspecific hybrids confirmed that they have 24 chromosomes. The F1 hybrids showed the presence of 19-20 univalents and 1-3 bivalents. The interspecific hybrid was treated with colchicine to produce a synthetic amphiploid (AABB, 2n = 48). Pollen fertility of the synthetic amphiploid was found to be greater than 50% and partial seed set was observed. Chromosome numbers in the PMCs of the synthetic amphiploid were 24II, showing normal pairing. Flow cytometric analysis also confirmed doubled genomic content in the synthetic amphiploid. Leaf morphological and anatomical studies of the synthetic amphiploid showed higher chlorophyll content and enlarged bundle sheath cells as compared with both of its parents. The synthetic amphiploid was backcrossed with PR122 to develop a series of addition and substitution lines for the transfer of useful genes from O. punctata with least linkage drag.


Assuntos
Cruzamentos Genéticos , Hibridização Genética , Oryza/genética , Melhoramento Vegetal , Ploidias , Cromossomos de Plantas , Estudos de Associação Genética , Meiose/genética , Oryza/anatomia & histologia , Folhas de Planta
12.
Ophthalmology ; 125(4): 529-536, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29217148

RESUMO

PURPOSE: To evaluate the prevalence and risk factors for diabetic retinopathy (DR) in the Singapore Epidemiology of Eye Diseases (SEED) Study. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Persons of Malay, Indian, and Chinese ethnicity aged 40+ years, living in Singapore. METHODS: Diabetes was defined as nonfasting plasma glucose ≥200 mg/dl (11.1 mmol/l), glycated hemoglobin A1c (HbA1c) >6.5%, self-reported physician-diagnosed diabetes, or the use of glucose-lowering medication. Retinal photographs, were graded for the presence and severity of DR using the modified Airlie House classification system. MAIN OUTCOME MEASURES: Diabetic retinopathy, diabetic macular edema (DME), vision-threatening diabetic retinopathy (VTDR), defined as the presence of severe nonproliferative or proliferative DR, or clinically significant macular edema (CSME). RESULTS: Of the 10 033 subjects, 2877 (28.7%) had diabetes and gradable photographs for analysis. The overall age-standardized prevalence (95% confidence interval [CI]) was 28.2% (25.9-30.6) for any DR, 7.6% (6.5-9.0) for DME, and 7.7% (6.6-9.0) for VTDR. Indians had a higher prevalence of any DR (30.7% vs. 26.2% in Chinese and 25.5% in Malays, P = 0.012); a similar trend was noted for any DME (P = 0.001) and CSME (P = 0.032). Independent risk factors for any DR were Indian ethnicity (odds ratio [OR], 1.41; 95% CI, 1.09-1.83, vs. Chinese), diabetes duration (OR, 1.10; 95% CI, 1.08-1.11, per year), HbA1c (OR, 1.25; 95% CI, 1.18-1.32, per %), serum glucose (OR, 1.03; 95% CI, 1.00-1.06, per mmol/l), and systolic blood pressure (OR, 1.14; 95% CI, 1.09-1.19, per 10 mmHg). Diastolic blood pressure (OR, 0.74; 95% CI, 0.65-0.84, per 10 mmHg increase), total cholesterol (OR, 0.87; 95% CI, 0.80-0.95, per mmol/l increase), and low-density lipoprotein (LDL) cholesterol (OR, 0.83; 95% CI, 0.74-0.92, per mmol/l increase) were associated with lower odds of any DR. Risk factors were largely similar across the 3 ethnic groups. CONCLUSIONS: Indian Singaporeans have a higher prevalence of DR and DME compared with Chinese and Malays. Major risk factors for DR in this study were similar across the 3 ethnic groups. Addressing these risk factors may reduce the impact of DR in Asia, regardless of ethnicity.


Assuntos
Povo Asiático/etnologia , Retinopatia Diabética/etnologia , Etnicidade/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/metabolismo , Pressão Sanguínea , Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Diabetes Mellitus Tipo 1/etnologia , Diabetes Mellitus Tipo 2/etnologia , Retinopatia Diabética/sangue , Retinopatia Diabética/classificação , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Edema Macular/sangue , Edema Macular/classificação , Edema Macular/etnologia , Masculino , Pessoa de Meia-Idade , Fotografação , Prevalência , Fatores de Risco , Singapura/epidemiologia
13.
Theor Appl Genet ; 131(5): 1163-1171, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29476225

RESUMO

KEY MESSAGE: A BPH-resistant locus designated as Bph34 identified in Oryza nivara acc. IRGC104646 on long arm of chromosome 4 using high-resolution mapping with 50 K SNP chip. BPH resistance contributed by locus showed dominant inheritance in F2 and F3. The Bph34 locus is 91 kb in size and contains 11 candidate genes. In addition to SNP markers, SSR markers, RM16994 and RM17007 co-segregated with the BPH resistance. These two SSR markers can facilitate marker-assisted transfer of the Bph34 locus into elite rice cultivars in all labs. Brown planthopper (BPH, Nilaparvata lugen Stål) is one of the most destructive insects of rice (Oryza sativa L.) causing significant yield losses annually. Exploiting host plant resistance to BPH and incorporating resistant genes in susceptible commercial cultivars is economical and environmentally friendly approach to manage this pest. Here, we report high-resolution mapping of a novel genetic locus for resistance to BPH, designated as Bph34 on long arm of rice chromosome 4. The locus was mapped using an interspecific F2 population derived from a cross between susceptible indica cultivar PR122 and BPH-resistant wild species, O. nivara acc. IRGC104646. Inheritance studies performed using F2 and F2:3 populations revealed the presence of single dominant gene. Construction of high-density linkage map using 50 K SNP chip (OsSNPnks) followed by QTL mapping identified single major locus at 28.8 LOD score between SNP markers, AX-95952039 and AX-95921548. The major locus contributing resistance to BPH designated as Bph34 and explained 68.3% of total phenotypic variance. The Bph34 locus is 91 Kb in size on Nipponbare reference genome-IRGSP-1.0 and contains 11 candidate genes. In addition to associated SNP markers, two SSR markers, RM16994 and RM17007, also co-segregated with the Bph34 which can be used efficiently for markers assisted transfer into elite rice cultivars across the labs.


Assuntos
Hemípteros , Herbivoria , Oryza/genética , Animais , Mapeamento Cromossômico , Cruzamentos Genéticos , Genes de Plantas , Ligação Genética , Loci Gênicos , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas
14.
Endocr Res ; 43(3): 186-194, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29624091

RESUMO

Purpose/Aim: Diabetic retinopathy (DR) is the most common diabetic microvascular complication, and it typically develops after 10 years of diabetes diagnosis. The primary aim of this study was to evaluate the association between adiposity and DR susceptibility among individuals with longstanding type 2 diabetes mellitus (T2D). MATERIALS AND METHODS: In this cross-sectional study, DR was assessed by fundus photography in 953 T2D subjects. DR prevalence by categories of T2D duration was evaluated. In a sub-cohort analysis, subjects having T2D for ≥10 years were divided into DR (N = 241) and non-DR (N = 377) groups. Measures of adiposity including body mass index (BMI), waist circumference (WC), and visceral fat area (VFA) were analyzed. Urinary albumin:creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were measured. RESULTS: DR prevalence markedly increased 10 years after T2D diagnosis (p < 0.001). Among subjects with T2D duration ≥10 years, BMI, WC, and VFA were elevated in DR compared with non-DR (all p < 0.05). Contrasting with BMI and WC, the association between VFA and DR sustained adjustment for demographics, metabolic factors, and insulin treatment (OR: 1.060, 95% CI: 1.004-1.119, p = 0.035). However, the association became insignificant after controlling for ACR and eGFR. Mediation analysis revealed that ACR and eGFR explained 47.3% of the relationship between VFA and DR. CONCLUSIONS: The findings suggest that visceral adiposity is associated with DR in individuals with longstanding T2D. This relationship may be attributable to generalized vascular injury as reflected by coexisting renal burden. Therefore, effective management of visceral adiposity and ameliorating renal burden may ameliorate susceptibility to DR.


Assuntos
Adiposidade/fisiologia , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/complicações , Gordura Intra-Abdominal , Obesidade Abdominal/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Singapura , Circunferência da Cintura/fisiologia , Adulto Jovem
15.
Ophthalmology ; 124(9): 1305-1313, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28501376

RESUMO

PURPOSE: To determine the 6-year incidence of early and late age-related macular degeneration (AMD) in a Singaporean Malay population and to validate the Age-Related Eye Disease Study (AREDS) simplified severity scale in Asians. DESIGN: Prospective, population cohort study. PARTICIPANTS: The Singapore Malay Eye Study baseline participants (age, ≥40 years; 2006-2008) were followed up in 2011 through 2013, and 1901 of 3280 of eligible participants (72.1%) took part. METHODS: Fundus photographs were graded using the Wisconsin AMD grading system. MAIN OUTCOME MEASURES: Incidence of early and late AMD. RESULTS: Gradable fundus photographs were available for 1809 participants who attended both baseline and 6-year follow-up examinations. The age-standardized incidences of early and late AMD were 5.89% (95% confidence interval [CI], 4.81-7.16) and 0.76% (95% CI, 0.42-1.29), respectively. The 5-year age-standardized incidence of early AMD (calculated based on the 6-year incidence) was lower in our population (5.58%; 95% CI, 4.43-7.01) compared with the Beaver Dam Eye Study population (8.19%). The incidence of late AMD in our population was similar to that of the Beaver Dam Eye Study population (0.98% [95% CI, 0.49-1.86] vs. 0.91%), the Blue Mountains Eye Study population (1.10% [95% CI, 0.52-9.56] vs. 1.10%), and the Hisayama Study population (1.09% [95% CI, 0.54-4.25] vs. 0.84%). The incidence of late AMD increased markedly with increasing baseline AREDS score (step 0, 0.23%; step 4, 9.09%). CONCLUSIONS: This study documented the incidence of early and late AMD in a Malay population. The AREDS simplified severity scale is useful in predicting the risk of late AMD development in Asians.


Assuntos
Povo Asiático/etnologia , Degeneração Macular/epidemiologia , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Técnicas de Diagnóstico Oftalmológico , Progressão da Doença , Feminino , Seguimentos , Humanos , Incidência , Degeneração Macular/diagnóstico , Malásia/etnologia , Masculino , Pessoa de Meia-Idade , Fotografação , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Distribuição por Sexo , Perfil de Impacto da Doença , Singapura/epidemiologia
16.
Transl Vis Sci Technol ; 13(8): 38, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39177994

RESUMO

Purpose: The purpose of this study was to evaluate longitudinal changes in choroidal vascular characteristics in childhood, and their relationship with eye growth and refractive error. Methods: Analysis of high-resolution optical coherence tomography (OCT) scans, collected over an 18-month period as part of the Role of Outdoor Activity in Myopia (ROAM) study, was conducted in 101 children (41 myopic, 60 non-myopic, age 10-15 years). OCT images were automatically analyzed and binarized using a deep learning software tool. The output was then used to compute changes in macular choroidal vascularity index (CVI), choroidal luminal, and stromal thickness over 18-months. Associations of these variables with refractive error and axial length were analyzed. Results: CVI decreased significantly, whereas luminal and stromal thickness increased significantly over 18 months (all P < 0.001). The magnitude of change was approximately double in stromal tissue compared to luminal tissue (luminal ß = 2.6 µm/year; 95% confidence interval [CI] = -1.0 to 4.1 µm/year; stromal ß = 5.2 µm/year; 95% CI = 4.0, 6.5 µm/year). A significant interaction between baseline axial length and change in CVI over time (P = 0.047) was observed, with a greater CVI reduction in those with shorter axial lengths. Significant associations were observed between the change in CVI, luminal thickness, stromal thickness, and change in axial length over time (all P < 0.05). Conclusions: Faster axial eye growth was associated with smaller reductions in CVI, and less increase in choroidal luminal and stromal thickness. The changes in choroidal vascularity, particularly in the stromal component, may thus be a marker for eye growth. Translational Relevance: This knowledge of the longitudinal changes in choroidal vascularity in childhood and their relationship with eye growth may assist clinicians in the future to better predict eye growth and myopia progression in childhood.


Assuntos
Corioide , Miopia , Tomografia de Coerência Óptica , Humanos , Corioide/irrigação sanguínea , Corioide/diagnóstico por imagem , Corioide/patologia , Miopia/patologia , Miopia/fisiopatologia , Miopia/diagnóstico por imagem , Criança , Masculino , Feminino , Adolescente , Comprimento Axial do Olho/diagnóstico por imagem , Comprimento Axial do Olho/patologia , Progressão da Doença
17.
Eye (Lond) ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39117703

RESUMO

Lacquer cracks, described as breaks in the Bruch's membrane, are unique lesions in the spectrum of fundus changes associated with pathological myopia. Lacquer cracks are generally believed to be relatively innocuous lesions by themselves; however, progression to other features of myopic macular degeneration, such as patchy chorioretinal atrophy and choroidal neovascularization, may result in irreversible visual impairment. With the rising prevalence of pathological myopia to epidemic proportions, particularly in the Asian countries, ophthalmologists expect to encounter lacquer cracks more frequently in clinical practice. Therefore, it is crucial for the ophthalmic community to be aware of lacquer cracks and to actively look for these lesions in myopic patients so that early detection and close monitoring can help prevent blinding complications. This article provides a comprehensive review on lacquer cracks in eyes with pathological myopia from a clinical perspective.

18.
Genes (Basel) ; 15(7)2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39062698

RESUMO

Sheath blight (ShB) is the most serious disease of rice (Oryza sativa L.), caused by the soil-borne fungus Rhizoctonia solani Kühn (R. solani). It poses a significant threat to global rice productivity, resulting in approximately 50% annual yield loss. Managing ShB is particularly challenging due to the broad host range of the pathogen, its necrotrophic nature, the emergence of new races, and the limited availability of highly resistant germplasm. In this study, we conducted QTL mapping using an F2 population derived from a cross between a partially resistant accession (IRGC81941A) of Oryza nivara and the susceptible rice cultivar Punjab rice 121 (PR121). Our analysis identified 29 QTLs for ShB resistance, collectively explaining a phenotypic variance ranging from 4.70 to 48.05%. Notably, a cluster of four QTLs (qRLH1.1, qRLH1.2, qRLH1.5, and qRLH1.8) on chromosome 1 consistently exhibit a resistant response against R. solani. These QTLs span from 0.096 to 420.1 Kb on the rice reference genome and contain several important genes, including Ser/Thr protein kinase, auxin-responsive protein, protease inhibitor/seed storage/LTP family protein, MLO domain-containing protein, disease-responsive protein, thaumatin-like protein, Avr9/Cf9-eliciting protein, and various transcription factors. Additionally, simple sequence repeats (SSR) markers RM212 and RM246 linked to these QTLs effectively distinguish resistant and susceptible rice cultivars, showing great promise for marker-assisted selection programs. Furthermore, our study identified pre-breeding lines in the advanced backcrossed population that exhibited superior agronomic traits and sheath blight resistance compared to the recurrent parent. These promising lines hold significant potential for enhancing the sheath blight resistance in elite cultivars through targeted improvement efforts.


Assuntos
Mapeamento Cromossômico , Resistência à Doença , Oryza , Doenças das Plantas , Locos de Características Quantitativas , Rhizoctonia , Oryza/genética , Oryza/microbiologia , Oryza/imunologia , Resistência à Doença/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/imunologia , Rhizoctonia/patogenicidade , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Fenótipo , Melhoramento Vegetal/métodos
19.
Curr Res Microb Sci ; 7: 100264, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39205828

RESUMO

Paddy straw is a versatile and valuable resource with multifaceted benefits for nutrient cycling, soil health, and climate mitigation. Its role as a rich nutrient source and organic matter significantly enhances soil vitality while improving soil structure and moisture retention. The impact of paddy straw extends beyond traditional agricultural benefits, encompassing the promotion of microbial activity, erosion control, and carbon sequestration, highlighting its crucial role in maintaining ecological balance. Furthermore, the potential of paddy straw in bioenergy is explored, encompassing its conversion into biogas, biofuels, and thermal energy. The inherent characteristics of paddy straw, including its high cellulose, hemicellulose, and lignin content, position it as a viable candidate for bioenergy production through innovative processes like pyrolysis, gasification, anaerobic digestion, and combustion. Recent research has uncovered state-of-the-art techniques and innovative technologies capable of converting paddy straw into valuable products, including sugar, ethanol, paper, and fiber, broadening its potential applications. This paper aims to underscore the possibilities for value creation through paddy straw, emphasizing its potential use in bioenergy, bio-products, and other environmental applications. Therefore, by recognizing and harnessing the value of paddy straw, we can advocate for sustainable farming practices, reduce waste, and pave the way for a resource-efficient circular economy. Incorporating paddy straw utilization into agricultural systems can pave the way for enhanced resource efficiency and a more sustainable circular economy.

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