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1.
Plant Physiol Biochem ; 203: 108084, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37832370

RESUMEN

Brassica rapa L. (2n = 20; AA) is a vegetable and oilseed crop that is grown all over the world. Its leaves, shoots, and seeds store significant amounts of minerals. We used inductively coupled plasma-optical emission spectroscopy (ICP-OES) to determine the concentrations of eleven minerals in the leaves and seeds of 195 advanced generation inbred lines, of which 92 represented natural (NR) B. rapa and the remaining 103 were derived (DR) from a set of mother genotypes originally extracted from an allotetraploid B. juncea (2n = 36; AABB). The inbred lines differed for the composition of leaf and seed minerals. Leaf concentrations of N, K, Zn, and Se were higher in the DR subpanel as compared to NR subpanel, along with high seed accumulations of K and Se. DArT genotyping and genome wide association mapping led to the identification of SNPs associated with leaf and seed mineral compositions. Chromosomes A03, A05, and A10 harboured the most associated loci. Annotations of the regions adjacent to respective GWAS peaks allowed prediction of genes known for acquisition, transport, and accumulation of minerals and heavy metal detoxification. Transcriptome analysis revealed differential expression patterns of the predicted candidates, with most genes either down-regulated in derived genotypes relative to natural forms or their expression being comparable between the two. General downregulation may be a consequence of extracting B. rapa from allotetraploid B. juncea through genome resection. Some of the identified SNPs may be used as DNA markers for breeding programmes designed to modify the leaf and seed mineral compositions.


Asunto(s)
Brassica rapa , Brassica rapa/genética , Estudio de Asociación del Genoma Completo , Fitomejoramiento , Hojas de la Planta/genética , Semillas/genética , Minerales
2.
Plant Genome ; 16(3): e20350, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37351954

RESUMEN

MicroRNAs (miRNAs) are 21-24 nt small RNAs (sRNAs) that negatively regulate protein-coding genes and/or trigger phased small-interfering RNA (phasiRNA) production. Two thousand nine hundred miRNA families, of which ∼40 are deeply conserved, have been identified in ∼80 different plant species genomes. miRNA functions in response to abiotic stresses is less understood than their roles in development. Only seven peanut MIRNA families are documented in miRBase, yet a reference genome assembly is now published and over 480 plant-like MIRNA loci were predicted in the diploid peanut progenitor Arachis duranensis genome. We explored by computational analysis of a leaf sRNA library and publicly available sRNA, degradome, and transcriptome datasets the miRNA and phasiRNA space associated with drought and heat stresses in peanut. We characterized 33 novel candidate and 33 ancient conserved families of MIRNAs and present degradome evidence for their cleavage activities on mRNA targets, including several noncanonical targets and novel phasiRNA-producing noncoding and mRNA loci with validated novel targets such as miR1509 targeting serine/threonine-protein phosphatase7 and miRc20 and ahy-miR3514 targeting penta-tricopeptide repeats (PPRs), in contradistinction to other claims of miR1509/173/7122 superfamily miRNAs indirectly targeting PPRs via TAS-like noncoding RNA loci. We characterized the inverse correlations of significantly differentially expressed drought- and heat-regulated miRNAs, assayed by sRNA blots or transcriptome datasets, with target mRNA expressions in the same datasets. Meta-analysis of an expression atlas and over representation of miRNA target genes in co-expression networks suggest that miRNAs have functions in unique aspects of peanut gynophore development. Genome-wide MIRNA annotation of the published allopolyploid peanut genome can facilitate molecular breeding of value-added traits.


Asunto(s)
MicroARNs , MicroARNs/genética , Arachis/genética , Sequías , Respuesta al Choque Térmico , ARN Mensajero/metabolismo
3.
Phys Rev E ; 107(1-1): 014221, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36797900

RESUMEN

Scroll wave dynamics are thought to underlie life-threatening ventricular fibrillation. However, direct observations of three-dimensional electrical scroll waves remain elusive, as there is no direct way to measure action potential wave patterns transmurally throughout the thick ventricular heart muscle. Here we study whether it is possible to reconstruct simulated scroll waves and scroll wave chaos using deep learning. We trained encoding-decoding convolutional neural networks to predict three-dimensional scroll wave dynamics inside bulk-shaped excitable media from two-dimensional observations of the wave dynamics on the bulk's surface. We tested whether observations from one or two opposing surfaces would be sufficient and whether transparency or measurements of surface deformations enhances the reconstruction. Further, we evaluated the approach's robustness against noise and tested the feasibility of predicting the bulk's thickness. We distinguished isotropic and anisotropic, as well as opaque and transparent, excitable media as models for cardiac tissue and the Belousov-Zhabotinsky chemical reaction, respectively. While we demonstrate that it is possible to reconstruct three-dimensional scroll wave dynamics, we also show that it is challenging to reconstruct complicated scroll wave chaos and that prediction outcomes depend on various factors such as transparency, anisotropy, and ultimately the thickness of the medium compared to the size of the scroll waves. In particular, we found that anisotropy provides crucial information for neural networks to decode depth, which facilitates the reconstructions. In the future, deep neural networks could be used to visualize intramural action potential wave patterns from epi- or endocardial measurements.


Asunto(s)
Arritmias Cardíacas , Corazón , Humanos , Corazón/fisiología , Miocardio , Ventrículos Cardíacos , Redes Neurales de la Computación
4.
Front Plant Sci ; 13: 882766, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35909769

RESUMEN

The defatted Brassica napus (rapeseed) meal can be high-protein feed for livestock as the protein value of rapeseed meal is higher than that of the majority of other vegetable proteins. Extensive work has already been carried out on developing canola rapeseed where the focus was on reducing erucic acid and glucosinolate content, with less consideration to other antinutritional factors such as tannin, phytate, sinapine, crude fiber, etc. The presence of these antinutrients limits the use and marketing of rapeseed meals and a significant amount of it goes unused and ends up as waste. We investigated the genetic architecture of crude protein, methionine, tryptophan, total phenols, ß-carotene, glucosinolates (GLSs), phytate, tannins, sinapine, and crude fiber content of defatted seed meal samples by conducting a genome-wide association study (GWAS), using a diversity panel comprising 96 B. napus genotypes. Genotyping by sequencing was used to identify 77,889 SNPs, spread over 19 chromosomes. Genetic diversity and phenotypic variations were generally high for the studied traits. A total of eleven genotypes were identified which showed high-quality protein, high antioxidants, and lower amount of antinutrients. A significant negative correlation between protein and limiting amino acids and a significant positive correlation between GLS and phytic acid were observed. General and mixed linear models were used to estimate the association between the SNP markers and the seed quality traits and quantile-quantile (QQ) plots were generated to allow the best-fit algorithm. Annotation of genomic regions around associated SNPs helped to predict various trait-related candidates such as ASP2 and EMB1027 (amino acid biosynthesis); HEMA2, GLU1, and PGM (tryptophan biosynthesis); MS3, CYSD1, and MTO1 (methionine biosynthesis); LYC (ß-carotene biosynthesis); HDR and ISPF (MEP pathway); COS1 (riboflavin synthesis); UGT (phenolics biosynthesis); NAC073 (cellulose and hemicellulose biosynthesis); CYT1 (cellulose biosynthesis); BGLU45 and BGLU46 (lignin biosynthesis); SOT12 and UGT88A1 (flavonoid pathway); and CYP79A2, DIN2, and GSTT2 (GLS metabolism), etc. The functional validation of these candidate genes could confirm key seed meal quality genes for germplasm enhancement programs directed at improving protein quality and reducing the antinutritional components in B. napus.

5.
Soft comput ; : 1-37, 2022 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-35103047

RESUMEN

In today's world, technology has become an inevitable part of human life. In fact, during the Covid-19 pandemic, everything from the corporate world to educational institutes has shifted from offline to online. It leads to exponential increase in intrusions and attacks over the Internet-based technologies. One of the lethal threat surfacing is the Distributed Denial of Service (DDoS) attack that can cripple down Internet-based services and applications in no time. The attackers are updating their skill strategies continuously and hence elude the existing detection mechanisms. Since the volume of data generated and stored has increased manifolds, the traditional detection mechanisms are not appropriate for detecting novel DDoS attacks. This paper systematically reviews the prominent literature specifically in deep learning to detect DDoS. The authors have explored four extensively used digital libraries (IEEE, ACM, ScienceDirect, Springer) and one scholarly search engine (Google scholar) for searching the recent literature. We have analyzed the relevant studies and the results of the SLR are categorized into five main research areas: (i) the different types of DDoS attack detection deep learning approaches, (ii) the methodologies, strengths, and weaknesses of existing deep learning approaches for DDoS attacks detection (iii) benchmarked datasets and classes of attacks in datasets used in the existing literature, and (iv) the preprocessing strategies, hyperparameter values, experimental setups, and performance metrics used in the existing literature (v) the research gaps, and future directions.

6.
Front Genet ; 13: 1061168, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36704344

RESUMEN

Flowering is a complex developmental process, with physiological and morphological phases influenced by a variety of external and internal factors. Interestingly, many mango cultivars tend to bear fruit biennially because of irregular flowering, and this has a negative impact on mango flowering and the subsequent yield, resulting in significant economic losses. In this article, transcriptome analysis was carried out on four tissues of mango cv. Dashehari (bearing tree leaf, shoot apex, inflorescence, and non-bearing tree leaf). De novo transcriptome assembly of RNA-seq reads of Dashehari using the Trinity pipeline generated 67,915 transcripts, with 25,776 genes identified. 85 flowering genes, represented by 179 transcripts, were differentially expressed in bearing vs. non-bearing leaf tissues. Gene set enrichment analysis of flowering genes identified significant upregulation of flowering related genes in inflorescence tissues compared to bearing leaf tissues. The flowering genes FT, CO, GI, ELF 4, FLD, FCA, AP1, LHY, and SCO1 were upregulated in the bearing leaf tissues. Pathway analysis of DEGs showed significant upregulation of phenylpropanoid and sucrose and starch pathways in non-bearing leaf tissue compared with bearing leaf tissue. The comparative transcriptome analysis performed in this study significantly increases the understanding of the molecular mechanisms driving the flowering process as well as alternative bearing in mango.

7.
Biotechnol Rep (Amst) ; 31: e00653, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34258242

RESUMEN

Hyaloperonospora brassicae causes downy mildew, a major disease of Brassicaceae species. We sequenced the genomes of two H. brassicae isolates of high (Sample B) and low (Sample C) virulence. Sequencing reads were first assembled de novo with software's SOAPdenovo2, ABySS V2.1 and Velvet V1.1 and later combined to create meta-assemblies with genome sizes of 72.762 and 76.950Mb and predicted gene densities of 1628 and 1644 /Mb, respectively. We could annotate 12.255 and 13,030 genes with high proportions (91-92%) of complete BUSCOs for Sample B and C, respectively. Comparative analysis revealed conserved and varied molecular machinery underlying the physiological specialisation and infection capabilities. BLAST analysis against PHI gene database suggested a relatively higher loss of genes for virulence and pathogenicity in Sample C compared to Sample B, reflecting pathogen evolution through differential rates of mutation and selection. These studies will enable identification and monitoring of H. brassicae virulence factors prevailing in-field.

8.
Sci Rep ; 11(1): 4278, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33608616

RESUMEN

Timely transition to flowering, maturity and plant height are important for agronomic adaptation and productivity of Indian mustard (B. juncea), which is a major edible oilseed crop of low input ecologies in Indian subcontinent. Breeding manipulation for these traits is difficult because of the involvement of multiple interacting genetic and environmental factors. Here, we report a genetic analysis of these traits using a population comprising 92 diverse genotypes of mustard. These genotypes were evaluated under deficient (N75), normal (N100) or excess (N125) conditions of nitrogen (N) application. Lower N availability induced early flowering and maturity in most genotypes, while high N conditions delayed both. A genotyping-by-sequencing approach helped to identify 406,888 SNP markers and undertake genome wide association studies (GWAS). 282 significant marker-trait associations (MTA's) were identified. We detected strong interactions between GWAS loci and nitrogen levels. Though some trait associated SNPs were detected repeatedly across fertility gradients, majority were identified under deficient or normal levels of N applications. Annotation of the genomic region (s) within ± 50 kb of the peak SNPs facilitated prediction of 30 candidate genes belonging to light perception, circadian, floral meristem identity, flowering regulation, gibberellic acid pathways and plant development. These included over one copy each of AGL24, AP1, FVE, FRI, GID1A and GNC. FLC and CO were predicted on chromosomes A02 and B08 respectively. CDF1, CO, FLC, AGL24, GNC and FAF2 appeared to influence the variation for plant height. Our findings may help in improving phenotypic plasticity of mustard across fertility gradients through marker-assisted breeding strategies.


Asunto(s)
Flores/genética , Estudio de Asociación del Genoma Completo , Planta de la Mostaza/fisiología , Nitrógeno/metabolismo , Sitios de Carácter Cuantitativo , Carácter Cuantitativo Heredable , Ligamiento Genético , Genoma de Planta , Genotipo , Fitomejoramiento , Polimorfismo de Nucleótido Simple
9.
Plant Mol Biol ; 105(1-2): 161-175, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32997301

RESUMEN

KEY MESSAGE: Genome wide association studies allowed prediction of 17 candidate genes for association with nitrogen use efficiency. Novel information obtained may provide better understanding of genomic controls underlying germplasm variations for this trait in Indian mustard. Nitrogen use efficiency (NUE) of Indian mustard (Brassica juncea (L.) Czern & Coss.) is low and most breeding efforts to combine NUE with crop performance have not succeeded. Underlying genetics also remain unexplored. We tested 92 SNP-genotyped inbred lines for yield component traits, N uptake efficiency (NUPEFF), nitrogen utilization efficiency (NUTEFF), nitrogen harvest index (NHI) and NUE for two years at two nitrogen doses (No without added N and N100 added @100 kg/ha). Genotypes IC-2489-88, M-633, MCP-632, HUJM 1080, GR-325 and DJ-65 recorded high NUE at low N. These also showed improved crop performance under high N. One determinate mustard genotype DJ-113 DT-3 revealed maximum NUTEFF. Genome wide association studies (GWAS) facilitated recognition of 17 quantitative trait loci (QTLs). Environment specificity was high. B-genome chromosomes (B02, B03, B05, B07 and B08) harbored many useful loci. We also used regional association mapping (RAM) to supplement results from GWAS. Annotation of the genomic regions around peak SNPs helped to predict several gene candidates for root architecture, N uptake, assimilation and remobilization. CAT9 (At1g05940) was consistently envisaged for both NUE and NUPEFF. Major N transporter genes, NRT1.8 and NRT3.1 were predicted for explaining variation for NUTEFF and NUPEFF, respectively. Most significant amino acid transporter gene, AAP1 appeared associated with NUE under limited N conditions. All these candidates were predicted in the regions of high linkage disequilibrium. Sequence information of the predicted candidate genes will permit development of molecular markers to aid breeding for high NUE.


Asunto(s)
Planta de la Mostaza/genética , Planta de la Mostaza/metabolismo , Nitrógeno/metabolismo , Genes de Plantas , Estudio de Asociación del Genoma Completo , Genotipo , Desequilibrio de Ligamiento , Fenotipo , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo
10.
Theor Appl Genet ; 134(2): 473-487, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33084931

RESUMEN

KEY MESSAGE: Genome wide association studies enabled prediction of many candidate genes for flowering, maturity and plant height under differing day-length conditions. Some genes were envisaged only from derived B. rapa. Flowering and plant height are the key life history traits. These are crucial for adaptation and productivity. Current investigations aimed to examine genotypic differences governing days to flowering, maturity and plant height under contrasting day-length conditions; and identify genomic regions governing the observed phenotypic variations. An association panel comprising 195 inbred lines, representing natural (NR) and derived (DR) forms of Brassica rapa (AA; 2n = 20), was evaluated at two sowing dates and two locations, representing different day-length regimes. Derived B. rapa is a unique pre-breeding material extracted from B. juncea (AABB; 2n = 36). Population structure analysis, using DArT genotypes established derived B. rapa as a genetic resource distinct from natural B. rapa. Genome wide association studies facilitated detection of many trait associated SNPs. Chromosomes A03, A05 and A09 harboured majority of these. Functional annotation of the associated SNPs and surrounding genome space(s) helped to predict 43 candidate genes. Many of these were predicted under specific day-length conditions. Important among these were the genes encoding floral meristem identity (SPL3, SPL15, AP3, BAM2), photoperiodic responses (COL2, AGL18, SPT, NF-YC4), gibberellic acid biosynthesis (GA1) and regulation of flowering (EBS). Some of the predicted genes were detected for DR subpanel alone. Genes controlling hormones, auxins and gibberellins appeared important for the regulation of plant height. Many of the significant SNPs were located on chromosomes harbouring previously reported QTLs and candidate genes. The identified loci may be used for marker-assisted selection after due validation.


Asunto(s)
Brassica rapa/crecimiento & desarrollo , Flores/crecimiento & desarrollo , Fitomejoramiento , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Brassica rapa/anatomía & histología , Brassica rapa/genética , Mapeo Cromosómico , Flores/anatomía & histología , Flores/genética , Genómica , Fenotipo , Plantas Modificadas Genéticamente/anatomía & histología , Plantas Modificadas Genéticamente/genética
11.
BMC Genomics ; 21(1): 484, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32669108

RESUMEN

BACKGROUND: Guava (Psidium guajava L.) is an important fruit crop of tropical and subtropical areas of the world. Genomics resources in guava are scanty. RNA-Seq based tissue specific expressed genomic information, de novo transcriptome assembly, functional annotation and differential expression among contrasting genotypes has a potential to set the stage for the functional genomics for traits of commerce like colored flesh and apple color peel. RESULTS: Development of fruit from flower involves orchestration of myriad molecular switches. We did comparative transcriptome sequencing on leaf, flower and fruit tissues of cv. Allahabad Safeda to understand important genes and pathways controlling fruit development. Tissue specific RNA sequencing and de novo transcriptome assembly using Trinity pipeline provided us the first reference transcriptome for guava consisting of 84,206 genes comprising 279,792 total transcripts with a N50 of 3603 bp. Blast2GO assigned annotation to 116,629 transcripts and PFam based HMM profile annotated 140,061 transcripts with protein domains. Differential expression with EdgeR identified 3033 genes in Allahabad Safeda tissues. Mapping the differentially expressed transcripts over molecular pathways indicate significant Ethylene and Abscisic acid hormonal changes and secondary metabolites, carbohydrate metabolism and fruit softening related gene transcripts during fruit development, maturation and ripening. Differential expression analysis among colored tissue comparisons in 3 cultivars Allahabad Safeda, Punjab Pink and Apple Color identified 68 candidate genes that might be controlling color development in guava fruit. Comparisons of red vs green peel in Apple Color, white pulp vs red pulp in Punjab Pink and fruit maturation vs ripening in non-colored Allahabad Safeda indicates up-regulation of ethylene biosynthesis accompanied to secondary metabolism like phenylpropanoid and monolignol pathways. CONCLUSIONS: Benchmarking Universal Single-Copy Orthologs analysis of de novo transcriptome of guava with eudicots identified 93.7% complete BUSCO genes. In silico differential gene expression among tissue types of Allahabad Safeda and validation of candidate genes with qRT-PCR in contrasting color genotypes promises the utility of this first guava transcriptome for its potential of tapping the genetic elements from germplasm collections for enhancing fruit traits.


Asunto(s)
Psidium/genética , Transcriptoma , Color , Flores/genética , Flores/metabolismo , Frutas/genética , Frutas/crecimiento & desarrollo , Frutas/metabolismo , Genes de Plantas , Genotipo , Redes y Vías Metabólicas/genética , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Psidium/crecimiento & desarrollo , Psidium/metabolismo , RNA-Seq , Metabolismo Secundario/genética , Regulación hacia Arriba
12.
Theor Appl Genet ; 133(10): 2949-2959, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32661588

RESUMEN

KEY MESSAGE: Rfo is located on a radish chromosome fragment (~ 108 Kb), which is seated in the middle of a pretty large C genome translocation at the distal region of chromosome A09 of B. juncea. Ogura cytoplasmic male sterility (CMS) is used to produce hybrids in Indian mustard (Brassica juncea L.). Fertility restorers for this CMS were developed by cross-hybridizing B. juncea (AABB; 2n = 36) with B. napus (AACC; 2n = 38) carrying radish Rfo gene. This hybrid production system is normally stable, but many commercial mustard hybrids show male sterile contaminants. We aimed to identify linkage drag associated with Rfo by comparing hybridity levels of 295 handmade CMS x Rfo crosses. Although Rfo was stably inherited, hybridity was < 85 percent in several combinations. Genome re-sequencing of five fertility restorers, mapping sequencing reads to B. juncea reference and synteny analysis with Raphanus sativus D81Rfo genomic region (AJ550021.2) helped to detect ~ 108 Kb of radish chromosome (R) fragment substitution in all fertility restorers. This radish segment substitution was itself located amidst a large C genome translocation on the terminal region of chromosome A09 of B. juncea. The size of alien segment substitution varied from 11.3 (NTCN-R9) to 22.0 Mb (NAJR-102B-R). We also developed an in silico SSR map for chromosome A09 and identified many homoeologous A to the C genome exchanges in the introgressed region. A to the R genome exchanges were rare. Annotation of the substituted fragment showed the gain of many novel genes from R and C genomes and the loss of B. juncea genes from the corresponding region. We have developed a KASPar marker for marker-aided transfer of Rfo and testing hybridity levels in seed production lots.


Asunto(s)
Mapeo Cromosómico , Cromosomas de las Plantas , Planta de la Mostaza/genética , Infertilidad Vegetal/genética , Secuencia de Bases , ADN de Plantas/genética , Marcadores Genéticos , Genoma de Planta , Hibridación Genética , Sintenía
13.
Mol Biol Rep ; 47(4): 2963-2974, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32219770

RESUMEN

We investigated phenotypic variations for pod shattering, pod length and number of seeds per pod in large germplasm collections of Brassica juncea (2n = 36; AABB) and its progenitor species, B. rapa (2n = 20; AA) and B. nigra (2n = 16; BB). Pod shatter resistance was measured as energy required for rupturing a mature dry pod, with a specially fabricated pendulum machine. Rupture energy (RE) ranged from 3.3 to 11.0 mJ in B. juncea. MCP 633, NR 3350 and Albeli required maximum energy to shatter a pod. It ranged from 2.5 to 7.8 mJ for B. rapa with an average of 5.5 mJ. B. nigra possessed easy to rupture pods. Correlation analysis showed strong associations among these traits in B. juncea and B. rapa. Genome wide association studies were conducted with select sets of B. juncea and B. rapa germplasm lines. Significant and annotated associations predict the role of FRUITFULL, MANNASE7, and NAC secondary wall thickening promoting factor (NST2) in the genetic regulation of shatter resistance in B. juncea. NST2 and SHP1 appeared important for pod length and seeds per pod in B. rapa. Candidate gene based association mapping also confirmed the role of SHP1 and NST2 in regulating pod shattering and related pod traits in B. rapa and B. juncea. Footprints of selection were detected in SHP1, SHP2 (B. rapa, B. nigra and B. juncea), RPL (B. rapa) and NAC (B. juncea). Our results provide insights into the genetic architecture of three pod traits. The identified genes are relevant to improving and securing crop productivity of mustard crop.


Asunto(s)
Planta de la Mostaza/genética , Semillas/genética , Mapeo Cromosómico/métodos , Genes de Plantas , Genoma de Planta , Estudio de Asociación del Genoma Completo , Genotipo , Fenotipo
14.
Sci Rep ; 9(1): 17089, 2019 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-31745129

RESUMEN

Sclerotinia stem rot caused by Sclerotinia sclerotiorum is a major disease of crop brassicas, with inadequate variation for resistance in primary gene pools. We utilized a wild Brassicaceae species with excellent resistance against stem rot to develop a set of B. juncea - B. fruticulosa introgression lines (ILs). These were assessed for resistance using a highly reproducible stem inoculation technique against a virulent pathogen isolate. Over 40% of ILs showed higher levels of resistance. IL-43, IL-175, IL-215, IL-223 and IL-277 were most resistant ILs over three crop seasons. Sequence reads (21x) from the three most diverse ILs were then used to create B. juncea pseudomolecules, by replacing SNPs of reference B. juncea with those of re-sequenced ILs. Genotyping by sequencing (GBS) was also carried out for 88 ILs. Resultant sequence tags were then mapped on to the B. juncea pseudomolecules, and SNP genotypes prepared for each IL. Genome wide association studies helped to map resistance responses to stem rot. A total of 13 significant loci were identified on seven B. juncea chromosomes (A01, A03, A04, A05, A08, A09 and B05). Annotation of the genomic region around identified SNPs allowed identification of 20 candidate genes belonging to major disease resistance protein families, including TIR-NBS-LRR class, Chitinase, Malectin/receptor-like protein kinase, defensin-like (DEFL), desulfoglucosinolate sulfotransferase protein and lipoxygenase. A majority of the significant SNPs could be validated using whole genome sequences (21x) from five advanced generation lines being bred for Sclerotinia resistance as compared to three susceptible B. juncea germplasm lines. Our findings not only provide critical new understanding of the defensive pathway of B. fruticulosa resistance, but will also enable development of marker candidates for assisted transfer of introgressed resistant loci in to agronomically superior cultivars of crop Brassica.


Asunto(s)
Ascomicetos/patogenicidad , Cromosomas de las Plantas/genética , Resistencia a la Enfermedad/genética , Genes de Plantas/genética , Planta de la Mostaza/genética , Enfermedades de las Plantas/genética , Polimorfismo de Nucleótido Simple , Mapeo Cromosómico , Pruebas Genéticas , Genoma de Planta , Infecciones/genética , Infecciones/microbiología , Planta de la Mostaza/inmunología , Planta de la Mostaza/microbiología , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Sitios de Carácter Cuantitativo
15.
Mol Biol Rep ; 46(4): 4235-4244, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31115836

RESUMEN

Nitrogen (N) is a critical input for plant growth and development. A better understanding of N uptake and utilization is important to develop plant breeding strategies for improving nitrogen use efficiency (NUE). With that objective in mind, we assayed a SNP-genotyped association panel comprising 92 inbred lines for the activities of nitrate reductase (NR), nitrite reductase (NIR), glutamine synthetase (GS) and glutamate synthase (GOGAT). All these enzymes are associated with N assimilation. The experiments were carried out at two levels of N application: no added N (N0) and agrnomically recommened dose (100 kg/ha) of N application (N100). Genome wide association studies (GWAS) helped to identify several marker-trait associations (MTAs), involving chromosomes A01, A06, A08, B02, B04, B05 and B08. These explained high phenotypic variation (up to 32%). Annotation of the genomic region(s) in or around significant SNPs allowed prediction of genes encoding high affinity nitrate transporters, glutamine synthetase 1.3, myb-like transcription factor family protein, bidirectional amino acid transporter 1, auxin signaling F-box 3 and oxidoreductases. This is the first attempt to use GWAS for identification of enzyme QTLs to explain variation for nitrogen assimilation enzymes in Brassica juncea.


Asunto(s)
Planta de la Mostaza/enzimología , Planta de la Mostaza/genética , Nitrógeno/metabolismo , Proteínas de Transporte de Anión/genética , Transporte Biológico/genética , Estudio de Asociación del Genoma Completo/métodos , Glutamato Sintasa/genética , Glutamato Sintasa/metabolismo , Glutamato-Amoníaco Ligasa/genética , Glutamato-Amoníaco Ligasa/metabolismo , Nitrato-Reductasa/genética , Nitrato-Reductasa/metabolismo , Transportadores de Nitrato , Nitrito Reductasas/genética , Nitrito Reductasas/metabolismo
16.
Int Sch Res Notices ; 2014: 257805, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-27351019

RESUMEN

Thalassemia and thalassemic hemoglobinopathies pose serious health problem leading to severe morbidity and mortality in Indian population. Plethora of hemoglobin variants is prevalent in multiethnic Indian population. The aim of the present study was to analyze laboratory aspects, namely, hematological profile and HPLC findings of the hemoglobin variants detected, and to discuss problems that we faced in diagnosis in a routine clinical laboratory. We screened a total of 4800 cases in a hospital based population of North India in a 2-years period of by automated HPLC method using the Variant Hemoglobin Testing System (Variant II Beta Thalassemia Short Program, Bio-Rad Laboratories) under the experimental conditions specified by the manufacturer. Whole blood in EDTA was used and red cell indices were determined using automated hematology analyzer. We detected 290 cases with abnormal variants in which beta thalassemia was the most common followed by hemoglobin E. Here, we discuss the laboratory aspects of various hemoglobin disorders and diagnostic difficulties in cases like borderline HbA2 values, presence of silent mutation, alpha thalassemia gene, and few rare variants which at times require correlation with genetic study. Special attention was given to HbA2 level even in presence of a structural variant to rule out coinheritance of beta thalassemia gene.

17.
J Contemp Brachytherapy ; 2(2): 53-60, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27829845

RESUMEN

PURPOSE: To analyze the effectiveness of biologically effective dose (BED) in two different regimens of HDR brachytherapy keeping the same total BED to point A and to compare the relationship of overall treatment time in terms of local control and bladder and rectal complications. MATERIAL AND METHODS: The study included two groups comprising a total of 90 cervical cancer patients who underwent external beam radiotherapy (EBRT) followed by HDR intracavitary brachytherapy (ICBT). EBRT treatment was delivered by a Co-60 teletherapy unit to a prescribed dose of 45 Gy with 1.8 Gy per fraction in 25 fractions over a period of five weeks. Parallel opposed anterior-posterior (AP/PA) fields with no central shielding were used, followed by the HDR ICBT dose, to point A, of either two fractions of 9.5 Gy with a gap of 10 days, or three fractions of 7.5 Gy with a gap of 7 days between the fractions. Gemcitabine (dose of 150 mg/m2) was given weekly to all the patients as a radiosensitizer. The calculate BED3 to point A was almost the same in both groups to keep the same late complication rates. The doses, and BED10 and BED3, were calculated at different bladder and rectal point as well as at the lymphatic trapezoid points. During and after treatment patients were evaluated for local control and complications for 24 months. RESULTS AND CONCLUSIONS: Doses and BEDs at different bladder, rectal and lymphatic trapezoid points, local control, and complications in both HDR ICBT groups did not have statistically significant differences (p > 0.05). Both HDR ICBT schedules are well tolerable and equally effective.

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