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1.
Plant Biotechnol J ; 20(4): 625-645, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35108444

RESUMO

LONELY GUY (LOG) was first identified in a screen of rice mutants with defects in meristem maintenance. In plants, LOG codes for cytokinin riboside 5'-monophosphate phosphoribohydrolase, which converts inactive cytokinin nucleotides directly to the active free bases. Many enzymes with the PGGxGTxxE motif have been misannotated as lysine decarboxylases; conversely not all enzymes containing this motif are cytokinin-specific LOGs. As LOG mutants clearly impact yield in rice, we investigated the LOG gene family in bread wheat. By interrogating the wheat (Triticum aestivum) genome database, we show that wheat has multiple LOGs. The close alignment of TaLOG1, TaLOG2 and TaLOG6 with the X-ray structures of two functional Arabidopsis thaliana LOGs allows us to infer that the wheat LOGs 1-11 are functional LOGs. Using RNA-seq data sets, we assessed TaLOG expression across 70 tissue types, their responses to various stressors, the pattern of cis-regulatory elements (CREs) and intron/exon patterns. TaLOG gene family members are expressed variously across tissue types. When the TaLOG CREs are compared with those of the cytokinin dehydrogenases (CKX) and glucosyltransferases (CGT), there is close alignment of CREs between TaLOGs and TaCKXs reflecting the key role of CKX in maintaining cytokinin homeostasis. However, we suggest that the main homeostatic mechanism controlling cytokinin levels in response to biotic and abiotic challenge resides in the CGTs, rather than LOG or CKX. However, LOG transgenics and identified mutants in rice variously impact yield, providing interesting avenues for investigation in wheat.


Assuntos
Arabidopsis , Briófitas , Oryza , Arabidopsis/genética , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Oryza/genética , Oryza/metabolismo , Triticum/genética , Triticum/metabolismo
2.
Plant Cell Environ ; 45(8): 2306-2323, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35545896

RESUMO

Stomata are important channels for the control of gas exchange between plants and the atmosphere. To examine the genetic architecture of wheat stomatal index, we performed a genome-wide association study (GWAS) using a panel of 539 wheat accessions and 450 678 polymorphic single nucleotide polymorphisms (SNPs) that were detected using wheat-specific 660K SNP array. A total of 130 SNPs were detected to be significantly associated with stomatal index in both leaf surfaces of wheat seedlings. These significant SNPs were distributed across 16 chromosomes and involved 2625 candidate genes which participate in stress response, metabolism and cell/organ development. Subsequent bulk segregant analysis (BSA), combined with GWAS identified one major haplotype on chromosome 2A, that is responsible for stomatal index on the abaxial leaf surface. Candidate gene association analysis revealed that genetic variation in the promoter region of the hexokinase gene TaHXK3-2A was significantly associated with the stomatal index. Moreover, transgenic analysis confirmed that TaHXK3-2A overexpression in wheat decreased the size of leaf pavement cells but increased stomatal density through the glucose metabolic pathway, resulting in drought sensitivity among TaHXK3-2A transgenic lines due to an increased transpiration rate. Taken together, these results provide valuable insights into the genetic control of the stomatal index in wheat seedlings.


Assuntos
Estudo de Associação Genômica Ampla , Triticum , Secas , Polimorfismo de Nucleotídeo Único/genética , Plântula/genética , Triticum/metabolismo
3.
Plant Dis ; 106(8): 2145-2154, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35108069

RESUMO

Powdery mildew is one of the most destructive diseases in wheat production. Identifying novel resistance genes and deploying them in new cultivars is the most effective approach to minimize wheat losses caused by powdery mildew. In this study, wheat breeding line PBDH1607 showed high resistance to powdery mildew at both the seedling and adult plant stages. Genetic analysis of the seedling data demonstrated that the resistance was controlled by a single dominant gene, tentatively designated PmPBDH. The ΔSNP index based on bulked segregant RNA sequencing indicated that PmPBDH was associated with an interval of about 30.8 Mb (713.5 to 744.3 Mb) on chromosome arm 4AL. Using newly developed markers, we mapped PmPBDH to a 3.2-cM interval covering 7.1 Mb (719,055,516 to 726,215,121 bp). This interval differed from those of Pm61 (717,963,176 to 719,260,469 bp), MlIW30 (732,769,506 to 732,790,522 bp), and MlNSF10 (729,275,816 to 731,365,462 bp) reported on the same chromosome arm. PmPBDH also differed from Pm61, MlIW30, and MlNSF10 by its response spectrum, origin, or inheritance mode, suggesting that PmPBDH should be a new Pm gene. In the candidate interval, five genes were found to be associated with PmPBDH via time course gene expression analysis, and thus they are candidate genes of PmPBDH. Six closely linked markers, including two kompetitive allele-specific PCR markers, were confirmed to be applicable for tracking PmPBDH in marker-assisted breeding.


Assuntos
Ascomicetos , Triticum , Ascomicetos/fisiologia , Mapeamento Cromossômico , Resistência à Doença/genética , Genes de Plantas/genética , Marcadores Genéticos , Melhoramento Vegetal , Doenças das Plantas/genética , Triticum/genética
4.
Plant Biotechnol J ; 19(5): 878-896, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33811433

RESUMO

The cytokinins, which are N6 -substituted adenine derivatives, control key aspects of crop productivity. Cytokinin levels are controlled via biosynthesis by isopentenyl transferase (IPT), destruction by cytokinin oxidase/dehydrogenase (CKX), and inactivation via glucosylation by cytokinin glucosyl transferases (CGTs). While both yield components and tolerance to drought and related abiotic stressors have been positively addressed via manipulation of IPT and/or CKX expression, much less attention has been paid to the CGTs. As naming of the CGTs has been unclear, we suggest COGT, CNGT, CONGT and CNOGT to describe the O-, N- and dual function CGTs. As specific CGT mutants of both rice and arabidopsis showed impacts on yield components, we interrogated the wheat genome database, IWGSC RefSeq v1.0 & v2.0, to investigate wheat CGTs. Besides providing unambiguous names for the 53 wheat CGTs, we show their expression patterns in 70 developmental tissues and their response characteristics to various stress conditions by reviewing more than 1000 RNA-seq data sets. These revealed various patterns of responses and showed expression generally being more limited in reproductive tissues than in vegetative tissues. Multiple cis-regulatory elements are present in the 3 kb upstream of the start codons of the 53 CGTs. Elements associated with abscisic acid, light and methyl jasmonate are particularly over-represented, indicative of the responsiveness of CGTs to the environment. These data sets indicate that CGTs have potential value for wheat improvement and that these could be targeted in TILLING or gene editing wheat breeding programmes.


Assuntos
Citocininas , Triticum , Regulação da Expressão Gênica de Plantas , Homeostase , Melhoramento Vegetal , Transferases , Triticum/genética
5.
Plant Dis ; 105(12): 4042-4050, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34260283

RESUMO

Wheat powdery mildew, caused by Blumeria graminis (DC.) Speer f. sp. tritici is a destructive disease seriously threatening yield and quality of common wheat (Triticum aestivum L., 2n=6x=42, AABBDD). Characterization of resistance genes against powdery mildew is useful in parental selection and for developing disease-resistant cultivars. Chinese wheat breeding line KN0816 has superior agronomic performance and resistance to powdery mildew at all growth stages. Genetic analysis using populations of KN0816 crossed with different susceptible parents indicated that a single dominant gene, tentatively designated PmKN0816, conferred seedling resistance to different B. graminis f. sp. tritici isolates. Using a bulked segregant analysis, PmKN0816 was mapped to the Pm6 interval on chromosome arm 2BL using polymorphic markers linked to the cataloged genes Pm6, Pm52, and Pm64, and flanked by the markers CISSR02g-6 and CIT02g-2, both with genetic distances of 0.7 cM. Analysis of closely linked molecular markers indicated that the marker alleles of PmKN0816 differed from those of other powdery mildew resistance genes on 2BL, including Pm6, Pm33, Pm51, Pm64, and PmQ. Based on the genetic and physical locations and response pattern to different B. graminis f. sp. tritici isolates, PmKN0816 is most likely a new powdery mildew resistance gene and possesses effective resistance to all the 14 tested B. graminis f. sp. tritici isolates. In view of the elite agronomic performance of KN0816 combined with the resistance, PmKN0816 is expected to become a valuable resistance gene in wheat breeding. To transfer PmKN0816 to different genetic backgrounds using marker-assisted selection (MAS), closely linked markers of PmKN0816 were evaluated, and four of them (CIT02g-2, CISSR02g-6, CIT02g-10, and CIT02g-17) were confirmed to be applicable for MAS in different genetic backgrounds.


Assuntos
Resistência à Doença , Doenças das Plantas , Triticum , Ascomicetos/patogenicidade , Mapeamento Cromossômico , Resistência à Doença/genética , Genes de Plantas , Marcadores Genéticos , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/microbiologia
6.
Plant Dis ; 105(10): 2844-2850, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33881917

RESUMO

Wheat powdery mildew is a devastating disease that seriously threatens yield worldwide. Utilization of host resistance is considered an effective strategy to minimize powdery mildew damage. Pm21, PmV, and Pm12 confer broad-spectrum resistance to wheat powdery mildew in China, of which Pm21 and PmV are allelic genes derived from the 6VS chromosome of Dasypyrum villosum, and Pm12 is derived from the 6SS chromosome of Aegilops speltoides and most likely orthologous to the former two genes. To accurately and efficiently transfer and pyramid these genes using marker-assisted selection (MAS), distinctive single-nucleotide polymorphisms (SNPs) among the exon sequences of Pm21, PmV, and Pm12 and their homologous sequences in the common wheat genome were identified and then used for developing diagnostic Kompetitive Allele-Specific PCR (KASP) markers. The markers were validated in different genotypes including transgenic vectors, transgenic lines, translocation lines, resistance stocks with documented Pm genes, and in multiple susceptible cultivars without Pm genes. As a result, we initially developed a KASP marker that can simultaneously diagnose Pm21, Pm12, and PmV. Subsequently, we obtained a highly diagnostic KASP marker for each of the three genes that could distinguish among the three genes and also accurately distinguish them from other resistant stocks with documented Pm genes and from multiple susceptible genotypes. Compared with previously reported markers, the highly diagnostic KASP markers developed in this study have the advantages of low cost, easy assay, accuracy, and potentially high throughput for MAS.


Assuntos
Resistência à Doença , Triticum , Alelos , Resistência à Doença/genética , Genes de Plantas/genética , Marcadores Genéticos/genética , Doenças das Plantas/genética , Reação em Cadeia da Polimerase , Triticum/genética
7.
Plant Biotechnol J ; 18(3): 614-630, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31782596

RESUMO

The plant hormone group, the cytokinins, is implicated in both qualitative and quantitative components of yield. Cytokinins have opposing actions in shoot and root growth-actions shown to involve cytokinin dehydrogenase (CKX), the enzyme that inactivates cytokinin. We revise and provide unambiguous names for the CKX gene family members in wheat, based on the most recently released wheat genome database, IWGSC RefSeq v1.0 & v2.0. We review expression data of CKX gene family members in wheat, revealing tissue-specific gene family member expression as well as sub-genome-specific expression. Manipulation of CKX in cereals shows clear impacts on yield, root growth and orientation, and Zn nutrition, but this also emphasizes the necessity to unlink promotive effects on grain yield from negative effects of cytokinin on root growth and uptake of mineral nutrients, particularly Zn and Fe. Wheat is the most widely grown cereal crop globally, yet is under-research compared with rice and maize. We highlight gaps in our knowledge of the involvement of CKX for wheat. We also highlight the necessity for accurate analysis of endogenous cytokinins, acknowledging why this is challenging, and provide examples where inadequate analyses of endogenous cytokinins have led to unjustified conclusions. We acknowledge that the allohexaploid nature of bread wheat poses challenges in terms of uncovering useful mutations. However, we predict TILLING followed by whole-exome sequencing will uncover informative mutations and we indicate the potential for stacking mutations within the three genomes to modify yield components. We model a wheat ideotype based on CKX manipulation.


Assuntos
Citocininas/fisiologia , Regulação da Expressão Gênica de Plantas , Oxirredutases/genética , Proteínas de Plantas/genética , Triticum/enzimologia , Família Multigênica , Triticum/genética
8.
J Exp Bot ; 68(7): 1569-1583, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28379423

RESUMO

The mechanisms linking C/N balance to N uptake and assimilation are central to plant responses to changing soil nutrient levels. Defoliation and subsequent regrowth of grasses both impact C partitioning, thereby creating a significant point of interaction with soil N availability. Using defoliation as an experimental treatment, we investigated the dynamic relationships between plant carbohydrate status and NO3--responsive uptake systems, transporter gene expression, and nitrate assimilation in Lolium perenne L. High- and low-affinity NO3- uptake was reduced in an N-dependent manner in response to a rapid and large shift in carbohydrate remobilization triggered by defoliation. This reduction in NO3- uptake was rescued by an exogenous glucose supplement, confirming the carbohydrate dependence of NO3- uptake. The regulation of NO3- uptake in response to the perturbation of the plant C/N ratio was associated with changes in expression of putative high- and low-affinity NO3- transporters. Furthermore, NO3- assimilation appears to be regulated by the C-N status of the plant, implying a mechanism that signals the availability of C metabolites for NO3- uptake and assimilation at the whole-plant level. We also show that cytokinins may be involved in the regulation of N acquisition and assimilation in response to the changing plant C/N ratio.


Assuntos
Metabolismo dos Carboidratos , Regulação da Expressão Gênica de Plantas , Lolium/genética , Lolium/metabolismo , Nitratos/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Lolium/crescimento & desenvolvimento , Nitrogênio/metabolismo , Proteínas de Plantas/metabolismo
9.
Ann Bot ; 119(5): 841-852, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-27864224

RESUMO

Background and Aims: Pisum sativum L. (pea) seed is a source of carbohydrate and protein for the developing plant. By studying pea seeds inoculated by the cytokinin-producing bacterium, Rhodococcus fascians , we sought to determine the impact of both an epiphytic (avirulent) strain and a pathogenic strain on source-sink activity within the cotyledons during and following germination. Methods: Bacterial spread was monitored microscopically, and real-time reverse transcription-quantitative PCR was used to determine the expression of cytokinin biosynthesis, degradation and response regulator gene family members, along with expression of family members of SWEET , SUT , CWINV and AAP genes - gene families identified initially in pea by transcriptomic analysis. The endogenous cytokinin content was also determined. Key Results: The cotyledons infected by the virulent strain remained intact and turned green, while multiple shoots were formed and root growth was reduced. The epiphytic strain had no such marked impact. Isopentenyl adenine was elevated in the cotyledons infected by the virulent strain. Strong expression of RfIPT , RfLOG and RfCKX was detected in the cotyledons infected by the virulent strain throughout the experiment, with elevated expression also observed for PsSWEET , PsSUT and PsINV gene family members. The epiphytic strain had some impact on the expression of these genes, especially at the later stages of reserve mobilization from the cotyledons. Conclusions: The pathogenic strain retained the cotyledons as a sink tissue for the pathogen rather than the cotyledon converting completely to a source tissue for the germinating plant. We suggest that the interaction of cytokinins, CWINVs and SWEETs may lead to the loss of apical dominance and the appearance of multiple shoots.


Assuntos
Pisum sativum/genética , Pisum sativum/microbiologia , Doenças das Plantas/microbiologia , Rhodococcus/fisiologia , Cotilédone/crescimento & desenvolvimento , Cotilédone/microbiologia , Citocininas/metabolismo , Germinação , Interações Hospedeiro-Patógeno , Reação em Cadeia da Polimerase , Sementes/microbiologia
10.
Int J Mol Sci ; 18(2)2017 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-28212324

RESUMO

For successful molecular breeding it is important to identify targets to the gene family level, and in the specific species of interest, in this case Pisum sativum L. The cytokinins have been identified as a key breeding target due to their influence on plant architecture, and on seed size and sink activity. We focused on the cytokinin biosynthetic gene family (the IPTs) and the gene family key to the destruction of cytokinins (the CKXs), as well as other gene families potentially affected by changing cytokinin levels. These included key meristem genes (WUS and BAM1) and the transporter gene families, sucrose transporters (SUTs) and amino acid permeases (AAPs). We used reverse transcription quantitative PCR (RT-qPCR) to monitor gene expression in the vegetative meristem and in pre- and post-fertilisation young pea fruits. PsWUS expression was specific to the shoot apical meristem while PsBAM1 was highly expressed in the shoot apical meristem (SAM) but was also expressed at a low level in the young fruit. Differential expression was shown between genes and within gene families for IPT, CKX, SUT, and AAP. PsCKX7 showed strong gene family member-specific expression in the SAM, and was also expressed in young pea fruits. We suggest that PsCKX7 is a potential target for downregulation via molecular breeding or gene editing.


Assuntos
Frutas/crescimento & desenvolvimento , Frutas/genética , Regulação da Expressão Gênica de Plantas , Meristema/genética , Pisum sativum/genética , Melhoramento Vegetal , Análise por Conglomerados , Perfilação da Expressão Gênica , Filogenia , Brotos de Planta/genética , Transcriptoma
11.
J Exp Bot ; 67(3): 593-606, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26525061

RESUMO

The cytokinins have been implicated in many facets of plant growth and development including cell division and differentiation, shoot and root growth, apical dominance, senescence, fruit and seed development, and the response to biotic and abiotic stressors. Cytokinin levels are regulated by a balance between biosynthesis [isopentenyl transferase (IPT)], activation [Lonely Guy (LOG)], inactivation (O-glucosyl transferase), re-activation (ß-glucosidase), and degradation [cytokinin oxidase/dehydrogenase (CKX)]. During senescence, the levels of active cytokinins decrease, with premature senescence leading to a decrease in yield. During the early stages of fruit and seed development, cytokinin levels are transiently elevated, and coincide with nuclear and cell divisions which are a determinant of final seed size. Exogenous application of cytokinin, ectopic expression of IPT, or down-regulation of CKX have, on occasions, led to increased seed yield, leading to the suggestion that cytokinin may be limiting yield. However, manipulation of cytokinins is complex, not only because of their pleiotropic nature but also because the genes coding for biosynthesis and metabolism belong to multigene families, the members of which are themselves spatially and temporally differentiated. Previous research on yield of rice showed that plant breeders could directly target the cytokinins. Modern genome editing tools could be employed to target and manipulate cytokinin levels to increase seed yield with the concurrent aim of maintaining quality. However, how the cytokinin level is modified and whether IPT or CKX is targeted may depend on whether the plant is considered to be in a source-limiting environment or to be sink limited.


Assuntos
Citocininas/metabolismo , Sementes/crescimento & desenvolvimento , Adaptação Fisiológica , Germinação , Estresse Fisiológico
12.
Physiol Plant ; 156(4): 497-511, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26661753

RESUMO

The efficiency of inorganic nitrogen (N) assimilation is a critical component of fertilizer use by plants and of forage production in Lolium perenne, an important pasture species worldwide. We present a spatiotemporal description of nitrate use efficiency in terms of metabolic responses and carbohydrate remobilization, together with components of cytokinin signal transduction following nitrate addition to N-impoverished plants. Perennial ryegrass (L. perenne cv. Grasslands Nui) plants were grown for 10 weeks in unfertilized soil and then treated with nitrate (5 mM) hydroponically. Metabolomic analysis by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry revealed a dynamic interaction between N and carbon metabolism over a week-long time course represented by the relative abundance of amino acids, tricarboxylic acid intermediates and stored water-soluble carbohydrates (WSCs). The initial response to N addition was characterized by a rapid remobilization of carbon stores from the low-molecular weight WSC, along with an increase in N content and assimilation into free amino acids. Subsequently, the shoot became the main source of carbon through remobilization of a large pool of high-molecular weight WSC. Associated quantification of cytokinin levels and expression profiling of putative cytokinin response regulator genes by quantitative reverse transcription polymerase chain reaction support a role for cytokinin in the mediation of the response to N addition in perennial ryegrass. The presence of high levels of cis-zeatin-type cytokinins is discussed in the context of hormonal homeostasis under the stress of steady-state N deficiency.


Assuntos
Carbono/metabolismo , Citocininas/metabolismo , Lolium/fisiologia , Nitratos/farmacologia , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Transporte Biológico , Fertilizantes , Cromatografia Gasosa-Espectrometria de Massas , Hidroponia , Lolium/efeitos dos fármacos , Metabolômica , Nitratos/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Solo/química , Zeatina/metabolismo
13.
Int J Mol Sci ; 17(12)2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27916945

RESUMO

Transporter genes and cytokinins are key targets for crop improvement. These genes are active during the development of the seed and its establishment as a strong sink. However, during germination, the seed transitions to being a source for the developing root and shoot. To determine if the sucrose transporter (SUT), amino acid permease (AAP), Sugar Will Eventually be Exported Transporter (SWEET), cell wall invertase (CWINV), cytokinin biosynthesis (IPT), activation (LOG) and degradation (CKX) gene family members are involved in both the sink and source activities of seeds, we used RT-qPCR to determine the expression of multiple gene family members, and LC-MS/MS to ascertain endogenous cytokinin levels in germinating Pisum sativum L. We show that genes that are actively expressed when the seed is a strong sink during its development, are also expressed when the seed is in the reverse role of being an active source during germination and early seedling growth. Cytokinins were detected in the imbibing seeds and were actively biosynthesised during germination. We conclude that, when the above gene family members are targeted for seed yield improvement, a downstream effect on subsequent seed germination or seedling vigour must be taken into consideration.


Assuntos
Citocininas/biossíntese , Germinação/genética , Pisum sativum/genética , Sementes/genética , Sistemas de Transporte de Aminoácidos/biossíntese , Sistemas de Transporte de Aminoácidos/genética , Parede Celular/enzimologia , Citocininas/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Transporte de Monossacarídeos/biossíntese , Proteínas de Transporte de Monossacarídeos/genética , Pisum sativum/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/genética , Plântula/genética , Sementes/crescimento & desenvolvimento , Espectrometria de Massas em Tandem , beta-Frutofuranosidase/biossíntese , beta-Frutofuranosidase/genética
14.
J Exp Bot ; 71(22): 6872-6875, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-33382897
15.
J Exp Bot ; 66(16): 5067-82, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25873685

RESUMO

Forage brassica (Brassica napus cv. Greenland) is bred for vegetative growth and biomass production, while its seed yield remains to be improved for seed producers without affecting forage yield and quality. Cytokinins affect seed yield by influencing flower, silique and seed number, and seed size. To identify specific cytokinin gene family members as targets for breeding, as well as genes associated with yield and/or quality, a B. napus transcriptome was obtained from a mixed sample including leaves, flower buds and siliques of various stages. Gene families for cytokinin biosynthesis (BnIPT1, 2, 3, 5, 7, 8 and 9), cytokinin degradation (BnCKX1 to BnCKX7), cell wall invertase (BnCWINV1 to BnCWINV6), sugar transporter (BnSUT1 to BnSUT6) and amino acid permease (BnAAP1 to BnAAP8) were identified. As B. napus is tetraploid, homoeologues of each gene family member were sought. Using multiple alignments and phylogenetic analysis, the parental genomes of the two B. napus homoeologues could be differentiated. RT-qPCR was then used to determine the expression of gene family members and their homoeologues in leaves, flowers, siliques and seeds of different developmental stages. The expression analysis showed both temporal and organ-specific expression profiles among members of these multi-gene families. Several pairs of homoeologues showed differential expression, both in terms of level of expression and differences in temporal or organ-specificity. BnCKX2 and 4 were identified as targets for TILLING, EcoTILLING and MAS.


Assuntos
Brassica napus/crescimento & desenvolvimento , Brassica napus/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Brassica napus/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/metabolismo , Análise de Sequência de DNA , Transcriptoma
16.
Artigo em Zh | MEDLINE | ID: mdl-25065222

RESUMO

One primary school and one middle school were selected from Gudong Town, Tengyue Town and Puchuan Township of Tengchong County, respectively, by using the lamination stochastic group sampling method. The intestinal parasite infections were investigated with the iodine-stained direct smear method and modified Kato-Katz thick smears method. A total of 1 134 students were investigated and the total infection rate of intestinal nematodes was 12.4% (141/1 134). The infection rate of Ascaris lumbricoides, Trichuris trichura, and hookworm was 9.4% (106/1 134), 2.8% (32/1 134), and 0.3% (3/1 134), respectively. The prevalence of intestinal nematodes among the students of urban (2.2%, 8/363) was lower than those of rural (17.3%, 133/771) (P < 0.01). The infection rate in students from Gudong Town was higher than those of Tengyue (2.2%, 8/363) and Puchuan County (2.3%, 8/35) (P < 0.01), whereas the economy level of Gudong Town (29.9%, 123/412) was the best in the three towns. After all, the infection rate of the middle school students (13.7%, 59/432) was higher than that of pupils (11.7%, 82/702) (P < 0.01). Compared with 2003, the prevalence of nematode infection among the school students in Tengchong County decreased significantly in 2013.


Assuntos
Infecções por Nematoides/epidemiologia , Animais , China/epidemiologia , Humanos , Prevalência , População Rural , Estudantes
17.
Plants (Basel) ; 12(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37687312

RESUMO

The subtilisin-like protease (SBT) family is widely known for its role in stress resistance to a number of stressors in different plant species, but is rarely studied in wheat. Subtilisin-like serine proteases (SBTs) are serine proteolytic enzymes that hydrolyze proteins into small peptides, which bind to receptors as signal molecules or ligands and participate in signal transduction. In this study, we identified 255 putative SBT genes from the wheat reference genome and then divided these into seven clades. Subsequently, we performed syntenic relation analysis, exon-intron organization, motif composition, and cis-element analysis. Further, expression analysis based on RNA-seq and tissue-specific expression patterns revealed that TaSBT gene family expression has multiple intrinsic functions during various abiotic and biotic stresses. Analysis of RNA-seq expression assays and further validation through qRT PCR suggested that some of the TaSBT genes have significant changes in expression levels during Pst interaction. TaSBT7, TaSBT26, TaSBT102, and TaSBT193 genes showed increasing expression levels during compatible and non-compatible interactions, while the expression levels of TaSBT111 and TaSBT213 showed a decreasing trend, indicating that these members of the wheat SBT gene family may have a role in wheat's defense against pathogens. In conclusion, these results expand our understanding of the SBT gene family, and provide a valuable reference for future research on the stress resistance function and comprehensive data of wheat SBT members.

18.
BMC Plant Biol ; 12: 78, 2012 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-22672647

RESUMO

BACKGROUND: As the global population continues to expand, increasing yield in bread wheat is of critical importance as 20% of the world's food supply is sourced from this cereal. Several recent studies of the molecular basis of grain yield indicate that the cytokinins are a key factor in determining grain yield. In this study, cytokinin gene family members in bread wheat were isolated from four multigene families which regulate cytokinin synthesis and metabolism, the isopentenyl transferases (IPT), cytokinin oxidases (CKX), zeatin O-glucosyltransferases (ZOG), and ß-glucosidases (GLU). As bread wheat is hexaploid, each gene family is also likely to be represented on the A, B and D genomes. By using a novel strategy of qRT-PCR with locus-specific primers shared among the three homoeologues of each family member, detailed expression profiles are provided of family members of these multigene families expressed during leaf, spike and seed development. RESULTS: The expression patterns of individual members of the IPT, CKX, ZOG, and GLU multigene families in wheat are shown to be tissue- and developmentally-specific. For instance, TaIPT2 and TaCKX1 were the most highly expressed family members during early seed development, with relative expression levels of up to 90- and 900-fold higher, respectively, than those in the lowest expressed samples. The expression of two cis-ZOG genes was sharply increased in older leaves, while an extremely high mRNA level of TaGLU1-1 was detected in young leaves. CONCLUSIONS: Key genes with tissue- and developmentally-specific expression have been identified which would be prime targets for genetic manipulation towards yield improvement in bread wheat breeding programmes, utilising TILLING and MAS strategies.


Assuntos
Citocininas/biossíntese , Regulação da Expressão Gênica de Plantas , Família Multigênica , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Triticum/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Triticum/classificação , Triticum/genética , Triticum/crescimento & desenvolvimento
19.
iScience ; 25(8): 104837, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35996580

RESUMO

Dielectric capacitors with higher working voltage and power density are favorable candidates for renewable energy systems and pulsed power applications. A polymer with high breakdown strength, low dielectric loss, great scalability, and reliability is a preferred dielectric material for dielectric capacitors. However, their low dielectric constant limits the polymer to achieve satisfying energy density. Therefore, great efforts have been made to get high-energy-density polymer dielectrics. By compositional and structural tailoring, the synergic integrations of the multiple components and optimized structural design effectively improved the energy storage properties. This review presents an overview of recent advancements in the field of high-energy-density polymer dielectrics via compositional and structural tailoring. The surface/interfacial engineering conducted on both microscale and macroscale for polymer dielectrics is the focus of this review. Challenges and the promising opportunities for the development of polymer dielectrics for capacitive energy storage applications are presented at the end of this review.

20.
IEEE Trans Vis Comput Graph ; 28(1): 508-517, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34591763

RESUMO

What makes speeches effective has long been a subject for debate, and until today there is broad controversy among public speaking experts about what factors make a speech effective as well as the roles of these factors in speeches. Moreover, there is a lack of quantitative analysis methods to help understand effective speaking strategies. In this paper, we propose E-ffective, a visual analytic system allowing speaking experts and novices to analyze both the role of speech factors and their contribution in effective speeches. From interviews with domain experts and investigating existing literature, we identified important factors to consider in inspirational speeches. We obtained the generated factors from multi-modal data that were then related to effectiveness data. Our system supports rapid understanding of critical factors in inspirational speeches, including the influence of emotions by means of novel visualization methods and interaction. Two novel visualizations include E-spiral (that shows the emotional shifts in speeches in a visually compact way) and E-script (that connects speech content with key speech delivery information). In our evaluation we studied the influence of our system on experts' domain knowledge about speech factors. We further studied the usability of the system by speaking novices and experts on assisting analysis of inspirational speech effectiveness.


Assuntos
Gráficos por Computador , Fala , Emoções
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