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1.
Nat Commun ; 12(1): 4674, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344879

RESUMO

In most organisms, the number and distribution of crossovers that occur during meiosis are tightly controlled. All chromosomes must receive at least one 'obligatory crossover' and crossovers are prevented from occurring near one another by 'crossover interference'. However, the mechanistic basis of this phenomenon of crossover interference has remained mostly mysterious. Using quantitative super-resolution cytogenetics and mathematical modelling, we investigate crossover positioning in the Arabidopsis thaliana wild-type, an over-expressor of the conserved E3 ligase HEI10, and a hei10 heterozygous line. We show that crossover positions can be explained by a predictive, diffusion-mediated coarsening model, in which large, approximately evenly-spaced HEI10 foci grow at the expense of smaller, closely-spaced clusters. We propose this coarsening process explains many aspects of Arabidopsis crossover positioning, including crossover interference. Consistent with this model, we also demonstrate that crossover positioning can be predictably modified in vivo simply by altering HEI10 dosage, with higher and lower dosage leading to weaker and stronger crossover interference, respectively. As HEI10 is a conserved member of the RING finger protein family that functions in the interference-sensitive pathway for crossover formation, we anticipate that similar mechanisms may regulate crossover positioning in diverse eukaryotes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas Cromossômicas não Histona/metabolismo , Troca Genética/genética , Meiose/genética , Proteínas de Arabidopsis/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Simulação por Computador , Dosagem de Genes , Estágio Paquíteno/genética , Complexo Sinaptonêmico/genética , Complexo Sinaptonêmico/metabolismo
2.
Int J Mol Sci ; 22(14)2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34299327

RESUMO

Adenylate kinase (ADK) is widely distributed in organisms and plays an important role in cellular energy homeostasis. In plants, ADK has important functions in plant growth and development regulation as well as in adaptation to the environment. However, little information is available about the ADK genes in tomato (Solanum lycopersicum), an important economic crop. To investigate the characteristics and functions of ADK genes in tomato, a total of 11 ADK genes were identified and named according to their chromosomal locations. The ADK family in Arabidopsis, tomato, potato, and rice was divided into six groups, and motif analysis revealed that each SlADK protein contained five to eight conserved motifs. A total of 4 to 19 exons were identified in tomato ADK gene family members, and interestingly, most members possessed 4 exons. Several stress response elements were identified in the promoter regions of SlADKs. The 11 SlADKs were randomly distributed on 9 of the 12 tomato chromosomes. Three duplication events were observed between tomato chromosomes, and a high degree of conservation of synteny was demonstrated between tomato and potato. The online TomExpress platform prediction revealed that SlADKs were expressed in various tissues and organs, basically consistent with the data obtained from real-time quantitative PCR (qPCR). The qPCR verification was also performed to determine the expression level of SlADKs and demonstrated that the genes responded to multiple abiotic stresses, such as drought, salt, and cold. Besides, the qPCR results showed that SlADK transcription was responsive to most of the applied hormone treatment. For correlation network analysis under 44 global conditions, the results showed that the number of 17, 3, 4, and 6 coexpressed genes matched with SlADK5, 8, 9, and 11, respectively. For specific gene function analysis, expression of SlADK10 was inhibited using virus-induced gene silencing (VIGS). Compared to wild-type plants, plants with silenced SlADK10 gene had poor drought resistance, indicating SlADK10 regulated drought tolerance of tomato positively. In summary, the information provided in the present study will be helpful to understand the evolutionary relationship and their roles of tomato ADK gene family in further research.


Assuntos
Adenilato Quinase/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/genética , Adenilato Quinase/biossíntese , Adenilato Quinase/metabolismo , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/metabolismo , Secas , Expressão Gênica , Perfilação da Expressão Gênica , Genoma de Planta , Estudo de Associação Genômica Ampla/métodos , Lycopersicon esculentum/enzimologia , Família Multigênica , Filogenia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo
3.
Science ; 372(6547): 1176-1181, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34112688

RESUMO

How eukaryotic cells assess and maintain sizes specific for their species and cell type remains unclear. We show that in the Arabidopsis shoot stem cell niche, cell size variability caused by asymmetric divisions is corrected by adjusting the growth period before DNA synthesis. KIP-related protein 4 (KRP4) inhibits progression to DNA synthesis and associates with mitotic chromosomes. The F BOX-LIKE 17 (FBL17) protein removes excess KRP4. Consequently, daughter cells are born with comparable amounts of KRP4. Inhibitor dilution models predicted that KRP4 inherited through chromatin would robustly regulate size, whereas inheritance of excess free KRP4 would disrupt size homeostasis, as confirmed by mutant analyses. We propose that a cell cycle regulator, stabilized by association with mitotic chromosomes, reads DNA content as a cell size-independent scale.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , DNA de Plantas/metabolismo , Meristema/citologia , Células Vegetais/fisiologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Divisão Celular Assimétrica , Ciclo Celular , Pontos de Checagem do Ciclo Celular , Divisão Celular , Tamanho Celular , Cromatina/metabolismo , Cromossomos de Plantas/metabolismo , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Replicação do DNA , Proteínas F-Box/metabolismo , Fase G1 , Mitose , Modelos Biológicos , Mutação , Fase S
4.
Int J Mol Sci ; 22(11)2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34070753

RESUMO

In situ imaging of molecular markers on a physical chromosome is an indispensable tool for refining genetic maps and validation genome assembly at the chromosomal level. Despite the tremendous progress in genome sequencing, the plant genome assembly at the chromosome level remains a challenge. Recently developed optical and Hi-C mapping are aimed at assistance in genome assembly. For high confidence in the genome assembly at chromosome level, more independent approaches are required. The present study is aimed at refining an ultrasensitive Tyr-FISH technique and developing a reliable and simple method of in situ mapping of a short unique DNA sequences on plant chromosomes. We have carefully analyzed the critical steps of the Tyr-FISH to find out the reasons behind the flaws of this technique. The accurate visualization of markers/genes appeared to be significantly dependent on the means of chromosome slide preparation, probe design and labeling, and high stringency washing. Appropriate adjustment of these steps allowed us to detect a short DNA sequence of 1.6 Kb with a frequency of 51.6%. Based on our results, we developed a more reliable and simple protocol for dual-color Tyr-FISH visualization of unique short DNA sequences on plant chromosomes. This new protocol can allow for more accurate determination of the physical distance between markers and can be applied for faster integration of genetic and cytogenetic maps.


Assuntos
Mapeamento Cromossômico/métodos , Cromossomos de Plantas/química , Genoma de Planta , Hibridização in Situ Fluorescente , Cebolas/genética , Coloração e Rotulagem/métodos , Cromossomos de Plantas/metabolismo , Sondas de DNA/síntese química , Sondas de DNA/metabolismo , DNA de Plantas/genética , DNA de Plantas/metabolismo , Ligação Genética , Marcadores Genéticos , Cebolas/metabolismo , Transcriptoma
5.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925461

RESUMO

The survival of cells depends on their ability to replicate correctly genetic material. Cells exposed to replication stress can experience a number of problems that may lead to deregulated proliferation, the development of cancer, and/or programmed cell death. In this article, we have induced prolonged replication arrest via hydroxyurea (HU) treatment and also premature chromosome condensation (PCC) by co-treatment with HU and caffeine (CF) in the root meristem cells of Vicia faba. We have analyzed the changes in the activities of retinoblastoma-like protein (RbS807/811ph). Results obtained from the immunocytochemical detection of RbS807/811ph allowed us to distinguish five unique activity profiles of pRb. We have also performed detailed 3D modeling using Blender 2.9.1., based on the original data and some final conclusions. 3D models helped us to visualize better the events occurring within the nuclei and acted as a high-resolution aid for presenting the results. We have found that, despite the decrease in pRb activity, its activity profiles were mostly intact and clearly recognizable, with some local alterations that may correspond to the increased demand in transcriptional activity. Our findings suggest that Vicia faba's ability to withstand harsh environments may come from its well-developed and highly effective response to replication stress.


Assuntos
Cafeína/farmacologia , Cromatina/efeitos dos fármacos , Hidroxiureia/farmacologia , Proteínas de Plantas/metabolismo , Vicia faba/efeitos dos fármacos , Cromatina/química , Cromatina/metabolismo , Cromossomos de Plantas/efeitos dos fármacos , Cromossomos de Plantas/metabolismo , Ciclina D1/metabolismo , Replicação do DNA/efeitos dos fármacos , Histonas/metabolismo , Processamento de Imagem Assistida por Computador , Interfase , Células Vegetais , Proteína do Retinoblastoma/metabolismo , Vicia faba/citologia , Vicia faba/genética
6.
Plant J ; 106(3): 588-600, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33788333

RESUMO

Polyploidy has played a crucial role in plant evolution, development and function. Synthetic autopolyploid represents an ideal system to investigate the effects of polyploidization on transcriptional regulation. In this study, we deciphered the impact of genome duplication at phenotypic and molecular levels in watermelon. Overall, 88% of the genes in tetraploid watermelon followed a >1:1 dosage effect, and accordingly, differentially expressed genes were largely upregulated. In addition, a great number of hypomethylated regions (1688) were identified in an isogenic tetraploid watermelon. These differentially methylated regions were localized in promoters and intergenic regions and near transcriptional start sites of the identified upregulated genes, which enhances the importance of methylation in gene regulation. These changes were reflected in sophisticated higher-order chromatin structures. The genome doubling caused switching of 108 A and 626 B compartments that harbored genes associated with growth, development and stress responses.


Assuntos
Cromatina/ultraestrutura , Citrullus/genética , Duplicação Gênica/genética , Regulação da Expressão Gênica de Plantas/genética , Cromatina/genética , Cromatina/metabolismo , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Cromossomos de Plantas/ultraestrutura , Citrullus/metabolismo , Epigenoma/genética , Estudos de Associação Genética , Genoma de Planta/genética , Poliploidia , Tetraploidia
7.
PLoS One ; 16(3): e0248184, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33684152

RESUMO

Fusarium head blight (FHB) is a disease of wheat (Triticum aestivum L.) that causes major yield losses in South America, as well as many other wheat growing regions around the world. FHB results in low quality, contaminated grain due to the production of mycotoxins such as deoxynivalenol (DON). In Brazil, FHB outbreaks are increasing in frequency and are currently controlled by fungicides which are costly and potentially harmful to the wider environment. To identify the genetic basis of resistance to FHB in Brazilian wheat, two mapping populations (Anahuac 75 × BR 18-Terena and BR 18-Terena × BRS 179) segregating for FHB resistance were phenotyped and quantitative trait loci (QTL) analysis was undertaken to identify genomic regions associated with FHB-related traits. A total of 14 QTL associated with FHB visual symptoms were identified, each of which explained 3.7-17.3% of the phenotypic variance. Two of these QTL were stable across environments. This suggests FHB resistance in Anahuac 75, BR 18-Terena and BRS 179 is controlled by multiple genetic loci that confer relatively minor differences in resistance. A major, novel QTL associated with DON accumulation was also identified on chromosome 4B (17.8% of the phenotypic variance), as well as a major QTL associated with thousand-grain weight on chromosome 6B (16.8% phenotypic variance). These QTL could be useful breeding targets, when pyramided with major sources of resistance such as Fhb1, to improve grain quality and reduce the reliance on fungicides in Brazil and other countries affected by FHB.


Assuntos
Cromossomos de Plantas/metabolismo , Resistência à Doença/genética , Fusarium , Doenças das Plantas/genética , Locos de Características Quantitativas , Triticum/genética , Brasil , Doenças das Plantas/microbiologia , Triticum/microbiologia
8.
Int J Mol Sci ; 22(4)2021 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-33672992

RESUMO

The importance of fluorescence light microscopy for understanding cellular and sub-cellular structures and functions is undeniable. However, the resolution is limited by light diffraction (~200-250 nm laterally, ~500-700 nm axially). Meanwhile, super-resolution microscopy, such as structured illumination microscopy (SIM), is being applied more and more to overcome this restriction. Instead, super-resolution by stimulated emission depletion (STED) microscopy achieving a resolution of ~50 nm laterally and ~130 nm axially has not yet frequently been applied in plant cell research due to the required specific sample preparation and stable dye staining. Single-molecule localization microscopy (SMLM) including photoactivated localization microscopy (PALM) has not yet been widely used, although this nanoscopic technique allows even the detection of single molecules. In this study, we compared protein imaging within metaphase chromosomes of barley via conventional wide-field and confocal microscopy, and the sub-diffraction methods SIM, STED, and SMLM. The chromosomes were labeled by DAPI (4',6-diamidino-2-phenylindol), a DNA-specific dye, and with antibodies against topoisomerase IIα (Topo II), a protein important for correct chromatin condensation. Compared to the diffraction-limited methods, the combination of the three different super-resolution imaging techniques delivered tremendous additional insights into the plant chromosome architecture through the achieved increased resolution.


Assuntos
Cromossomos de Plantas/genética , Hordeum/genética , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Imagem Individual de Molécula/métodos , Cromossomos de Plantas/química , Cromossomos de Plantas/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Corantes Fluorescentes/química , Hordeum/citologia , Indóis/química , Metáfase/genética , Reprodutibilidade dos Testes
9.
PLoS One ; 16(2): e0247170, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606812

RESUMO

Glutathione transferases (GSTs) constitute an ancient, ubiquitous, multi-functional antioxidant enzyme superfamily that has great importance on cellular detoxification against abiotic and biotic stresses as well as plant development and growth. The present study aimed to a comprehensive genome-wide identification and functional characterization of GST family in one of the economically important legume plants-Medicago truncatula. Here, we have identified a total of ninety-two putative MtGST genes that code for 120 proteins. All these members were classified into twelve classes based on their phylogenetic relationship and the presence of structural conserved domain/motif. Among them, 7 MtGST gene pairs were identified to have segmental duplication. Expression profiling of MtGST transcripts revealed their high level of organ/tissue-specific expression in most of the developmental stages and anatomical tissues. The transcripts of MtGSTU5, MtGSTU8, MtGSTU17, MtGSTU46, and MtGSTU47 showed significant up-regulation in response to various abiotic and biotic stresses. Moreover, transcripts of MtGSTU8, MtGSTU14, MtGSTU28, MtGSTU30, MtGSTU34, MtGSTU46 and MtGSTF8 were found to be highly upregulated in response to drought treatment for 24h and 48h. Among the highly stress-responsive MtGST members, MtGSTU17 showed strong affinity towards its conventional substrates reduced glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB) with the lowest binding energy of-5.7 kcal/mol and -6.5 kcal/mol, respectively. Furthermore, the substrate-binding site residues of MtGSTU17 were found to be highly conserved. These findings will facilitate the further functional and evolutionary characterization of GST genes in Medicago.


Assuntos
Glutationa Transferase/metabolismo , Medicago truncatula/enzimologia , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Cromossomos de Plantas/metabolismo , Evolução Molecular , Duplicação Gênica , Glutationa/química , Glutationa/metabolismo , Glutationa Transferase/classificação , Glutationa Transferase/genética , Glicosilação , Medicago truncatula/genética , Medicago truncatula/crescimento & desenvolvimento , Repetições de Microssatélites/genética , Simulação de Acoplamento Molecular , Filogenia , Proteínas de Plantas/classificação , Proteínas de Plantas/genética , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Transcriptoma
10.
Int J Biol Macromol ; 175: 188-198, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33549671

RESUMO

Membrane-bound fatty acid desaturase (FAD) gene family plays crucial roles in regulation of fatty acid (FA) compositions in plants. Sunflower (Helianthus annuus L.) is an important oilseed crop in the world; however, no comprehensive study on exploring the role of FAD family in relation to stress tolerance in sunflower has been performed yet. In this study, we identified 40 putative FAD genes in H. annuus (HaFAD), which were unevenly distributed across 13 of the total 17 chromosomes. Phylogenetic analysis indicated that HaFAD genes were divided into four subfamilies, as supported by highly conserved gene structures and motifs. Collinearity analysis showed that tandem duplication events played a crucial role in the expansion of HaFAD gene family. In addition, tissue-specific expression showed that 32 HaFAD genes were widely expressed in various tissues or organs of sunflower. Furthermore, qRT-PCR results revealed significant expression changes of HaFAD genes in response to abiotic (cadmium, drought) and biotic (Orobanche cumana) stresses, suggesting their important functions in response to different stresses. Therefore, our results provide insights into HaFAD gene family in response to different stresses, and some specific up-regulated genes such as HaFAD3.2, HaADS8, HaFAD2.1, and HaADS9 would be the potential candidate genes for the sunflower tolerance breeding.


Assuntos
Ácidos Graxos Dessaturases/genética , Helianthus/metabolismo , Cromossomos de Plantas/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Estudo de Associação Genômica Ampla , Helianthus/química , Família Multigênica , Filogenia , Melhoramento Vegetal , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Transcriptoma/genética
11.
Mol Biol Rep ; 48(1): 731-742, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33389532

RESUMO

Rusts are a group of major diseases that have an adverse effect on crop production. Those targeting wheat are found in three principal forms: leaf, stripe, and stem rust. Leaf rust causes foliar disease in wheat; in Egypt, this causes a significant annual yield loss. The deployment of resistant genotypes has proved to be a relatively economical and environmentally sustainable method of controlling the disease. Gene pyramiding can be performed using traditional breeding techniques. Additionally, pathotypes can be introduced to examine specific leaf rust genes, or the breeder may conduct more complex breeding methods. Indirect selection via DNA markers linked to resistance genes may facilitate the transfer of targeted genes, either individually or in combination, even in a disease-free environment. The use of selective crosses to counter virulent races of leaf, stripe, and stem rust has resulted in the transfer of several resistance genes into new wheat germplasm from cultivated or wild species. Quantitative trait locus (QTL) technology has been adopted in a wide variety of novel approaches and is becoming increasingly recognized in wheat breeding. Moreover, several researchers have reported the transference of leaf and stripe rust resistance genes into susceptible wheat cultivars.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Folhas de Planta/genética , Triticum/genética , Basidiomycota/imunologia , Mapeamento Cromossômico , Cromossomos de Plantas/química , Cromossomos de Plantas/metabolismo , Ligação Genética , Marcadores Genéticos , Genótipo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Folhas de Planta/classificação , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Locos de Características Quantitativas , Triticum/classificação , Triticum/imunologia , Triticum/microbiologia
12.
Plant Signal Behav ; 16(4): 1873586, 2021 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-33427565

RESUMO

Phragmoplasts, which comprise microtubules, actin filaments, and membrane vesicles, are responsible for cell plate formation and expansion during plant cytokinesis. Our previous research using the actin polymerization inhibitor latrunculin B (LatB) to investigate the role of actin filaments suggested the existence of two types of microtubules: 1) initial microtubules sensitive to LatB but unassociated with NACK1 kinesin and 2) later LatB-insensitive, NACK1-associated microtubules. The organization of initial phragmoplast microtubules might have been disrupted by the LatB treatment; this hypothesis remained unverified, however, as the exact timing of cell plate membrane accumulation could not be determined. In the present study, we further investigated the timing of cell plate formation during LatB treatment. We monitored chromosome separation during anaphase as well as accumulation of FM4-64-stained cell plate membranes in dividing transgenic tobacco BY-2 cells expressing RFP-tagged histone H2B. We observed that LatB treatment prolonged the time between the slowdown of daughter chromosome migration and the accumulation of cell plate membranes. This result suggests that disruption of actin filaments resulted in delayed cell plate formation possibly by perturbation of initial phragmoplast microtubules or cell plate assembly.


Assuntos
Citoesqueleto de Actina/metabolismo , Membrana Celular/metabolismo , Segregação de Cromossomos , Citocinese , Cromossomos de Plantas/metabolismo , Fatores de Tempo , Tabaco/citologia
13.
Gene ; 770: 145348, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33333230

RESUMO

Heat shock factors (Hsfs) and heat shock proteins (Hsps) play a critical role in the molecular mechanisms such as plant development and defense against abiotic. As an important food crop, maize is vulnerable to adverse environment such as heat stress and water logging, which leads to a decline in yield and quality. To date, very little is known regarding the structure and function of Hsf and Hsp genes in maize. Although some Hsf and Hsp genes have been characterized in maize, analysis of the entire Hsf and Hsp70 gene families were not completed following Maize (B73) Genome Sequencing Project. Therefore, studying their molecular mechanism and revealing their biological function in plant stress resistance process will contribute to reveal important theoretical significance and application value for improving corn yield and quality. In this study, we have identified 25 ZmHsf and 22 ZmHsp70 genes in maize. The structural characteristics and phylogenetic relationships of the Hsf and Hsp70 gene families of Arabidopsis thaliana, rice and maize were compared. The final 25 ZmHsf proteins and 22 ZmHsp70 proteins were divided into three and four subfamilies, respectively. In addition, chromosomal localization indicated that the ZmHsf and ZmHsp70 genes were unevenly distributed on the chromosome, and the gene structure map revealed the characteristics of their structures. Finally, transcriptome analysis indicated that most of the ZmHsf and ZmHsp70 genes showed different expression patterns at different developmental stages of maize. Further, by semi-quantitative RT-PCR and quantitative real-time PCR analysis, all 25 ZmHsf and 22 ZmHsp70 genes were confirmed to respond to heat stress treatment, indicating that they have potential effects in heat stress response. The analyses performed by combining co-expression network with protein-protein interaction network among the members of the Hsf and Hsp70 gene families in maize further enabled us to recognize components involved in the regulatory network associated with hsfs and hsp70s complex. The predicted subcellular location revealed that maize Hsp70 proteins exhibited a various subcellular distribution, which may be associated with functional diversification in heat stress response. Taken together, our study provides comprehensive information on the members of Hsf and Hsp70 gene families and will help in elucidating their exact function in maize.


Assuntos
Cromossomos de Plantas , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Choque Térmico HSP70 , Família Multigênica/fisiologia , Proteínas de Plantas , Zea mays , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Estudo de Associação Genômica Ampla , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Zea mays/genética , Zea mays/metabolismo
14.
Genes (Basel) ; 11(12)2020 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322817

RESUMO

Long non-coding RNAs (lncRNAs) play critical regulatory roles in various biological processes. However, the presence of lncRNAs and how they function in plant polyploidy are still largely unknown. Hence, we examined the profile of lncRNAs in a nascent allotetraploid Cucumis hytivus (S14), its diploid parents, and the F1 hybrid, to reveal the function of lncRNAs in plant-interspecific hybridization and whole genome duplication. Results showed that 2206 lncRNAs evenly transcribed from all 19 chromosomes were identified in C. hytivus, 44.6% of which were from intergenic regions. Based on the expression trend in allopolyploidization, we found that a high proportion of lncRNAs (94.6%) showed up-regulated expression to varying degrees following hybridization. However, few lncRNAs (33, 2.1%) were non-additively expressed after genome duplication, suggesting the significant effect of hybridization on lncRNAs, rather than genome duplication. Furthermore, 253 cis-regulated target genes were predicted for these differentially expressed lncRNAs in S14, which mainly participated in chloroplast biological regulation (e.g., chlorophyll synthesis and light harvesting system). Overall, this study provides new insight into the function of lncRNAs during the processes of hybridization and polyploidization in plant evolution.


Assuntos
Cromossomos de Plantas , Cucumis , Genoma de Planta , Poliploidia , RNA Longo não Codificante , RNA de Plantas , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Cucumis/genética , Cucumis/metabolismo , RNA Longo não Codificante/biossíntese , RNA Longo não Codificante/genética , RNA de Plantas/biossíntese , RNA de Plantas/genética
15.
Nat Commun ; 11(1): 5875, 2020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-33208749

RESUMO

Senna tora is a widely used medicinal plant. Its health benefits have been attributed to the large quantity of anthraquinones, but how they are made in plants remains a mystery. To identify the genes responsible for plant anthraquinone biosynthesis, we reveal the genome sequence of S. tora at the chromosome level with 526 Mb (96%) assembled into 13 chromosomes. Comparison among related plant species shows that a chalcone synthase-like (CHS-L) gene family has lineage-specifically and rapidly expanded in S. tora. Combining genomics, transcriptomics, metabolomics, and biochemistry, we identify a CHS-L gene contributing to the biosynthesis of anthraquinones. The S. tora reference genome will accelerate the discovery of biologically active anthraquinone biosynthesis pathways in medicinal plants.


Assuntos
Antraquinonas/metabolismo , Genoma de Planta , Proteínas de Plantas/genética , Senna (Planta)/metabolismo , Antraquinonas/química , Vias Biossintéticas , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Senna (Planta)/química , Senna (Planta)/genética
16.
Nat Commun ; 11(1): 5269, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33077749

RESUMO

Azaleas (Ericaceae) comprise one of the most diverse ornamental plants, renowned for their cultural and economic importance. We present a chromosome-scale genome assembly for Rhododendron simsii, the primary ancestor of azalea cultivars. Genome analyses unveil the remnants of an ancient whole-genome duplication preceding the radiation of most Ericaceae, likely contributing to the genomic architecture of flowering time. Small-scale gene duplications contribute to the expansion of gene families involved in azalea pigment biosynthesis. We reconstruct entire metabolic pathways for anthocyanins and carotenoids and their potential regulatory networks by detailed analysis of time-ordered gene co-expression networks. MYB, bHLH, and WD40 transcription factors may collectively regulate anthocyanin accumulation in R. simsii, particularly at the initial stages of flower coloration, and with WRKY transcription factors controlling progressive flower coloring at later stages. This work provides a cornerstone for understanding the underlying genetics governing flower timing and coloration and could accelerate selective breeding in azalea.


Assuntos
Cromossomos de Plantas/genética , Genoma de Planta , Proteínas de Plantas/genética , Rhododendron/genética , Antocianinas/biossíntese , Vias Biossintéticas , Carotenoides/metabolismo , Cromossomos de Plantas/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Família Multigênica , Proteínas de Plantas/metabolismo , Rhododendron/crescimento & desenvolvimento , Rhododendron/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
PLoS One ; 15(10): e0240869, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33057421

RESUMO

The rye (Secale L.) genome is large, and it contains many classes of repetitive sequences. Secale species differ in terms of genome size, heterochromatin content, and global methylation level; however, the organization of individual types of sequences in chromosomes is relatively similar. The content of the abundant subtelomeric heterochromatin fraction in rye do not correlate with the global level of cytosine methylation, hence immunofluorescence detection of 5-methylcytosine (5-mC) distribution in metaphase chromosomes was performed. The distribution patterns of 5-methylcytosine in the chromosomes of Secale species/subspecies were generally similar. 5-methylcytosine signals were dispersed along the entire length of the chromosome arms of all chromosomes, indicating high levels of methylation, especially at retrotransposon sequences. 5-mC signals were absent in the centromeric and telomeric regions, as well as in subtelomeric blocks of constitutive heterochromatin, in each of the taxa studied. Pericentromeric domains were methylated, however, there was a certain level of polymorphism in these areas, as was the case with the nucleolus organizer region. Sequence methylation within the region of the heterochromatin intercalary bands were also demonstrated to be heterogenous. Unexpectedly, there was a lack of methylation in rye subtelomeres, indicating that heterochromatin is a very diverse fraction of chromatin, and its epigenetic regulation or potential influence on adjacent regions can be more complex than has conventionally been thought. Like telomeres and centromeres, subtelomeric heterochromatin can has a specific role, and the absence of 5-mC is required to maintain the heterochromatin state.


Assuntos
5-Metilcitosina/metabolismo , Cromossomos de Plantas/metabolismo , Secale/metabolismo , Mapeamento Cromossômico , Epigênese Genética , Tamanho do Genoma , Metáfase , Secale/classificação , Secale/genética
18.
Int J Mol Sci ; 21(18)2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32971899

RESUMO

The oat × maize chromosome addition (OMA) lines, as hybrids between C3 and C4 plants, can potentially help us understand the process of C4 photosynthesis. However, photosynthesis is often affected by adverse environmental conditions, including drought stress. Therefore, to assess the functioning of the photosynthetic apparatus in OMA lines under drought stress, the chlorophyll content and chlorophyll a fluorescence (CF) parameters were investigated. With optimal hydration, most of the tested OMA lines, compared to oat cv. Bingo, showed higher pigment content, and some of them were characterized by increased values of selected CF parameters. Although 14 days of drought caused a decrease of chlorophylls and carotenoids, only slight changes in CF parameters were observed, which can indicate proper photosynthetic efficiency in most of examined OMA lines compared to oat cv. Bingo. The obtained data revealed that expected changes in hybrid functioning depend more on the specific maize chromosome and its interaction with the oat genome rather than the number of retained chromosomes. OMA lines not only constitute a powerful tool for maize genomics but also are a source of valuable variation in plant breeding, and can help us to understand plant susceptibility to drought. Our research confirms more efficient functioning of hybrid photosynthetic apparatus than oat cv. Bingo, therefore contributes to raising new questions in the fields of plant physiology and biochemistry. Due to the fact that the oat genome is not fully sequenced yet, the mechanism of enhanced photosynthetic efficiency in OMA lines requires further research.


Assuntos
Avena , Cromossomos de Plantas , Cruzamentos Genéticos , Estresse Fisiológico , Zea mays , Avena/genética , Avena/metabolismo , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Desidratação , Zea mays/genética , Zea mays/metabolismo
19.
Int J Mol Sci ; 21(15)2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32722187

RESUMO

Durum wheat (Triticum turgidum L. ssp. durum) production can experience significant yield losses due to crown rot (CR) disease. Losses are usually exacerbated when disease infection coincides with terminal drought. Durum wheat is very susceptible to CR, and resistant germplasm is not currently available in elite breeding pools. We hypothesize that deploying physiological traits for drought adaptation, such as optimal root system architecture to reduce water stress, might minimize losses due to CR infection. This study evaluated a subset of lines from a nested association mapping population for stay-green traits, CR incidence and yield in field experiments as well as root traits under controlled conditions. Weekly measurements of normalized difference vegetative index (NDVI) in the field were used to model canopy senescence and to determine stay-green traits for each genotype. Genome-wide association studies using DArTseq molecular markers identified quantitative trait loci (QTLs) on chromosome 6B (qCR-6B) associated with CR tolerance and stay-green. We explored the value of qCR-6B and a major QTL for root angle QTL qSRA-6A using yield datasets from six rainfed environments, including two environments with high CR disease pressure. In the absence of CR, the favorable allele for qSRA-6A provided an average yield advantage of 0.57 t·ha-1, whereas in the presence of CR, the combination of favorable alleles for both qSRA-6A and qCR-6B resulted in a yield advantage of 0.90 t·ha-1. Results of this study highlight the value of combining above- and belowground physiological traits to enhance yield potential. We anticipate that these insights will assist breeders to design improved durum varieties that mitigate production losses due to water deficit and CR.


Assuntos
Cromossomos de Plantas , Locos de Características Quantitativas , Triticum , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Cruzamentos Genéticos , Desidratação/genética , Desidratação/metabolismo , Estudo de Associação Genômica Ampla , Triticum/genética , Triticum/crescimento & desenvolvimento
20.
Proc Natl Acad Sci U S A ; 117(24): 13800-13809, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32493747

RESUMO

While colocalization within a bacterial operon enables coexpression of the constituent genes, the mechanistic logic of clustering of nonhomologous monocistronic genes in eukaryotes is not immediately obvious. Biosynthetic gene clusters that encode pathways for specialized metabolites are an exception to the classical eukaryote rule of random gene location and provide paradigmatic exemplars with which to understand eukaryotic cluster dynamics and regulation. Here, using 3C, Hi-C, and Capture Hi-C (CHi-C) organ-specific chromosome conformation capture techniques along with high-resolution microscopy, we investigate how chromosome topology relates to transcriptional activity of clustered biosynthetic pathway genes in Arabidopsis thaliana Our analyses reveal that biosynthetic gene clusters are embedded in local hot spots of 3D contacts that segregate cluster regions from the surrounding chromosome environment. The spatial conformation of these cluster-associated domains differs between transcriptionally active and silenced clusters. We further show that silenced clusters associate with heterochromatic chromosomal domains toward the periphery of the nucleus, while transcriptionally active clusters relocate away from the nuclear periphery. Examination of chromosome structure at unrelated clusters in maize, rice, and tomato indicates that integration of clustered pathway genes into distinct topological domains is a common feature in plant genomes. Our results shed light on the potential mechanisms that constrain coexpression within clusters of nonhomologous eukaryotic genes and suggest that gene clustering in the one-dimensional chromosome is accompanied by compartmentalization of the 3D chromosome.


Assuntos
Arabidopsis/genética , Cromossomos de Plantas/genética , Lycopersicon esculentum/genética , Família Multigênica , Proteínas de Plantas/genética , Zea mays/genética , Arabidopsis/metabolismo , Cromossomos de Plantas/metabolismo , Genoma de Planta , Lycopersicon esculentum/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Zea mays/metabolismo
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