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1.
J Sci Food Agric ; 100(3): 1080-1091, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31650556

RESUMO

BACKGROUND: The newly developed sugarcorn is conceived for dual-purpose use as a potential biofuel feedstock and a high-energy silage crop. Its agronomic traits are, however, not fully appraised under the umbrella of nitrogen (N) management and with canopy reflectance indicator. A 3-year field study was conducted to examine the responses of silage biomass, stalk sugar concentration, sugar and juice yields to various N applications; and determine the quantitative relationships between canopy reflectance, expressed as the normalized difference vegetation index (NDVI), and stalk sucrose or other sugar measures in a dual-purpose sugarcorn (cv. 'CO384xC103'), in comparison with a commercial leafy silage-specific hybrid (cv. 'Pride A5892G3 EDF'). RESULTS: The moderate N rate, 125 kg ha-1 , produced similar stalk sucrose, silage and grain yields, compared to the high rate (250 kg N ha-1 ), regardless of application methods. The NDVI signatures measured at the V8-V10 stage exhibited significant (P < 0.01) and exponential relationships with stalk sucrose concentrations, sucrose and juice yields at the R3 stage, and with silage yield at approximately 65% whole-plant moisture, the optimum silage-harvest window. CONCLUSION: The results indicate that the moderate N rate, 125 kg ha-1 , which is recommended for conventional grain corn production in the region, was likely close to the economic optimum N rate for leafy silage-specific and sugarcorn. Canopy reflectance, measured at the early growth stages, can be used as a potential indicator of sugar and silage production, and this quantitative relationship necessitates further evaluation with more genotypes and under wide environmental conditions. © 2019 Her Majesty the Queen in Right of Canada Journal of The Science of Food and Agriculture © 2019 Society of Chemical Industry.


Assuntos
Silagem/análise , Açúcares/química , Zea mays/química , Zea mays/crescimento & desenvolvimento , Produção Agrícola , Sucos de Frutas e Vegetais/análise , Nitrogênio/análise , Nitrogênio/metabolismo , Caules de Planta/química , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Açúcares/metabolismo , Zea mays/genética
2.
Mol Genet Genomics ; 295(1): 47-54, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31420737

RESUMO

Stem trichomes and seed fibers originate from epidermal cells and partially share a regulatory pathway at the molecular level. In Gossypium barbadense, two insertions of a Ty1 long-terminal repeat-retrotransposon [transposable element TE1 and TE2] in a homeodomain-leucine zipper gene (HD1) result in glabrous stems. The primers used to identify the TE insertions in G. barbadense were applied to screen for the same events in 81 modern G. hirsutum varieties and 31 wild races. Three wild races were found carrying the same TEs as G. barbadense. However, the TE insertions in two of these wild races occurred at different sites (4th exon), therefore, named TE3, while the TE in the other wild race occurred at the same site as TE2. An RNA sequencing and qRT-PCR analysis indicated that the loss of HD1 function was caused by the TE insertion. Genetic mapping revealed a strong association between glabrous stems and TE3 insertions, confirming that HD1 is a critical gene for stem trichome initiation in G. hirsutum, as in G. barbadense. Using the long-terminal repeat sequence as a query to search against the Texas Marker-1 reference genome sequence, we found that the TE occurred after tetraploid cotton formation and evolved at different rates in G. hirsutum and G. barbadense. Interestingly, at least three independent insertion events of the same retrotransposon occurred preferentially in the A sub-genome's HD1 gene, but not in the D sub-genome of G. hirsutum or G. barbadense, suggesting that an unknown TE insertion mechanism and resultant gene function changes may have hastened cotton speciation.


Assuntos
Proteínas de Arabidopsis/genética , Gossypium/genética , Histona Desacetilases/genética , Mutagênese Insercional/genética , Caules de Planta/genética , Retroelementos/genética , Sequências Repetidas Terminais/genética , Tricomas/genética , Mapeamento Cromossômico/métodos , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Zíper de Leucina/genética , Fenótipo , Filogenia , Tetraploidia
3.
PLoS One ; 14(12): e0226599, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31860684

RESUMO

The MADS-box gene family encodes transcription factors with many biological functions that extensively regulate plant growth, development and reproduction. Erigeron breviscapus is a medicinal herb used widely in traditional Chinese medicine, and is believed to improve blood circulation and ameliorate platelet coagulation. In order to gain a detailed understanding of how transcription factor expression may regulate the growth of this potentially important medicinal plant, a genome-wide analysis of the MADS-box gene family of E. breviscapus is needed. In the present study, 44 MADS-box genes were identified in E. breviscapus and categorized into five subgroups (MIKC, Mα, Mß, Mγ and Mδ) according to their phylogenetic relationships with the Arabidopsis MADS-box genes. Additionally, the functional domain, subcellular location and motif compositions of the E. breviscapus MADS-box gene products were characterized. The expression levels for each of the E. breviscapus MADS-box (EbMADS) genes were analyzed in flower, leaf, stem and root organs, and showed that the majority of EbMADS genes were expressed in flowers. Meanwhile, some MADS genes were found to express high levels in leaf, stem and root, indicating that the MADS-box genes are involved in various aspects of the physiological and developmental processes of the E. breviscapus. The results from gene expression analysis under different pollination treatments revealed that the MADS-box genes were highly expressed after non-pollinated treatment. To the best of our knowledge, this study describes the first genome-wide analysis of the E. breviscapus MADS-box gene family, and the results provide valuable information for understanding of the classification, cloning and putative functions of the MADS-box family.


Assuntos
Erigeron/genética , Perfilação da Expressão Gênica/métodos , Proteínas de Domínio MADS/genética , Sequenciamento Completo do Genoma/métodos , Evolução Molecular , Flores/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/química , Família Multigênica , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Caules de Planta/genética , Plantas Medicinais , Domínios Proteicos
4.
BMC Plant Biol ; 19(1): 435, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31638898

RESUMO

BACKGROUND: Adventitious root (AR) formation is a critical developmental process in cutting propagation for the horticultural industry. While auxin has been shown to regulate this process, the exact mechanism and details preceding AR formation remain unclear. Even though AR and lateral root (LR) formation share common developmental processes, there are exist some differences that need to be closely examined at the cytological level. Tomato stem cuttings, which readily form adventitious roots, represent the perfect system to study the influence of auxin on AR formation and to compare AR and LR organogenesis. RESULTS: Here we show the progression by which AR form from founder cells in the basal pericycle cell layers in tomato stem cuttings. The first disordered clumps of cells assumed a dome shape that later differentiated into functional AR cell layers. Further growth resulted in emergence of mature AR through the epidermis following programmed cell death of epidermal cells. Auxin and ethylene levels increased in the basal stem cutting within 1 h. Tomato lines expressing the auxin response element DR5pro:YFP showed an increase in auxin distribution during the AR initiation phase, and was mainly concentrated in the meristematic cells of the developing AR. Treatment of stem cuttings with auxin, increased the number of AR primordia and the length of AR, while stem cuttings treated with the pre-emergent herbicide/auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) occasionally developed thick, agravitropic AR. Hormone profile analyses showed that auxin positively regulated AR formation, whereas perturbations to zeatin, salicylic acid, and abscisic acid homeostasis suggested minor roles during tomato stem rooting. The gene expression of specific auxin transporters increased during specific developmental phases of AR formation. CONCLUSION: These data show that AR formation in tomato stems is a complex process. Upon perception of a wounding stimulus, expression of auxin transporter genes and accumulation of auxin at founder cell initiation sites in pericycle cell layers and later in the meristematic cells of the AR primordia were observed. A clear understanding and documentation of these events in tomato is critical to resolve AR formation in recalcitrant species like hardwoods and improve stem cutting propagation efficiency and effectiveness.


Assuntos
Ácidos Indolacéticos/metabolismo , Lycopersicon esculentum/genética , Reguladores de Crescimento de Planta/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento
5.
BMC Genomics ; 20(1): 785, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664907

RESUMO

BACKGROUND: The cellular machinery for cell wall synthesis and metabolism is encoded by members of large multi-gene families. Maize is both a genetic model for grass species and a potential source of lignocellulosic biomass from crop residues. Genetic improvement of maize for its utility as a bioenergy feedstock depends on identification of the specific gene family members expressed during secondary wall development in stems. RESULTS: High-throughput sequencing of transcripts expressed in developing rind tissues of stem internodes provided a comprehensive inventory of cell wall-related genes in maize (Zea mays, cultivar B73). Of 1239 of these genes, 854 were expressed among the internodes at ≥95 reads per 20 M, and 693 of them at ≥500 reads per 20 M. Grasses have cell wall compositions distinct from non-commelinid species; only one-quarter of maize cell wall-related genes expressed in stems were putatively orthologous with those of the eudicot Arabidopsis. Using a slope-metric algorithm, five distinct patterns for sub-sets of co-expressed genes were defined across a time course of stem development. For the subset of genes associated with secondary wall formation, fifteen sequence motifs were found in promoter regions. The same members of gene families were often expressed in two maize inbreds, B73 and Mo17, but levels of gene expression between them varied, with 30% of all genes exhibiting at least a 5-fold difference at any stage. Although presence-absence and copy-number variation might account for much of these differences, fold-changes of expression of a CADa and a FLA11 gene were attributed to polymorphisms in promoter response elements. CONCLUSIONS: Large genetic variation in maize as a species precludes the extrapolation of cell wall-related gene expression networks even from one common inbred line to another. Elucidation of genotype-specific expression patterns and their regulatory controls will be needed for association panels of inbreds and landraces to fully exploit genetic variation in maize and other bioenergy grass species.


Assuntos
Parede Celular/genética , Caules de Planta/genética , Transcriptoma , Zea mays/genética , Arabidopsis/genética , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Celulose/biossíntese , Lignina/biossíntese , Família Multigênica , Melhoramento Vegetal , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/metabolismo , Regiões Promotoras Genéticas , Xilanos/biossíntese , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Zea mays/ultraestrutura
6.
Nat Commun ; 10(1): 4417, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31562307

RESUMO

Alterations in light quality significantly affect plant growth and development. In canopy shade, phytochrome photoreceptors perceive reduced ratios of red to far-red light (R:FR) and initiate stem elongation to enable plants to overtop competitors. This shade avoidance response is achieved via the stabilisation and activation of PHYTOCHROME INTERACTING FACTORs (PIFs) which elevate auxin biosynthesis. UV-B inhibits shade avoidance by reducing the abundance and activity of PIFs, yet the molecular mechanisms controlling PIF abundance in UV-B are unknown. Here we show that the UV-B photoreceptor UVR8 promotes rapid PIF5 degradation via the ubiquitin-proteasome system in a response requiring the N terminus of PIF5. In planta interactions between UVR8 and PIF5 are not observed. We further demonstrate that PIF5 interacts with the E3 ligase COP1, promoting PIF5 stabilisation in light-grown plants. Binding of UVR8 to COP1 in UV-B disrupts this stabilisation, providing a mechanism to rapidly lower PIF5 abundance in sunlight.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Caules de Planta/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas Cromossômicas não Histona/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Desenvolvimento Vegetal/genética , Desenvolvimento Vegetal/efeitos da radiação , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Estabilidade Proteica , Luz Solar , Ubiquitina-Proteína Ligases/genética , Raios Ultravioleta
7.
Genes (Basel) ; 10(9)2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500166

RESUMO

Tillering and spike differentiation are two key events for wheat (Triticum aestivum L.). A study on the transcriptomes and microRNA group profiles of wheat at the two key developmental stages will bring insight into the molecular regulation mechanisms. Guomai 301 is a representative excellent new high yield wheat cultivar in the Henan province in China. The transcriptomes and microRNA (miRNA) groups of tiller primordia (TPs), stem tips (STs), and young spikes (YSs) in Guomai 301 were compared to each other. A total of 1741 tillering specifically expressed and 281 early spikes differentiating specifically expressed differentially expressed genes (DEGs) were identified. Six major expression profile clusters of tissue-specific DEGs for the three tissues were classified by gene co-expression analysis using K-means cluster. The ribosome (ko03010), photosynthesis-antenna proteins (ko00196), and plant hormone signal transduction (ko04075) were the main metabolic pathways in TPs, STs, and YSs, respectively. Similarly, 67 TP specifically expressed and 19 YS specifically expressed differentially expressed miRNAs were identified, 65 of them were novel. The roles of 3 well known miRNAs, tae-miR156, tae-miR164, and tae-miR167a, in post-transcriptional regulation were similar to that of other researches. There were 651 significant negative miRNA-mRNA interaction pairs in TPs and YSs, involving 63 differentially expressed miRNAs (fold change > 4) and 416 differentially expressed mRNAs. Among them 12 key known miRNAs and 16 novel miRNAs were further analyzed, and miRNA-mRNA regulatory networks during tillering and early spike differentiating were established.


Assuntos
Redes Reguladoras de Genes , MicroRNAs/genética , Triticum/genética , Regulação da Expressão Gênica de Plantas , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Transcriptoma , Triticum/crescimento & desenvolvimento
8.
Genes (Basel) ; 10(9)2019 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-31500311

RESUMO

Wood, the most abundant biomass on Earth, is composed of secondary xylem differentiated from vascular cambium. However, the underlying molecular mechanisms of wood formation remain largely unclear. To gain insight into wood formation, we performed a series of wood-forming tissue-specific transcriptome analyses from a hybrid poplar (Populus alba × P. glandulosa, clone BH) using RNA-seq. Together with shoot apex and leaf tissue, cambium and xylem tissues were isolated from vertical stem segments representing a gradient of secondary growth developmental stages (i.e., immature, intermediate, and mature stem). In a comparative transcriptome analysis of the 'developing xylem' and 'leaf' tissue, we could identify critical players catalyzing each biosynthetic step of secondary wall components (e.g., cellulose, xylan, and lignin). Several candidate genes involved in the initiation of vascular cambium formation were found via a co-expression network analysis using abundantly expressed genes in the 'intermediate stem-derived cambium' tissue. We found that transgenic Arabidopsis plants overexpressing the PtrHAM4-1, a GRAS family transcription factor, resulted in a significant increase of vascular cambium development. This phenotype was successfully reproduced in the transgenic poplars overexpressing the PtrHAM4-1. Taken together, our results may serve as a springboard for further research to unravel the molecular mechanism of wood formation, one of the most important biological processes on this planet.


Assuntos
Câmbio/genética , Parede Celular/genética , Populus/genética , Transcriptoma , Câmbio/crescimento & desenvolvimento , Parede Celular/metabolismo , Lignina/biossíntese , Lignina/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Populus/crescimento & desenvolvimento , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Xilanos/biossíntese , Xilanos/genética , Xilema/genética , Xilema/crescimento & desenvolvimento
9.
Plant Sci ; 287: 110200, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31481227

RESUMO

The cuticle plays a critical role as barrier between plant and environment. Here, cuticular wax morphology, cuticular wax and cutin monomer composition, and expression of associated genes in five above ground organs were examined in model extremophyte Thellungiella salsugineum. Alkanes, ketones, and 2-alcohols were the predominant wax constitutes in rosette leaves, inflorescence stem leaves, stems, and siliques, whereas alkanes and acids were the predominant cuticular lipids in whole flowers. Unsubstituted acids were the most abundant cutin monomers in vegetative organs, especially C18:2 dioic acids, which reached the highest levels in stems. Hydroxy fatty acids were the predominant cutin monomers in flowers, especially 16-OH C16:0 and diOH C16:0. High-throughput RNA-Seq analysis using the Hiseq4000 platform was performed on these five above organs of T. salsugineum, and the differentially expressed lipid-associated genes and their associated metabolic pathways were identified. Expression of genes associated in previous reports to cuticle production, including those having roles in cuticle lipid biosynthesis, transport, and regulation were examined. The association of cuticle lipid composition and gene expression within different organs of T. salsugineum, and potential relationships between T. salsugineum's extreme cuticle and its adaptation to extreme environments is discussed.


Assuntos
Brassicaceae/fisiologia , Lipídeos de Membrana/química , Adaptação Fisiológica , Brassicaceae/genética , Brassicaceae/ultraestrutura , Meio Ambiente , Ácidos Graxos/análise , Flores/genética , Flores/fisiologia , Flores/ultraestrutura , Lipídeos/análise , Epiderme Vegetal/genética , Epiderme Vegetal/fisiologia , Epiderme Vegetal/ultraestrutura , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/ultraestrutura , Caules de Planta/genética , Caules de Planta/fisiologia , Caules de Planta/ultraestrutura , Ceras/química
10.
Genes (Basel) ; 10(9)2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514462

RESUMO

Laccase is a widely used industrial oxidase for food processing, dye synthesis, paper making, and pollution remediation. At present, laccases used by industries come mainly from fungi. Plants contain numerous genes encoding laccase enzymes that show properties which are distinct from that of the fungal laccases. These plant-specific laccases may have better potential for industrial purposes. The aim of this work was to conduct a genome-wide search for the soybean laccase genes and analyze their characteristics and specific functions. A total of 93 putative laccase genes (GmLac) were identified from the soybean genome. All 93 GmLac enzymes contain three typical Cu-oxidase domains, and they were classified into five groups based on phylogenetic analysis. Although adjacent members on the tree showed highly similar exon/intron organization and motif composition, there were differences among the members within a class for both conserved and differentiated functions. Based on the expression patterns, some members of laccase were expressed in specific tissues/organs, while some exhibited a constitutive expression pattern. Analysis of the transcriptome revealed that some laccase genes might be involved in providing resistance to oomycetes. Analysis of the selective pressures acting on the laccase gene family in the process of soybean domestication revealed that 10 genes could have been under artificial selection during the domestication process. Four of these genes may have contributed to the transition of the soft and thin stem of wild soybean species into strong, thick, and erect stems of the cultivated soybean species. Our study provides a foundation for future functional studies of the soybean laccase gene family.


Assuntos
Evolução Molecular , Lacase/genética , Proteínas de Plantas/genética , Caules de Planta/genética , Seleção Genética , Soja/genética , Resistência à Doença , Lacase/química , Lacase/metabolismo , Família Multigênica , Melhoramento Vegetal/métodos , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Caules de Planta/fisiologia , Soja/enzimologia , Soja/microbiologia
11.
Genes (Basel) ; 10(8)2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31387302

RESUMO

Oilseed rape (Brassica napus) is the second largest oilseed crop worldwide. As an architecture component of B. napus, thickness of pod canopy (TPC) plays an important role in yield formation, especially under high-density cultivation conditions. However, the mechanisms underlying the regulation of TPC remain unclear. RNA and microRNA (miRNA) profiling of two groups of B. napus lines with significantly different TPC at the bolting with a tiny bud stage revealed differential expressions of numerous genes involved in nitrogen-related pathways. Expression of several nitrogen-related response genes, including ASP5, ASP2, ASN3, ATCYSC1, PAL2, APT2, CRTISO, and COX15, was dramatically changed in the thick TPC lines compared to those in the thin TPC lines. Differentially expressed miRNAs also included many involved in nitrogen-related pathways. Expression of most target genes was negatively associated with corresponding miRNAs, such as miR159, miR6029, and miR827. In addition, 12 (including miR319, miR845, and miR158) differentially expressed miRNAs between two plant tissues sampled (stem apex and flower bud) were identified, implying that they might have roles in determining overall plant architecture. These results suggest that nitrogen signaling may play a pivotal role in regulating TPC in B. napus.


Assuntos
Brassica/genética , MicroRNAs/genética , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , MicroRNAs/metabolismo , Nitrogênio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/metabolismo
12.
DNA Cell Biol ; 38(10): 1056-1068, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31403329

RESUMO

The AP2/ERF (APETALA2/ETHYLENE RESPONSE FACTOR) transcription factor represents one of the largest plant-specific transcriptional regulators in plants. ERF plays important roles in the regulation of various developmental processes and acts as a mediator in plant external stress responses. However, the research of the ERF gene family is still limited in alfalfa (Medicago sativa L.), one of the most important forage legume species in the world. In the present study, a total of 159 ERF genes were identified, and the phylogenetic reconstruction, classification, conserved motifs, signal peptide prediction, and expression patterns under salt, drought, and low-temperature stresses of these ERF genes were comprehensively analyzed. The ERF genes family in alfalfa could be classified into 10 groups and predicted to be strongly homologous. Based on the structure and functions relationships, the III and IV subfamilies were more likely to play functions in abiotic stresses and 18 MsERF genes were selected for further quantitative real-time PCR validation in different stresses treatment. The results showed that all these MsERF genes were upregulated under three stresses except MsERF008. This study identified the possibility of abiotic tolerance candidate genes playing various roles in stress resistance at the whole-genome level, which would provide primary understanding for exploring ERF-mediated tolerance in alfalfa.


Assuntos
Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Medicago sativa/genética , Folhas de Planta/genética , Proteínas de Plantas/genética , Temperatura Baixa , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Secas , Perfilação da Expressão Gênica , Medicago sativa/classificação , Medicago sativa/metabolismo , Filogenia , Folhas de Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/metabolismo , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Mapeamento de Interação de Proteínas , Isoformas de Proteínas , Salinidade , Estresse Fisiológico
13.
Mol Biotechnol ; 61(9): 703-713, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31286381

RESUMO

Lycopene ε-cyclases (LCYEs) are key enzymes in carotenoid biosynthesis converting red lycopene to downstream lutein. The flowers of marigold (Tagetes erecta) have been superior sources to supply lutein. However, the transcriptional regulatory mechanisms of LCYe in lutein synthesis are still unclear in marigold. In this work, the expression pattern of the TeLCYe gene in marigold indicated that TeLCYe mainly expressed in floral organs. To gain a better understanding of the expression and regulatory mechanism of TeLCYe gene, the TeLCYe promoter was isolated, sequenced, and analyzed through bioinformatics tools. The results suggested that the sequence of TeLCYe promoter contained various putative cis-acting elements responsive to exogenous and endogenous factors. The full-length TeLCYe promoter and three 5'-deletion fragments were fused to the GUS reporter gene and transferred into tobacco to test the promoter activities. A strong GUS activity was observed in stems of seedlings, leaves of seedlings, middle stems, top leaves, petals, stamens, and stigmas in transgenic tobacco containing full-length TeLCYe promoter LP0-2086. Deletion of - 910 to - 429 bp 5' to ATG significantly increased the GUS activity in chloroplast-rich tissues and floral organs, while deletion occurring from 1170 to 910 bp upstream ATG decreased the TeLCYe promoter strength in stems of seedlings, leaves of seedlings, top leaves and sepals. Functional characterization of the full-length TeLCYe promoter and its' deletion fragments in stable transgenic tobacco indicated that the LP0-2086 contains some specific cis-acting elements, which might result in the high-level expression of in floral organs, and LP2-910 might contain some specific cis-acting elements which improved GUS activities in vegetable tissues.


Assuntos
Regulação da Expressão Gênica de Plantas , Liases Intramoleculares/genética , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Tagetes/genética , Tabaco/genética , Biologia Computacional/métodos , Flores/enzimologia , Flores/genética , Genes Reporter , Glucuronidase/genética , Glucuronidase/metabolismo , Liases Intramoleculares/metabolismo , Luteína/biossíntese , Licopeno/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/genética , Proteínas de Plantas/metabolismo , Caules de Planta/enzimologia , Caules de Planta/genética , Plantas Geneticamente Modificadas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Plântula/enzimologia , Plântula/genética , Tagetes/enzimologia , Tabaco/enzimologia
14.
PLoS One ; 14(7): e0219055, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31339881

RESUMO

Vascular tissue in plants provides a resource distribution network for water and nutrients that exhibits remarkable diversity in patterning among different species. In many succulent plants, the vascular network includes longitudinally-oriented supplemental vascular bundles (SVBs) in the central core of the succulent stems and roots in addition to the more typical zone of vascular tissue development (vascular cambium) in a cylinder at the periphery of the succulent organ. Plant SVBs evolved in over 38 plant families often in tandem with evolutionary increases in stem and root parenchyma storage tissue, so it is of interest to understand the evolutionary-developmental processes responsible for their recurrent evolution and patterning. Previous mathematical models have successfully recreated the two-dimensional vascular patterns in stem and root cross sections, but such models have yet to recreate three-dimensional vascular patterning. Here, a stochastic reaction-diffusion model of plant vascular bundle patterning is developed in an effort to highlight a potential mechanism of three dimensional patterning-Turing pattern formation coupled with longitudinal efflux of a regulatory molecule. A relatively simple model of four or five molecules recreated empirical SVB patterns and many other common vascular arrangements. SVBs failed to develop below a threshold width of parenchymatous tissues, suggesting a mechanism of evolutionary character loss due to changes in the spatial context in which development takes place. Altered diffusion rates of the modeled activator and substrate molecules affected the number and size of the simulated SVBs. This work provides a first mathematical model employing a stochastic Turing-type mechanism that recreates three dimensional vascular patterns seen in plant stems. The model offers predictions that can be tested using molecular-genetic approaches. Evolutionary-developmental ramifications concerning evolution of diffusion rates, organ size and geometry are discussed.


Assuntos
Modelos Biológicos , Caules de Planta/crescimento & desenvolvimento , Feixe Vascular de Plantas/crescimento & desenvolvimento , Algoritmos , Evolução Biológica , Padronização Corporal/genética , Câmbio/genética , Câmbio/crescimento & desenvolvimento , Simulação por Computador , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Morfogênese/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/genética , Feixe Vascular de Plantas/genética , Processos Estocásticos
15.
Int J Mol Sci ; 20(14)2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31337083

RESUMO

Histone acetylation and deacetylation play essential roles in eukaryotic gene regulation. HD2 (HD-tuins) proteins were previously identified as plant-specific histone deacetylases. In this study, we investigated the function of the HDT1 gene in the formation of stem vascular tissue in Arabidopsis thaliana. The height and thickness of the inflorescence stems in the hdt1 mutant was lower than that of wild-type plants. Paraffin sections showed that the cell number increased compared to the wild type, while transmission electron microscopy showed that the size of individual tracheary elements and fiber cells significantly decreased in the hdt1 mutant. In addition, the cell wall thickness of tracheary elements and fiber cells increased. We also found that the lignin content in the stem of the hdt1 mutants increased compared to that of the wild type. Transcriptomic data revealed that the expression levels of many biosynthetic genes related to secondary wall components, including cellulose, lignin biosynthesis, and hormone-related genes, were altered, which may lead to the altered phenotype in vascular tissue of the hdt1 mutant. These results suggested that HDT1 is involved in development of the vascular tissue of the stem by affecting cell proliferation and differentiation.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Histona Desacetilases/genética , Desenvolvimento Vegetal/genética , Caules de Planta/genética , Feixe Vascular de Plantas/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/metabolismo , Lignina/metabolismo , Mutação , Fenótipo , Caules de Planta/metabolismo , Feixe Vascular de Plantas/metabolismo , Xilema/citologia , Xilema/genética , Xilema/metabolismo
16.
PLoS One ; 14(7): e0218336, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31265465

RESUMO

Flavonoids are one of the largest secondary metabolite groups, which are widely present in plants. Flavonoids include anthocyanins, proanthocyanidins, flavonols and isoflavones. In particular, proanthocyanidins possess beneficial effects for ruminant animals in preventing lethal pasture bloat. As a major legume forage, alfalfa (Medicago sativa) contains little proanthocyanidins in foliage to combat bloat. In an attempt to improve proanthocyanidin content in alfalfa foliage, we over-expressed two MYB transcription factors (CsMYB5-1 and CsMYB5-2) from tea plant that is rich in proanthocyanidins. We showed that, via targeted metabolite and transcript analyses, the transgenic alfalfa plants accumulated higher levels of flavonoids in stems/leaves than the control, in particular anthocyanins and proanthocyanidins. Over-expression of CsMYB5-1 and CsMYB5-2 induced the expression levels of genes involved in flavonoid pathway, especially anthocyanin/proanthocyanidin-specific pathway genes DFR, ANS and ANR in stems/leaves. Both anthocyanin/proanthocyanidin content and the expression levels of several genes were conversely decreased in flowers of the transgenic lines than in control. Our results indicated that CsMYB5-1 and CsMYB5-2 differently regulate anthocyanins/proanthocyanidins in stems/leaves and flowers. Our study provides a guide for increasing anthocyanin/proanthocyanidin accumulation in foliage of legume forage corps by genetic engineering. These results also suggest that it is feasible to cultivate new varieties for forage production to potentially solve pasture bloat, by introducing transcription factors from typical plants with high proanthocyanidin level.


Assuntos
Antocianinas , Camellia sinensis/genética , Expressão Ectópica do Gene , Medicago sativa , Proteínas de Plantas , Plantas Geneticamente Modificadas , Proantocianidinas , Fatores de Transcrição , Animais , Antocianinas/biossíntese , Antocianinas/genética , Medicago sativa/genética , Medicago sativa/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Caules de Planta/genética , Caules de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proantocianidinas/biossíntese , Proantocianidinas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
Planta ; 250(2): 629-642, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31139926

RESUMO

MAIN CONCLUSION: Primitive wheat follows an opposite metabolic law from modern wheat with regard to leaf biomass/reproductive growth vs above-ground biomass that is under the regulation of non-hydraulic root signals and that influences resource acquisition and utilization. Non-hydraulic root signals (nHRS) are so far affirmed as a unique positive response to drying soil in wheat, and may imply huge differences in energy metabolism and source-sink relationships between primitive and modern wheat species. Using a pot-culture split-root technique to induce nHRS, four primitive wheat genotypes (two diploids and two tetraploids) and four modern wheat ones (released from different breeding decades) were compared to address the above issue. The nHRS was continuously induced in drying soil, ensuring the operation of energy metabolism under the influence of nHRS. We found that primitive wheat followed an opposite size-dependent allometric pattern (logy = αlogx + logß) in comparison with modern wheat. The relationships between ear biomass (y-axis) vs above-ground biomass (x-axis), and between reproductive biomass (y-axis) and vegetative (x-axis) biomass fell into a typical allometric pattern in primitive wheat (α > 1), and the nHRS significantly increased α (P < 0.01). However, in modern wheat, they turned to be in an isometric pattern (α ≈ 1). Regardless of nHRS, either leaf (i.e., metabolic rate) or stem biomass generally exhibited an isometric relationship with above-ground biomass in primitive wheat (α ≈ 1), while in modern wheat they fell into an allometric pattern (α > 1). Allometric scaling of specific leaf area (SLA) or biomass density showed superior capabilities of resource acquisition and utilization in modern wheat over primitive ones. We therefore proposed a generalized model to reveal how modern wheat possesses the pronounced population yield advantage over primitive wheat, and its implications on wheat domestication.


Assuntos
Transdução de Sinais , Triticum/fisiologia , Biomassa , Diploide , Domesticação , Secas , Genótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/fisiologia , Reprodução , Solo/química , Triticum/genética , Triticum/crescimento & desenvolvimento
18.
Biol Pharm Bull ; 42(4): 552-560, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30930415

RESUMO

Field surveys of Ephedra plants were conducted in the Zaravshan Mountains of Tajikistan. E. equisetina, E. intermedia, and their putative hybrids were collected. They were identified based on their phenotypes and their sequences of nuclear ribosomal DNA internal transcribed spacer 1 (ITS1) region. Sequencing and species-specific PCR analyses of their ITS1 sequences revealed six putative hybrids of E. equisetina and E. intermedia. The total ephedrine and pseudoephedrine content of most of the Ephedra samples collected in Tajikistan were higher than the 0.7% lower limit prescribed by the Japanese pharmacopoeia, 17th edition (JP17), and varied from 0.34 to 3.21% by dry weight. The total alkaloid level of E. intermedia (11E08-1) cultivated in Japan varied from 1.77 to 2.30% by dry weight, which was much higher than the 0.7% lower limit prescribed by JP17.


Assuntos
Alcaloides/análise , Ephedra , Altitude , Cruzamentos Genéticos , Ephedra/química , Ephedra/genética , Efedrina/análise , Hibridização Genética , Caules de Planta/química , Caules de Planta/genética , Pseudoefedrina/análise , Tadjiquistão
19.
Mol Plant ; 12(3): 360-373, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30853061

RESUMO

To optimize fitness, plants must efficiently allocate their resources between growth and defense. Although phytohormone crosstalk has emerged as a major player in balancing growth and defense, the genetic basis by which plants manage this balance remains elusive. We previously identified a quantitative disease-resistance locus, qRfg2, in maize (Zea mays) that protects against the fungal disease Gibberella stalk rot. Here, through map-based cloning, we demonstrate that the causal gene at qRfg2 is ZmAuxRP1, which encodes a plastid stroma-localized auxin-regulated protein. ZmAuxRP1 responded quickly to pathogen challenge with a rapid yet transient reduction in expression that led to arrested root growth but enhanced resistance to Gibberella stalk rot and Fusarium ear rot. ZmAuxRP1 was shown to promote the biosynthesis of indole-3-acetic acid (IAA), while suppressing the formation of benzoxazinoid defense compounds. ZmAuxRP1 presumably acts as a resource regulator modulating indole-3-glycerol phosphate and/or indole flux at the branch point between the IAA and benzoxazinoid biosynthetic pathways. The concerted interplay between IAA and benzoxazinoids can regulate the growth-defense balance in a timely and efficient manner to optimize plant fitness.


Assuntos
Resistência à Doença , Ácidos Indolacéticos/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/imunologia , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/microbiologia , Zea mays/imunologia , Fusarium/fisiologia , Gibberella/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/imunologia , Proteínas de Plantas/genética , Raízes de Plantas/imunologia , Caules de Planta/genética , Caules de Planta/imunologia , Zea mays/genética , Zea mays/microbiologia
20.
Nat Commun ; 10(1): 619, 2019 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-30728357

RESUMO

Axis formation is a fundamental issue in developmental biology. Axis formation and patterning in plant leaves is crucial for morphology and crop productivity. Here, we reveal the basis of proximal-distal patterning in rice leaves, which consist of a proximal sheath, a distal blade, and boundary organs formed between these two regions. Analysis of the three rice homologs of the Arabidopsis BLADE-ON-PETIOLE1 (BOP1) gene indicates that OsBOPs activate proximal sheath differentiation and suppress distal blade differentiation. Temporal expression changes of OsBOPs are responsible for the developmental changes in the sheath:blade ratio. We further identify that the change in the sheath:blade ratio during the juvenile phase is controlled by the miR156/SPL pathway, which modifies the level and pattern of expression of OsBOPs. OsBOPs are also essential for differentiation of the boundary organs. We propose that OsBOPs, the main regulators of proximal-distal patterning, control temporal changes in the sheath:blade ratio of rice leaves.


Assuntos
Padronização Corporal , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Oryza/crescimento & desenvolvimento , Oryza/genética , Desenvolvimento Vegetal/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Diferenciação Celular/genética , MicroRNAs/metabolismo , Proteínas Nucleares/metabolismo , Oryza/anatomia & histologia , Oryza/citologia , Fenótipo , Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Proteínas de Plantas/genética , Caules de Planta/anatomia & histologia , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Proteínas Repressoras/metabolismo
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