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1.
Nat Commun ; 11(1): 4079, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796936

RESUMO

DNA methylation is an epigenetic modification that specifies the basic state of pluripotent stem cells and regulates the developmental transition from stem cells to various cell types. In flowering plants, the shoot apical meristem (SAM) contains a pluripotent stem cell population which generates the aerial part of plants including the germ cells. Under appropriate conditions, the SAM undergoes a developmental transition from a leaf-forming vegetative SAM to an inflorescence- and flower-forming reproductive SAM. While SAM characteristics are largely altered in this transition, the complete picture of DNA methylation remains elusive. Here, by analyzing whole-genome DNA methylation of isolated rice SAMs in the vegetative and reproductive stages, we show that methylation at CHH sites is kept high, particularly at transposable elements (TEs), in the vegetative SAM relative to the differentiated leaf, and increases in the reproductive SAM via the RNA-dependent DNA methylation pathway. We also show that half of the TEs that were highly methylated in gametes had already undergone CHH hypermethylation in the SAM. Our results indicate that changes in DNA methylation begin in the SAM long before germ cell differentiation to protect the genome from harmful TEs.


Assuntos
Metilação de DNA , Meristema/crescimento & desenvolvimento , Meristema/genética , Oryza/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/genética , Elementos de DNA Transponíveis , Biologia do Desenvolvimento , Epigenômica , Flores , Regulação da Expressão Gênica de Plantas , Inflorescência , Folhas de Planta/metabolismo , Proteínas de Plantas/genética
2.
Nature ; 583(7815): 277-281, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32528176

RESUMO

Plant hormones known as strigolactones control plant development and interactions between host plants and symbiotic fungi or parasitic weeds1-4. In Arabidopsis thaliana and rice, the proteins DWARF14 (D14), MORE AXILLARY GROWTH 2 (MAX2), SUPPRESSOR OF MAX2-LIKE 6, 7 and 8 (SMXL6, SMXL7 and SMXL8) and their orthologues form a complex upon strigolactone perception and play a central part in strigolactone signalling5-10. However, whether and how strigolactones activate downstream transcription remains largely unknown. Here we use a synthetic strigolactone to identify 401 strigolactone-responsive genes in Arabidopsis, and show that these plant hormones regulate shoot branching, leaf shape and anthocyanin accumulation mainly through transcriptional activation of the BRANCHED 1, TCP DOMAIN PROTEIN 1 and PRODUCTION OF ANTHOCYANIN PIGMENT 1 genes. We find that SMXL6 targets 729 genes in the Arabidopsis genome and represses the transcription of SMXL6, SMXL7 and SMXL8 by binding directly to their promoters, showing that SMXL6 serves as an autoregulated transcription factor to maintain the homeostasis of strigolactone signalling. These findings reveal an unanticipated mechanism through which a transcriptional repressor of hormone signalling can directly recognize DNA and regulate transcription in higher plants.


Assuntos
Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Compostos Heterocíclicos com 3 Anéis/metabolismo , Lactonas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Transdução de Sinais/genética , Transcrição Genética , Antocianinas/biossíntese , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Genes de Plantas/genética , Reguladores de Crescimento de Planta/biossíntese , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
Proc Natl Acad Sci U S A ; 117(21): 11523-11530, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32393640

RESUMO

Shoot architecture is critical for optimizing plant adaptation and productivity. In contrast with annuals, branching in perennials native to temperate and boreal regions must be coordinated with seasonal growth cycles. How branching is coordinated with seasonal growth is poorly understood. We identified key components of the genetic network that controls branching and its regulation by seasonal cues in the model tree hybrid aspen. Our results demonstrate that branching and its control by seasonal cues is mediated by mutually antagonistic action of aspen orthologs of the flowering regulators TERMINAL FLOWER 1 (TFL1) and APETALA1 (LIKE APETALA 1/LAP1). LAP1 promotes branching through local action in axillary buds. LAP1 acts in a cytokinin-dependent manner, stimulating expression of the cell-cycle regulator AIL1 and suppressing BRANCHED1 expression to promote branching. Short photoperiod and low temperature, the major seasonal cues heralding winter, suppress branching by simultaneous activation of TFL1 and repression of the LAP1 pathway. Our results thus reveal the genetic network mediating control of branching and its regulation by environmental cues facilitating integration of branching with seasonal growth control in perennial trees.


Assuntos
Regulação da Expressão Gênica de Plantas , Brotos de Planta , Populus , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Fotoperíodo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/genética , Brotos de Planta/fisiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Populus/genética , Populus/crescimento & desenvolvimento , Estações do Ano
4.
Nat Commun ; 11(1): 2223, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376862

RESUMO

Stem cells are one of the foundational evolutionary novelties that allowed the independent emergence of multicellularity in the plant and animal lineages. In plants, the homeodomain (HD) transcription factor WUSCHEL (WUS) is essential for the maintenance of stem cells in the shoot apical meristem. WUS has been reported to bind to diverse DNA motifs and to act as transcriptional activator and repressor. However, the mechanisms underlying this remarkable behavior have remained unclear. Here, we quantitatively delineate WUS binding to three divergent DNA motifs and resolve the relevant structural underpinnings. We show that WUS exhibits a strong binding preference for TGAA repeat sequences, while retaining the ability to weakly bind to TAAT elements. This behavior is attributable to the formation of dimers through interactions of specific residues in the HD that stabilize WUS DNA interaction. Our results provide a mechanistic basis for dissecting WUS dependent regulatory networks in plant stem cell control.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/metabolismo , Motivos de Nucleotídeos/genética , Arabidopsis/química , Arabidopsis/genética , Proteínas de Arabidopsis/genética , DNA/metabolismo , Dimerização , Proteínas de Homeodomínio/genética , Brotos de Planta/genética , Ligação Proteica , Sequências Repetitivas de Ácido Nucleico/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
PLoS One ; 15(5): e0233076, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428011

RESUMO

Nitrogen is an important nutrient for plant growth and tuber quality of potato. Since potato crop requires high dose of N, improving nitrogen use efficiency (NUE) of plant is an inevitable approach to minimize N fertilization. The aim of this study was to identify and characterize microRNAs (miRNAs) by small RNA sequencing in potato plants grown in aeroponic under two contrasting N (high and low) regimes. A total of 119 conserved miRNAs belonging to 41 miRNAs families, and 1002 putative novel miRNAs were identified. From total, 52 and 54 conserved miRNAs, and 404 and 628 putative novel miRNAs were differentially expressed in roots and shoots, respectively under low N stress. Of total 34,135 predicted targets, the gene ontology (GO) analysis indicated that maximum targets belong to biological process followed by molecular function and cellular component. Eexpression levels of the selected miRNAs and targets were validated by real time-quantitative polymerase chain reaction (RT-qPCR) analysis. Two predicted targets of potential miRNAs (miR397 and miR398) were validated by 5' RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends). In general, predicted targets are associated with stress-related, kinase, transporters and transcription factors such as universal stress protein, heat shock protein, salt-tolerance protein, calmodulin binding protein, serine-threonine protein kinsae, Cdk10/11- cyclin dependent kinase, amino acid transporter, nitrate transporter, sugar transporter, transcription factor, F-box family protein, and zinc finger protein etc. Our study highlights that miR397 and miR398 play crucial role in potato during low N stress management. Moreover, study provides insights to modulate miRNAs and their predicted targets to develop N-use efficient potato using transgenic/genome-editing tools in future.


Assuntos
Perfilação da Expressão Gênica/métodos , MicroRNAs/genética , Solanum tuberosum/crescimento & desenvolvimento , Sequenciamento Completo do Genoma/métodos , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Nitrogênio/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , RNA de Plantas/genética , Análise de Sequência de RNA , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Estresse Fisiológico
6.
Plant Mol Biol ; 103(4-5): 561-580, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32405802

RESUMO

KEY MESSAGE: CmHKT1;1 selectively exports Na+ from plant cells. Upon NaCl stress, its expression increased in a salt-tolerant melon cultivar. Overexpression of CmHKT1;1 increased transgenic Arabidopsis salt tolerance through improved K+/Na+ balance. High-affinity K+ transporters (HKTs) are thought to be involved in reducing Na+ in plant shoots under salt stress and modulating salt tolerance, but their function in a moderately salt-tolerant species of melon (Cucumis melo L.) remains unclear. In this study, a Na+ transporter gene, CmHKT1;1 (GenBank accession number: MK986658), was isolated from melons based on genome data. The transcript of CmHKT1;1 was relatively more abundant in roots than in stems or leaves from melon seedlings. The tobacco transient expression system showed that CmHKT1;1 was plasma-membrane localized. Upon salt stress, CmHKT1;1 expression was more strongly upregulated in a salt-tolerant melon cultivar, 'Bingxuecui' (BXC) compared with a salt-sensitive cultivar, 'Yulu' (YL). Electrophysiological evidence demonstrated that CmHKT1;1 only transported Na+, rather than K+, when expressed in Xenopus laevis oocytes. Overexpression of CmHKT1;1 increased salt sensitivity in Saccharomyces cerevisiae and salt tolerance in Arabidopsis thaliana. Under NaCl treatments, transgenic Arabidopsis plants accumulated significantly lower concentrations of Na+ in shoots than wild type plants and showed a better K+/Na+ balance, leading to better Fv/Fm, root length, biomass, and enhanced plant growth. The CmHKT1;1 gene may serve as a useful candidate for improving crop salt tolerance.


Assuntos
Arabidopsis/metabolismo , Cucumis melo/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Arabidopsis/genética , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Clorofila/análise , Clonagem Molecular , Cucumis melo/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana Transportadoras/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Saccharomyces cerevisiae/genética , Tolerância ao Sal , Plântula/genética , Plântula/metabolismo , Alinhamento de Sequência , Análise de Sequência de Proteína , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Simportadores/genética , Simportadores/metabolismo , Tabaco/genética , Tabaco/metabolismo
7.
PLoS One ; 15(2): e0228118, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32012182

RESUMO

Random regression models (RRM) are used extensively for genomic inference and prediction of time-valued traits in animal breeding, but only recently have been used in plant systems. High-throughput phenotyping (HTP) platforms provide a powerful means to collect high-dimensional phenotypes throughout the growing season for large populations. However, to date, selection of an appropriate statistical genomic framework to integrate multiple temporal traits for genomic prediction in plants remains unexplored. Here, we demonstrate the utility of a multi-trait RRM (MT-RRM) for genomic prediction of daily water usage (WU) in rice (Oryza sativa) through joint modeling with shoot biomass (projected shoot area, PSA). Three hundred and fifty-seven accessions were phenotyped daily for WU and PSA over 20 days using a greenhouse-based HTP platform. MT-RRMs that modeled additive genetic and permanent environmental effects for both traits using quadratic Legendre polynomials were used to assess genomic correlations between traits and genomic prediction for WU. Predictive abilities of the MT-RRMs were assessed using two cross-validation (CV) scenarios. The first scenario was designed to predict genetic values for WU at all time points for a set of accessions with unobserved WU. The second scenario was designed to forecast future genetic values for WU for a panel of known accessions with records for WU at earlier time periods. In each scenario we evaluated two MT-RRMs in which PSA records were absent or available for time points in the testing population. Weak to strong genomic correlations between WU and PSA were observed across the days of imaging (0.29-0.870.38-0.80). In both CV scenarios, MT-RRMs showed better predictive abilities compared to single-trait RRM, and prediction accuracies were greatly improved when PSA records were available for the testing population. In summary, these frameworks provide an effective approach to predict temporal physiological traits that are difficult or expensive to quantify in large populations.


Assuntos
Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Oryza/genética , Fenótipo , Biomassa , Genótipo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Análise de Regressão , Água/metabolismo
8.
Nat Commun ; 11(1): 641, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005881

RESUMO

Plants modulate the efficiency of root nitrogen (N) acquisition in response to shoot N demand. However, molecular components directly involved in this shoot-to-root communication remain to be identified. Here, we show that phloem-mobile CEPD-like 2 (CEPDL2) polypeptide is upregulated in the leaf vasculature in response to decreased shoot N status and, after translocation to the roots, promotes high-affinity uptake and root-to-shoot transport of nitrate. Loss of CEPDL2 leads to a reduction in shoot nitrate content and plant biomass. CEPDL2 contributes to N acquisition cooperatively with CEPD1 and CEPD2 which mediate root N status, and the complete loss of all three proteins severely impairs N homeostasis in plants. Reciprocal grafting analysis provides conclusive evidence that the shoot CEPDL2/CEPD1/2 genotype defines the high-affinity nitrate uptake activity in root. Our results indicate that plants integrate shoot N status and root N status in leaves and systemically regulate the efficiency of root N acquisition.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Glutarredoxinas/metabolismo , Nitratos/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Glutarredoxinas/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Raízes de Plantas/genética , Brotos de Planta/genética
9.
Plant Cell Rep ; 39(4): 543-552, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32025802

RESUMO

KEY MESSAGE: BIG regulates the shoot stem cell population. The shoot apical meristem (SAM) contains a population of self-renewing cells, and provides daughter cells for initiation and development of aerial parts of plants. However, the underlying mechanisms of SAM size regulation remain largely unclear. Here, we identified a mutant that displayed a large SAM, designated big-shoot meristem (big-m), in Arabidopsis thaliana. The phenotype of big-m is caused by a new T-DNA insertion allele of BIG, causing a loss of function. The big-m mutant had more stem cells in the SAM than in the wild type. Expression of WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM) was promoted in big-m compared with the wild type, showing that BIG functions upstream of WUS and STM. Therefore, BIG is an important regulator of the stem cell population in the SAM. Furthermore, genetic analysis indicated that BIG acts synergistically with PIN-FORMED1 (PIN1) in controlling SAM size. Our results suggest that BIG plays an important role in controlling Arabidopsis thaliana SAM growth via PIN1-mediated auxin homeostasis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Meristema/citologia , Meristema/genética , Brotos de Planta/citologia , Brotos de Planta/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação a Calmodulina/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Mutagênese Insercional , Fenótipo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo
10.
Ecotoxicol Environ Saf ; 190: 110178, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31927193

RESUMO

Given the limitation of crop production in Cd-polluted areas, the identification and selection of plant genotypes tolerant to Cd stress are of great significance. In the present work, we show the existence of genotypic variation for Cd tolerance in common bean. The laboratory screening of 25 bean genotypes indicated a significant positive correlation of the mean productivity (MP) and the geometric mean productivity (GMP) with plant fresh weight both in control and Cd-treated plants. A principal component analysis further confirmed this variation and, together with other analyses, led to the selection of genotypes G-11867, Taylor, Emerson, and D-81083 as tolerant genotypes. A total of six bean genotypes with different degrees of Cd tolerance were selected, and their long-term physiological responses to Cd (0, 45, and 90 mg/kg soil) were evaluated. Increasing Cd concentrations led to higher Cd accumulation both in roots and shoots, and to significant rises in the levels of the oxidative stress biomarkers malondialdehyde (MDA), dityrosine (D-T), and 8-hydroxy-2'-deoxyguanosine (8-OH-2'-dG). Remarkable reductions in plant hormone levels and chlorophyll contents, as well as in dry and fresh weight, were observed in Cd-treated plants. Among the examined genotypes, Emerson, Taylor, and G-11867 were found to be more tolerant to Cd owing to lower Cd accumulation and lower oxidative stress levels, as well as higher chlorophyll and hormone contents. Our results contribute to the understanding of the physiological and biochemical basis of Cd tolerance in bean plants and may therefore, be useful for breeding programs directed towards obtaining bean varieties showing low Cd accumulation.


Assuntos
Aclimatação/genética , Cádmio/toxicidade , Phaseolus/efeitos dos fármacos , Poluentes do Solo/toxicidade , 8-Hidroxi-2'-Desoxiguanosina/metabolismo , Clorofila/metabolismo , Genótipo , Malondialdeído/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/genética , Brotos de Planta/metabolismo , Estresse Fisiológico/genética , Tirosina/análogos & derivados , Tirosina/metabolismo
11.
Proc Natl Acad Sci U S A ; 117(3): 1596-1605, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31907313

RESUMO

Hybrid-poplar tree plantations provide a source for biofuel and biomass, but they also increase forest isoprene emissions. The consequences of increased isoprene emissions include higher rates of tropospheric ozone production, increases in the lifetime of methane, and increases in atmospheric aerosol production, all of which affect the global energy budget and/or lead to the degradation of air quality. Using RNA interference (RNAi) to suppress isoprene emission, we show that this trait, which is thought to be required for the tolerance of abiotic stress, is not required for high rates of photosynthesis and woody biomass production in the agroforest plantation environment, even in areas with high levels of climatic stress. Biomass production over 4 y in plantations in Arizona and Oregon was similar among genetic lines that emitted or did not emit significant amounts of isoprene. Lines that had substantially reduced isoprene emission rates also showed decreases in flavonol pigments, which reduce oxidative damage during extremes of abiotic stress, a pattern that would be expected to amplify metabolic dysfunction in the absence of isoprene production in stress-prone climate regimes. However, compensatory increases in the expression of other proteomic components, especially those associated with the production of protective compounds, such as carotenoids and terpenoids, and the fact that most biomass is produced prior to the hottest and driest part of the growing season explain the observed pattern of high biomass production with low isoprene emission. Our results show that it is possible to reduce the deleterious influences of isoprene on the atmosphere, while sustaining woody biomass production in temperate agroforest plantations.


Assuntos
Atmosfera , Hemiterpenos/biossíntese , Hibridização Genética , Populus/crescimento & desenvolvimento , Populus/metabolismo , Poluição do Ar , Arizona , Biocombustíveis , Biomassa , Butadienos , Dióxido de Carbono/metabolismo , Carotenoides/metabolismo , Clima , Oregon , Fotossíntese , Folhas de Planta/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Populus/genética , Proteoma , Interferência de RNA , Estações do Ano , Estresse Fisiológico , Terpenos/metabolismo , Termotolerância/fisiologia , Madeira
13.
BMC Plant Biol ; 20(1): 47, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996144

RESUMO

BACKGROUND: Shoot branching is an important trait of plants that allows them to adapt to environment changes. Strigolactones (SLs) are newly identified plant hormones that inhibit shoot branching in plants. The SL biosynthesis genes CCD7 (carotenoid cleavage dioxygenase 7) and CCD8 have been found to regulate branching in several herbaceous plants by taking advantage of their loss-of-function mutants. However, the role for CCD7 and CCD8 in shoot branching control in grapevine is still unknown due to the lack of corresponding mutants. RESULTS: Here we employed the CRISPR/Cas9 system to edit the VvCCD7 and VvCCD8 genes in the grape hybrid 41B. The 41B embryogenic cells can easily be transformed and used for regeneration of the corresponding transformed plants. Sequencing analysis revealed that gene editing has been used successfully to target both VvCCD genes in 41B embryogenic cells. After regeneration, six 41B plantlets were identified as transgenic plants carrying the CCD8-sgRNA expression cassette. Among these, four plants showed mutation in the target region and were selected as ccd8 mutants. These ccd8 mutants showed increased shoot branching compared to the corresponding wild-type plants. In addition, no off-target mutation was detected in the tested mutants at predicted off-target sites. CONCLUSIONS: Our results underline the key role of VvCCD8 in the control of grapevine shoot branching.


Assuntos
Proteínas de Arabidopsis/genética , Dioxigenases/genética , Brotos de Planta/genética , Vitis/genética , Sistemas CRISPR-Cas , Edição de Genes , Técnicas de Inativação de Genes , Genes de Plantas , Brotos de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas
14.
Plant Cell Rep ; 39(4): 445-455, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31912218

RESUMO

KEY MESSAGE: An AP2 family gene CBX1 is involved in mycorrhizal symbiosis and growth of Lotus japonicus. APETALA 2 (AP2) transcriptional regulator is highly conserved in plants. CBX1 from Lotus japonicus is a member of AP2 family. AMF (Arbuscular mycorrhizal fungi) inoculation experiment demonstrated that expression of CBX1 was significantly induced by AMF. Further promoter analysis showed that the - 764 to - 498 bp region of the CBX1 promoter containing CTTC motif is the AMF responsive region. Functional analysis of cbx1 mutant suggested CBX1 is critical for mycorrhizal symbiosis, especially for arbuscule formation. Moreover, under noncolonized condition, overexpression of CBX1 reduced the root length of L. japonicus but increased the size of root system and shoot length, whereas cbx1 mutant reduced the root size and shoot length, but not effect on root length. In addition, cbx1 altered activity of monolignol biosynthetic gene and increased lignin levels. Collectively, these data indicated that CBX1 is a positive regulator of symbiotic activity and plays roles in the growth of L. japonicus.


Assuntos
Lotus/microbiologia , Micorrizas/metabolismo , Proteínas de Plantas/metabolismo , Simbiose/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Lignina/biossíntese , Lignina/genética , Lignina/metabolismo , Lotus/genética , Lotus/crescimento & desenvolvimento , Lotus/metabolismo , Mutação , Micorrizas/genética , Micorrizas/crescimento & desenvolvimento , Proteínas de Plantas/genética , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , RNA-Seq , Simbiose/fisiologia , Fatores de Transcrição/genética , Transcriptoma/genética , Regulação para Cima
15.
Plant Cell Rep ; 39(4): 431-444, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31984435

RESUMO

KEY MESSAGE: This review summarizes recent knowledge on functions of WUS and WUS-related homeobox (WOX) transcription factors in diverse signaling pathways governing shoot meristem biology and several other aspects of plant dynamics. Transcription factors (TFs) are master regulators involved in controlling different cellular and biological functions as well as diverse signaling pathways in plant growth and development. WUSCHEL (WUS) is a homeodomain transcription factor necessary for the maintenance of the stem cell niche in the shoot apical meristem, the differentiation of lateral primordia, plant cell totipotency and other diverse cellular processes. Recent research about WUS has uncovered several unique features including the complex signaling pathways that further improve the understanding of vital network for meristem biology and crop productivity. In addition, several reports bridge the gap between WUS expression and plant signaling pathway by identifying different WUS and WUS-related homeobox (WOX) genes during the formation of shoot (apical and axillary) meristems, vegetative-to-embryo transition, genetic transformation, and other aspects of plant growth and development. In this respect, the WOX family of TFs comprises multiple members involved in diverse signaling pathways, but how these pathways are regulated remains to be elucidated. Here, we review the current status and recent discoveries on the functions of WUS and newly identified WOX family members in the regulatory network of various aspects of plant dynamics.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Flores/metabolismo , Proteínas de Homeodomínio/metabolismo , Meristema/metabolismo , Brotos de Planta/metabolismo , Arabidopsis/embriologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Diferenciação Celular/genética , Citocininas/metabolismo , Epigênese Genética , Flores/embriologia , Flores/genética , Flores/crescimento & desenvolvimento , Proteínas de Homeodomínio/genética , Meristema/genética , Meristema/crescimento & desenvolvimento , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Regeneração/genética , Transdução de Sinais , Nicho de Células-Tronco , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
J Sci Food Agric ; 100(4): 1505-1514, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31756273

RESUMO

BACKGROUND: Greater proportions of purple tea buds and leaves usually appear in the summer, which seriously affects the color and taste quality of green tea products, yet the metabolism of purple tea shoots in summer remains unclear. Here, the metabolomic profiles and gene expression of related flavonoid metabolic pathways in the purple and normal green shoots of 'Longjing 43', and the quality of green tea made with these two phenotypes, were analyzed and compared. RESULTS: Differential metabolites identified using high-performance liquid chromatography-Orbitrap/mass spectrometry indicated that anthocyanin biosynthesis in purple leaves was enriched, with higher levels of anthocyanidins (delphinidin-hexose-coumaroyl showed the greatest increase), proanthocyanidins (oligomers of catechins) and kaempferol glycoside. Expression patterns of the genes ANR, ANS, FLS, LAR, C4H, PAL, CHI, CHS and DFR revealed that the metabolism of anthocyanin is positively regulated by high temperature and/or light levels in summer. Gas chromatography-mass spectrometry results showed that, in purple tea shoots, the metabolism of carbohydrates was enriched whereas that of amino acids was diminished, while their mannose, fructose, d-galactose, sorbose and d-glucose contents were more than double those found in green leaves. A sensory evaluation confirmed that a greater quantity of purple shoots had a greater negative impact on green tea quality because of a bitter taste and dark color (leaves and infusions were tested). CONCLUSIONS: These results highlight the need for and possibility of improving commercial tea quality via cultivation that controls the temperature or light of tea gardens during the summer. © 2019 Society of Chemical Industry.


Assuntos
Antocianinas/biossíntese , Camellia sinensis/metabolismo , Brotos de Planta/metabolismo , Camellia sinensis/química , Camellia sinensis/genética , Camellia sinensis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Estações do Ano
17.
Nat Biotechnol ; 38(1): 84-89, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31844292

RESUMO

Plant gene editing is typically performed by delivering reagents such as Cas9 and single guide RNAs to explants in culture. Edited cells are then induced to differentiate into whole plants by exposure to various hormones. The creation of edited plants through tissue culture is often inefficient, time-consuming, works for only limited species and genotypes, and causes unintended changes to the genome and epigenome. Here we report two methods to generate gene-edited dicotyledonous plants through de novo meristem induction. Developmental regulators and gene-editing reagents are delivered to somatic cells of whole plants. This induces meristems that produce shoots with targeted DNA modifications, and gene edits are transmitted to the next generation. The de novo induction of gene-edited meristems sidesteps the need for tissue culture and promises to overcome a bottleneck in plant gene editing.


Assuntos
Edição de Genes , Meristema/genética , Tabaco/genética , Sequência de Bases , Proteína 9 Associada à CRISPR/metabolismo , Mutação/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/genética , Plantas Geneticamente Modificadas , Plântula/genética , Solo , Tabaco/crescimento & desenvolvimento , Transgenes
18.
Int J Mol Sci ; 20(24)2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31835299

RESUMO

Jasmonates (JAs) together with jasmonic acid and its offshoots are lipid-derived endogenous hormones that play key roles in both developmental processes and different defense responses in plants. JAs have been studied intensively in the past decades for their substantial roles in plant defense comebacks against diverse environmental stresses among model plants. However, the role of this phytohormone has been poorly investigated in the monocotyledonous species against abiotic stresses. In this study, a JA biosynthesis mutant opr7opr8 was used for the investigation of JA roles in the salt stress responses of maize seedlings, whose roots were exposed to 0 to 300 mM NaCl. Foliar stomatal observation showed that opr7opr8 had a larger stomatal aperture than wild type (WT) (B73) under salinity stress, indicating that JA positively regulates guard cell movement under salt stress. The results regarding chlorophyll content and leaf senescence showed that opr7opr8 exhibited delayed leaf senescence under salt stress as compared to WT, indicating that JA plays a role in salt-inducing cell death and subsequent leaf senescence. Moreover, the morphological parameters, including the length of the shoots and roots, and the fresh and dry weights of the shoots and roots, showed that after 7 days of salt treatment, opr7opr8 had heavier and longer shoots than WT but slighter and shorter roots than WT. In addition, ion analysis showed that opr7opr8 accumulated less sodium but more potassium in the leaves than WT but more sodium and less potassium in the roots than WT, suggesting that JA deficiency causes higher salt stress to the roots but less stress to the leaves of the seedlings. Reactive oxygen species (ROS) analysis showed that opr7opr8 produced less H2O2 than WT in the leaves but more H2O2 in the roots under salt treatment, and correspondingly, ROS-scavenging enzymes superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) showed a similar variation, i.e., opr7opr8 has lower enzymatic activities in the shoots but higher activities in the roots than WT under salt treatment. For osmotic adjustment, opr7opr8 produced less proline in the shoots at 100 and 300 mM NaCl treatments but more in the roots than the WT roots under all salt treatments. In addition, the gene expression for abscisic acid (ABA) biosynthesis under salt stress was investigated. Results showed that the expression levels of four key enzymes of ABA biosynthesis, ZEP1, NCED5, AO1, and VP10, were significantly downregulated in the shoots as compared to WT under salt treatment. Putting all the data together, we concluded that JA-deficiency in maize seedlings reduced the salt-stress responses in the shoots but exaggerated the responses in the roots. In addition, endogenous JA acted as a positive regulator for the transportation of sodium ions from the roots to the shoots because the mutant opr7opr8 had a higher level of sodium in the roots but a significantly lower level in the shoots than WT. Furthermore, JA may act as a positive regulator for ABA biosynthesis in the leaves under salt stress.


Assuntos
Ciclopentanos , Oxilipinas , Proteínas de Plantas , Raízes de Plantas , Estresse Salino/genética , Plântula , Zea mays , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Plântula/genética , Plântula/metabolismo , Zea mays/genética , Zea mays/metabolismo
19.
Nat Plants ; 5(12): 1216-1221, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31819220

RESUMO

Plants are able to sense a rise in temperature of several degrees, and appropriately adapt their metabolic and growth processes. To this end, plants produce various signalling molecules that act throughout the plant body. Here, we report that root-derived GA12, a precursor of the bioactive gibberellins, mediates thermo-responsive shoot growth in Arabidopsis. Our data suggest that root-to-shoot translocation of GA12 enables a flexible growth response to ambient temperature changes.


Assuntos
Arabidopsis/metabolismo , Giberelinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/genética , Brotos de Planta/metabolismo , Temperatura
20.
PLoS Biol ; 17(12): e3000560, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31815938

RESUMO

Land plant shoot structures evolved a diversity of lateral organs as morphological adaptations to the terrestrial environment, with lateral organs arising independently in different lineages. Vascular plants and bryophytes (basally diverging land plants) develop lateral organs from meristems of sporophytes and gametophytes, respectively. Understanding the mechanisms of lateral organ development among divergent plant lineages is crucial for understanding the evolutionary process of morphological diversification of land plants. However, our current knowledge of lateral organ differentiation mechanisms comes almost entirely from studies of seed plants, and thus, it remains unclear how these lateral structures evolved and whether common regulatory mechanisms control the development of analogous lateral organs. Here, we performed a mutant screen in the liverwort Marchantia polymorpha, a bryophyte, which produces gametophyte axes with nonphotosynthetic scalelike lateral organs. We found that an Arabidopsis LIGHT-DEPENDENT SHORT HYPOCOTYLS 1 and Oryza G1 (ALOG) family protein, named M. polymorpha LATERAL ORGAN SUPRESSOR 1 (MpLOS1), regulates meristem maintenance and lateral organ development in Marchantia. A mutation in MpLOS1, preferentially expressed in lateral organs, induces lateral organs with misspecified identity and increased cell number and, furthermore, causes defects in apical meristem maintenance. Remarkably, MpLOS1 expression rescued the elongated spikelet phenotype of a MpLOS1 homolog in rice. This suggests that ALOG genes regulate the development of lateral organs in both gametophyte and sporophyte shoots by repressing cell divisions. We propose that the recruitment of ALOG-mediated growth repression was in part responsible for the convergent evolution of independently evolved lateral organs among highly divergent plant lineages, contributing to the morphological diversification of land plants.


Assuntos
Meristema/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Arabidopsis/genética , Evolução Biológica , Evolução Molecular , Regulação da Expressão Gênica de Plantas/genética , Meristema/genética , Meristema/crescimento & desenvolvimento , Oryza/genética , Fenótipo , Filogenia , Proteínas de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Plantas/genética , Plantas Geneticamente Modificadas/metabolismo
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