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1.
Planta ; 254(4): 69, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34498125

RESUMO

MAIN CONCLUSION: Indole 3-hexanoic acid is a novel auxin and regulates plant growth and development. Auxin is a signaling molecule that influences most aspects of plant development. Although many small bioactive molecules have been developed as auxin analogues, naturally occurring auxin and the detailed mechanisms of its specific actions in plants remain to be fully elucidated. In this study, to screen auxin responses, we used a novel picolinate synthetic auxin, 3-indole hexanoic acid (IHA), which is similar in structure to indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA). IHA showed classical auxin activity in the regulation of root growth, gene expression, and PIN-FORMED abundance. Physiological and genetic analyses indicated that IHA may be perceived by the auxin receptor TIR1 and transported by the G-class ATP-binding cassette protein ABCG36 and its homolog ABCG37. Importantly, IHA was detected in planta and converted into IBA depending on the peroxisomal ß-oxidation. Together, these findings reveal a novel auxin pathway component and suggest possible undiscovered modes of auxin metabolism regulation in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Caproatos , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Indóis , Raízes de Plantas/metabolismo
2.
BMC Genomics ; 22(1): 642, 2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34482814

RESUMO

BACKGROUND: RNA polymerase II plays critical roles in transcription in eukaryotic organisms. C-terminal Domain Phosphatase-like 1 (CPL1) regulates the phosphorylation state of the C-terminal domain of RNA polymerase II subunit B1, which is critical in determining RNA polymerase II activity. CPL1 plays an important role in miRNA biogenesis, plant growth and stress responses. Although cpl1 mutant showes delayed-flowering phenotype, the molecular mechanism behind CPL1's role in floral transition is still unknown. RESULTS: To study the role of CPL1 during the floral transition, we first tested phenotypes of cpl1-3 mutant, which harbors a point-mutation. The cpl1-3 mutant contains a G-to-A transition in the second exon, which results in an amino acid substitution from Glu to Lys (E116K). Further analyses found that the mutated amino acid (Glu) was conserved in these species. As a result, we found that the cpl1-3 mutant experienced delayed flowering under both long- and short-day conditions, and CPL1 is involved in the vernalization pathway. Transcriptome analysis identified 109 genes differentially expressed in the cpl1 mutant, with 2 being involved in floral transition. Differential expression of the two flowering-related DEGs was further validated by qRT-PCR. CONCLUSIONS: Flowering genetic pathways analysis coupled with transciptomic analysis provides potential genes related to floral transition in the cpl1-3 mutant, and a framework for future studies of the molecular mechanisms behind CPL1's role in floral transition.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flores/fisiologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas , Mutação , Fosfoproteínas Fosfatases/genética , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/metabolismo
3.
Sheng Wu Gong Cheng Xue Bao ; 37(8): 2645-2657, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34472285

RESUMO

Lysine acetylation is one of the major post-translational modifications and plays critical roles in regulating gene expression and protein function. Histone deacetylases (HDACs) are responsible for the removal of acetyl groups from the lysines of both histone and non-histone proteins. The RPD3 family is the most widely studied HDACs. This article summarizes the regulatory mechanisms of Arabidopsis RPD3 family in several growth and development processes, which provide a reference for studying the mechanisms of RPD3 family members in regulating plant development. Moreover, this review may provide ideas and clues for exploring the functions of other members of HDACs family.


Assuntos
Arabidopsis , Desenvolvimento Vegetal , Arabidopsis/genética , Arabidopsis/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histonas , Desenvolvimento Vegetal/genética
4.
Planta ; 254(4): 71, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34505938

RESUMO

MAIN CONCLUSION: Plant class IV ACBPs diverged with the split of monocots and eudicots. Difference in the subcellular localization supported the functional variation of plant class IV ACBP. Acyl-CoA-binding proteins (ACBPs) are divided into class I-IV in plants. Class IV ACBPs are kelch motif containing proteins that are specific to plants. The currently known subcellular localizations of plant class IV ACBPs are either in the cytosol (Arabidopsis) or in the peroxisomes (rice). However, it is not clear whether peroxisomal localization of class IV ACBP is a shared character that distinguishes eudicots and monocots. Here, the phylogeny of class IV ACBPs from 73 plant species and subcellular localization of class IV ACBPs from six monocots and eudicots were conducted. Phylogenetic analysis of 112 orthologues revealed that monocot class IV ACBPs were basal to the monophyletic clade formed by eudicots and basal angiosperm. Transient expression of GFP fusions in onion epidermal cells demonstrated that monocot maize (Zea mays), wheat (Triticum aestivum), and sorghum (Sorghum bicolor) and eudicot poplar (Populus trichocarpa) all contained at least one peroxisomal localized class IV ACBP, while orthologues from cucumber (Cucumis sativus L.) and soybean (Glycine max) were all cytosolic. Combining the location of Arabidopsis and rice class IV ACBPs, it indicates that maintaining at least one peroxisomal class IV ACBP could be a shared feature within the tested monocots, while cytosolic class IV ACBPs would be preferred in the tested eudicots. Furthermore, the interaction between OsACBP6 and peroxisomal ATP-binding cassette (ABC) transporter provided clues for the functional mechanism of OsACBP6.


Assuntos
Arabidopsis , Inibidor da Ligação a Diazepam , Arabidopsis/metabolismo , Proteínas de Transporte/genética , Coenzima A , Inibidor da Ligação a Diazepam/genética , Inibidor da Ligação a Diazepam/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
5.
Planta ; 254(4): 78, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34536142

RESUMO

MAIN CONCLUSION: 51 MdbZIP genes were identified from the apple genome by bioinformatics methods. MhABF-OE improved tolerance to saline-alkali stress in Arabidopsis, indicating it is involved in positive regulation of saline-alkali stress response. Saline-alkali stress is a major abiotic stress limiting plant growth all over the world. Members of the bZIP family play an important role in regulating gene expression in response to many kinds of biotic and abiotic stress, including salt stress. According to the transcriptome data, 51 MdbZIP genes responding to saline-alkali stress were identified in apple genome, and their gene structures, conserved protein motifs, phylogenetic analysis, chromosome localization, and promoter cis-acting elements were analyzed. Based on transcriptome data analysis, a MdbZIP family gene (MD15G1081800), which was highly expressed under stress, was selected to isolate and named as MhABF. Expression profile analysis by quantitative real-time PCR confirmed that the expression of MhABF in the leaves of Malus halliana was 10.6-fold higher than that of the control (0 days) after 2 days of stress. Then an MhABF gene was isolated from apple rootstock M. halliana. CaMV35S promoter drived MhABF gene expression vector was constructed to infect Arabidopsis with Agrobacterium-mediated infection. And overexpression MhABF gene plants were obtained. Compared with wild type, transgenic plants grew better under saline-alkali stress and the MhABF-OE lines showed higher chlorophyll content, POD, SOD and CAT activity, which indicated that they had strong resistance to stress. These results indicate that MhABF plays an important role in plant resistance to saline-alkali stress, which lays a foundation for further study on the functions in apple.


Assuntos
Arabidopsis , Malus , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Malus/genética , Malus/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética
6.
Int J Mol Sci ; 22(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34445155

RESUMO

A main characteristic of sphingolipids is the presence of a very long chain fatty acid (VLCFA) whose function in cellular processes is not yet fully understood. VLCFAs of sphingolipids are involved in the intracellular traffic to the vacuole and the maturation of early endosomes into late endosomes is one of the major pathways for vacuolar traffic. Additionally, the anionic phospholipid phosphatidylinositol-3-phosphate (PtdIns (3)P or PI3P) is involved in protein sorting and recruitment of small GTPase effectors at late endosomes/multivesicular bodies (MVBs) during vacuolar trafficking. In contrast to animal cells, PI3P mainly localizes to late endosomes in plant cells and to a minor extent to a discrete sub-domain of the plant's early endosome (EE)/trans-Golgi network (TGN) where the endosomal maturation occurs. However, the mechanisms that control the relative levels of PI3P between TGN and MVBs are unknown. Using metazachlor, an inhibitor of VLCFA synthesis, we found that VLCFAs are involved in the TGN/MVB distribution of PI3P. This effect is independent from either synthesis of PI3P by PI3-kinase or degradation of PI(3,5)P2 into PI3P by the SUPPRESSOR OF ACTIN1 (SAC1) phosphatase. Using high-resolution live cell imaging microscopy, we detected transient associations between TGNs and MVBs but VLCFAs are not involved in those interactions. Nonetheless, our results suggest that PI3P might be transferable from TGN to MVBs and that VLCFAs act in this process.


Assuntos
Arabidopsis/metabolismo , Endossomos/metabolismo , Ácidos Graxos/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Vias Biossintéticas , Esfingolipídeos/metabolismo , Rede trans-Golgi/metabolismo
7.
Planta ; 254(3): 54, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34410495

RESUMO

MAIN CONCLUSION: The expression of full-length cDNAs encoding lavender AGAMOUS-like (LaAG-like) and SEPALLATA3-like (LaSEP3-like) transcription factors induces early flowering and impacts the leaf morphology at a strong expression level in Arabidopsis. Lavandula angustifolia is widely cultivated as an ornamental plant due to its attractive flower structure, and as a source of valuable essential oils for use in cosmetics, alternative medicines, and culinary products. We recently employed RNA-Seq and transcript profiling to describe a number of transcription factors (TFs) that potentially control flower development in this plant. In this study, we investigated the roles of two TFs, LaAGAMOUS-like (LaAG-like) and LaSEPALLATA3-like (LaSEP3-like), that exhibited substantial homology to Arabidopsis thaliana floral development genes, AGAMOUS and SEPALLATA3, respectively, in flowering initiation in Arabidopsis. We stably and constitutively expressed LaAG-like and LaSEP3-like cDNAs in separate Arabidopsis plants. All transgenic plants flowered earlier than the wild-type controls. However, plants that modestly overexpressed the gene were phenotypically normal, while those that strongly expressed the transgene developed curly leaves. We also assessed the expression of five endogenous flowering time regulating genes, from which high expression of Flowering Locus T (AtFT) mRNA in both LaAG-like (type-I and -II) and LaSEP3-like (type-I), and Leafy (AtLFY) mRNAs in LaSEP3-like (type-I) transgenic plants were detected, compared to wild-type controls. Our results suggest that with controlled expression, lavender AG-like and SEP3-like genes are potentially useful for the regulation of flowering time in commercial lavender species, and could be used for plant improvement studies through molecular genetics and targeted breeding programs.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Lavandula , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Lavandula/metabolismo , Proteínas de Domínio MADS/genética , Melhoramento Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Proteínas Repressoras
8.
Int J Mol Sci ; 22(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34360673

RESUMO

Auxin is a key regulator of plant development affecting the formation and maturation of reproductive structures. The apoplastic route of auxin transport engages influx and efflux facilitators from the PIN, AUX and ABCB families. The polar localization of these proteins and constant recycling from the plasma membrane to endosomes is dependent on Rab-mediated vesicular traffic. Rab proteins are anchored to membranes via posttranslational addition of two geranylgeranyl moieties by the Rab Geranylgeranyl Transferase enzyme (RGT), which consists of RGTA, RGTB and REP subunits. Here, we present data showing that seed development in the rgtb1 mutant, with decreased vesicular transport capacity, is disturbed. Both pre- and post-fertilization events are affected, leading to a decrease in seed yield. Pollen tube recognition at the stigma and its guidance to the micropyle is compromised and the seed coat forms incorrectly. Excess auxin in the sporophytic tissues of the ovule in the rgtb1 plants leads to an increased tendency of autonomous endosperm formation in unfertilized ovules and influences embryo development in a maternal sporophytic manner. The results show the importance of vesicular traffic for sexual reproduction in flowering plants, and highlight RGTB1 as a key component of sporophytic-filial signaling.


Assuntos
Arabidopsis/enzimologia , Sementes/enzimologia , Transdução de Sinais , Alquil e Aril Transferases/metabolismo , Alquil e Aril Transferases/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Mutação , Tubo Polínico/fisiologia , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
9.
Int J Mol Sci ; 22(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34360680

RESUMO

Plants have evolutionarily established resistance responses to a variety of abiotic stress conditions, in which ABA mediates the integrated regulation of these stress responses. Numerous proteins function at the transcription level or at the protein level when contributing to controls of the ABA signaling process. Although osmotin is identified as a salt-inducible protein, its function in the abiotic stress response is yet to be elucidated. To examine the role of Arabidopsis OSMOTIN 34 (OSM34) in the ABA signaling pathway, a deletion mutant osm34 generated by a CRISPR/Cas9 system and the double mutant osm34 osml (osmotin 34-like) were analyzed for various ABA responses. Both osm34 and osm34 osml showed reduced levels of ABA responses in seeds and leaves. Moreover, proline level and expression of the proline biosynthesis gene P5CS1 was significantly reduced in osm34 osml. Interestingly, OSM34 binds to SKP2A, an F-Box protein whose transcription is induced by ABA. The protein stability of OSM34 was determined to be under the control of the 26S proteasome. In conclusion, our data suggest that OSM34 functions as a positive regulator in the generation of ABA responses and is under post-translational control.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Transdução de Sinais , Estresse Fisiológico , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Glutamato-5-Semialdeído Desidrogenase/genética , Complexos Multienzimáticos/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Prolina/análise , Proteólise
10.
Nat Commun ; 12(1): 4944, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400629

RESUMO

Plants use nitrate, ammonium, and organic nitrogen in the soil as nitrogen sources. Since the elevated CO2 environment predicted for the near future will reduce nitrate utilization by C3 species, ammonium is attracting great interest. However, abundant ammonium nutrition impairs growth, i.e., ammonium toxicity, the primary cause of which remains to be determined. Here, we show that ammonium assimilation by GLUTAMINE SYNTHETASE 2 (GLN2) localized in the plastid rather than ammonium accumulation is a primary cause for toxicity, which challenges the textbook knowledge. With exposure to toxic levels of ammonium, the shoot GLN2 reaction produced an abundance of protons within cells, thereby elevating shoot acidity and stimulating expression of acidic stress-responsive genes. Application of an alkaline ammonia solution to the ammonium medium efficiently alleviated the ammonium toxicity with a concomitant reduction in shoot acidity. Consequently, we conclude that a primary cause of ammonium toxicity is acidic stress.


Assuntos
Compostos de Amônio/metabolismo , Compostos de Amônio/toxicidade , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Glutamato-Amônia Ligase/metabolismo , Plastídeos/metabolismo , Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Glutamato-Amônia Ligase/efeitos dos fármacos , Glutamato-Amônia Ligase/genética , Nitratos/metabolismo , Nitrogênio/metabolismo , Brotos de Planta/metabolismo
11.
J Plant Physiol ; 264: 153487, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34358944

RESUMO

AtCYP38, a thylakoid lumen localized immunophilin, is found to be essential for photosystem II assembly and maintenance, but how AtCYP38 functions in chloroplast remains unknown. Based on previous functional studies and its crystal structure, we hypothesize that AtCYP38 should function via binding its targets or cofactors in the thylakoid lumen. To identify potential interacting proteins of AtCYP38, we first adopted ATTED-II and STRING web-tools, and found 12 proteins functionally related to AtCYP38. We then screened a yeast two-hybrid library including an Arabidopsis genome wide cDNA with different domain of AtCYP38, and five thylakoid lumen-localized targets were identified. In order to specifically search interacting proteins of AtCYP38 in the thylakoid lumen, we generated a yeast two-hybrid mini library including the thylakoid lumenal proteins and lumenal fractions of thylakoid membrane proteins, and we obtained six thylakoid membrane proteins and nine thylakoid lumenal proteins as interacting proteins of AtCYP38. The interactions between AtCYP38 and several potential targets were further confirmed via pull-down and co-immunoprecipitation assays. Together, a couple of new potential candidate interacting proteins of AtCYP38 were identified, and the results will lay a foundation for unveiling the regulatory mechanisms in photosynthesis by AtCYP38.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Ciclofilinas/metabolismo , Proteínas de Arabidopsis/fisiologia , Ciclofilinas/fisiologia , Imunoprecipitação , Complexo de Proteína do Fotossistema II/metabolismo , Domínios e Motivos de Interação entre Proteínas , Técnicas do Sistema de Duplo-Híbrido
12.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360890

RESUMO

The thylakoid lumen houses proteins that are vital for photosynthetic electron transport, including water-splitting at photosystem (PS) II and shuttling of electrons from cytochrome b6f to PSI. Other lumen proteins maintain photosynthetic activity through biogenesis and turnover of PSII complexes. Although all lumen proteins are soluble, these known details have highlighted interactions of some lumen proteins with thylakoid membranes or thylakoid-intrinsic proteins. Meanwhile, the functional details of most lumen proteins, as well as their distribution between the soluble and membrane-associated lumen fractions, remain unknown. The current study isolated the soluble free lumen (FL) and membrane-associated lumen (MAL) fractions from Arabidopsis thaliana, and used gel- and mass spectrometry-based proteomics methods to analyze the contents of each proteome. These results identified 60 lumenal proteins, and clearly distinguished the difference between the FL and MAL proteomes. The most abundant proteins in the FL fraction were involved in PSII assembly and repair, while the MAL proteome was enriched in proteins that support the oxygen-evolving complex (OEC). Novel proteins, including a new PsbP domain-containing isoform, as well as several novel post-translational modifications and N-termini, are reported, and bi-dimensional separation of the lumen proteome identified several protein oligomers in the thylakoid lumen.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Membranas Intracelulares/metabolismo , Complexo de Proteína do Fotossistema II/química , Complexo de Proteína do Fotossistema II/metabolismo , Proteoma , Tilacoides/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Eletroforese em Gel Bidimensional/métodos , Eletroforese em Gel de Poliacrilamida/métodos , Espectrometria de Massas/métodos , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema II/genética , Filogenia , Processamento de Proteína Pós-Traducional , Proteômica/métodos
13.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360938

RESUMO

During seed germination, desiccation tolerance is lost in the radicle with progressing radicle protrusion and seedling establishment. This process is accompanied by comprehensive changes in the metabolome and proteome. Germination of Arabidopsis seeds was investigated over 72 h with special focus on the heat-stable proteome including late embryogenesis abundant (LEA) proteins together with changes in primary metabolites. Six metabolites in dry seeds known to be important for seed longevity decreased during germination and seedling establishment, while all other metabolites increased simultaneously with activation of growth and development. Thermo-stable proteins were associated with a multitude of biological processes. In the heat-stable proteome, a relatively similar proportion of fully ordered and fully intrinsically disordered proteins (IDP) was discovered. Highly disordered proteins were found to be associated with functional categories development, protein, RNA and stress. As expected, the majority of LEA proteins decreased during germination and seedling establishment. However, four germination-specific dehydrins were identified, not present in dry seeds. A network analysis of proteins, metabolites and amino acids generated during the course of germination revealed a highly connected LEA protein network.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis , Germinação , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Plântula/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Temperatura Alta
14.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445480

RESUMO

Multivesicular body (MVB)-mediated endosomal sorting and macroautophagy are the main pathways mediating the transport of cellular components to the vacuole and are essential for maintaining cellular homeostasis. The interplay of these two pathways remains poorly understood in plants. In this study, we show that FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1 (FREE1), which was previously identified as a plant-specific component of the endosomal sorting complex required for transport (ESCRT), essential for MVB biogenesis and plant growth, can be transported to the vacuole for degradation in response to iron deficiency. The vacuolar transport of ubiquitinated FREE1 protein is mediated by the autophagy pathway. As a consequence, the autophagy deficient mutants, atg5-1 and atg7-2, accumulate more endogenous FREE1 protein and display hypersensitivity to iron deficiency. Furthermore, under iron-deficient growth condition autophagy related genes are upregulated to promote the autophagic degradation of FREE1, thereby possibly relieving the repressive effect of FREE1 on iron absorption. Collectively, our findings demonstrate a unique regulatory mode of protein turnover of the ESCRT machinery through the autophagy pathway to respond to iron deficiency in plants.


Assuntos
Proteínas de Arabidopsis/química , Arabidopsis/metabolismo , Proteínas Relacionadas à Autofagia/genética , Ferro/metabolismo , Proteínas de Transporte Vesicular/química , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Autofagia , Transporte Biológico , Complexos Endossomais de Distribuição Requeridos para Transporte , Endossomos/metabolismo , Mutação , Proteólise , Ubiquitinação
15.
J Agric Food Chem ; 69(35): 10069-10081, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34410120

RESUMO

Many studies have shown that phenolic compounds such as lignin and flavonoids enhance plant resistance. Tea plants are rich in flavonoid compounds. Whether these compounds are related to tea plant resistance is unclear. In this study, an interesting conclusion was drawn on the basis of experimental results: in response to abiotic stress (except for sucrose treatment), gene expression was increased in the phenylpropanoid and lignin pathways and was reduced in the flavonoid pathway in tea plants. CsHCTs, the genes located at the branch point of the lignin and flavonoid pathways, are most suitable for regulating the ratio of carbon flow in the lignin pathway and flavonoid synthesis. Enzymatic and genetic modification experiments proved that CsHCTs encode hydroxycinnamoyl-coenzyme A:shikimate/quinate hydroxycinnamoyl transferase in vitro and in vivo. Furthermore, the genetic modification results showed that the contents of phenolic acids and lignin were increased in tobacco and Arabidopsis plants overexpressing CsHCTs, whereas the content of flavonol glycosides was decreased. Both types of transgenic plants showed resistance to many abiotic stresses and bacterial infections. We speculate that CsHCTs participate in regulation of the metabolic flow of carbon from the flavonoid pathway to the chlorogenic acid, caffeoylshikimic acid, and lignin pathways to increase resistance to biotic and abiotic stresses.


Assuntos
Arabidopsis , Camellia sinensis , Arabidopsis/genética , Arabidopsis/metabolismo , Camellia sinensis/metabolismo , Regulação da Expressão Gênica de Plantas , Lignina/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico , Chá
16.
Nat Commun ; 12(1): 4682, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344886

RESUMO

A key impediment to studying water-related mechanisms in plants is the inability to non-invasively image water fluxes in cells at high temporal and spatial resolution. Here, we report that Raman microspectroscopy, complemented by hydrodynamic modelling, can achieve this goal - monitoring hydrodynamics within living root tissues at cell- and sub-second-scale resolutions. Raman imaging of water-transporting xylem vessels in Arabidopsis thaliana mutant roots reveals faster xylem water transport in endodermal diffusion barrier mutants. Furthermore, transverse line scans across the root suggest water transported via the root xylem does not re-enter outer root tissues nor the surrounding soil when en-route to shoot tissues if endodermal diffusion barriers are intact, thereby separating 'two water worlds'.


Assuntos
Raízes de Plantas/metabolismo , Água/metabolismo , Arabidopsis/anatomia & histologia , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/metabolismo , Transporte Biológico , Hidrodinâmica , Modelos Biológicos , Mutação , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/citologia , Raízes de Plantas/genética , Brotos de Planta/metabolismo , Estômatos de Plantas/metabolismo , Análise Espectral Raman , Xilema/metabolismo
17.
BMC Plant Biol ; 21(1): 347, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301191

RESUMO

BACKGROUND: Tomato (Solanum lycopersicum) is one of the most important horticultural crops, with a marked preference for nitrate as an inorganic nitrogen source. The molecular mechanisms of nitrate uptake and assimilation are poorly understood in tomato. NIN-like proteins (NLPs) are conserved, plant-specific transcription factors that play crucial roles in nitrate signaling. RESULTS: In this study, genome-wide analysis identified six NLP members in tomato genome. These members were clustered into three clades in a phylogenetic tree. Comparative genomic analysis showed that SlNLP genes exhibited collinear relationships to NLPs in Arabidopsis, canola, maize and rice, and that the expansion of the SlNLP family mainly resulted from segmental duplications in the tomato genome. Tissue-specific expression analysis showed that one of the close homologs of AtNLP6/7, SlNLP3, was strongly expressed in roots during both the seedling and flowering stages, that SlNLP4 and SlNLP6 exhibited preferential expression in stems and leaves and that SlNLP6 was expressed at high levels in fruits. Furthermore, the nitrate uptake in tomato roots and the expression patterns of SlNLP genes were measured under nitrogen deficiency and nitrate resupply conditions. Four SlNLPs, SlNLP1, SlNLP2, SlNLP4 and SlNLP6, were upregulated after nitrogen starvation. And SlNLP1 and SlNLP5 were induced rapidly and temporally by nitrate. CONCLUSIONS: These results provide significant insights into the potential diverse functions of SlNLPs to regulate nitrate uptake.


Assuntos
Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Nitratos/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Transdução de Sinais/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Brassica napus/genética , Brassica napus/metabolismo , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Oryza/genética , Oryza/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Zea mays/genética , Zea mays/metabolismo
19.
Methods Mol Biol ; 2312: 89-107, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34228286

RESUMO

The quest to engineer increasingly complex synthetic gene networks in mammalian and plant cells requires an ever-growing portfolio of orthogonal gene expression systems. To control gene expression, light is of particular interest due to high spatial and temporal resolution, ease of dosage and simplicity of administration, enabling increasingly sophisticated man-machine interfaces. However, the majority of applied optogenetic switches are crowded in the UVB, blue and red/far-red light parts of the optical spectrum, limiting the number of simultaneously applicable stimuli. This problem is even more pertinent in plant cells, in which UV-A/B, blue, and red light-responsive photoreceptors are already expressed endogenously. To alleviate these challenges, we developed a green light responsive gene switch, based on the light-sensitive bacterial transcription factor CarH from Thermus thermophilus and its cognate DNA operator sequence CarO. The switch is characterized by high reversibility, high transgene expression levels, and low leakiness, leading to up to 350-fold induction ratios in mammalian cells. In this chapter, we describe the essential steps to build functional components of the green light-regulated gene switch, followed by detailed protocols to quantify transgene expression over time in mammalian cells. In addition, we expand this protocol with a description of how the optogenetic switch can be implemented in protoplasts of A. thaliana.


Assuntos
Arabidopsis/efeitos da radiação , Proteínas de Bactérias/efeitos da radiação , Engenharia Celular , Genes de Troca , Luz , Optogenética , Plantas Geneticamente Modificadas/efeitos da radiação , Thermus thermophilus/genética , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Técnicas de Cultura de Células , Células Cultivadas , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Genes Reporter , Humanos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Thermus thermophilus/metabolismo , Fatores de Tempo , Transfecção
20.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203360

RESUMO

NAC (NAM, ATAF1/2, and CUC2) transcription factors are ubiquitously distributed in eukaryotes and play significant roles in stress response. However, the functional verifications of NACs in Picea (P.) wilsonii remain largely uncharacterized. Here, we identified the NAC transcription factor PwNAC11 as a mediator of drought stress, which was significantly upregulated in P. wilsonii under drought and abscisic acid (ABA) treatments. Yeast two-hybrid assays showed that both the full length and C-terminal of PwNAC11 had transcriptional activation activity and PwNAC11 protein cannot form a homodimer by itself. Subcellular observation demonstrated that PwNAC11 protein was located in nucleus. The overexpression of PwNAC11 in Arabidopsis obviously improved the tolerance to drought stress but delayed flowering time under nonstress conditions. The steady-state level of antioxidant enzymes' activities and light energy conversion efficiency were significantly increased in PwNAC11 transgenic lines under dehydration compared to wild plants. PwNAC11 transgenic lines showed hypersensitivity to ABA and PwNAC11 activated the expression of the downstream gene ERD1 by binding to ABA-responsive elements (ABREs) instead of drought-responsive elements (DREs). Genetic evidence demonstrated that PwNAC11 physically interacted with an ABA-induced protein-ABRE Binding Factor3 (ABF3)-and promoted the activation of ERD1 promoter, which implied an ABA-dependent signaling cascade controlled by PwNAC11. In addition, qRT-PCR and yeast assays showed that an ABA-independent gene-DREB2A-was also probably involved in PwNAC11-mediated drought stress response. Taken together, our results provide the evidence that PwNAC11 plays a dominant role in plants positively responding to early drought stress and ABF3 and DREB2A synergistically regulate the expression of ERD1.


Assuntos
Plantas Geneticamente Modificadas/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Ligação Proteica , Fatores de Transcrição/genética
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