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1.
BMC Plant Biol ; 21(1): 402, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470613

RESUMO

BACKGROUND: Plant-parasitic nematodes and herbivorous insects have a significant negative impact on global crop production. A successful approach to protect crops from these pests is the in planta expression of nematotoxic or entomotoxic proteins such as crystal proteins from Bacillus thuringiensis (Bt) or plant lectins. However, the efficacy of this approach is threatened by emergence of resistance in nematode and insect populations to these proteins. To solve this problem, novel nematotoxic and entomotoxic proteins are needed. During the last two decades, several cytoplasmic lectins from mushrooms with nematicidal and insecticidal activity have been characterized. In this study, we tested the potential of Marasmius oreades agglutinin (MOA) to furnish Arabidopsis plants with resistance towards three economically important crop pests: the two plant-parasitic nematodes Heterodera schachtii and Meloidogyne incognita and the herbivorous diamondback moth Plutella xylostella. RESULTS: The expression of MOA does not affect plant growth under axenic conditions which is an essential parameter in the engineering of genetically modified crops. The transgenic Arabidopsis lines showed nearly complete resistance to H. schachtii, in that the number of female and male nematodes per cm root was reduced by 86-91 % and 43-93 % compared to WT, respectively. M. incognita proved to be less susceptible to the MOA protein in that 18-25 % and 26-35 % less galls and nematode egg masses, respectively, were observed in the transgenic lines. Larvae of the herbivorous P. xylostella foraging on MOA-expression lines showed a lower relative mass gain (22-38 %) and survival rate (15-24 %) than those feeding on WT plants. CONCLUSIONS: The results of our in planta experiments reveal a robust nematicidal and insecticidal activity of the fungal lectin MOA against important agricultural pests which may be exploited for crop protection.


Assuntos
Aglutininas/farmacologia , Arabidopsis/parasitologia , Herbivoria , Marasmius/química , Nematoides/fisiologia , Aglutininas/química , Animais , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mariposas/fisiologia , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas
2.
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
3.
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
4.
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
5.
Nat Commun ; 12(1): 4979, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404804

RESUMO

Relative contributions of pre-existing vs de novo genomic variation to adaptation are poorly understood, especially in polyploid organisms. We assess this in high resolution using autotetraploid Arabidopsis arenosa, which repeatedly adapted to toxic serpentine soils that exhibit skewed elemental profiles. Leveraging a fivefold replicated serpentine invasion, we assess selection on SNPs and structural variants (TEs) in 78 resequenced individuals and discover significant parallelism in candidate genes involved in ion homeostasis. We further model parallel selection and infer repeated sweeps on a shared pool of variants in nearly all these loci, supporting theoretical expectations. A single striking exception is represented by TWO PORE CHANNEL 1, which exhibits convergent evolution from independent de novo mutations at an identical, otherwise conserved site at the calcium channel selectivity gate. Taken together, this suggests that polyploid populations can rapidly adapt to environmental extremes, calling on both pre-existing variation and novel polymorphisms.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Alelos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Genoma de Planta , Poliploidia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Canais de Cálcio/metabolismo , Mutação , Polimorfismo de Nucleotídeo Único , Alcaloides de Triptamina e Secologanina/metabolismo , Solo/química
6.
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
7.
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
8.
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
9.
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
10.
Nucleic Acids Res ; 49(15): 8900-8922, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34370034

RESUMO

In eukaryotes, the major nuclear export pathway for mature mRNAs uses the dimeric receptor TAP/p15, which is recruited to mRNAs via the multisubunit TREX complex, comprising the THO core and different export adaptors. Viruses that replicate in the nucleus adopt different strategies to hijack cellular export factors and achieve cytoplasmic translation of their mRNAs. No export receptors are known in plants, but Arabidopsis TREX resembles the mammalian complex, with a conserved hexameric THO core associated with ALY and UIEF proteins, as well as UAP56 and MOS11. The latter protein is an orthologue of mammalian CIP29. The nuclear export mechanism for viral mRNAs has not been described in plants. To understand this process, we investigated the export of mRNAs of the pararetrovirus CaMV in Arabidopsis and demonstrated that it is inhibited in plants deficient in ALY, MOS11 and/or TEX1. Deficiency for these factors renders plants partially resistant to CaMV infection. Two CaMV proteins, the coat protein P4 and reverse transcriptase P5, are important for nuclear export. P4 and P5 interact and co-localise in the nucleus with the cellular export factor MOS11. The highly structured 5' leader region of 35S RNAs was identified as an export enhancing element that interacts with ALY1, ALY3 and MOS11 in vitro.


Assuntos
Regiões 5' não Traduzidas , Proteínas de Arabidopsis/metabolismo , Núcleo Celular/virologia , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Proteínas Virais/metabolismo , Transporte Ativo do Núcleo Celular , Arabidopsis/virologia , Proteínas de Arabidopsis/fisiologia , Proteínas do Capsídeo/metabolismo , Caulimovirus/genética , Caulimovirus/metabolismo , Núcleo Celular/metabolismo , Doenças das Plantas/virologia , RNA Viral/química , DNA Polimerase Dirigida por RNA/metabolismo
11.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361039

RESUMO

Plant G proteins are versatile components of transmembrane signaling transduction pathways. The deficient mutant of heterotrimeric G protein leads to defects in plant growth and development, suggesting that it regulates the GA pathway in Arabidopsis. However, the molecular mechanism of G protein regulation of the GA pathway is not understood in plants. In this study, two G protein ß subunit (AGB1) mutants, agb1-2 and N692967, were dwarfed after exogenous application of GA3. AGB1 interacts with the DNA-binding domain MYB62, a GA pathway suppressor. Transgenic plants were obtained through overexpression of MYB62 in two backgrounds including the wild-type (MYB62/WT Col-0) and agb1 mutants (MYB62/agb1) in Arabidopsis. Genetic analysis showed that under GA3 treatment, the height of the transgenic plants MYB62/WT and MYB62/agb1 was lower than that of WT. The height of MYB62/agb1 plants was closer to MYB62/WT plants and higher than that of mutants agb1-2 and N692967, suggesting that MYB62 is downstream of AGB1 in the GA pathway. qRT-PCR and competitive DNA binding assays indicated that MYB62 can bind MYB elements in the promoter of GA2ox7, a GA degradation gene, to activate GA2ox7 transcription. AGB1 affected binding of MYB62 on the promoter of GA2ox7, thereby negatively regulating th eactivity of MYB62.


Assuntos
Proteínas de Arabidopsis/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Giberelinas/metabolismo , Arabidopsis , Proteínas de Arabidopsis/genética , Sítios de Ligação , Subunidades beta da Proteína de Ligação ao GTP/genética , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica
12.
Nat Commun ; 12(1): 4674, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344879

RESUMO

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


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas Cromossômicas não Histona/metabolismo , Troca Genética/genética , Meiose/genética , Proteínas de Arabidopsis/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Simulação por Computador , Dosagem de Genes , Estágio Paquíteno/genética , Complexo Sinaptonêmico/genética , Complexo Sinaptonêmico/metabolismo
13.
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
14.
Nat Commun ; 12(1): 4760, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362909

RESUMO

The MADS transcription factors (TF) are an ancient eukaryotic protein family. In plants, the family is divided into two main lineages. Here, we demonstrate that DNA binding in both lineages absolutely requires a short amino acid sequence C-terminal to the MADS domain (M domain) called the Intervening domain (I domain) that was previously defined only in type II lineage MADS. Structural elucidation of the MI domains from the floral regulator, SEPALLATA3 (SEP3), shows a conserved fold with the I domain acting to stabilise the M domain. Using the floral organ identity MADS TFs, SEP3, APETALA1 (AP1) and AGAMOUS (AG), domain swapping demonstrate that the I domain alters genome-wide DNA-binding specificity and dimerisation specificity. Introducing AG carrying the I domain of AP1 in the Arabidopsis ap1 mutant resulted in strong complementation and restoration of first and second whorl organs. Taken together, these data demonstrate that the I domain acts as an integral part of the DNA-binding domain and significantly contributes to the functional identity of the MADS TF.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Homeodomínio/química , Fatores de Transcrição/química , Proteína AGAMOUS de Arabidopsis/química , Proteína AGAMOUS de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Flores , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Domínio MADS/metabolismo , Fenótipo , Domínios e Motivos de Interação entre Proteínas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Nat Commun ; 12(1): 4804, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376671

RESUMO

Plants respond to warm temperature by increased elongation growth of organs to enhance cooling capacity. Phytohormones, such as auxin and brassinosteroids, regulate this growth process. However, our view on the players involved in warm temperature-mediated growth remains fragmentary. Here, we show that warm temperature leads to an increased expression of JOXs and ST2A, genes controlling jasmonate catabolism. This leads to an elevated 12HSO4-JA level and consequently to a reduced level of bioactive jasmonates. Ultimately this results in more JAZ proteins, which facilitates plant growth under warm temperature conditions. Taken together, understanding the conserved role of jasmonate signalling during thermomorphogenesis contributes to ensuring food security under a changing climate.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Ciclopentanos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Oxilipinas/metabolismo , Temperatura , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais
16.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208100

RESUMO

Stress granules (SGs) are dynamic RNA-protein complexes localized in the cytoplasm that rapidly form under stress conditions and disperse when normal conditions are restored. The formation of SGs depends on the Ras-GAP SH3 domain-binding protein (G3BP). Formations, interactions and functions of plant and human SGs are strikingly similar, suggesting a conserved mechanism. However, functional analyses of plant G3BPs are missing. Thus, members of the Arabidopsis thaliana G3BP (AtG3BP) protein family were investigated in a complementation assay in a human G3BP knock-out cell line. It was shown that two out of seven AtG3BPs were able to complement the function of their human homolog. GFP-AtG3BP fusion proteins co-localized with human SG marker proteins Caprin-1 and eIF4G1 and restored SG formation in G3BP double KO cells. Interaction between AtG3BP-1 and -7 and known human G3BP interaction partners such as Caprin-1 and USP10 was also demonstrated by co-immunoprecipitation. In addition, an RG/RGG domain exchange from Arabidopsis G3BP into the human G3BP background showed the ability for complementation. In summary, our results support a conserved mechanism of SG function over the kingdoms, which will help to further elucidate the biological function of the Arabidopsis G3BP protein family.


Assuntos
Arabidopsis/metabolismo , Grânulos Citoplasmáticos/metabolismo , Estresse Fisiológico , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Linhagem Celular Tumoral , Proteínas de Fluorescência Verde/metabolismo , Humanos , Fenótipo , Filogenia , Ligação Proteica , Domínios Proteicos
17.
BMC Plant Biol ; 21(1): 320, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217224

RESUMO

N-terminal acetylation (NTA) is a highly abundant protein modification catalyzed by N-terminal acetyltransferases (NATs) in eukaryotes. However, the plant NATs and their biological functions have been poorly explored. Here we reveal that loss of function of CKRC3 and NBC-1, the auxiliary subunit (Naa25) and catalytic subunit (Naa20) of Arabidopsis NatB, respectively, led to defects in skotomorphogenesis and triple responses of ethylene. Proteome profiling and WB test revealed that the 1-amincyclopropane-1-carboxylate oxidase (ACO, catalyzing the last step of ethylene biosynthesis pathway) activity was significantly down-regulated in natb mutants, leading to reduced endogenous ethylene content. The defective phenotypes could be fully rescued by application of exogenous ethylene, but less by its precursor ACC. The present results reveal a previously unknown regulation mechanism at the co-translational protein level for ethylene homeostasis, in which the NatB-mediated NTA of ACOs render them an intracellular stability to maintain ethylene homeostasis for normal growth and responses.


Assuntos
Aminoácido Oxirredutases/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Homeostase , Acetiltransferase N-Terminal B/metabolismo , Acetilação , Sequência de Aminoácidos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Biocatálise , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas , Morfogênese , Mutação/genética , Proteoma/metabolismo , Regulação para Cima/genética
18.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201662

RESUMO

Gene expression and phytohormone contents were measured in response to elevating ascorbate in the absence of other confounding stimuli such as high light and abiotic stresses. Young Arabidopsis plants were treated with 25 mM solutions of l-galactose pathway intermediates l-galactose (l-gal) or l-galactono-1,4-lactone (l-galL), as well as L-ascorbic acid (AsA), with 25 mM glucose used as control. Feeding increased rosette AsA 2- to 4-fold but there was little change in AsA biosynthetic gene transcripts. Of the ascorbate recycling genes, only Dehydroascorbate reductase 1 expression was increased. Some known regulatory genes displayed increased expression and included ANAC019, ANAC072, ATHB12, ZAT10 and ZAT12. Investigation of the ANAC019/ANAC072/ATHB12 gene regulatory network revealed a high proportion of ABA regulated genes. Measurement of a subset of jasmonate, ABA, auxin (IAA) and salicylic acid compounds revealed consistent increases in ABA (up to 4.2-fold) and phaseic acid (PA; up to 5-fold), and less consistently certain jasmonates, IAA, but no change in salicylic acid levels. Increased ABA is likely due to increased transcripts for the ABA biosynthetic gene NCED3. There were also smaller increases in transcripts for transcription factors ATHB7, ERD1, and ABF3. These results provide insights into how increasing AsA content can mediate increased abiotic stress tolerance.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Ácido Ascórbico/metabolismo , Glutationa Transferase/genética , Reguladores de Crescimento de Plantas/metabolismo , Estresse Fisiológico/fisiologia , Ácido Abscísico/metabolismo , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Ascorbato Oxidase/genética , Ascorbato Oxidase/metabolismo , Ácido Ascórbico/genética , Ciclopentanos/metabolismo , Galactose/farmacologia , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Glutationa Transferase/metabolismo , Ácidos Hexurônicos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/genética , Sesquiterpenos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
19.
Plant Sci ; 310: 110983, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315599

RESUMO

The Arabidopsis thaliana R2R3-MYB transcription factor AtMYB32 and its homologs AtMYB4 and AtMYB7 play crucial roles in the regulation of phenylpropanoid metabolism. In addition, AtMYB4 and AtMYB7 are involved in the response to abiotic stress. However, the function of AtMYB32 remains unclear. In this study, we found that AtMYB32 is induced by abscisic acid (ABA) and repressed by drought stress. AtMYB32 positively regulates ABA-mediated seed germination and early seedling development. The expression of ABSCISIC ACID-INSENSITIVE 3 (ABI3), ABI4 and ABI5, which encode key positive regulators of ABA signaling, was upregulated in response to ABA in AtMYB32-overexpressing plants and downregulated in the atmyb32-1 mutant. In addition, we found that the atmyb32-1 mutant was drought resistant. Consistent with the drought-resistant phenotype, the transcript levels of C-repeat binding factor 4 (CBF4) were higher in the atmyb32-1 mutant in response to drought stress. Electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP) assays revealed that AtMYB32 binds directly to the ABI3, ABI4, ABI5 and CBF4 promoters both in vitro and in vivo. Genetically, ABI4 was found to be epistatic to AtMYB32 for ABA-induced inhibition of seed germination and early seedling development. Taken together, our findings revealed that AtMYB32 regulates the ABA response by directly promoting ABI3, ABI4 and ABI5 expression and that the drought stress response likely occurs because of repression of CBF4 expression.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/efeitos dos fármacos , Secas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Transativadores/efeitos dos fármacos , Fatores de Transcrição/efeitos dos fármacos
20.
Plant Sci ; 310: 110990, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315604

RESUMO

Transfer cells (TCs) develop extensive wall ingrowths to facilitate enhanced rates of membrane transport. In Arabidopsis, TCs trans-differentiate from phloem parenchyma (PP) cells abutting the sieve element/companion cell complex in minor veins of foliar tissues and, based on anatomy and expression of SWEET sucrose uniporters, are assumed to play pivotal roles in phloem loading. While wall ingrowth deposition in PP TCs is a dynamic process responding to abiotic stresses such as high light and cold, the transcriptional control of PP TC development, including deposition of the wall ingrowths themselves, is not understood. PP TC development is a trait of vegetative phase change, potentially linking wall ingrowth deposition with floral induction. Transcript profiling by RNA-seq identified NAC056 and NAC018 (NARS1 and NARS2) as putative regulators of wall ingrowth deposition, while recent single cell RNA-seq analysis of leaf vasculature identified PP-specific expression of NAC056. Numerous membrane transporters, particularly of the UmamiT family of amino acid efflux carriers, were also identified. Collectively, these findings, and the recent discovery that wall ingrowth deposition is regulated by sucrose-dependent loading activity of these cells, provide new insights into the biology of PP TCs and their importance to phloem loading in Arabidopsis, establishing these cells as a key transport hub for phloem loading.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Floema/metabolismo , Proteínas de Arabidopsis/genética , Parede Celular/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Folhas de Planta/metabolismo , Análise de Sequência de RNA/métodos
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