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1.
Commun Biol ; 7(1): 150, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38316905

RESUMO

Plants rely on precise regulation of their stomatal pores to effectively carry out photosynthesis while managing water status. The Arabidopsis CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a critical light signaling repressor, is known to repress stomatal opening, but the exact cellular mechanisms remain unknown. Here, we show that COP1 regulates stomatal movement by controlling the pH levels in guard cells. cop1-4 mutants have larger stomatal apertures and disrupted pH dynamics within guard cells, characterized by increased vacuolar and cytosolic pH and reduced apoplastic pH, leading to abnormal stomatal responses. The altered pH profiles are attributed to the increased plasma membrane (PM) H+-ATPase activity of cop1-4 mutants. Moreover, cop1-4 mutants resist to growth defect caused by alkali stress posed on roots. Overall, our study highlights the crucial role of COP1 in maintaining pH homeostasis of guard cells by regulating PM H+-ATPase activity, and demonstrates how proton movement affects stomatal movement and plant growth.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Estômatos de Plantas/genética , Luz , Homeostase , Concentração de Íons de Hidrogênio , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismo
2.
BMC Plant Biol ; 24(1): 87, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38311744

RESUMO

BACKGROUND: GOLDEN-like (GLK) transcription factors are central regulators of chloroplast biogenesis in Arabidopsis and other species. Findings from Arabidopsis show that these factors also contribute to photosynthetic acclimation, e.g. to variation in light intensity, and are controlled by retrograde signals emanating from the chloroplast. However, the natural variation of GLK1-centered gene-regulatory networks in Arabidopsis is largely unexplored. RESULTS: By evaluating the activities of GLK1 target genes and GLK1 itself in vegetative leaves of natural Arabidopsis accessions grown under standard conditions, we uncovered variation in the activity of GLK1 centered regulatory networks. This is linked with the ecogeographic origin of the accessions, and can be associated with a complex genetic variation across loci acting in different functional pathways, including photosynthesis, ROS and brassinosteroid pathways. Our results identify candidate upstream regulators that contribute to a basal level of GLK1 activity in rosette leaves, which can then impact the capacity to acclimate to different environmental conditions. Indeed, accessions with higher GLK1 activity, arising from habitats with a high monthly variation in solar radiation levels, may show lower levels of photoinhibition at higher light intensities. CONCLUSIONS: Our results provide evidence for natural variation in GLK1 regulatory activities in vegetative leaves. This variation is associated with ecogeographic origin and can contribute to acclimation to high light conditions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fotossíntese/genética , Luz , Variação Genética , Aclimatação/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
Plant Cell Rep ; 43(2): 55, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315238

RESUMO

KEY MESSAGE: ABI5 functions in ABA-mediated anthocyanin accumulation in plant response to low phosphate. Low phosphate (LP)-induced anthocyanin biosynthesis and accumulation play an important role in plant adaptive response to phosphate starvation conditions. However, whether and how the stress phytohormone abscisic acid (ABA) participates in LP-induced anthocyanin accumulation remain elusive. Here, we report that ABA is required for LP-induced anthocyanin accumulation in Arabidopsis thaliana. Disrupting ABA DEFICIENT2 (ABA2), a key ABA-biosynthetic gene, or BETA-GLUCOSIDASE1 (BG1), a major gene implicated in converting conjugated ABA to active ABA, significantly impairs LP-induced anthocyanin accumulation, as LP-induced expression of the anthocyanin-biosynthetic genes Chalcone Synthase (CHS) is dampened in the aba2 and bg1 mutant. In addition, LP-induced anthocyanin accumulation is defective in the mutants of ABA signaling pathway, including ABA receptors, ABA Insensitive2, and the transcription factors ABA Insensitive5 (ABI5), suggesting a role of ABI5 in ABA-mediated upregulation of anthocyanin-biosynthetic genes in plant response to LP. Indeed, LP-induced expression of CHS is repressed in the abi5-7 mutant but further promoted in the ABI5-overexpressing plants compared to the wild-type. Moreover, ABI5 can bind to and transcriptionally activate CHS, and the defectiveness of LP-induced anthocyanin accumulation in abi5-7 can be restored by overexpressing CHS. Collectively, our findings illustrates that ABI5 functions in ABA-mediated LP-induced anthocyanin accumulation in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Antocianinas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Sementes/genética , Regulação da Expressão Gênica de Plantas , Germinação/genética
4.
Sci Rep ; 14(1): 2770, 2024 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-38307936

RESUMO

Late Embryogenesis Abundant (LEA) proteins are a group of intrinsically disordered proteins implicated in plant responses to water deficit. In vitro studies revealed that LEA proteins protect reporter enzymes from inactivation during low water availability. Group 4 LEA proteins constitute a conserved protein family, displaying in vitro protective capabilities. Under water deficiency or macromolecular crowding, the N-terminal of these proteins adopts an alpha-helix conformation. This region has been identified as responsible for the protein in vitro protective activity. This study investigates whether the attainment of alpha-helix conformation and/or particular amino acid residues are required for the in vitro protective activity. The LEA4-5 protein from Arabidopsis thaliana was used to generate mutant proteins. The mutations altered conserved residues, deleted specific conserved regions, or introduced prolines to hinder alpha-helix formation. The results indicate that conserved residues are not essential for LEA4-5 protective function. Interestingly, the C-terminal region was found to contribute to this function. Moreover, alpha-helix conformation is necessary for the protective activity only when the C-terminal region is deleted. Overall, LEA4-5 shows the ability to adopt alternative functional conformations under the tested conditions. These findings shed light on the in vitro mechanisms by which LEA proteins protect against water deficit stress.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Água/metabolismo , Desenvolvimento Embrionário
5.
Nat Commun ; 15(1): 1025, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38310199

RESUMO

RNA modification C2-methyladenosine (m2A) exists in both rRNA and tRNA of Escherichia coli (E. coli), installed by the methyltransferase RlmN using a radical-S-adenosylmethionine (SAM) mechanism. However, the precise function of m2A in tRNA and its ubiquity in plants have remained unclear. Here we discover the presence of m2A in chloroplast rRNA and tRNA, as well as cytosolic tRNA, in multiple plant species. We identify six m2A-modified chloroplast tRNAs and two m2A-modified cytosolic tRNAs across different plants. Furthermore, we characterize three Arabidopsis m2A methyltransferases-RLMNL1, RLMNL2, and RLMNL3-which methylate chloroplast rRNA, chloroplast tRNA, and cytosolic tRNA, respectively. Our findings demonstrate that m2A37 promotes a relaxed conformation of tRNA, enhancing translation efficiency in chloroplast and cytosol by facilitating decoding of tandem m2A-tRNA-dependent codons. This study provides insights into the molecular function and biological significance of m2A, uncovering a layer of translation regulation in plants.


Assuntos
Arabidopsis , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , RNA de Transferência/genética , RNA de Transferência/metabolismo , Metiltransferases/metabolismo , Códon/genética , S-Adenosilmetionina/metabolismo , Plantas/metabolismo , RNA Ribossômico/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Biossíntese de Proteínas
6.
Plant Cell Rep ; 43(2): 53, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315261

RESUMO

KEY MESSAGE: Retromer protein AtVPS29 upregulates the SLY1 protein and downregulates the RGA protein, positively stimulating the development of the root meristematic zone, which indicates an important role of AtVPS29 in gibberellin signaling. In plants, the large retromer complex is known to play roles in multiple development processes, including cell polarity, programmed cell death, and root hair growth in Arabidopsis. However, many of its roles in plant development remain unknown. Here, we show that Arabidopsis trimeric retromer protein AtVPS29 (vacuolar protein sorting 29) modulates gibberellin signaling. The SLEEPY1 (SLY1) protein, known as a positive regulator of gibberellic acid (GA) signaling, exhibited lower abundance in vps29-3 mutants compared to wild-type (WT) plants. Conversely, the DELLA repressor protein, targeted by the E3 ubiquitin ligase SCF (Skp, Cullin, F-box) complex and acting as a negative regulator of GA signaling, showed increased abundance in vps29-3 mutants compared to WT. The vps29-3 mutants exhibited decreased sensitivity to exogenous GA supply in contrast to WT, despite an upregulation in the expression of GA receptor genes within the vps29-3 mutants. In addition, the expression of the GA synthesis genes was downregulated in vps29-3 mutants, implying that the loss of AtVPS29 causes the downregulation of GA synthesis and signaling. Furthermore, vps29-3 mutants exhibited a reduced meristematic zone accompanied by a decreased cell number. Together, these data indicate that AtVPS29 positively regulates SLY1-mediated GA signaling and plant growth.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Giberelinas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Mutação/genética , Proteínas Repressoras/metabolismo , Regulação da Expressão Gênica de Plantas
7.
Proc Natl Acad Sci U S A ; 121(7): e2322375121, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38315835

RESUMO

Protein S-acyl transferases (PATs) catalyze S-acylation, a reversible post-translational modification critical for membrane association, trafficking, and stability of substrate proteins. Many plant proteins are potentially S-acylated but few have corresponding PATs identified. By using genomic editing, confocal imaging, pharmacological, genetic, and biochemical assays, we demonstrate that three Arabidopsis class C PATs positively regulate BR signaling through S-acylation of BRASSINOSTEROID-SIGNALING KINASE1 (BSK1). PAT19, PAT20, and PAT22 associate with the plasma membrane (PM) and the trans-Golgi network/early endosome (TGN/EE). Functional loss of all three genes results in a plethora of defects, indicative of reduced BR signaling and rescued by enhanced BR signaling. PAT19, PAT20, and PAT22 interact with BSK1 and are critical for the S-acylation of BSK1, and for BR signaling. The PM abundance of BSK1 was reduced by functional loss of PAT19, PAT20, and PAT22 whereas abolished by its S-acylation-deficient point mutations, suggesting a key role of S-acylation in its PM targeting. Finally, an active BR analog induces vacuolar trafficking and degradation of PAT19, PAT20, or PAT22, suggesting that the S-acylation of BSK1 by the three PATs serves as a negative feedback module in BR signaling.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Transdução de Sinais , Arabidopsis/metabolismo , Transferases/metabolismo , Acilação , Regulação da Expressão Gênica de Plantas
8.
Nat Commun ; 15(1): 1221, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336824

RESUMO

Exposure of plants to ultraviolet-B (UV-B) radiation initiates transcriptional responses that modify metabolism, physiology and development to enhance viability in sunlight. Many of these regulatory responses to UV-B radiation are mediated by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). Following photoreception, UVR8 interacts directly with multiple proteins to regulate gene expression, but the mechanisms that control differential protein binding to initiate distinct responses are unknown. Here we show that UVR8 is phosphorylated at several sites and that UV-B stimulates phosphorylation at Serine 402. Site-directed mutagenesis to mimic Serine 402 phosphorylation promotes binding of UVR8 to REPRESSOR OF UV-B PHOTOMORPHOGENESIS (RUP) proteins, which negatively regulate UVR8 action. Complementation of the uvr8 mutant with phosphonull or phosphomimetic variants suggests that phosphorylation of Serine 402 modifies UVR8 activity and promotes flavonoid biosynthesis, a key UV-B-stimulated response that enhances plant protection and crop nutritional quality. This research provides a basis to understand how UVR8 interacts differentially with effector proteins to regulate plant responses to UV-B radiation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas Cromossômicas não Histona , Raios Ultravioleta , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Regulação da Expressão Gênica de Plantas , Fosforilação , Serina/metabolismo
9.
Nat Commun ; 15(1): 1286, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38346986

RESUMO

The nuclear matrix is a nuclear compartment that has diverse functions in chromatin regulation and transcription. However, how this structure influences epigenetic modifications and gene expression in plants is largely unknown. In this study, we show that a nuclear matrix binding protein, AHL22, together with the two transcriptional repressors FRS7 and FRS12, regulates hypocotyl elongation by suppressing the expression of a group of genes known as SMALL AUXIN UP RNAs (SAURs) in Arabidopsis thaliana. The transcriptional repression of SAURs depends on their attachment to the nuclear matrix. The AHL22 complex not only brings these SAURs, which contain matrix attachment regions (MARs), to the nuclear matrix, but it also recruits the histone deacetylase HDA15 to the SAUR loci. This leads to the removal of H3 acetylation at the SAUR loci and the suppression of hypocotyl elongation. Taken together, our results indicate that MAR-binding proteins act as a hub for chromatin and epigenetic regulators. Moreover, we present a mechanism by which nuclear matrix attachment to chromatin regulates histone modifications, transcription, and hypocotyl elongation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Cromatina/genética , Cromatina/metabolismo , Hipocótilo/genética , Hipocótilo/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Matriz Nuclear/metabolismo , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Histona Desacetilases/metabolismo
10.
BMC Plant Biol ; 24(1): 120, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38369495

RESUMO

BACKGROUND: Plants have acquired a repertoire of mechanisms to combat biotic stressors, which may vary depending on the feeding strategies of herbivores and the plant species. Hormonal regulation crucially modulates this malleable defense response. Jasmonic acid (JA) and salicylic acid (SA) stand out as pivotal regulators of defense, while other hormones like abscisic acid (ABA), ethylene (ET), gibberellic acid (GA) or auxin also play a role in modulating plant-pest interactions. The plant defense response has been described to elicit effects in distal tissues, whereby aboveground herbivory can influence belowground response, and vice versa. This impact on distal tissues may be contingent upon the feeding guild, even affecting both the recovery of infested tissues and those that have not suffered active infestation. RESULTS: To study how phytophagous with distinct feeding strategies may differently trigger the plant defense response during and after infestation in both infested and distal tissues, Arabidopsis thaliana L. rosettes were infested separately with the chewing herbivore Pieris brassicae L. and the piercing-sucker Tetranychus urticae Koch. Moderate infestation conditions were selected for both pests, though no quantitative control of damage levels was carried out. Feeding mode did distinctly influence the transcriptomic response of the plant under these conditions. Though overall affected processes were similar under either infestation, their magnitude differed significantly. Plants infested with P. brassicae exhibited a short-term response, involving stress-related genes, JA and ABA regulation and suppressing growth-related genes. In contrast, T. urticae elicited a longer transcriptomic response in plants, albeit with a lower degree of differential expression, in particular influencing SA regulation. These distinct defense responses transcended beyond infestation and through the roots, where hormonal response, flavonoid regulation or cell wall reorganization were differentially affected. CONCLUSION: These outcomes confirm that the existent divergent transcriptomic responses elicited by herbivores employing distinct feeding strategies possess the capacity to extend beyond infestation and even affect tissues that have not been directly infested. This remarks the importance of considering the entire plant's response to localized biotic stresses.


Assuntos
Arabidopsis , Borboletas , Animais , Transcriptoma , Herbivoria/fisiologia , Mastigação , Borboletas/fisiologia , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Ciclopentanos/metabolismo
11.
Nat Commun ; 15(1): 1472, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38368437

RESUMO

Understanding how plants alter their development and architecture in response to ambient temperature is crucial for breeding resilient crops. Here, we identify the quantitative trait locus qMULTIPLE INFLORESCENCE BRANCH 2 (qMIB2), which modulates inflorescence branching in response to high ambient temperature in tomato (Solanum lycopersicum). The non-functional mib2 allele may have been selected in large-fruited varieties to ensure larger and more uniform fruits under varying temperatures. MIB2 gene encodes a homolog of the Arabidopsis thaliana transcription factor SPATULA; its expression is induced in meristems at high temperature. MIB2 directly binds to the promoter of its downstream gene CONSTANS-Like1 (SlCOL1) by recognizing the conserved G-box motif to activate SlCOL1 expression in reproductive meristems. Overexpressing SlCOL1 rescue the reduced inflorescence branching of mib2, suggesting how the MIB2-SlCOL1 module helps tomato inflorescences adapt to high temperature. Our findings reveal the molecular mechanism underlying inflorescence thermomorphogenesis and provide a target for breeding climate-resilient crops.


Assuntos
Arabidopsis , Solanum lycopersicum , Inflorescência , Solanum lycopersicum/genética , Melhoramento Vegetal , Meristema/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
12.
Elife ; 122024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372335

RESUMO

Aldehydes, being an integral part of carbon metabolism, energy generation, and signalling pathways, are ingrained in plant physiology. Land plants have developed intricate metabolic pathways which involve production of reactive aldehydes and its detoxification to survive harsh terrestrial environments. Here, we show that physiologically produced aldehydes, i.e., formaldehyde and methylglyoxal in addition to acetaldehyde, generate adducts with aminoacyl-tRNAs, a substrate for protein synthesis. Plants are unique in possessing two distinct chiral proofreading systems, D-aminoacyl-tRNA deacylase1 (DTD1) and DTD2, of bacterial and archaeal origins, respectively. Extensive biochemical analysis revealed that only archaeal DTD2 can remove the stable D-aminoacyl adducts on tRNA thereby shielding archaea and plants from these system-generated aldehydes. Using Arabidopsis as a model system, we have shown that the loss of DTD2 gene renders plants susceptible to these toxic aldehydes as they generate stable alkyl modification on D-aminoacyl-tRNAs, which are recycled only by DTD2. Bioinformatic analysis identifies the expansion of aldehyde metabolising repertoire in land plant ancestors which strongly correlates with the recruitment of archaeal DTD2. Finally, we demonstrate that the overexpression of DTD2 offers better protection against aldehydes than in wild type Arabidopsis highlighting its role as a multi-aldehyde detoxifier that can be explored as a transgenic crop development strategy.


Assuntos
Aldeídos , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Aminoacil-RNA de Transferência/metabolismo , Bactérias/genética , Archaea/genética , Archaea/metabolismo , RNA de Transferência
13.
Plant Cell Rep ; 43(3): 68, 2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38341844

RESUMO

KEY MESSAGE: The gametophytic epigenetic regulators, MEA and DME, extend their synergistic role to the sporophytic development by regulating the meristematic activity via restricting the gene expression in the shoot apex. The gametophyte-to-sporophyte transition facilitates the alternation of generations in a plant life cycle. The epigenetic regulators DEMETER (DME) and MEDEA (MEA) synergistically control central cell proliferation and differentiation, ensuring proper gametophyte-to-sporophyte transition in Arabidopsis. Mutant alleles of DME and MEA are female gametophyte lethal, eluding the recovery of recessive homozygotes to examine their role in the sporophyte. Here, we exploited the paternal transmission of these mutant alleles coupled with CENH3-haploid inducer to generate mea-1;dme-2 sporophytes. Strikingly, the simultaneous loss of function of MEA and DME leads to the emergence of ectopic shoot meristems at the apical pole of the plant body axis. DME and MEA are expressed in the developing shoot apex and regulate the expression of various shoot-promoting factors. Chromatin immunoprecipitation (ChIP), DNA methylation, and gene expression analysis revealed several shoot regulators as potential targets of MEA and DME. RNA interference-mediated transcriptional downregulation of shoot-promoting factors STM, CUC2, and PLT5 rescued the twin-plant phenotype to WT in 9-23% of mea-1-/-;dme-2-/- plants. Our findings reveal a previously unrecognized synergistic role of MEA and DME in restricting the meristematic activity at the shoot apex during sporophytic development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Células Germinativas Vegetais/metabolismo , Impressão Genômica , Metilação de DNA/genética , Regulação da Expressão Gênica de Plantas/genética , N-Glicosil Hidrolases/genética , N-Glicosil Hidrolases/metabolismo , Transativadores/genética
14.
Sci Adv ; 10(7): eadd5108, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38354245

RESUMO

The plant pathogen Pseudomonas syringae encodes a type III secretion system avirulence effector protein, AvrB, that induces a form of programmed cell death called the hypersensitive response in plants as a defense mechanism against systemic infection. Despite the well-documented catalytic activities observed in other Fido (Fic, Doc, and AvrB) proteins, the enzymatic activity and target substrates of AvrB have remained elusive. Here, we show that AvrB is an unprecedented glycosyltransferase that transfers rhamnose from UDP-rhamnose to a threonine residue of the Arabidopsis guardee protein RIN4. We report structures of various enzymatic states of the AvrB-catalyzed rhamnosylation reaction of RIN4, which reveal the structural and mechanistic basis for rhamnosylation by a Fido protein. Collectively, our results uncover an unexpected reaction performed by a prototypical member of the Fido superfamily while providing important insights into the plant hypersensitive response pathway and foreshadowing more diverse chemistry used by Fido proteins and their substrates.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Glicosiltransferases/metabolismo , Proteínas de Bactérias/metabolismo , Arabidopsis/metabolismo , Pseudomonas syringae/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
15.
Proc Natl Acad Sci U S A ; 121(8): e2312853121, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38349881

RESUMO

Light is a crucial environmental factor that impacts various aspects of plant development. Phytochromes, as light sensors, regulate myriads of downstream genes to mediate developmental reprogramming in response to changes in environmental conditions. CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) is an E3 ligase for a number of substrates in light signaling, acting as a central repressor of photomorphogenesis. The interplay between phytochrome B (phyB) and COP1 forms an antagonistic regulatory module that triggers extensive gene expression reprogramming when exposed to light. Here, we uncover a role of COP1 in light-dependent chromatin remodeling through the regulation of VIL1 (VIN3-LIKE 1)/VERNALIZATION 5, a Polycomb protein. VIL1 directly interacts with phyB and regulates photomorphogenesis through the formation of repressive chromatin loops at downstream growth-promoting genes in response to light. Furthermore, we reveal that COP1 governs light-dependent formation of chromatin loop and limiting a repressive histone modification to fine-tune expressions of growth-promoting genes during photomorphogenesis through VIL1.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Montagem e Desmontagem da Cromatina , Fitocromo/metabolismo , Fitocromo B/genética , Fitocromo B/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Cromatina/genética , Cromatina/metabolismo , Regulação da Expressão Gênica de Plantas , Luz , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
Carbohydr Polym ; 330: 121838, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38368088

RESUMO

As a key component in cell walls of numerous organisms ranging from green algae to higher plants, AGPs play principal roles in many biological processes such as cell-cell adhesion and regulating Ca2+ signaling pathway as a Ca2+-capacitor. Consistently, AGP structures vary from species to species and from tissue to tissue. To understand the functions of AGPs, it is vital to know their structural differences relative to their location in the plant. Thus, AGPs were purified from different Arabidopsis tissues. Analyses of these AGPs demonstrated that the AGPs comprised covalently linked pectin and AGP, referred to as pectic-AGPs. Importantly, these pectic-AGPs were glycosylated with a remarkable variety of polysaccharides including homogalacturonan, rhamnogalacturonan-I, and type II arabinogalactan at different ratios and lengths. This result not only suggests that pectic-AGP is a major form of Arabidopsis AGPs, but also supports AGPs serve as crosslinkers covalently connecting pectins with structures tailored for tissue-specific functions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Plantas/metabolismo , Mucoproteínas/metabolismo , Pectinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Parede Celular/química
17.
Proc Natl Acad Sci U S A ; 121(6): e2313092121, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38300870

RESUMO

Root development is tightly controlled by light, and the response is thought to depend on signal transmission from the shoot. Here, we show that the root apical meristem perceives light independently from aboveground organs to activate the light-regulated transcription factor ELONGATED HYPOCOTYL5 (HY5). The ROS balance between H2O2 and superoxide anion in the root is disturbed under darkness with increased H2O2. We demonstrate that root-derived HY5 directly activates PER6 expression to eliminate H2O2. Moreover, HY5 directly represses UPBEAT1, a known inhibitor of peroxidases, to release the expression of PERs, partially contributing to the light control of ROS balance in the root. Our results reveal an unexpected ability in roots with specific photoreception and provide a mechanistic framework for the HY5-mediated interaction between light and ROS signaling in early root development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Peróxido de Hidrogênio/metabolismo , Luz , Regulação da Expressão Gênica de Plantas
18.
Science ; 383(6683): 589-590, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38330113

RESUMO

Plants measure the duration of metabolic activity to promote rapid growth in long days.


Assuntos
Arabidopsis , Fotoperíodo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Redes e Vias Metabólicas
19.
Plant Mol Biol ; 114(1): 17, 2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38342783

RESUMO

Fluoride is an environmental toxin prevalent in water, soil, and air. A fluoride transporter called Fluoride EXporter (FEX) has been discovered across all domains of life, including bacteria, single cell eukaryotes, and all plants, that is required for fluoride tolerance. How FEX functions to protect multicellular plants is unknown. In order to distinguish between different models, the dynamic movement of fluoride in wildtype (WT) and fex mutant plants was monitored using [18F]fluoride with positron emission tomography. Significant differences were observed in the washout behavior following initial fluoride uptake between plants with and without a functioning FEX. [18F]Fluoride traveled quickly up the floral stem and into terminal tissues in WT plants. In contrast, the fluoride did not move out of the lower regions of the stem in mutant plants resulting in clearance rates near zero. The roots were not the primary locus of FEX action, nor did FEX direct fluoride to a specific tissue. Fluoride efflux by WT plants was saturated at high fluoride concentrations resulting in a pattern like the fex mutant. The kinetics of fluoride movement suggested that FEX mediates a fluoride transport mechanism throughout the plant where each individual cell benefits from FEX expression.


Assuntos
Arabidopsis , Fluoretos , Fluoretos/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Transporte Biológico
20.
Physiol Plant ; 176(1): e14191, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38351287

RESUMO

F-box proteins constitute a significant family in eukaryotes and, as a component of the Skp1p-cullin-F-box complex, are considered critical for cellular protein degradation and other biological processes in plants. Despite their importance, the functions of F-box proteins, particularly those with C-terminal leucine-rich repeat (LRR) domains, remain largely unknown in plants. Therefore, the present study conducted genome-wide identification and in silico characterization of F-BOX proteins with C-terminal LRR domains in soybean (Glycine max L.) (GmFBXLs). A total of 45 GmFBXLs were identified. The phylogenetic analysis showed that GmFBXLs could be subdivided into ten subgroups and exhibited a close relationship with those from Arabidopsis thaliana, Cicer aretineum, and Medicago trunculata. It was observed that most cis-regulatory elements in the promoter regions of GmFBXLs are involved in hormone signalling, stress responses, and developmental stages. In silico transcriptome data illustrated diverse expression patterns of the identified GmFBXLs across various tissues, such as shoot apical meristem, flower, green pods, leaves, nodules, and roots. Overexpressing (OE) GmFBXL12 in Tianlong No.1 cultivar resulted in a significant difference in seed size, number of pods, and number of seeds per plant, indicated a potential increase in yield compared to wild type. This study offers valuable perspectives into the role of FBXLs in soybean, serving as a foundation for future research. Additionally, the identified OE lines represent valuable genetic resources for enhancing seed-related traits in soybean.


Assuntos
Arabidopsis , Proteínas F-Box , /genética , Filogenia , Sementes/genética , Sementes/metabolismo , Arabidopsis/metabolismo , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
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