RESUMEN
Bisphenol compounds (BPs) have various industrial uses and can enter the environment through various sources. To evaluate the ecotoxicity of BPs and identify potential gene candidates involved in the plant toxicity, Arabidopsis thaliana was exposed to bisphenol A (BPA), BPB, BPE, BPF, and BPS at 1, 3, 10 mg/L for a duration of 14 days, and their growth status were monitored. At day 14, roots and leaves were collected for internal BPs exposure concentration detection, RNA-seq (only roots), and morphological observations. As shown in the results, exposure to BPs significantly disturbed root elongation, exhibiting a trend of stimulation at low concentration and inhibition at high concentration. Additionally, BPs exhibited pronounced generation of reactive oxygen species, while none of the pollutants caused significant changes in root morphology. Internal exposure concentration analysis indicated that BPs tended to accumulate in the roots, with BPS exhibiting the highest level of accumulation. The results of RNA-seq indicated that the shared 211 differently expressed genes (DEGs) of these 5 exposure groups were enriched in defense response, generation of precursor metabolites, response to organic substance, response to oxygen-containing, response to hormone, oxidation-reduction process and so on. Regarding unique DEGs in each group, BPS was mainly associated with the redox pathway, BPB primarily influenced seed germination, and BPA, BPE and BPF were primarily involved in metabolic signaling pathways. Our results provide new insights for BPs induced adverse effects on Arabidopsis thaliana and suggest that the ecological risks associated with BPA alternatives cannot be ignored.
Asunto(s)
Arabidopsis , Compuestos de Bencidrilo , Oxidación-Reducción , Fenoles , Raíces de Plantas , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Fenoles/toxicidad , Compuestos de Bencidrilo/toxicidad , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , RNA-Seq , Análisis de Secuencia de ARN , Contaminantes del Suelo/toxicidadRESUMEN
In this issue of Molecular Cell, Xie et al.1 revealed that the proteasome is a constitutive component of plant stress granules (SGs), and that enhanced proteolytic activity is essential for efficient SG disassembly and plant survival during the stress response.
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Gránulos Citoplasmáticos , Homeostasis , Complejo de la Endopetidasa Proteasomal , Estrés Fisiológico , Complejo de la Endopetidasa Proteasomal/metabolismo , Gránulos Citoplasmáticos/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/enzimología , ProteolisisRESUMEN
The long-term balancing selection acting on mating types or sex-determining genes is expected to lead to the accumulation of deleterious mutations in the tightly linked chromosomal segments that are locally 'sheltered' from purifying selection. However, the factors determining the extent of this accumulation are poorly understood. Here, we took advantage of variations in the intensity of balancing selection along a dominance hierarchy formed by alleles at the sporophytic self-incompatibility system of the Brassicaceae to compare the pace at which linked deleterious mutations accumulate among them. We first experimentally measured the phenotypic manifestation of the linked load at three different levels of the dominance hierarchy. We then sequenced and phased polymorphisms in the chromosomal regions linked to 126 distinct copies of S-alleles in two populations of Arabidopsis halleri and three populations of Arabidopsis lyrata. We find that linkage to the S-locus locally distorts phylogenies over about 10-30 kb along the chromosome. The more intense balancing selection on dominant S-alleles results in greater fixation of linked deleterious mutations, while recessive S-alleles accumulate more linked deleterious mutations that are segregating. Hence, the structure rather than the overall magnitude of the linked genetic load differs between dominant and recessive S-alleles. Our results have consequences for the long-term evolution of new S-alleles, the evolution of dominance modifiers between them, and raise the question of why the non-recombining regions of some sex and mating type chromosomes expand over evolutionary times while others, such as the S-locus of the Brassicaceae, remain restricted to small chromosomal regions.
Asunto(s)
Alelos , Arabidopsis , Arabidopsis/genética , Selección Genética , Autoincompatibilidad en las Plantas con Flores/genética , Carga Genética , Mutación , Genes Dominantes , FenotipoRESUMEN
Climate change severely affects crop production. Cotton is one of the primary fiber crops in the world and its production is susceptible to various environmental stresses, especially drought and salinity. Development of stress tolerant genotypes is the only way to escape from these environmental constraints. We identified sixteen homologs of the Arabidopsis JUB1 gene in cotton. Expression of GhJUB1_3-At was significantly induced in the temporal expression analysis of GhJUB1 genes in the roots of drought tolerant (H177) and susceptible (S9612) cotton genotypes under drought. The silencing of the GhJUB1_3-At gene alone and together with its paralogue GhJUB1_3-Dt reduced the drought tolerance in cotton plants. The transgenic lines exhibited tolerance to the drought and salt stress as compared to the wildtype (WT). The chlorophyll and relative water contents of wildtype decreased under drought as compared to the transgenic lines. The transgenic lines showed decreased H2O2 and increased proline levels under drought and salt stress, as compared to the WT, indicating that the transgenic lines have drought and salt stress tolerance. The expression analysis of the transgenic lines and WT revealed that GAI was upregulated in the transgenic lines in normal conditions as compared to the WT. Under drought and salt treatment, RAB18 and RD29A were strongly upregulated in the transgenic lines as compared to the WT. Conclusively, GhJUB1_3-At is not an auto activator and it is regulated by the crosstalk of GhHB7, GhRAP2-3 and GhRAV1. GhRAV1, a negative regulator of abiotic stress tolerance and positive regulator of leaf senescence, suppresses the expression of GhJUB1_3-At under severe circumstances leading to plant death.
Asunto(s)
Sequías , Regulación de la Expresión Génica de las Plantas , Gossypium , Proteínas de Plantas , Plantas Modificadas Genéticamente , Tolerancia a la Sal , Gossypium/genética , Gossypium/fisiología , Gossypium/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tolerancia a la Sal/genética , Estrés Fisiológico/genética , Estrés Salino/genética , Estrés Salino/fisiología , Arabidopsis/genética , Arabidopsis/fisiologíaRESUMEN
The Arabidopsis SUPERMAN (SUP) gene and its orthologs in eudicots are crucial in regulating the number of reproductive floral organs. In Medicago truncatula, in addition to this function, a novel role in controlling meristem activity during compound inflorescence development was assigned to the SUP-ortholog (MtSUP). These findings led us to investigate whether the role of SUP genes in inflorescence development was legume-specific or could be extended to other eudicots. To assess that, we used Solanum lycopersicum as a model system with a cymose complex inflorescence and Arabidopsis thaliana as the best-known example of simple inflorescence. We conducted a detailed comparative expression analysis of SlSUP and SUP from vegetative stages to flower transition. In addition, we performed an exhaustive phenotypic characterisation of two different slsup and sup mutants during the plant life cycle. Our findings reveal that SlSUP is required for precise regulation of the meristems that control shoot and inflorescence architecture in tomato. In contrast, in Arabidopsis, SUP performs no meristematic function, but we found a role of SUP in floral transition. Our findings suggest that the functional divergence of SUP-like genes contributed to the modification of inflorescence architecture during angiosperm evolution.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Inflorescencia , Meristema , Solanum lycopersicum , Inflorescencia/genética , Inflorescencia/crecimiento & desarrollo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/fisiología , Solanum lycopersicum/genética , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/fisiología , Meristema/genética , Meristema/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/crecimiento & desarrollo , Flores/fisiología , Mutación/genética , Fenotipo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
KEY MESSAGE: We used marker-free technologies to study chromatin at cellular resolution. Our results show asymmetric chromatin distribution, explore chromatin dynamics during mitosis, and reveal structural differences between trichoblast and atrichoblast cell. The shapes, sizes, and structural organizations of plant nuclei vary considerably among cell types, tissues, and species. This diversity is dependent on various factors, including cellular function, developmental stage, and environmental or physiological conditions. The differences in nuclear structure reflect the state of chromatin, which, in turn, controls gene expression and regulates cell fate. To examine the interrelationship between nuclear structure, cell morphology, and tissue-specific cell proliferation and differentiation processes, we conducted multiple visualizations of H3K4me1, H3K9me2, 4',6-diamidino-2-phenylindole, 5-ethynyl 2'-deoxyuridine, and SCRI Renaissance 2200, followed by subsequent quantitative analysis of individual cells and nuclei. By assigning cylindrical coordinates to the nuclei in the iRoCS toolbox, we were able to construct in situ digital three-dimensional chromatin maps for all the tissue layers of individual roots. A detailed analysis of the nuclei features of H3K4me1 and H3K9me2 in the mitotic and the elongation zones in trichoblast and atrichoblast cells at the root apical meristem revealed cell type-specific chromatin dynamics with asymmetric distribution of euchromatin and heterochromatin marks that may be associated with cell cycle and cell differentiation characteristics of specific cells. Furthermore, the spatial distribution of nuclei stained with 5-ethynyl 2'-deoxyuridine in the epidermis and cortex tissues suggests short-range coordination of cell division and nuclear migration in a linear sequence through an unknown regulatory mechanism.
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Arabidopsis , Diferenciación Celular , División Celular , Núcleo Celular , Cromatina , Meristema , Meristema/citología , Meristema/genética , Cromatina/metabolismo , Arabidopsis/citología , Arabidopsis/genética , Núcleo Celular/metabolismo , Histonas/metabolismo , Mitosis , Raíces de Plantas/citología , Raíces de Plantas/genéticaRESUMEN
Flowering, the change from vegetative development to the reproductive phase, represents a crucial and intricate stage in the life cycle of plants, which is tightly controlled by both internal and external factors. In this study, we investigated the effect of Ascophyllum nodosum extract (ANE) on the flowering time of Arabidopsis. We found that a 0.1% concentration of ANE induced flowering in Arabidopsis, accompanied by the upregulation of key flowering time genes: FT (FLOWERING LOCUS T), SOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1), and LFY (LEAFY). Further investigation showed that ANE specifically promotes flowering through the MIR156-mediated age pathway. ANE treatment resulted in the repression of negative regulator genes, MIR156, while simultaneously enhancing the expression of positive regulator genes, including SPLs and MIR172. This, in turn, led to the downregulation of AP2-like genes, which are known as floral repressors. It is worth noting that ANE did not alleviate the late flowering phenotype of MIR156-overexpressing plants and spl mutants. Furthermore, ANE-derived fucoidan mimics the function of sugars in regulating MIR156, closely mirroring the effects induced by ANE treatments. It suppresses the transcript levels of MIR156 and AP2-like genes while inducing those of SPLs and MIR172, thereby reinforcing the involvement of fucoidan in the control of flowering by ANE. In summary, our results demonstrate that ANE induces flowering by modulating the MIR156-SPL module within the age pathway, and this effect is mediated by fucoidan.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ascophyllum , Flores , Regulación de la Expresión Génica de las Plantas , MicroARNs , MicroARNs/genética , MicroARNs/metabolismo , Arabidopsis/genética , Arabidopsis/efectos de los fármacos , Arabidopsis/fisiología , Flores/efectos de los fármacos , Flores/genética , Flores/fisiología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Extractos Vegetales/farmacología , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Microtubule-based vesicle trafficking usually relies upon kinesin and dynein motors and few reports describe microtubule polymerisation driving directional vesicle trafficking. Here we show that Arabidopsis END BINDING1b (EB1b), a microtubule plus-end binding protein, directly interacts with SYP121, a SNARE protein that mediates the trafficking of the K+ channel KAT1 and its distribution to the plasma membrane (PM) in Arabidopsis guard cells. Knockout of AtEB1b and its homologous proteins results in a modest but significant change in the distribution of KAT1 and SYP121 in guard cells and consequently delays light-induced stomatal opening. Live-cell imaging reveals that a portion of SYP121-associated endomembrane compartments co-localise with AtEB1b at the growing ends of microtubules, trafficking along with the growth of microtubules for targeting to the PM. Our study reveals a mechanism of vesicle trafficking driven by microtubule growth, which is involved in the redistribution of PM proteins to modulate guard cell movement.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Membrana Celular , Proteínas Asociadas a Microtúbulos , Microtúbulos , Estomas de Plantas , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Microtúbulos/metabolismo , Estomas de Plantas/metabolismo , Estomas de Plantas/fisiología , Membrana Celular/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Transporte de Proteínas , Katanina/metabolismo , Katanina/genética , Movimiento Celular , Proteínas de Ciclo CelularRESUMEN
With the availability of high-quality full genome polymorphism (SNPs) data, it becomes feasible to study the past demographic and selective history of populations in exquisite detail. However, such inferences still suffer from a lack of statistical resolution for recent, for example bottlenecks, events, and/or for populations with small nucleotide diversity. Additional heritable (epi)genetic markers, such as indels, transposable elements, microsatellites, or cytosine methylation, may provide further, yet untapped, information on the recent past population history. We extend the Sequential Markovian Coalescent (SMC) framework to jointly use SNPs and other hyper-mutable markers. We are able to (1) improve the accuracy of demographic inference in recent times, (2) uncover past demographic events hidden to SNP-based inference methods, and (3) infer the hyper-mutable marker mutation rates under a finite site model. As a proof of principle, we focus on demographic inference in Arabidopsis thaliana using DNA methylation diversity data from 10 European natural accessions. We demonstrate that segregating single methylated polymorphisms (SMPs) satisfy the modeling assumptions of the SMC framework, while differentially methylated regions (DMRs) are not suitable as their length exceeds that of the genomic distance between two recombination events. Combining SNPs and SMPs while accounting for site- and region-level epimutation processes, we provide new estimates of the glacial age bottleneck and post-glacial population expansion of the European A. thaliana population. Our SMC framework readily accounts for a wide range of heritable genomic markers, thus paving the way for next-generation inference of evolutionary history by combining information from several genetic and epigenetic markers.
Asunto(s)
Arabidopsis , Metilación de ADN , Epigenómica , Arabidopsis/genética , Epigenómica/métodos , Metilación de ADN/genética , Polimorfismo de Nucleótido Simple , Genómica/métodos , Genética de Población/métodosRESUMEN
In plants, a local infection can lead to systemic acquired resistance (SAR) through increased production of salicylic acid (SA). For many years, the identity of the mobile signal and its direct transduction mechanism for systemic SA synthesis in initiating SAR have been debated. We found that in Arabidopsis thaliana, after a local infection, the conserved cysteine residue of the transcription factor CCA1 HIKING EXPEDITION (CHE) undergoes sulfenylation in systemic tissues, which enhances its binding to the promoter of the SA-synthesis gene ISOCHORISMATE SYNTHASE1 (ICS1) and increases SA production. Furthermore, hydrogen peroxide (H2O2) produced through NADPH oxidases is the mobile signal that sulfenylates CHE in a concentration-dependent manner. Accumulation of SA and the previously reported signal molecules, such as N-hydroxypipecolic acid (NHP), then form a signal amplification loop to establish SAR.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Peróxido de Hidrógeno , Enfermedades de las Plantas , Ácido Salicílico , Factores de Transcripción , Arabidopsis/genética , Arabidopsis/microbiología , Arabidopsis/inmunología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Peróxido de Hidrógeno/metabolismo , Ácido Salicílico/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Enfermedades de las Plantas/microbiología , Resistencia a la Enfermedad/genética , Regiones Promotoras Genéticas , Transferasas Intramoleculares/metabolismo , Transferasas Intramoleculares/genética , NADPH Oxidasas/metabolismo , NADPH Oxidasas/genética , Regulación de la Expresión Génica de las Plantas , Cisteína/metabolismo , Transducción de Señal , Pseudomonas syringaeRESUMEN
The m6A epitranscriptomic mark is the most abundant and widespread internal RNA chemical modification, which through the control of RNA acts as an important factor of eukaryote reproduction, growth, morphogenesis and stress response. The main m6A readers constitute a super family of proteins with hundreds of members that share a so-called YTH RNA binding domain. The majority of YTH proteins carry no obvious additional domain except for an Intrinsically Disordered Region (IDR). In Arabidopsis thaliana IDRs are important for the functional specialization among the different YTH proteins, known as Evolutionarily Conserved C-Terminal region, ECT 1 to 12. Here by studying the ECT2 protein and using an in vitro biochemical characterization, we show that full-length ECT2 and its YTH domain alone have a distinct ability to bind m6A, conversely to previously characterized YTH readers. We identify peptide regions outside of ECT2 YTH domain, in the N-terminal IDR, that regulate its binding to m6A-methylated RNA. Furthermore, we show that the selectivity of ECT2 binding for m6A is enhanced by a high uridine content within its neighbouring sequence, where ECT2 N-terminal IDR is believed to contact the target RNA in vivo. Finally, we also identify small structural elements, located next to ECT2 YTH domain and conserved in a large set of YTH proteins, that enhance its binding to m6A-methylated RNA. We propose from these findings that some of these regulatory regions are not limited to ECT2 or YTH readers of flowering plants but may be widespread among eukaryotic YTH readers.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Unión Proteica , Proteínas de Unión al ARN , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética , Dominios Proteicos , ARN de Planta/metabolismo , ARN de Planta/química , ARN de Planta/genética , Adenosina/metabolismo , Secuencia de Aminoácidos , Metilación , Proteínas Intrínsecamente Desordenadas/metabolismo , Proteínas Intrínsecamente Desordenadas/química , Proteínas Intrínsecamente Desordenadas/genética , Sitios de Unión , Péptidos y Proteínas de Señalización IntracelularRESUMEN
The pathogen Agrobacterium tumefaciens is known for causing crown gall tumours in plants. However, it has also been harnessed as a valuable tool for plant genetic transformation. Apart from the T-DNA, Agrobacterium also delivers at least five virulence proteins into the host plant cells, which are required for an efficient infection. One of these virulence proteins is VirD5. F-box proteins, encoded in the host plant genome or the Ti plasmid, and the ubiquitin/26S proteasome system (UPS) also play an important role in facilitating Agrobacterium infection. Our study identified two Arabidopsis F-box proteins, D5BF1 and D5BF2, that bind VirD5 and facilitate its degradation via the UPS. Additionally, we found that Agrobacterium partially suppresses the expression of D5BF1 and D5BF2. Lastly, stable transformation and tumorigenesis efficiency assays revealed that D5BF1 and D5BF2 negatively regulate the Agrobacterium infection process, showing that the plant F-box proteins and UPS play a role in defending against Agrobacterium infection.
Asunto(s)
Agrobacterium tumefaciens , Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Transformación Genética , Arabidopsis/microbiología , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/patogenicidad , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Carcinogénesis/genética , Tumores de Planta/microbiología , Complejo de la Endopetidasa Proteasomal/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Abscisic acid (ABA) is the primary preventing factor of seed germination, which is crucial to plant survival and propagation. ABA-induced seed germination inhibition is mainly mediated by the dimeric PYR/PYL/RCAR (PYLs) family members. However, little is known about the relevance between dimeric stability of PYLs and seed germination. Here, we reveal that stabilization of PYL dimer can relieve ABA-induced inhibition of seed germination using chemical genetic approaches. Di-nitrobensulfamide (DBSA), a computationally designed chemical probe, yields around ten-fold improvement in receptor affinity relative to ABA. DBSA reverses ABA-induced inhibition of seed germination mainly through dimeric receptors and recovers the expression of ABA-responsive genes. DBSA maintains PYR1 in dimeric state during protein oligomeric state experiment. X-ray crystallography shows that DBSA targets a pocket in PYL dimer interface and may stabilize PYL dimer by forming hydrogen networks. Our results illustrate the potential of PYL dimer stabilization in preventing ABA-induced seed germination inhibition.
Asunto(s)
Ácido Abscísico , Proteínas de Arabidopsis , Arabidopsis , Germinación , Semillas , Germinación/efectos de los fármacos , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacología , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/efectos de los fármacos , Arabidopsis/metabolismo , Arabidopsis/genética , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Multimerización de Proteína/efectos de los fármacos , Cristalografía por Rayos X , Sulfonamidas/farmacología , Sulfonamidas/química , Proteínas de Transporte de MembranaRESUMEN
BACKGROUND: Telomeric repeat arrays at the ends of chromosomes are highly dynamic in composition, but their repetitive nature and technological limitations have made it difficult to assess their true variation in genome diversity surveys. RESULTS: We have comprehensively characterized the sequence variation immediately adjacent to the canonical telomeric repeat arrays at the very ends of chromosomes in 74 genetically diverse Arabidopsis thaliana accessions. We first describe several types of distinct telomeric repeat units and then identify evolutionary processes such as local homogenization and higher-order repeat formation that shape diversity of chromosome ends. By comparing largely isogenic samples, we also determine repeat number variation of the degenerate and variant telomeric repeat array at both the germline and somatic levels. Finally, our analysis of haplotype structure uncovers chromosome end-specific patterns in the distribution of variant telomeric repeats, and their linkage to the more proximal non-coding region. CONCLUSIONS: Our findings illustrate the spectrum of telomeric repeat variation at multiple levels in A. thaliana-in germline and soma, across all chromosome ends, and across genetic groups-thereby expanding our knowledge of the evolution of chromosome ends.
Asunto(s)
Arabidopsis , Cromosomas de las Plantas , Variación Genética , Telómero , Arabidopsis/genética , Telómero/genética , Secuencias Repetitivas de Ácidos Nucleicos , Haplotipos , Evolución Molecular , Genoma de PlantaRESUMEN
Plant pathogens pose a high risk of yield losses and threaten food security. Technological and scientific advances have improved our understanding of the molecular processes underlying host-pathogen interactions, which paves the way for new strategies in crop disease management beyond the limits of conventional breeding. Cross-family transfer of immune receptor genes is one such strategy that takes advantage of common plant immune signalling pathways to improve disease resistance in crops. Sensing of microbe- or host damage-associated molecular patterns (MAMPs/DAMPs) by plasma membrane-resident pattern recognition receptors (PRR) activates pattern-triggered immunity (PTI) and restricts the spread of a broad spectrum of pathogens in the host plant. In the model plant Arabidopsis thaliana, the S-domain receptor-like kinase LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION (AtLORE, SD1-29) functions as a PRR, which senses medium-chain-length 3-hydroxylated fatty acids (mc-3-OH-FAs), such as 3-OH-C10:0, and 3-hydroxyalkanoates (HAAs) of microbial origin to activate PTI. In this study, we show that ectopic expression of the Brassicaceae-specific PRR AtLORE in the solanaceous crop species Solanum lycopersicum leads to the gain of 3-OH-C10:0 immune sensing without altering plant development. AtLORE-transgenic tomato shows enhanced resistance against Pseudomonas syringae pv. tomato DC3000 and Alternaria solani NL03003. Applying 3-OH-C10:0 to the soil before infection induces resistance against the oomycete pathogen Phytophthora infestans Pi100 and further enhances resistance to A. solani NL03003. Our study proposes a potential application of AtLORE-transgenic crop plants and mc-3-OH-FAs as resistance-inducing biostimulants in disease management.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Resistencia a la Enfermedad , Ácidos Grasos , Enfermedades de las Plantas , Solanum lycopersicum , Solanum lycopersicum/microbiología , Solanum lycopersicum/inmunología , Solanum lycopersicum/genética , Arabidopsis/inmunología , Arabidopsis/microbiología , Arabidopsis/genética , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Ácidos Grasos/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Pseudomonas syringae/patogenicidad , Inmunidad de la Planta , Plantas Modificadas GenéticamenteRESUMEN
The precise regulation of stem cells in the shoot apical meristems (SAMs) involves the function of the homeodomain transcription factor (TF)-WUSCHEL (WUS). WUS has been shown to move from the site of production-the rib-meristem (RM), into overlaying cells of the central zone (CZ), where it specifies stem cells and also regulates the transcription of CLAVATA3 (CLV3). The secreted signalling peptide CLV3 activates a receptor kinase signalling that restricts WUS transcription and also regulates the nuclear gradient of WUS by offsetting nuclear export. WUS has been shown to regulate both CLV3 levels and spatial activation, restricting its expression to a few cells in the CZ. The HAIRY MERISTEM (HAM), a GRASS-domain class of TFs expressed in the RM, has been shown to physically interact with WUS and regulate CLV3 expression. However, the mechanisms by which this interaction regulates CLV3 expression non-cell autonomously remain unclear. Here, we show that HAM function is required for regulating the WUS protein stability, and the CLV3 expression responds to altered WUS protein levels in ham mutants. Thus, HAM proteins non-cell autonomously regulates CLV3 expression.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio , Meristema , Meristema/genética , Meristema/metabolismo , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Mutación/genéticaRESUMEN
DELLA proteins are conserved master growth regulators that play a central role in controlling plant development in response to internal and environmental cues. DELLAs function as transcription regulators, which are recruited to target promoters by binding to transcription factors (TFs) and histone H2A via their GRAS domain. Recent studies showed that DELLA stability is regulated post-translationally via two mechanisms, phytohormone gibberellin-induced polyubiquitination for its rapid degradation, and Small Ubiquitin-like Modifier (SUMO)-conjugation to increase its accumulation. Moreover, DELLA activity is dynamically modulated by two distinct glycosylations: DELLA-TF interactions are enhanced by O-fucosylation, but inhibited by O-linked N-acetylglucosamine (O-GlcNAc) modification. However, the role of DELLA phosphorylation remains unclear as previous studies showing conflicting results ranging from findings that suggest phosphorylation promotes or reduces DELLA degradation to others indicating it has no effect on its stability. Here, we identify phosphorylation sites in REPRESSOR OF ga1-3 (RGA, an AtDELLA) purified from Arabidopsis by mass spectrometry analysis, and show that phosphorylation of two RGA peptides in the PolyS and PolyS/T regions enhances RGA activity by promoting H2A binding and RGA association with target promoters. Notably, phosphorylation does not affect RGA-TF interactions or RGA stability. Our study has uncovered a molecular mechanism of phosphorylation-induced DELLA activity.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Cromatina , Regulación de la Expresión Génica de las Plantas , Histonas , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fosforilación , Histonas/metabolismo , Cromatina/metabolismo , Unión Proteica , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Giberelinas/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Plantas Modificadas Genéticamente , Regiones Promotoras GenéticasRESUMEN
Heat stress (HS) poses a significant challenge to plant survival, necessitating sophisticated molecular mechanisms to maintain cellular homeostasis. Here, we identify SICKLE (SIC) as a key modulator of HS responses in Arabidopsis (Arabidopsis thaliana). SIC is required for the sequestration of RNA DEBRANCHING ENZYME 1 (DBR1), a rate-limiting enzyme of lariat intronic RNA (lariRNA) decay, into stress granules (SGs). The sequestration of DBR1 by SIC enhances the accumulation of lariRNAs, branched circular RNAs derived from excised introns during pre-mRNA splicing, which in turn promote the transcription of their parental genes. Our findings further demonstrate that SIC-mediated DBR1 sequestration in SGs is crucial for plant HS tolerance, as deletion of the N-terminus of SIC (SIC1-244) impairs DBR1 sequestration and compromises plant response to HS. Overall, our study unveils a mechanism of transcriptional regulation in the HS response, where lariRNAs are enriched through DBR1 sequestration, ultimately promoting the transcription of heat stress tolerance genes.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Respuesta al Choque Térmico , Intrones , Empalme del ARN , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Respuesta al Choque Térmico/genética , Intrones/genética , Gránulos de Estrés/metabolismo , Gránulos de Estrés/genética , ARN de Planta/metabolismo , ARN de Planta/genética , Termotolerancia/genética , ARN Circular/metabolismo , ARN Circular/genética , Plantas Modificadas GenéticamenteRESUMEN
Soil salinity is detrimental to plant growth and remains a major threat to crop productivity of the world. Plants employ various physiological and molecular mechanisms to maintain growth under salt stress. Identification of genes and genetic loci underlying plant salt tolerance holds the key to breeding salt tolerant crops. CIPK-CBL pathways regulate adaptive responses of plants (especially ion transport) to abiotic stresses via fine-tuned Ca2+ signal transduction. In this study, we showed that over-expression of OsCIPK17 in Arabidopsis enhanced primary root elongation under salt stress, which is in a Ca2+ dependent manner. Further investigation revealed that, under salt stress, OsCIPK17 transcript level was significantly induced and its protein moved from the cytosol to the tonoplast. Using both Y2H and BiFC, tonoplast-localised OsCBL2 and OsCBL3 were shown to interact with OsCIPK17. Interestingly, over-expressing salt-induced OsCBL2 or OsCBL3 in Arabidopsis led to enhanced primary root elongation under salt stress. In this process, OsCIPK17 was shown recruited to the tonoplast (similar to the effect of salt stress). Furthermore, transgenic Arabidopsis lines individually over-expressing OsCIPK17, OsCBL2 and OsCBL3 all demonstrated larger biomass and less Na + accumulation in the shoot under salt stress. All data combined suggest that OsCIPK17- OsCBL2/3 module is a major component of shoot Na+ exclusion and therefore plant salt tolerance, which is through enhanced Na + compartmentation into the vacuole in the root. OsCIPK17 and OsCBL2/3 are therefore potential genetic targets that can be used for delivering salt tolerant rice cultivars.
Asunto(s)
Arabidopsis , Oryza , Proteínas de Plantas , Brotes de la Planta , Plantas Modificadas Genéticamente , Tolerancia a la Sal , Sodio , Arabidopsis/genética , Arabidopsis/metabolismo , Oryza/genética , Oryza/metabolismo , Tolerancia a la Sal/genética , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sodio/metabolismo , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/genética , Raíces de Plantas/metabolismoRESUMEN
Synthetic plant activators represent a promising novel class of green pesticides that can triggering endogenous plant immunity against pathogen invasion. In our previous study, we developed a series of fluorinated compounds capable of eliciting disease resistance in plants; however, the underlying regulatory mechanisms remained unclear. In this study, we systematically investigated the mechanism of plant immune activation using four synthetic plant activators in Arabidopsis thaliana (A. thaliana), including two fluorine-substituted and two nonfluorine-substituted molecules. Our findings revealed that the fluorinated compounds exhibited superior disease resistance activity compared to the non-fluorinated molecules. Gene expression analysis in systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related pathways demonstrated that fluorine substitution effectively regulated both SAR- and ISR-pathway activation, highlighting the distinct roles of fluorine in modulating the plant immune system. Notably, the prolonged ROS burst was observed in chloroplasts following treatment with all four plant activators, contrasting with the transient ROS burst induced by natural elicitors. These results provide insights into the unique mechanisms underlying synthetic plant activator-induced plant immunity. Furthermore, comprehensive proteomic analysis revealed a robust immune response mediated by fluorine-substituted plant activators. These findings offer novel insights into the role of fluorine substitution in SAR- and ISR-associated immune signaling pathways and their distinct impact on ROS production within chloroplasts.