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1.
Plant J ; 117(3): 747-765, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37926922

RESUMEN

Brassinazole Resistant 1 (BZR1) and bri1 EMS Suppressor 1 (BES1) are key transcription factors that mediate brassinosteroid (BR)-responsive gene expression in Arabidopsis. The BZR1/BES1 family is composed of BZR1, BES1, and four BES1/BZR1 homologs (BEH1-BEH4). However, little is known about whether BEHs are regulated by BR signaling in the same way as BZR1 and BES1. We comparatively analyzed the functional characteristics of six BZR1/BES1 family members and their regulatory mechanisms in BR signaling using genetic and biochemical analyses. We also compared their subcellular localizations regulated by the phosphorylation status, interaction with GSK3-like kinases, and heterodimeric combination. We found that all BZR1/BES1 family members restored the phenotypic defects of bri1-5 by their overexpression. Unexpectedly, BEH2-overexpressing plants showed the most distinct phenotype with enhanced BR responses. RNA-Seq analysis indicated that overexpression of both BZR1 and BEH2 regulates BR-responsive gene expression, but BEH2 has a much greater proportion of BR-independent gene expression than BZR1. Unlike BZR1 and BES1, the BR-regulated subcellular translocation of the four BEHs was not tightly correlated with their phosphorylation status. Notably, BEH1 and BEH2 are predominantly localized in the nucleus, which induces the nuclear accumulation of other BZR1/BES1 family proteins through heterodimerization. Altogether, our comparative analyses suggest that BEH1 and BEH2 play an important role in the functional interaction between BZR1/BES1 family transcription factors.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Triazoles , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas , Glucógeno Sintasa Quinasa 3/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
2.
Plant J ; 114(6): 1443-1457, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36948884

RESUMEN

Nitrogen (N) is one of the most essential mineral elements for plants. Brassinosteroids (BRs) play key roles in plant growth and development. Emerging evidence indicates that BRs participate in the responses to nitrate deficiency. However, the precise molecular mechanism underlying the BR signaling pathway in regulating nitrate deficiency remains largely unknown. The transcription factor BES1 regulates the expression of many genes in response to BRs. Root length, nitrate uptake and N concentration of bes1-D mutants were higher than those of wild-type under nitrate deficiency. BES1 levels strongly increased under low nitrate conditions, especially in the non-phosphorylated (active) form. Furthermore, BES1 directly bound to the promoters of NRT2.1 and NRT2.2 to promote their expression under nitrate deficiency. Taken together, BES1 is a key mediator that links BR signaling under nitrate deficiency by modulating high affinity nitrate transporters in plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Unión al ADN , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Nitratos/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Transporte de Anión/metabolismo
3.
Plant Cell Physiol ; 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38896040

RESUMEN

BRI1-EMS Suppressor 1 (BES1) and Brassinazole resistant 1 (BZR1) are two highly similar master transcription factors of the brassinosteroid (BR) signaling pathway that regulate a variety of plant growth and development processes as well as stress responses. Previous genetic and biochemical analyses have established a complex regulatory network to control the two transcription factors. This network includes coordination with other transcription factors and interactors, multiple post-translational modifications (PTMs), and differential subcellular localizations. In this review, we systematically detail the functions and regulatory mechanisms of various PTMs: phosphorylation/dephosphorylation, ubiquitination/deubiquitination, SUMOylation/deSUMOylation, oxidation/reduction, in regulating the subcellular localization, protein stability, and the transcriptional activity of BES1/BZR1. We also discuss the current knowledge about the BES1/BZR1-interactors mediating the dynamic nucleocytoplasmic shuttling of BES1 and BZR1.

4.
Small ; : e2402611, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-39031806

RESUMEN

Microalgae are increasingly playing a significant role in many areas of research and development. Recent studies have demonstrated their ability to aid wound healing by their ability to generate oxygen, aiding the healing process. Bearing this in mind, the capability to spray/spin deposit microalgae in suspension (solution) or compartmentalize living microalgae within architectures such as fibers/scaffolds and beads, would have significance as healing mechanisms for addressing a wide range of wounds. Reconstructing microalgae-bearing architectures as either scaffolds or beads could be generated via electric field (bio-electrospraying and cell electrospinning) and non-electric field (aerodynamically assisted bio-jetting/threading) driven technologies. However, before studying the biomechanical properties of the generated living architectures, the microalgae exposed to these techniques must be interrogated from a molecular level upward first, to establish these techniques, have no negative effects brought on the processed microalgae. Therefore these studies, demonstrate the ability of both these jetting and threading technologies to directly handle living microalgae, in suspension or within a polymeric suspension, safely, and form algae-bearing architectures such as beads and fibers/scaffolds.

5.
Antonie Van Leeuwenhoek ; 117(1): 10, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38170279

RESUMEN

Exo-electrogenic microorganisms are characterized by their special metabolic capability of transferring metabolic electrons out of their cell, into insoluble external electron acceptors such as iron or manganese oxides and electrodes, or vice versa take up electron from electrodes. Their conventional application is primarily limited to microbial fuel cells for electrical power generation and microbial electrolysis cells for the production of value-added products such as biohydrogen, biomethane and hydrogen peroxide. The utility of exo-electrogenic organisms has expanded into many other applications in recent times. Such examples include microbial desalination cells, microbial electro-synthesis cells producing value-added chemicals such as bio-butanol and their applications in other carbon sequestration technologies. Additionally, electrochemically-active organisms are now beginning to be employed in biosensor applications for environmental monitoring. Additionally, the utility of biocathodes in bio-electrochemical systems is also a novel application in catalyzing the cathodic oxygen reduction reaction to enhance their electrochemical performance. Advances have also been made in the expansion and use of other organisms such as the usage of photosynthetic microorganisms for the fabrication of self-sustained bio-electrochemical systems. This review attempts to provide a comprehensive picture of the state-of the art of exo-electrogenic organisms and their novel utility in bioelectrochemical systems.


Asunto(s)
Fuentes de Energía Bioeléctrica , Electrólisis , Electrodos , Fotosíntesis
6.
Int J Mol Sci ; 25(5)2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38474317

RESUMEN

The BRI1 EMS suppressor 1(BES1) transcription factor is a crucial regulator in the signaling pathway of Brassinosteroid (BR) and plays an important role in plant growth and response to abiotic stress. Although the identification and functional validation of BES1 genes have been extensively explored in various plant species, the understanding of their role in woody plants-particularly the endangered species Phoebe bournei (Hemsl.) Yang-remains limited. In this study, we identified nine members of the BES1 gene family in the genome of P. bournei; these nine members were unevenly distributed across four chromosomes. In our further evolutionary analysis of PbBES1, we discovered that PbBES1 can be divided into three subfamilies (Class I, Class II, and Class IV) based on the evolutionary tree constructed with Arabidopsis thaliana, Oryza sativa, and Solanum lycopersicum. Each subfamily contains 2-5 PbBES1 genes. There were nine pairs of homologous BES1 genes in the synteny analysis of PbBES1 and AtBES1. Three segmental replication events and one pair of tandem duplication events were present among the PbBES1 family members. Additionally, we conducted promoter cis-acting element analysis and discovered that PbBES1 contains binding sites for plant growth and development, cell cycle regulation, and response to abiotic stress. PbBES1.2 is highly expressed in root bark, stem bark, root xylem, and stem xylem. PbBES1.3 was expressed in five tissues. Moreover, we examined the expression profiles of five representative PbBES1 genes under heat and drought stress. These experiments preliminarily verified their responsiveness and functional roles in mediating responses to abiotic stress. This study provides important clues to elucidate the functional characteristics of the BES1 gene family, and at the same time provides new insights and valuable information for the regulation of resistance in P. bournei.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Factores de Transcripción/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Brasinoesteroides/metabolismo , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las Plantas , Filogenia , Proteínas de Plantas/genética , Familia de Multigenes , Proteínas de Unión al ADN/metabolismo
7.
BMC Bioinformatics ; 24(1): 406, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37904095

RESUMEN

The commercial adoption of BCI technologies for both clinical and non-clinical applications is drawing scientists to the creation of wearable devices for daily living. Emotions are essential to human existence and have a significant impact on thinking. Emotion is frequently linked to rational decision-making, perception, interpersonal interaction, and even basic human intellect. The requirement for trustworthy and implementable methods for the detection of individual emotional responses is needed with rising attention of the scientific community towards the establishment of some significant emotional connections among people and computers. This work introduces EEG recognition model, where the input signal is pre-processed using band pass filter. Then, the features like discrete wavelet transform (DWT), band power, spectral flatness, and improved Entropy are extracted. Further, for recognition, tri-classifiers like long short term memory (LSTM), improved deep belief network (DBN) and recurrent neural network (RNN) are used. Also to enhance tri-model classifier performance, the weights of LSTM, improved DBN, and RNN are tuned by model named as shark smell updated BES optimization (SSU-BES). Finally, the perfection of SSU-BES is demonstrated over diverse metrics.


Asunto(s)
Algoritmos , Electroencefalografía , Humanos , Electroencefalografía/métodos , Redes Neurales de la Computación , Emociones/fisiología
8.
Plant Cell Physiol ; 63(12): 1873-1889, 2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-35489066

RESUMEN

Strigolactones (SLs) are carotenoid-derived phytohormones governing a wide range of physiological processes, including drought-associated stomatal closure. We have previously shown in tomato that SLs regulate the so-called after-effect of drought, whereby stomatal conductance is not completely restored for some time during recovery after a drought spell, irrespective of the water potential. To ease the elucidation of its molecular underpinnings, we investigated whether this SL effect is conserved in Arabidopsis thaliana by contrasting the physiological performances of the wild-type with SL-depleted (more axillary growth 4, max4) and insensitive (dwarf 14, d14) mutants in a drought and recovery protocol. Physiological analyses showed that SLs are important to achieve a complete after-effect in A. thaliana, while transcriptome results suggested that the SL-dependent modulation of drought responses extends to a large subset (about 4/5) of genes displaying memory transcription patterns. Among these, we show that the activation of over 30 genes related to abscisic acid metabolism and signaling strongly depends on SL signaling. Furthermore, by using promoter-enrichment tools, we identified putative cis- and trans-acting factors that may be important in the SL-dependent and SL-independent regulation of genes during drought and recovery. Finally, in order to test the accuracy of our bioinformatic prediction, we confirmed one of the most promising transcription factor candidates mediating SL signaling effects on transcriptional drought memory-BRI-EMS SUPPRESSOR1 (BES1). Our findings reveal that SLs are master regulators of Arabidopsis transcriptional memory upon drought and that this role is partially mediated by the BES1 transcription factor.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sequías , Lactonas/metabolismo , Perfilación de la Expresión Génica , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transductores , Regulación de la Expresión Génica de las Plantas , Proteínas de Unión al ADN/metabolismo
9.
Environ Sci Technol ; 57(8): 3369-3379, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36790331

RESUMEN

Organic waste streams can be converted into high-value platform chemicals such as medium-chain carboxylic acids (MCCAs) using mixed microbial communities via chain elongation. However, the heterogeneity of waste streams and the use of complex microbial communities can lead to undesirable reactions, thus decreasing process efficiency. We explored suppressing excessive ethanol oxidation to acetate (EEO) by increasing the hydrogen partial pressure (PH2) through hydrogenotrophic methanogenesis inhibition by periodically adding 2-bromoethanesulfonate (2-BES) to an MCCA-producing bioreactor to reach 10 mM of 2-BES upon addition. The bioreactor was fed with pretreated food waste and brewery waste containing high concentrations of short-chain carboxylic acids and ethanol, respectively. While 2-BES addition initially reduced EEO, some methanogens (Methanobrevibacter spp.) persisted and resistant populations were selected over time. Besides changing the methanogenic community structure, adding 2-BES also changed the bacterial community structure due to its impact on PH2. While we demonstrated that PH2 could be manipulated using 2-BES to control EEO, methods that do not require the addition of a chemical inhibitor should be explored to maintain optimum PH2 for long-term suppression of EEO.


Asunto(s)
Euryarchaeota , Eliminación de Residuos , Etanol , Hidrógeno , Alimentos , Presión Parcial , Acetatos , Ácidos Carboxílicos , Metano
10.
Environ Res ; 231(Pt 1): 116042, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37142084

RESUMEN

Bio-electrochemical systems (BESs) have attracted wide attention in the field of wastewater treatment owing to their fast electron transfer rate and high performance. Unfortunately, the low electro-chemical activity of carbonaceous materials commonly used in BESs remains a bottleneck for their practical applications. Especially, for refractory pollutants remediation, the efficiency is largely limited by the cathode property in term of (bio)-electrochemical reduction of highly oxidized functional groups. Herein, a reduced graphene oxide (rGO) and polyaniline (PANI) modified electrode was fabricated via two-step electro-deposition using carbon brush as raw material. Benefiting from the modified graphene sheets and PANI nanoparticles, the rGO/PANI electrode shows highly conductive network with the electro-active surface area increased by 12 times (0.013 mF cm-2) and the charge transfer resistance decreased by 92% (0.23Ω) comparing with the unmodified one. Most importantly, the rGO/PANI electrode used as abiotic cathode achieves highly efficient azo dye removal from wastewater. The highest decolorization efficiency reaches 96 ± 0.03% within 24 h and the maximum decolorization rate is as high as 20.9 ± 1.45 g h-1·m-3. The features of improved electro-chemical activity and enhanced pollutant removal efficiency provide a new insight toward development of high performance BESs via electrode modification for practical application.


Asunto(s)
Grafito , Grafito/química , Compuestos Azo , Electrodos
11.
Sensors (Basel) ; 23(13)2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37447806

RESUMEN

Due to energy constraints and people's increasing requirements for indoor thermal comfort, improving energy efficiency while ensuring thermal comfort has become the focus of research in the design and operation of HVAC systems. This study took office rooms with few people occupying them in Wuhan as the research object. The EnergyPlus-Fluent co-simulation method was used to study the impact of 12 forms of air distribution on the thermal environment and air-conditioner energy consumption. The results indicate that 3 m/s supply air velocity and 45° supply air angle are more suitable for the case model in this study. The EnergyPlus-Fluent co-simulation method used in this paper provides a reference for the study of indoor environments in offices with few people occupying them.


Asunto(s)
Contaminación del Aire Interior , Fenómenos Fisiológicos , Humanos , Aire Acondicionado/métodos , Simulación por Computador
12.
Int J Mol Sci ; 24(3)2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36768611

RESUMEN

The BES1 (BRI1-EMSSUPPRESSOR1) gene family play a vital role in the BR (brassinosteroid) signaling pathway, which is involved in the growth and development, biotic, abiotic, and hormone stress response in many plants. However, there are few reports of BES1 in Cucurbita moschata. In this study, 50 BES1 genes were identified in six Cucurbitaceae species by genome-wide analysis, which could be classified into 3 groups according to their gene structural features and motif compositions, and 13 CmoBES1 genes in Cucurbita moschata were mapped on 10 chromosomes. Quantitative real-time PCR analysis showed that the CmoBES1 genes displayed differential expression under different abiotic stress and hormone treatments. Subcellular localization showed that the most of CmoBES1 proteins localized in nucleus and cytoplasm, and transactivation assay indicated 9 CmoBES1 proteins played roles as transcription factors. Our analysis of BES1s diversity, localization, and expression in Curcubitaceae contributes to the better understanding of the essential roles of these transcription factors in plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Cucurbita , Cucurbitaceae , Proteínas de Unión al ADN/metabolismo , Cucurbita/genética , Cucurbita/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Cucurbitaceae/genética , Cucurbitaceae/metabolismo , Proteínas Nucleares/genética , Factores de Transcripción/metabolismo , Brasinoesteroides/metabolismo , Plantas/metabolismo , Hormonas/metabolismo , Regulación de la Expresión Génica de las Plantas
13.
J Integr Plant Biol ; 65(5): 1226-1240, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36511120

RESUMEN

RAV1 (Related to ABI3/VP1) is a plant-specific B3 and AP2 domain-containing transcription factor that acts as a negative regulator of growth in many plant species. The expression of RAV1 is downregulated by brassinosteroids (BRs); large-scale transcriptome analyses have shown that the expression of RAV1 was previously targeted by BRI1-EMS-SUPPRESOR1 (BES1) and BRASSINAZOLE-RESISTANT1 (BZR1), which are critical transcription factors for the BR-signaling process. Using RAV1-overexpressing transgenic plants, we showed that RAV1 overexpression reduced the BR signaling capacity, resulting in the downregulation of BR biosynthetic genes and BES1 expression. Furthermore, we demonstrated that BES1, not BZR1, is directly bound to the RAV1 promoter and repressed RAV1 expression, and vice versa; RAV1 is also bound to the BES1 promoter and repressed BES1 expression. This mutual inhibition was specific to RAV1 and BES1 because RAV1 exhibited binding activity to the BZR1 promoter but did not repress BZR1 expression. We observed that constitutively activated BR signaling phenotypes in bes1-D were attenuated by the repression of endogenous BES1 expression in transgenic bes1-D plants overexpressing RAV1. RNA-sequencing analysis of RAV1-overexpressing transgenic plants and bes1-D mutant plants revealed differentially expressed genes by RAV1 and BES1 and genes that were oppositely co-regulated by RAV1 and BES1. RAV1 and BES1 regulated different transcriptomes but co-regulated a specific set of genes responsible for the balance between growth and defense. These results suggested that the mutual inhibitory transcriptional activities of RAV1 and BES1 provide fine regulatory mechanisms for plant growth and development.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides/farmacología , Brasinoesteroides/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Desarrollo de la Planta , Plantas Modificadas Genéticamente/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
14.
J Struct Biol ; 214(3): 107885, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35961473

RESUMEN

Plant ß-amylase (BAM) proteins play an essential role in growth, development, stress response, and hormone regulation. Despite their typical (ß/α)8 barrel structure as active catalysts in starch breakdown, catalytically inactive BAMs are implicated in diverse yet elusive functions in plants. The noncatalytic BAM7/8 contain N-terminal BZR1 domains and were shown to be involved in the regulation of brassinosteroid signaling and possibly serve as sensors of yet an uncharacterized metabolic signal. While the structures of several catalytically active BAMs have been reported, structural characterization of the catalytically inactive BZR1-type BAMs remain unknown. Here, we determine the crystal structure of ß-amylase domain of Zea mays BAM8/BES1/BZR1-5 and provide comprehensive insights into its noncatalytic adaptation. Using structural-guided comparison combined with biochemical analysis and molecular dynamics simulations, we revealed conformational changes in multiple distinct highly conserved regions resulting in rearrangement of the binding pocket. Altogether, this study adds a new layer of understanding to starch breakdown mechanism and elucidates the acquired adjustments of noncatalytic BZR1-type BAMs as putative regulatory domains and/or metabolic sensors in plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , beta-Amilasa , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Unión al ADN/metabolismo , Proteínas de Plantas/metabolismo , Plantas , Almidón/metabolismo , Zea mays/metabolismo , beta-Amilasa/química , beta-Amilasa/metabolismo
15.
Plant Cell Physiol ; 63(4): 535-549, 2022 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-35137197

RESUMEN

Leaf morphogenetic activity determines its shape diversity. However, our knowledge of the regulatory mechanism in maintaining leaf morphogenetic capacity is still limited. In tomato, gibberellin (GA) negatively regulates leaf complexity by shortening the morphogenetic window. We here report a tomato BRI1-EMS-suppressor 1 transcription factor, SlBES1.8, that promoted the simplification of leaf pattern in a similar manner as GA functions. OE-SlBES1.8 plants exhibited reduced sensibility to exogenous GA3 treatment whereas showed increased sensibility to the application of GA biosynthesis inhibitor, paclobutrazol. In line with the phenotypic observation, the endogenous bioactive GA contents were increased in OE-SlBES1.8 lines, which certainly promoted the degradation of the GA signaling negative regulator, SlDELLA. Moreover, transcriptomic analysis uncovered a set of overlapping genomic targets of SlBES1.8 and GA, and most of them were regulated in the same way. Expression studies showed the repression of SlBES1.8 to the transcriptions of two GA-deactivated genes, SlGA2ox2 and SlGA2ox6, and one GA receptor, SlGID1b-1. Further experiments confirmed the direct regulation of SlBES1.8 to their promoters. On the other hand, SlDELLA physically interacted with SlBES1.8 and further inhibited its transcriptional regulation activity by abolishing SlBES1.8-DNA binding. Conclusively, by mediating GA deactivation and signaling, SlBES1.8 greatly influenced tomato leaf morphogenesis.


Asunto(s)
Solanum lycopersicum , Regulación de la Expresión Génica de las Plantas , Giberelinas/metabolismo , Giberelinas/farmacología , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Organogénesis de las Plantas , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
16.
EMBO J ; 37(23)2018 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-30389669

RESUMEN

The Arabidopsis PIF4 and BES1/BZR1 transcription factors antagonize light signaling by facilitating co-activated expression of a large number of cell wall-loosening and auxin-related genes. While PIF4 directly activates expression of these targets, BES1 and BZR1 activity switch from a repressive to an activator function, depending on interaction with TOPLESS and other families of regulators including PIFs. However, the complexity of this regulation and its role in diurnal control of plant growth and brassinosteroid (BR) levels is little understood. We show by using a protein array that BES1, PIF4, and the BES1-PIF4 complex recognize different DNA elements, thus revealing a distinctive cis-regulatory code beneath BES1-repressive and PIF4 co-activation function. BES1 homodimers bind to conserved BRRE- and G-box elements in the BR biosynthetic promoters and inhibit their expression during the day, while elevated PIF4 competes for BES1 homodimer formation, resulting in de-repressed BR biosynthesis at dawn and in response to warmth. Our findings demonstrate a central role of PIF4 in BR synthesis activation, increased BR levels being essential to thermomorphogenic hypocotyl growth.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Brasinoesteroides/biosíntesis , Hipocótilo/crecimiento & desarrollo , Fotoperiodo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteínas de Unión al ADN , Regulación de la Expresión Génica de las Plantas/fisiología , Hipocótilo/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Multimerización de Proteína/fisiología
17.
Plant Cell Environ ; 45(9): 2762-2779, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35770732

RESUMEN

Cold stress resulting from chilling and freezing temperatures substantially inhibits plant growth and reduces crop production worldwide. Tremendous research efforts have been focused on elucidating the molecular mechanisms of freezing tolerance in plants. However, little is known about the molecular nature of chilling stress responses in plants. Here we found that two allelic mutants in a spliceosome component gene SmEb (smeb-1 and smeb-2) are defective in development and responses to chilling stress. RNA-seq analysis revealed that SmEb controls the splicing of many pre-messenger RNAs (mRNAs) under chilling stress. Our results suggest that SmEb is important to maintain proper ratio of the two COP1 splicing variants (COP1a/COP1b) to fine tune the level of HY5. In addition, the transcription factor BES1 shows a dramatic defect in pre-mRNA splicing in the smeb mutants. Ectopic expression of the two BES1 splicing variants enhances the chilling sensitivity of the smeb-1 mutant. Furthermore, biochemical and genetic analysis showed that CBFs act as negative upstream regulators of SmEb by directly suppressing its transcription. Together, our results demonstrate that proper alternative splicing of pre-mRNAs controlled by the spliceosome component SmEb is critical for plant development and chilling stress responses.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Empalme Alternativo/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Frío , Regulación de la Expresión Génica de las Plantas , Desarrollo de la Planta , ARN Mensajero/metabolismo , Empalmosomas/genética , Empalmosomas/metabolismo
18.
Microb Cell Fact ; 21(1): 178, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36050762

RESUMEN

BACKGROUND: Electro-fermentation (EF) is an emerging tool for bioprocess intensification. Benefits are especially expected for bioprocesses in which the cells are enabled to exchange electrons with electrode surfaces directly. It has also been demonstrated that the use of electrical energy in BES can increase bioprocess performance by indirect secondary effects. In this case, the electricity is used to alter process parameters and indirectly activate desired pathways. In many bioprocesses, oxidation-reduction potential (ORP) is a crucial process parameter. While C. pasteurianum fermentation of glycerol has been shown to be significantly influenced electrochemically, the underlying mechanisms are not clear. To this end, we developed a system for the electrochemical control of ORP in continuous culture to quantitatively study the effects of ORP alteration on C. pasteurianum by metabolic flux analysis (MFA), targeted metabolomics, sensitivity and regulation analysis. RESULTS: In the ORP range of -462 mV to -250 mV, the developed algorithm enabled a stable anodic electrochemical control of ORP at desired set-points and a fixed dilution rate of 0.1 h-1. An overall increase of 57% in the molar yield for 1,3-propanediol was observed by an ORP increase from -462 to -250 mV. MFA suggests that C. pasteurianum possesses and uses cellular energy generation mechanisms in addition to substrate-level phosphorylation. The sensitivity analysis showed that ORP exerted its strongest impact on the reaction of pyruvate-ferredoxin-oxidoreductase. The regulation analysis revealed that this influence is mainly of a direct nature. Hence, the observed metabolic shifts are primarily caused by direct inhibition of the enzyme upon electrochemical production of oxygen. A similar effect was observed for the enzyme pyruvate-formate-lyase at elevated ORP levels. CONCLUSIONS: The results show that electrochemical ORP alteration is a suitable tool to steer the metabolism of C. pasteurianum and increase product yield for 1,3-propanediol in continuous culture. The approach might also be useful for application with further anaerobic or anoxic bioprocesses. However, to maximize the technique's efficiency, it is essential to understand the chemistry behind the ORP change and how the microbial system responds to it by transmitted or direct effects.


Asunto(s)
Clostridium , Glicerol , Clostridium/metabolismo , Fermentación , Glicerol/metabolismo , Oxidación-Reducción , Piruvatos/metabolismo
19.
Int J Mol Sci ; 23(17)2022 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-36077547

RESUMEN

The BES1/BZR1 family is a plant-specific small group of transcription factors possessing a non-canonical bHLH domain. Genetic and biochemical analyses within the last two decades have demonstrated that members of this family are key transcription factors in regulating the expression of brassinosteroid (BR) response genes. Several recent genetic and evolutionary studies, however, have clearly indicated that the BES1/BZR1 family transcription factors also function in regulating several aspects of plant development via BR-independent pathways, suggesting they are not BR specific. In this review, we summarize our current understanding of this family of transcription factors, the mechanisms regulating their activities, DNA binding motifs, and target genes. We selectively discuss a number of their biological functions via BR-dependent and particularly independent pathways, which were recently revealed by loss-of-function genetic analyses. We also highlight a few possible future directions.


Asunto(s)
Proteínas de Arabidopsis , Brasinoesteroides , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides/metabolismo , Regulación de la Expresión Génica de las Plantas , Desarrollo de la Planta/genética , Transducción de Señal/fisiología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
20.
Int J Mol Sci ; 23(11)2022 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-35682705

RESUMEN

The BRI1-EMS suppressor 1 (BES1)/brassinazole-resistant 1(BZR1) transcription factors play crucial roles in plant growth, development, and stress response. However, little is known about the function of maize's BES1/BZR1s. In this study, the ZmBES1/BZR1-3 and ZmBES1/BZR1-9 genes were cloned from maize's inbred line, B73, and they were functionally evaluated by analyzing their expression pattern, subcellular localization, transcriptional activation activity, as well as their heterologous expression in Arabidopsis, respectively. The results of the qRT-PCR showed that the ZmBES1/BZR1-3 and ZmBES1/BZR1-9 genes were predominantly expressed in the root, and their expression was significantly down-regulated by drought stress. The ZmBES1/BZR1-3 and ZmBES1/BZR1-9 proteins localized in the nucleus but showed no transcriptional activation activity as a monomer. Subsequently, it was found that the heterologous expression of the ZmBES1/BZR1-3 and ZmBES1/BZR1-9 genes in Arabidopsis decreased drought tolerance, respectively. The transgenic lines showed a more serious wilting phenotype, shorter root length, lower fresh weight, and higher relative electrolyte leakage (REL) and malondialdehyde (MDA) content compared to the control under drought stress. The RNA-sequencing data showed that the 70.67% and 93.27% differentially expressed genes (DEGs) were significantly down-regulated in ZmBES1/BZR1-3 and ZmBES1/BZR1-9 transgenic Arabidopsis, respectively. The DEGs of ZmBES1/BZR1-3 gene's expressing lines were mainly associated with oxidative stress response and amino acid metabolic process and enriched in phenylpropanoid biosynthesis and protein processing in the endoplasmic reticulum. But the DEGs of the ZmBES1/BZR1-9 gene's expressing lines were predominantly annotated with water deprivation, extracellular stimuli, and jasmonic acid and enriched in phenylpropanoid biosynthesis and plant hormone signal transduction. Moreover, ZmBES1/BZR1-9 increased stomatal aperture in transgenic Arabidopsis under drought stress. This study indicates that ZmBES1/BZR1-3 and ZmBES1/BZR1-9 negatively regulate drought tolerance via different pathways in transgenic Arabidopsis, and it provides insights into the underlying the function of BES1/BZR1s in crops.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Unión al ADN/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Estrés Fisiológico/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Zea mays/metabolismo
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