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1.
Cells ; 11(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36359833

RESUMO

The effect of red (RL, 660 nm) and blue (BL, 450 nm) light on phy mutant tomato plants was studied. The rates of photosynthesis (Pn) and transpiration, the efficiency of the primary photochemical processes of photosynthesis, the contents of flavonoids and phenolic compounds, the low-molecular-weight antioxidant capacity (Trolox equivalent antioxidant capacity (TEAC)) of leaf extracts, and the expression of light-dependent genes were evaluated. Under RL, BL, and white fluorescent light (WFL), the Pn values decreased in the order: WT > phyb2 > phyaphyb2 > phyaphyb1phyb2, except for the Pn in phyb2 on BL. Phyb2 also had a larger number of stomata under BL and, as a result, it reached maximum transpiration. The noticeable accumulation of flavonoids and phenolic compounds was observed only in the phyb2 and phyaphyb2 mutants upon irradiation with BL, which agrees with the increased TEAC in the leaf extracts. We suggest that the increased antioxidant activity under PHYB2 deficiency and the maintenance of high photosynthesis under BL are based on an increase in the expression of the early signaling transcription factors genes BBX, HY5. The largest decrease in the content of flavonoids and TEAC was manifested with a deficiency in PHYB1, which is probably the key to maintaining the antioxidant status in BL plants.


Assuntos
Lycopersicon esculentum , Fitocromo , Fitocromo/genética , Fitocromo/metabolismo , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Flavonoides , Antioxidantes/metabolismo , Fotossíntese/genética , Extratos Vegetais/metabolismo
2.
Int J Mol Sci ; 23(22)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36430613

RESUMO

Plants are sessile organisms forced to adapt to environmental variations recurring in a day-night cycle. Extensive research has uncovered the transcriptional control of plants' inner clock and has revealed at least some part of the intricate and elaborate regulatory mechanisms that govern plant diel responses and provide adaptation to the ever-changing environment. Here, we analyzed the proteome of the Arabidopsis thaliana mutant genotypes collected in the middle of the day and the middle of the night, including four mutants in the phytochrome (phyA, phyB, phyC, and phyD) and the circadian clock protein LHY. Our approach provided a novel insight into the diel regulations, identifying 640 significant changes in the night-day protein abundance. The comparison with previous studies confirmed that a large portion of identified proteins was a known target of diurnal regulation. However, more than 300 were novel oscillations hidden under standard growth chamber conditions or not manifested in the wild type. Our results indicated a prominent role for ROS metabolism and phytohormone cytokinin in the observed regulations, and the consecutive analyses confirmed that. The cytokinin signaling significantly increased at night, and in the mutants, the hydrogen peroxide content was lower, and the night-day variation seemed to be lost in the phyD genotype. Furthermore, regulations in the lhy and phyB mutants were partially similar to those found in the catalase mutant cat2, indicating shared ROS-mediated signaling pathways. Our data also shed light on the role of the relatively poorly characterized Phytochrome D, pointing to its connection to glutathione metabolism and the regulation of glutathione S-transferases.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Fitocromo/genética , Fitocromo/metabolismo , Fitocromo B/metabolismo , Proteoma/genética , Proteoma/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/metabolismo , Citocininas/metabolismo , Glutationa/metabolismo , Apoproteínas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
3.
Nat Commun ; 13(1): 6838, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369284

RESUMO

Phytochromes are ubiquitous photoreceptors responsible for sensing light in plants, fungi and bacteria. Their photoactivation is initiated by the photoisomerization of the embedded chromophore, triggering large conformational changes in the protein. Despite numerous experimental and computational studies, the role of chromophore-protein interactions in controlling the mechanism and timescale of the process remains elusive. Here, we combine nonadiabatic surface hopping trajectories and adiabatic molecular dynamics simulations to reveal the molecular details of such control for the Deinococcus radiodurans bacteriophytochrome. Our simulations reveal that chromophore photoisomerization proceeds through a hula-twist mechanism whose kinetics is mainly determined by the hydrogen bond of the chromophore with a close-by histidine. The resulting photoproduct relaxes to an early intermediate stabilized by a tyrosine, and finally evolves into a late intermediate, featuring a more disordered binding pocket and a weakening of the aspartate-to-arginine salt-bridge interaction, whose cleavage is essential to interconvert the phytochrome to the active state.


Assuntos
Deinococcus , Fitocromo , Fitocromo/metabolismo , Deinococcus/metabolismo , Fotoquímica , Cinética , Ligação de Hidrogênio , Proteínas de Bactérias/metabolismo
4.
Int J Mol Sci ; 23(19)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36233359

RESUMO

Common wheat, Triticum aestivum, is the most widely grown staple crop worldwide. To catch up with the increasing global population and cope with the changing climate, it is valuable to breed wheat cultivars that are tolerant to abiotic or shade stresses for density farming. Arabidopsis LONG HYPOCOTYL IN FAR-RED 1 (AtHFR1), a photomorphogenesis-promoting factor, is involved in multiple light-related signaling pathways and inhibits seedling etiolation and shade avoidance. We report that overexpression of AtHFR1 in wheat inhibits etiolation phenotypes under various light and shade conditions, leading to shortened plant height and increased spike number relative to non-transgenic plants in the field. Ectopic expression of AtHFR1 in wheat increases the transcript levels of TaCAB and TaCHS as observed previously in Arabidopsis, indicating that the AtHFR1 transgene can activate the light signal transduction pathway in wheat. AtHFR1 transgenic seedlings significantly exhibit tolerance to osmotic stress during seed germination compared to non-transgenic wheat. The AtHFR1 transgene represses transcription of TaFT1, TaCO1, and TaCO2, delaying development of the shoot apex and heading in wheat. Furthermore, the AtHFR1 transgene in wheat inhibits transcript levels of PHYTOCHROME-INTERACTING FACTOR 3-LIKEs (TaPIL13, TaPIL15-1B, and TaPIL15-1D), downregulating the target gene STAYGREEN (TaSGR), and thus delaying dark-induced leaf senescence. In the field, grain yields of three AtHFR1 transgenic lines were 18.2-48.1% higher than those of non-transgenic wheat. In summary, genetic modification of light signaling pathways using a photomorphogenesis-promoting factor has positive effects on grain yield due to changes in plant architecture and resource allocation and enhances tolerances to osmotic stress and shade avoidance response.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas , Pressão Osmótica , Fitocromo/genética , Fitocromo/metabolismo , Melhoramento Vegetal , Plântula/metabolismo , Triticum/metabolismo
5.
Nat Commun ; 13(1): 5659, 2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-36216814

RESUMO

Plant growth ultimately depends on fixed carbon, thus the available light for photosynthesis. Due to canopy light absorption properties, vegetative shade combines low blue (LB) light and a low red to far-red ratio (LRFR). In shade-avoiding plants, these two conditions independently trigger growth adaptations to enhance light access. However, how these conditions, differing in light quality and quantity, similarly promote hypocotyl growth remains unknown. Using RNA sequencing we show that these two features of shade trigger different transcriptional reprogramming. LB induces starvation responses, suggesting a switch to a catabolic state. Accordingly, LB promotes autophagy. In contrast, LRFR induced anabolism including expression of sterol biosynthesis genes in hypocotyls in a manner dependent on PHYTOCHROME-INTERACTING FACTORs (PIFs). Genetic analyses show that the combination of sterol biosynthesis and autophagy is essential for hypocotyl growth promotion in vegetative shade. We propose that vegetative shade enhances hypocotyl growth by combining autophagy-mediated recycling and promotion of specific lipid biosynthetic processes.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Autofagia/genética , Carbono/metabolismo , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/genética , Luz , Lipídeos , Fitocromo/metabolismo , Esteróis/metabolismo
6.
Proc Natl Acad Sci U S A ; 119(41): e2208708119, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36191205

RESUMO

Photoperiod is an important environmental cue. Plants can distinguish the seasons and flower at the right time through sensing the photoperiod. Soybean is a sensitive short-day crop, and the timing of flowering varies greatly at different latitudes, thus affecting yields. Soybean cultivars in high latitudes adapt to the long day by the impairment of two phytochrome genes, PHYA3 and PHYA2, and the legume-specific flowering suppressor, E1. However, the regulating mechanism underlying phyA and E1 in soybean remains largely unknown. Here, we classified the regulation of the E1 family by phyA2 and phyA3 at the transcriptional and posttranscriptional levels, revealing that phyA2 and phyA3 regulate E1 by directly binding to LUX proteins, the critical component of the evening complex, to regulate the stability of LUX proteins. In addition, phyA2 and phyA3 can also directly associate with E1 and its homologs to stabilize the E1 proteins. Therefore, phyA homologs control the core flowering suppressor E1 at both the transcriptional and posttranscriptional levels, to double ensure the E1 activity. Thus, our results disclose a photoperiod flowering mechanism in plants by which the phytochrome A regulates LUX and E1 activity.


Assuntos
Fotoperíodo , Fitocromo , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Fitocromo/genética , Fitocromo/metabolismo , Fitocromo A/genética , Fitocromo A/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Soja/metabolismo
7.
Proc Natl Acad Sci U S A ; 119(44): e2214565119, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36282917

RESUMO

Light signals perceived by a group of photoreceptors have profound effects on the physiology, growth, and development of plants. The red/far-red light-absorbing phytochromes (phys) modulate these aspects by intricately regulating gene expression at multiple levels. Here, we report the identification and functional characterization of an RNA-binding splicing factor, SWAP1 (SUPPRESSOR-OF-WHITE-APRICOT/SURP RNA-BINDING DOMAIN-CONTAINING PROTEIN1). Loss-of-function swap1-1 mutant is hyposensitive to red light and exhibits a day length-independent early flowering phenotype. SWAP1 physically interacts with two other splicing factors, (SFPS) SPLICING FACTOR FOR PHYTOCHROME SIGNALING and (RRC1) REDUCED RED LIGHT RESPONSES IN CRY1CRY2 BACKGROUND 1 in a light-independent manner and forms a ternary complex. In addition, SWAP1 physically interacts with photoactivated phyB and colocalizes with nuclear phyB photobodies. Phenotypic analyses show that the swap1sfps, swap1rrc1, and sfpsrrc1 double mutants display hypocotyl lengths similar to that of the respective single mutants under red light, suggesting that they function in the same genetic pathway. The swap1sfps double and swap1sfpsrrc1 triple mutants display pleiotropic phenotypes, including sterility at the adult stage. Deep RNA sequencing (RNA-seq) analyses show that SWAP1 regulates the gene expression and pre-messenger RNA (mRNA) alternative splicing of a large number of genes, including those involved in plant responses to light signaling. A comparative analysis of alternative splicing among single, double, and triple mutants showed that all three splicing factors coordinately regulate the alternative splicing of a subset of genes. Our study uncovered the function of a splicing factor that modulates light-regulated alternative splicing by interacting with photoactivated phyB and other splicing factors.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Fitocromo B/genética , Fitocromo B/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Fitocromo/genética , Fitocromo/metabolismo , Luz , RNA Mensageiro/metabolismo , Regulação da Expressão Gênica de Plantas , Mutação
8.
Plant Physiol ; 190(4): 2706-2721, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36063057

RESUMO

While moderately elevated ambient temperatures do not trigger stress responses in plants, they do substantially stimulate the growth of specific organs through a process known as thermomorphogenesis. The basic helix-loop-helix transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) plays a central role in regulating thermomorphogenetic hypocotyl elongation in various plant species, including Arabidopsis (Arabidopsis thaliana). Although it is well known that PIF4 and its co-activator HEMERA (HMR) promote plant thermosensory growth by activating genes involved in the biosynthesis and signaling of the phytohormone auxin, the detailed molecular mechanism of such transcriptional activation is not clear. In this report, we investigated the role of the Mediator complex in the PIF4/HMR-mediated thermoresponsive gene expression. Through the characterization of various mutants of the Mediator complex, a tail subunit named MED14 was identified as an essential factor for thermomorphogenetic hypocotyl growth. MED14 was required for the thermal induction of PIF4 target genes but had a marginal effect on the levels of PIF4 and HMR. Further transcriptomic analyses confirmed that the expression of numerous PIF4/HMR-dependent, auxin-related genes required MED14 at warm temperatures. Moreover, PIF4 and HMR physically interacted with MED14 and both were indispensable for the association of MED14 with the promoters of these thermoresponsive genes. While PIF4 did not regulate MED14 levels, HMR was required for the transcript abundance of MED14. Taken together, these results unveil an important thermomorphogenetic mechanism, in which PIF4 and HMR recruit the Mediator complex to activate auxin-related growth-promoting genes when plants sense moderate increases in ambient temperature.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Fitocromo/genética , Fitocromo/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Arabidopsis/metabolismo , Hipocótilo , Ácidos Indolacéticos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Complexo Mediador/metabolismo , Fatores de Transcrição/metabolismo
9.
EMBO Rep ; 23(10): e54371, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36062942

RESUMO

Light and ambient high temperature (HT) have opposite effects on seed germination. Light induces seed germination through activating the photoreceptor phytochrome B (phyB), resulting in the stabilization of the transcription factor HFR1, which in turn sequesters the suppressor PIF1. HT suppresses seed germination and triggers protein S-nitrosylation. Here, we find that HT suppresses seed germination by inducing the S-nitrosylation of HFR1 at C164, resulting in its degradation, the release of PIF1, and the activation of PIF1-targeted SOMNUS (SOM) expression to alter gibberellin (GA) and abscisic acid (ABA) metabolism. Active phyB (phyBY276H ) antagonizes HFR1 S-nitrosylation and degradation by increasing S-nitrosoglutathione reductase (GSNOR) activity. In line with this, substituting cysteine-164 of HFR1 with serine (HFR1C164S ) abolishes the S-nitrosylation of HFR1 and decreases the HT-induced degradation of HFR1. Taken together, our study suggests that HT and phyB antagonistically modulate the S-nitrosylation level of HFR1 to coordinate seed germination, and provides the possibility to enhance seed thermotolerance through gene-editing of HFR1.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cisteína/metabolismo , Proteínas de Ligação a DNA , Regulação da Expressão Gênica de Plantas , Germinação/genética , Giberelinas/metabolismo , Giberelinas/farmacologia , Luz , Fitocromo/metabolismo , Fitocromo B/genética , Fitocromo B/metabolismo , Proteína S/metabolismo , Proteína S/farmacologia , Sementes/genética , Serina/metabolismo , Temperatura , Fatores de Transcrição/metabolismo
10.
New Phytol ; 236(5): 1809-1823, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36178253

RESUMO

Phytochromes play vital roles in the regulation of flowering time, but little is known in Panicoideae species, especially the C4 model Setaria. Here, genomic variations of PHYTOCHROME C (PHYC) between wild and cultivated Setaria gene pools were analysed and three SiphyC mutants were identified. The function of SiPHYC was verified by CRISPR-Cas9 approach and transcriptome sequencing. Furthermore, efficiency of indoor cultivation of SiphyC mutants were systematically evaluated. An extreme purified selection of PHYC was detected in wild to cultivated domestication process of Setaria. SiphyC mutants and knockout transgenic plants showed an early heading date and a loss of response to short-day photoperiod. Furthermore, variable expression of SiFTa, SiMADS14 and SiMADS15 might be responsible for promoting flowering of SiphyC mutants. Moreover, SiphyC mutant was four times that of the indoor plot ratio of wild-type and produced over 200 seeds within 45 d per individual. Our results suggest that domestication-associated SiPHYC repressed flowering and determined Setaria as a short-day plant, and SiphyC mutants possess the potential for creating efficient indoor cultivation system suitable for research on Setaria as a model, and either for maize or sorghum as well.


Assuntos
Fitocromo , Setaria (Planta) , Fitocromo/metabolismo , Domesticação , Setaria (Planta)/genética , Fotoperíodo , Plantas Geneticamente Modificadas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
11.
Int J Mol Sci ; 23(15)2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35955826

RESUMO

Photosensory proteins known as photoreceptors (PHRs) are crucial for delineating light environments in synchronization with other environmental cues and regulating their physiological variables in plants. However, this has not been well studied in the Brassica genus, which includes several important agricultural and horticultural crops. Herein, we identified five major PHR gene families-phytochrome (PHY), cryptochrome (CRY), phototropin (PHOT), F-box containing flavin binding proteins (ZTL/FKF1/LKP2), and UV RESISTANCE LOCUS 8 (UVR8)-genomic scales and classified them into subfamilies based on their phylogenetic clustering with Arabidopsis homologues. The molecular evolution characteristics of Brassica PHR members indicated indirect expansion and lost one to six gene copies at subfamily levels. The segmental duplication was possibly the driving force of the evolution and amplification of Brassica PHRs. Gene replication retention and gene loss events of CRY, PHY, and PHOT members found in diploid progenitors were highly conserved in their tetraploid hybrids. However, hybridization events were attributed to quantitative changes in UVR8 and ZTL/FKF1/LKP2 members. All PHR members underwent purifying selection. In addition, the transcript expression profiles of PHR genes in different tissue and in response to exogenous ABA, and abiotic stress conditions suggested their multiple biological significance. This study is helpful in understanding the molecular evolution characteristics of Brassica PHRs and lays the foundation for their functional characterization.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Brassica , Proteínas F-Box , Fitocromo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Brassica/genética , Brassica/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Criptocromos/genética , Evolução Molecular , Proteínas F-Box/genética , Regulação da Expressão Gênica de Plantas , Fototropinas/genética , Filogenia , Fitocromo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
12.
Nat Plants ; 8(9): 1082-1093, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35970973

RESUMO

How specificity is conferred within gene regulatory networks is an important problem in biology. The basic helix-loop-helix PHYTOCHROME-INTERACTING FACTORs (PIFs) and single zinc-finger CYCLING DOF FACTORs (CDFs) mediate growth responses of Arabidopsis to light and temperature. We show that these two classes of transcription factor (TF) act cooperatively. CDF2 and PIF4 are temporally and spatially co-expressed, they interact to form a protein complex and act in the same genetic pathway to promote hypocotyl cell elongation. Furthermore, PIF4 substantially strengthens genome-wide occupancy of CDF2 at a subset of its target genes. One of these, YUCCA8, encodes an auxin biosynthesis enzyme whose transcription is increased by PIF4 and CDF2 to contribute to hypocotyl elongation. The binding sites of PIF4 and CDF2 in YUCCA8 are closely spaced, and in vitro PIF4 enhances binding of CDF2. We propose that this occurs by direct protein interaction and because PIF4 binding alters DNA conformation. Thus, we define mechanisms by which PIF and CDF TFs cooperate to achieve regulatory specificity and promote cell elongation in response to light.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , DNA/metabolismo , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hipocótilo , Ácidos Indolacéticos/metabolismo , Luz , Fitocromo/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Zinco/metabolismo
13.
J Exp Bot ; 73(19): 6646-6662, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-35946571

RESUMO

Plant height and flowering time are important agronomic traits that directly affect soybean [Glycine max (L.) Merr.] adaptability and yield. Here, the Glycine max long internode 1 (Gmlin1) mutant was selected from an ethyl methyl sulfonate (EMS)-mutated Williams 82 population due to its long internodes and early flowering. Using bulked segregant analysis (BSA), the Gmlin1 locus was mapped to Glyma.02G304700, a homologue of the Arabidopsis HY2 gene, which encodes a phytochromobilin (PΦB) synthase involved in phytochrome chromophore synthesis. Mutation of GmHY2a results in failure of the de-etiolation response under both red and far-red light. The Gmlin1 mutant exhibits a constitutive shade avoidance response under normal light, and the mutations influence the auxin and gibberellin pathways to promote internode elongation. The Gmlin1 mutant also exhibits decreased photoperiod sensitivity. In addition, the soybean photoperiod repressor gene E1 is down-regulated in the Gmlin1 mutant, resulting in accelerated flowering. The nuclear import of phytochrome A (GmphyA) and GmphyB following light treatment is decreased in Gmlin1 protoplasts, indicating that the weak light response of the Gmlin1 mutant is caused by a decrease in functional phytochrome. Together, these results indicate that GmHY2a plays an important role in soybean phytochrome biosynthesis and provide insights into the adaptability of the soybean plant.


Assuntos
Arabidopsis , Fitocromo , Soja/genética , Soja/metabolismo , Fitocromo/metabolismo , Oxirredutases/metabolismo , Arabidopsis/metabolismo , Fotoperíodo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas
14.
J Integr Plant Biol ; 64(10): 1901-1915, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35924740

RESUMO

Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1's role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with and phosphorylate FERONIA (FER), a known cell growth regulator, and trigger downstream phototropic bending growth in Arabidopsis hypocotyls. fer mutants showed defects in phototropic growth, similar to phot1/2 mutant. FER also interacts with and phosphorylates phytochrome kinase substrates, the phot1 downstream substrates. The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light, both of which are critical for phototropic bending growth in hypocotyls. Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Fototropinas/genética , Fototropinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Hipocótilo/metabolismo , Fitocromo/metabolismo , Ácidos Indolacéticos/metabolismo , Luz
15.
Nat Commun ; 13(1): 4942, 2022 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-36038577

RESUMO

The size of plant organs is highly responsive to environmental conditions. The plant's embryonic stem, or hypocotyl, displays phenotypic plasticity, in response to light and temperature. The hypocotyl of shade avoiding species elongates to outcompete neighboring plants and secure access to sunlight. Similar elongation occurs in high temperature. However, it is poorly understood how environmental light and temperature cues interact to effect plant growth. We found that shade combined with warm temperature produces a synergistic hypocotyl growth response that dependent on PHYTOCHROME-INTERACTING FACTOR 7 (PIF7) and auxin. This unique but agriculturally relevant scenario was almost totally independent on PIF4 activity. We show that warm temperature is sufficient to promote PIF7 DNA binding but not transcriptional activation and we demonstrate that additional, unknown factor/s must be working downstream of the phyB-PIF-auxin module. Our findings will improve the predictions of how plants will respond to increased ambient temperatures when grown at high density.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fator VII/genética , Fator VII/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/metabolismo , Ácidos Indolacéticos/metabolismo , Luz , Fitocromo/metabolismo
16.
ACS Synth Biol ; 11(10): 3354-3367, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-35998606

RESUMO

In optogenetics, as in nature, sensory photoreceptors serve to control cellular processes by light. Bacteriophytochrome (BphP) photoreceptors sense red and far-red light via a biliverdin chromophore and, in response, cycle between the spectroscopically, structurally, and functionally distinct Pr and Pfr states. BphPs commonly belong to two-component systems that control the phosphorylation of cognate response regulators and downstream gene expression through histidine kinase modules. We recently demonstrated that the paradigm BphP from Deinococcus radiodurans exclusively acts as a phosphatase but that its photosensory module can control the histidine kinase activity of homologous receptors. Here, we apply this insight to reprogram two widely used setups for bacterial gene expression from blue-light to red-light control. The resultant pREDusk and pREDawn systems allow gene expression to be regulated down and up, respectively, uniformly under red light by 100-fold or more. Both setups are realized as portable, single plasmids that encode all necessary components including the biliverdin-producing machinery. The triggering by red light affords high spatial resolution down to the single-cell level. As pREDusk and pREDawn respond sensitively to red light, they support multiplexing with optogenetic systems sensitive to other light colors. Owing to the superior tissue penetration of red light, the pREDawn system can be triggered at therapeutically safe light intensities through material layers, replicating the optical properties of the skin and skull. Given these advantages, pREDusk and pREDawn enable red-light-regulated expression for diverse use cases in bacteria.


Assuntos
Fitocromo , Histidina Quinase/metabolismo , Fitocromo/genética , Fitocromo/metabolismo , Biliverdina , Optogenética , Luz , Bactérias/genética , Monoéster Fosfórico Hidrolases
17.
Plant Cell ; 34(11): 4293-4312, 2022 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-35929789

RESUMO

Stomata are crucial valves coordinating the fixation of carbon dioxide by photosynthesis and water loss through leaf transpiration. Phytochrome interacting factors (PIFs) are negative regulators of red light responses that belong to the basic helix-loop-helix family of transcription factors. Here, we show that the rice (Oryza sativa) PIF family gene OsPIL15 acts as a negative regulator of stomatal aperture to control transpiration in rice. OsPIL15 reduces stomatal aperture by activating rice ABSCISIC ACID INSENSITIVE 5 (OsABI5), which encodes a critical positive regulator of ABSCISIC ACID (ABA) signaling in rice. Moreover, OsPIL15 interacts with the NIGT1/HRS1/HHO family transcription factor rice HRS1 HOMOLOG 3 (OsHHO3) to possibly enhance the regulation of stomatal aperture. Notably, we discovered that the maize (Zea mays) PIF family genes ZmPIF1 and ZmPIF3, which are homologous to OsPIL15, are also involved in the regulation of stomatal aperture in maize, indicating that PIF-mediated regulation of stomatal aperture may be conserved in the plant lineage. Our findings explain the molecular mechanism by which PIFs play a role in red-light-mediated stomatal opening, and demonstrate that PIFs regulate stomatal aperture by coordinating the red light and ABA signaling pathways.


Assuntos
Oryza , Fitocromo , Ácido Abscísico/metabolismo , Fitocromo/genética , Fitocromo/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/metabolismo , Luz , Zea mays/genética , Estômatos de Plantas/metabolismo
18.
Plant Cell ; 34(11): 4213-4231, 2022 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-35929801

RESUMO

TANDEM ZINC-FINGER/PLUS3 (TZP) is a transcriptional regulator that acts at the crossroads of light and photoperiodic signaling. Here, we unveil a role for TZP in fine-tuning hypocotyl elongation under red light and long-day conditions. We provide genetic evidence for a synergistic action between TZP and PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) in regulating the protein abundance of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and downstream gene expression in response to red light and long days (LDs). Furthermore, we show that TZP is a positive regulator of the red/far-red light receptor and thermosensor phytochrome B (phyB) by promoting phyB protein abundance, nuclear body formation, and signaling. Our data therefore assign a function to TZP in regulating two key red light signaling components, phyB and PIF4, but also uncover a new role for PCH1 in regulating hypocotyl elongation in LDs. Our findings provide a framework for the understanding of the mechanisms associated with the TZP signal integration network and their importance for optimizing plant growth and adaptation to a changing environment.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Fitocromo B/genética , Fitocromo B/metabolismo , Hipocótilo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Fitocromo/metabolismo , Zinco/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
19.
Int J Mol Sci ; 23(15)2022 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-35897731

RESUMO

Myrothamnus flabellifolia is the only woody resurrection plant found in the world and can survive from long-term desiccation. Therefore, M. flabellifolia could be considered as a valuable resource for study of plant adaptation to abiotic stress. However, few genes related to its drought tolerance have been functionally characterized and the molecular mechanisms underlying the stress tolerance of M. flabellifolia are largely unknown. The phytochrome interacting factor (PIF) family is a group of basic helix-loop-helix (bHLH) transcription factors and functions as the core regulator in plant growth and development. However, less is known of its participation in abiotic stress response. In this study, we isolated and characterized a dehydration-inducible PIF gene MfPIF8 from M. flabellifolia. Heterologous expression of MfPIF8 in Arabidopsis enhanced tolerance to drought and salinity stresses at seedling and adult stages. It significantly increased primary root length and stomatal aperture (ration of length/width) under stress treatments and decreased water loss rate. Compared with WT, the transgenic lines overexpressing MfPIF8 exhibited higher chlorophyll content and lower malondialdehyde accumulation. The abilities of osmotic adjustment and reactive oxygen species scavenging were also enhanced in MfPIF8 transgenic lines. These results suggest that MfPIF8 may participate in the positive regulation of abiotic stress responses. Additional investigation of its mechanism is needed in the future.


Assuntos
Arabidopsis , Fitocromo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Fitocromo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Tolerância ao Sal/genética , Estresse Fisiológico/genética
20.
ACS Sens ; 7(7): 1855-1866, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35775925

RESUMO

Bright monomeric near-infrared fluorescent proteins (NIR-FPs) are useful as markers for labeling proteins and cells and as sensors for reporting molecular activities in living cells and organisms. However, current monomeric NIR-FPs are dim under excitation with common 633/635/640 nm lasers, limiting their broad use in cellular/subcellular level imaging. Here, we report a bright monomeric NIR-FP with maximum excitation at 633 nm, named mIFP663, engineered from Xanthomonas campestris pv Campestris phytochrome (XccBphP). mIFP663 has high molecular brightness with a large extinction coefficient (86,600 M-1 cm-1) and a decent quantum yield (19.4%), and high cellular brightness that is 3-6 times greater than those of spectrally similar NIR-FPs in HEK293T cells in the presence of exogenous BV. Moreover, we demonstrate that mIFP663 is able to label critical cellular and viral proteins without perturbing subcellular localization and virus replication, respectively. Finally, with mIFP663, we engineer improved bimolecular fluorescence complementation (BiFC) and new bioluminescent resonance energy transfer (BRET) systems to detect protein-protein interactions in living cells.


Assuntos
Fitocromo , Células HEK293 , Células HeLa , Humanos , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência/métodos , Fitocromo/metabolismo
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