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1.
Int J Mol Sci ; 22(16)2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34445457

RESUMO

Strigolactones (SLs) regulate plant shoot development by inhibiting axillary bud growth and branching. However, the role of SLs in wintersweet (Chimonanthus praecox) shoot branching remains unknown. Here, we identified and isolated two wintersweet genes, CCD7 and CCD8, involved in the SL biosynthetic pathway. Quantitative real-time PCR revealed that CpCCD7 and CpCCD8 were down-regulated in wintersweet during branching. When new shoots were formed, expression levels of CpCCD7 and CpCCD8 were almost the same as the control (un-decapitation). CpCCD7 was expressed in all tissues, with the highest expression in shoot tips and roots, while CpCCD8 showed the highest expression in roots. Both CpCCD7 and CpCCD8 localized to chloroplasts in Arabidopsis. CpCCD7 and CpCCD8 overexpression restored the phenotypes of branching mutant max3-9 and max4-1, respectively. CpCCD7 overexpression reduced the rosette branch number, whereas CpCCD8 overexpression lines showed no phenotypic differences compared with wild-type plants. Additionally, the expression of AtBRC1 was significantly up-regulated in transgenic lines, indicating that two CpCCD genes functioned similarly to the homologous genes of the Arabidopsis. Overall, our study demonstrates that CpCCD7 and CpCCD8 exhibit conserved functions in the CCD pathway, which controls shoot development in wintersweet. This research provides a molecular and theoretical basis for further understanding branch development in wintersweet.


Assuntos
Arabidopsis , Calycanthaceae/genética , Dioxigenases , Genes de Plantas , Proteínas de Plantas , Raízes de Plantas , Plantas Geneticamente Modificadas , Arabidopsis/enzimologia , Arabidopsis/genética , Calycanthaceae/enzimologia , Dioxigenases/biossíntese , Dioxigenases/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética
2.
Toxins (Basel) ; 13(5)2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946742

RESUMO

Fusarium graminearum, the causal agent of Fusarium head blight (FHB), produces trichothecenes including deoxynivalenol (DON), nivalenol (NIV), and 3,7,15-trihydroxy-12,13-epoxytrichothec-9-ene (NX-3). These toxins contaminate grains and cause profound health problems in humans and animals. To explore exploiting a fungal self-protection mechanism in plants, we examined the ability of F. graminearum trichothecene 3-O-acetyltransferase (FgTri101) to detoxify several key trichothecenes produced by F. graminearum: DON, 15-ADON, NX-3, and NIV. FgTri101 was cloned from F. graminearum and expressed in Arabidopsis plants. We compared the phytotoxic effects of purified DON, NIV, and NX-3 on the root growth of transgenic Arabidopsis expressing FgTri101. Compared to wild type and GUS controls, FgTri101 transgenic Arabidopsis plants displayed significantly longer root length on media containing DON and NX-3. Furthermore, we confirmed that the FgTri101 transgenic plants acetylated DON to 3-ADON, 15-ADON to 3,15-diADON, and NX-3 to NX-2, but did not acetylate NIV. Approximately 90% of the converted toxins were excreted into the media. Our study indicates that transgenic Arabidopsis expressing FgTri101 can provide plant protection by detoxifying trichothecenes and excreting the acetylated toxins out of plant cells. Characterization of plant transporters involved in trichothecene efflux will provide novel targets to reduce FHB and mycotoxin contamination in economically important plant crops.


Assuntos
Acetiltransferases/metabolismo , Fusarium/genética , Tricotecenos/metabolismo , Acetilação , Acetiltransferases/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/metabolismo , Clonagem Molecular , Fusarium/enzimologia , Fusarium/metabolismo , Inativação Metabólica/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plântula/metabolismo
3.
Food Chem ; 356: 129684, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33812194

RESUMO

In this study, we aim to develop a novel loop mediated isothermal amplification (LAMP) coupled with TaqMan (LAMP-TaqMan) method for quick qualitative detection of genetically modified organism (GMOs). We designed four LAMP primers and one TaqMan probe for the LAMP-TaqMan detection method to detect the nopaline synthase gene (NOS) terminator in GMOs. This assay enabled the amplification of DNA within ~20 min at a constant temperature of 65 °C. This assay detected as few as five copies of target sequences, which had a high specificity similar to the TaqMan qPCR method. Furthermore, the LAMP-TaqMan detection method was successfully used to amplify and detect DNA from food samples of the major crops (soybean, maize, rice, etc.). In summary, a novel LAMP-TaqMan assay has been developed, which has the similar sensitivity but takes less time than the TaqMan qPCR method. This method offers a novel approach for rapid detection of GMOs in foods.


Assuntos
Aminoácido Oxirredutases/genética , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Plantas Geneticamente Modificadas/enzimologia , Produtos Agrícolas/enzimologia , Produtos Agrícolas/genética , Primers do DNA/química , Primers do DNA/metabolismo , DNA de Plantas/análise , DNA de Plantas/metabolismo , Limite de Detecção , Plantas Geneticamente Modificadas/genética , Soja/enzimologia , Soja/genética , Zea mays/enzimologia , Zea mays/genética
4.
J Plant Physiol ; 260: 153404, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33744782

RESUMO

Isochorismate synthase (ICS) is a key enzyme for the synthesis of salicylic acid (SA) in plants. SA mediates plant responses to both biotic and abiotic stresses. In previous studies, we found that overexpression of ICS (ICSOE) or suppression of ICS (ICSRNAi) affected the host response to Fusarium graminearum in barley. However, whether the barley ICS gene plays a role in adapting to abiotic stresses remains to be determined. In the present study, expression of the ICS gene was upregulated when treated with 20 % PEG6000, and ICSOE lines were more drought tolerant than wild type (WT) and ICSRNAi. In addition, the abscisic acid (ABA) levels in the ICSOE lines were higher than those in the WT and ICSRNAi lines under drought stress. High ABA levels significantly reduced Gs and E, which may impact water retention under drought stress. Under drought conditions, the activity of antioxidant enzymes was significantly higher in the ICSOE lines, correlating with a lower levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Enhanced antioxidant competence also contributed to drought tolerance in ICSOE lines. These findings help elucidate the abiotic stress resistance of the ICS pathway in barley.


Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Hordeum/fisiologia , Transferases Intramoleculares/genética , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Hordeum/enzimologia , Hordeum/genética , Transferases Intramoleculares/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia
5.
Commun Biol ; 4(1): 215, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33594248

RESUMO

Some plant trans-1,4-prenyltransferases (TPTs) produce ultrahigh molecular weight trans-1,4-polyisoprene (TPI) with a molecular weight of over 1.0 million. Although plant-derived TPI has been utilized in various industries, its biosynthesis and physiological function(s) are unclear. Here, we identified three novel Eucommia ulmoides TPT isoforms-EuTPT1, 3, and 5, which synthesized TPI in vitro without other components. Crystal structure analysis of EuTPT3 revealed a dimeric architecture with a central hydrophobic tunnel. Mutation of Cys94 and Ala95 on the central hydrophobic tunnel no longer synthesizd TPI, indicating that Cys94 and Ala95 were essential for forming the dimeric architecture of ultralong-chain TPTs and TPI biosynthesis. A spatiotemporal analysis of the physiological function of TPI in E. ulmoides suggested that it is involved in seed development and maturation. Thus, our analysis provides functional and mechanistic insights into TPI biosynthesis and uncovers biological roles of TPI in plants.


Assuntos
Dimetilaliltranstransferase/metabolismo , Eucommiaceae/enzimologia , Hemiterpenos/biossíntese , Látex/biossíntese , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Dimetilaliltranstransferase/química , Dimetilaliltranstransferase/genética , Eucommiaceae/genética , Hemiterpenos/química , Látex/química , Modelos Moleculares , Peso Molecular , Mutação , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Conformação Proteica , Relação Estrutura-Atividade
6.
PLoS One ; 16(1): e0244305, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33444331

RESUMO

The Glycine max xyloglucan endotransglycosylase/hydrolase (EC 2.4.1.207), GmXTH43, has been identified through RNA sequencing of RNA isolated through laser microdissection of Heterodera glycines-parasitized root cells (syncytia) undergoing the process of defense. Experiments reveal that genetically increasing XTH43 transcript abundance in the H. glycines-susceptible genotype G. max[Williams 82/PI 518671] decreases parasitism. Experiments presented here show decreasing XTH43 transcript abundance through RNA interference (RNAi) in the H. glycines-resistant G. max[Peking/PI 548402] increases susceptibility, but it is unclear what role XTH43 performs. The experiments presented here show XTH43 overexpression decreases the relative length of xyloglucan (XyG) chains, however, there is an increase in the amount of those shorter chains. In contrast, XTH43 RNAi increases XyG chain length. The experiments show that XTH43 has the capability to function, when increased in its expression, to limit XyG chain extension. This outcome would likely impair the ability of the cell wall to expand. Consequently, XTH43 could provide an enzymatically-driven capability to the cell that would allow it to limit the ability of parasitic nematodes like H. glycines to develop a feeding structure that, otherwise, would facilitate parasitism. The experiments presented here provide experimentally-based proof that XTHs can function in ways that could be viewed as being able to limit the expansion of the cell wall.


Assuntos
Glucanos/metabolismo , Glicosiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Soja/parasitologia , Tylenchida/fisiologia , Xilanos/metabolismo , Animais , Cromatografia em Gel , Feminino , Genótipo , Glucanos/química , Glicosiltransferases/antagonistas & inibidores , Glicosiltransferases/genética , Interações Hospedeiro-Parasita , Peso Molecular , Raízes de Plantas/parasitologia , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Análise de Componente Principal , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Soja/enzimologia , Soja/genética , Xilanos/química
7.
Toxins (Basel) ; 13(2)2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499086

RESUMO

Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.


Assuntos
Antivirais/farmacologia , Controle Biológico de Vetores , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas/enzimologia , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Inativadoras de Ribossomos/farmacologia , Toxinas Biológicas/farmacologia , Viroses/tratamento farmacológico , Vírus/efeitos dos fármacos , Animais , Antivirais/isolamento & purificação , Humanos , Doenças das Plantas/genética , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/virologia , Inibidores da Síntese de Proteínas/isolamento & purificação , Proteínas Inativadoras de Ribossomos/isolamento & purificação , Toxinas Biológicas/isolamento & purificação , Viroses/metabolismo , Viroses/virologia , Vírus/metabolismo , Vírus/patogenicidade
8.
Plant Biol (Stuttg) ; 23(2): 341-350, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32808478

RESUMO

Polyamines play an important role in stress response. In the pathway of polyamines synthesis, S-adenosylmethionine decarboxylase (SAMDC) is one of the key enzymes. In this study, a full length cDNA of SAMDC (AhSAMDC) was isolated from peanut (Arachis hypogaea L.). Phylogenetic analysis revealed high sequence similarity between AhSAMDC and SAMDC from other plants. In peanut seedlings exposed to sodium chloride (NaCl), the transcript level of AhSAMDC in roots was the highest at 24 h that decreased sharply at 72 and 96 h after 150 mM NaCl treatment. However, the expression of AhSAMDC in peanut leaves was significantly inhibited, and the transcript levels in leaves were not different compared with control These results implied the tissue-specific and time-specific expression of AhSAMDC. The physiological effects and functional mechanism of AhSAMDC were further evaluated by overexpressing AhSAMDC in tobaccos. The transgenic tobacco lines exhibited higher germination rate and longer root length under salt stress. Reduced membrane damage, higher antioxidant enzyme activity, and higher proline content were also observed in the transgenic tobacco seedlings. What's more, AhSAMDC also led to higher contents of spermidine and spermine, which can help to scavenge reactive oxygen species. Together, this study suggests that AhSAMDC enhances plant resistance to salt stress by improving polyamine content and alleviating membrane damage.


Assuntos
Adenosilmetionina Descarboxilase , Arachis , Plantas Geneticamente Modificadas , Estresse Salino , Tabaco , Adenosilmetionina Descarboxilase/genética , Adenosilmetionina Descarboxilase/metabolismo , Arachis/enzimologia , Arachis/genética , Regulação da Expressão Gênica de Plantas , Filogenia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Estresse Salino/genética , Cloreto de Sódio/toxicidade , Tabaco/efeitos dos fármacos , Tabaco/enzimologia , Tabaco/genética
9.
J Exp Bot ; 72(5): 1634-1648, 2021 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-33249501

RESUMO

The salicinoids are phenolic glycosides that are characteristic secondary metabolites of the Salicaceae, particularly willows and poplars. Despite the well-known pharmacology of salicin, that led to the development of aspirin >100 years ago, the biosynthetic pathways leading to salicinoids have yet to be defined. Here, we describe the identification, cloning, and biochemical characterization of SpUGT71L2 and SpUGT71L3-isozymic glycosyltransferases from Salix purpurea-that function in the glucosylation of ortho-substituted phenols. The best substrate in vitro was salicyl-7-benzoate. Its product, salicyl-7-benzoate glucoside, was shown to be endogenous in poplar and willow. Together they are inferred to be early intermediates in the biosynthesis of salicortin and related metabolites in planta. The role of this UDP-glycosyltransferase was confirmed via the metabolomic analysis of transgenic plants produced by RNAi knockdown of the poplar orthologue (UGT71L1) in the hybrid clone Populus tremula×P. alba, INRA 717-1B4.


Assuntos
Glicosídeos/biossíntese , Glicosiltransferases , Salix , Glicosiltransferases/genética , Plantas Geneticamente Modificadas/enzimologia , Populus/genética , Salix/enzimologia , Salix/genética , Difosfato de Uridina
10.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322321

RESUMO

The present study was designed to serve as a comprehensive analysis of Citrus sinensis (C. sinensis) pectin acetylesterases (CsPAEs), and to assess the roles of these PAEs involved in the development of citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri (Xcc) infection. A total of six CsPAEs were identified in the genome of C. sinensis, with these genes being unevenly distributed across chromosomes 3, 6, and 9, and the unassembled scaffolds. A subset of CsPAEs were found to be involved in responses to Xcc infection. In particular, CsPAE2 was identified to be associated with such infections, as it was upregulated in CBC-susceptible variety Wanjincheng and inversely in CBC-resistant variety Calamondin. Transgenic citrus plants overexpressing CsPAE2 were found to be more susceptible to CBC, whereas the silencing of this gene was sufficient to confer CBC resistance. Together, these findings provide evolutionary insights into and functional information about the CsPAE family. This study also suggests that CsPAE2 is a potential candidate gene that negatively contributes to bacterial canker disease and can be used to breed CBC-resistant citrus plants.


Assuntos
Esterases/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Xanthomonas/patogenicidade , Esterases/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/enzimologia
11.
Planta ; 252(5): 89, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33064214

RESUMO

MAIN CONCLUSION: Molecular function ofRING E3 ligase SbHCI1is involved in ABA-mediated basal heat stress tolerancein sorghum. Global warming generally reduces plant survival, owing to the negative effects of high temperatures on plant development. However, little is known about the role of Really Interesting New Gene (RING) E3 ligase in the heat stress responses of plants. As such, the aim of the present study was to characterize the molecular functions of the Sorghum bicolor ortholog of the Oryza sativa gene for Heat- and Cold-Induced RING finger protein 1 (SbHCI1). Subcellular localization revealed that SbHCI1 was mainly associated with the cytosol and that it moved to the Golgi apparatus under heat stress conditions. The fluorescent signals of SbHCI1 substrate proteins were observed to migrate to the cytoplasm under heat stress conditions. Bimolecular fluorescence complementation (BiFC) and yeast two-hybrid (Y2H) assays revealed that SbHCI1 physically interacted with OsHCI1 ortholog partner proteins in the cytoplasm. Moreover, an in vitro ubiquitination assay revealed that SbHCI1 polyubiquitinated each of the three interacting proteins. The ectopic overexpression of SbHCI1 in Arabidopsis revealed that the protein was capable of inducing abscisic acid (ABA)-hypersensitivity and basal heat stress tolerance. Therefore, SbHCI1 possesses E3 ligase activity and may function as a positive regulator of heat stress responses through the modulation of interacting proteins.


Assuntos
Ácido Abscísico , Temperatura Alta , Proteínas de Plantas , Sorghum , Estresse Fisiológico , Ubiquitina-Proteína Ligases , Ácido Abscísico/farmacologia , Arabidopsis/genética , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Sorghum/efeitos dos fármacos , Sorghum/enzimologia , Sorghum/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
12.
Plant Physiol Biochem ; 154: 538-546, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32912487

RESUMO

The sulfite reductase gene in Medicago sativa L. (MsSiR) encodes sulfite reductase (SiR) and catalyses the conversion of sulfite to sulfate in the sulfite assimilation pathway. In this study, we investigated the role of MsSiR in alfalfa by generating transgenic alfalfa that ectopically expressed MsSiR under the control of the CaMV35S promoter. The differences in alkali tolerance between the MsSiR-overexpressing and wild-type (WT) plants were analyzed, and the MsSiR-overexpressing plants exhibited an improved phenotype under alkali stress. Compared to WT plants, these plants demonstrated improved antioxidant activity as well as decreased H2O2 and O2- contents and increased glutathione reduced (GSH), Cysteine (Cys) and glutathione oxidized (GSSG) contents. MsSiR-overexpressing plants also exhibited high levels of adenosyl phosphosulfate reductases (APR), sulfite oxidase (SO) and MsSiR expression under alkali stress. It was speculated that MsSiR is involved in sulfur metabolism pathways, including the stabilization of sulfate and sulfite levels and the synthesis of GSH. These two processes achieve alkali tolerance by positively regulating the detoxification and antioxidant activities of alfalfa.


Assuntos
Álcalis/efeitos adversos , Glutationa/análise , Medicago sativa , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/genética , Proteínas de Plantas/genética , Antioxidantes/análise , Peróxido de Hidrogênio , Medicago sativa/enzimologia , Medicago sativa/genética , Plantas Geneticamente Modificadas/enzimologia , Estresse Fisiológico
13.
Plant Physiol Biochem ; 154: 557-563, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32912489

RESUMO

The ubiquitin-proteasome system (UPS) is one of the main ways of eukaryotic protein degradation and post-translational modification. It has proven as an essential process for plants to respond to abiotic stresses. Plant U-box (PUB) protein acts as a ubiquitin ligase, which recognizes and ubiquitinates the target proteins. Many PUBs have been involved in water stress in Arabidopsis and rice, but similar comprehensive studies in potato remained limited. In this study, the overexpressed and interfered transgenic potato plants of StPUB27 were obtained and their performances were evaluated under osmotic stress. The result showed that overexpression of StPUB27 accelerated the dehydration of detached leaves companied with greater stomatal conductance, while the down-regulated StPUB27 expression by RNA interference (RNAi) showed a smaller stomatal conductance and a lower rate of water loss in detached leaves, thus showing higher tolerance to osmotic stress. In addition, no significant changes in the proline content were observed between StPUB27 overexpressed and RNAi potato plants. The result demonstrated that potato E3 ubiquitin ligase PUB27 may negatively regulate drought tolerance by mediating stomatal conductance.


Assuntos
Secas , Proteínas de Plantas/metabolismo , Estômatos de Plantas/fisiologia , Solanum tuberosum , Ubiquitina-Proteína Ligases/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/enzimologia , Solanum tuberosum/enzimologia , Solanum tuberosum/genética , Estresse Fisiológico , Ubiquitina-Proteína Ligases/genética
14.
Int J Mol Sci ; 21(18)2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32927724

RESUMO

Glycogen synthase kinase 3 (GSK3) is a highly conserved kinase present in all eukaryotes and functions as a key regulator of a wide range of physiological and developmental processes. The kinase, known in land plants as GSK3/SHAGGY-like kinase (GSK), is a key player in the brassinosteroid (BR) signaling pathway. The GSK genes, through the BRs, affect diverse developmental processes and modulate responses to environmental factors. In this work, we describe functional analysis of HvGSK1.1, which is one of the GSK3/SHAGGY-like orthologs in barley. The RNAi-mediated silencing of the target HvGSK1.1 gene was associated with modified expression of its paralogs HvGSK1.2, HvGSK2.1, HvGSK3.1, and HvGSK4.1 in plants grown in normal and in salt stress conditions. Low nucleotide similarity between the silencing fragment and barley GSK genes and the presence of BR-dependent transcription factors' binding sites in promoter regions of barley and rice GSK genes imply an innate mechanism responsible for co-regulation of the genes. The results of the leaf inclination assay indicated that silencing of HvGSK1.1 and the changes of GSK paralogs enhanced the BR-dependent signaling in the plants. The strongest phenotype of transgenic lines with downregulated HvGSK1.1 and GSK paralogs had greater biomass of the seedlings grown in normal conditions and salt stress as well as elevated kernel weight of plants grown in normal conditions. Both traits showed a strong negative correlation with the transcript level of the target gene and the paralogs. The characteristics of barley lines with silenced expression of HvGSK1.1 are compatible with the expected phenotypes of plants with enhanced BR signaling. The results show that manipulation of the GSK-encoding genes provides data to explore their biological functions and confirm it as a feasible strategy to generate plants with improved agricultural traits.


Assuntos
Quinases da Glicogênio Sintase/fisiologia , Hordeum/fisiologia , Tolerância ao Sal/genética , Sementes/crescimento & desenvolvimento , Biomassa , Brassinosteroides/metabolismo , Inativação Gênica , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
15.
Int J Mol Sci ; 21(19)2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32987929

RESUMO

In the present study, we have shown the transcriptional changes in a chlorosis model transgenic tobacco plant, i-amiCHLI, in which an artificial micro RNA is expressed in a chemically inducible manner to silence the expression of CHLI genes encoding a subunit of a chlorophyll biosynthetic enzyme. Comparison to the inducer-treated and untreated control non-transformants and untreated i-amiCHLI revealed that 3568 and 3582 genes were up- and down-regulated, respectively, in the inducer-treated i-amiCHLI plants. Gene Ontology enrichment analysis of these differentially expressed genes indicated the upregulation of the genes related to innate immune responses, and cell death pathways, and the downregulation of genes for photosynthesis, plastid organization, and primary and secondary metabolic pathways in the inducer-treated i-amiCHLI plants. The cell death in the chlorotic tissues with a preceding H2O2 production was observed in the inducer-treated i-amiCHLI plants, confirming the activation of the immune response. The involvement of activated innate immune response in the chlorosis development was supported by the comparative expression analysis between the two transgenic chlorosis model systems, i-amiCHLI and i-hpHSP90C, in which nuclear genes encoding different chloroplast proteins were similarly silenced.


Assuntos
Fotossíntese/genética , Necrose e Clorose das Plantas/genética , Proteínas de Plantas/genética , Tabaco , Transcriptoma , Clorofila/biossíntese , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Plantas Geneticamente Modificadas/enzimologia , Tabaco/enzimologia , Tabaco/genética
16.
Int J Mol Sci ; 21(19)2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32977586

RESUMO

Floral scent is a key ornamental trait that determines the quality and commercial value of orchids. Geraniol, an important volatile monoterpene in orchids that attracts pollinators, is also involved in responses to stresses but the geraniol synthase (GES) responsible for its synthesis in the medicinal orchid Dendrobium officinale has not yet been identified. In this study, three potential geraniol synthases were mined from the D. officinale genome. DoGES1, which was localized in chloroplasts, was characterized as a geraniol synthase. DoGES1 was highly expressed in flowers, especially in petals. DoGES1 transcript levels were high in the budding stage of D. officinale flowers at 11:00 a.m. DoGES1 catalyzed geraniol in vitro, and transient expression of DoGES1 in Nicotiana benthamiana leaves resulted in the accumulation of geraniol in vivo. These findings on DoGES1 advance our understanding of geraniol biosynthesis in orchids, and lay the basis for genetic modification of floral scent in D. officinale or in other ornamental orchids.


Assuntos
Proteínas de Cloroplastos , Cloroplastos , Dendrobium , Flores , Odorantes , Monoéster Fosfórico Hidrolases , Proteínas de Cloroplastos/genética , Proteínas de Cloroplastos/metabolismo , Cloroplastos/enzimologia , Cloroplastos/genética , Dendrobium/enzimologia , Dendrobium/genética , Flores/enzimologia , Flores/genética , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Tabaco/enzimologia , Tabaco/genética
17.
Plant Sci ; 298: 110584, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32771144

RESUMO

As one of the subtropical and tropical fruit trees, Citrus sinensis is sensitive to cold stress. However, most transcription factors (TFs) that regulate cold tolerance in citrus have not yet been reported. A phytochrome-interacting transcription factor (PIF) gene (CsPIF8) in citrus was significantly upregulated under cold stress. Overexpression of CsPIF8 increased cold tolerance in transgenic tomato plants and grapefruit callus, whereas virus-induced gene silencing-mediated suppression of PIF8 increased cold sensitivity in seedlings of Poncirus trifoliata. Superoxide dismutase (SOD) reduces the superoxide anion (O2-) level to enhance cold tolerance in plants. Chromatin immunoprecipitation combined with high-throughput sequencing, yeast one hybrid, electrophoretic mobility shift and dual luciferase assays showed that CsPIF8 directly bound the E-box (CANNTG) of CsSOD promoter and activated the promoter of CsSOD. Furthermore, the expression level of CsSOD and CsSOD activity were significantly increased, whereas the level of O2- was significantly reduced in the transgenic lines. The Poncirus trifoliata seedlings with VIGS-mediated suppression of PIF8 exhibited the opposite effects. These results have shown that CsPIF8 improved cold tolerance in citrus through regulating the expression level of SOD and SOD activity. These findings may provide novel insights into the regulation of PIF8 in the response to cold stress in citrus.


Assuntos
Citrus sinensis/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Poncirus/genética , Fatores de Transcrição/genética , Citrus sinensis/enzimologia , Citrus sinensis/metabolismo , Temperatura Baixa , Inativação Gênica , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/metabolismo , Poncirus/crescimento & desenvolvimento , Poncirus/metabolismo , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Superóxido Dismutase/metabolismo , Termotolerância/genética , Fatores de Transcrição/metabolismo
18.
J Integr Plant Biol ; 62(9): 1399-1417, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32786047

RESUMO

The endosomal sorting complex required for transport (ESCRT) machinery is an ancient, evolutionarily conserved membrane remodeling complex that is essential for multivesicular body (MVB) biogenesis in eukaryotes. FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1 (FREE1), which was previously identified as a plant-specific ESCRT component, modulates MVB-mediated endosomal sorting and autophagic degradation. Although the basic cellular functions of FREE1 as an ESCRT component have been described, the regulators that control FREE1 turnover remain unknown. Here, we analyzed how FREE1 homeostasis is mediated by the RING-finger E3 ubiquitin ligases, SINA of Arabidopsis thaliana (SINATs), in response to iron deficiency. Under iron-deficient growth conditions, SINAT1-4 were induced and ubiquitinated FREE1, thereby promoting its degradation and relieving the repressive effect of FREE1 on iron absorption. By contrast, SINAT5, another SINAT member that lacks ubiquitin ligase activity due to the absence of the RING domain, functions as a protector protein which stabilizes FREE1. Collectively, our findings uncover a hitherto unknown mechanism of homeostatic regulation of FREE1, and demonstrate a unique regulatory SINAT-FREE1 module that subtly regulates plant response to iron deficiency stress.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Plantas Geneticamente Modificadas/genética , Transporte Proteico , Ubiquitina-Proteína Ligases/genética , Proteínas de Transporte Vesicular/genética
19.
Theor Appl Genet ; 133(10): 2961-2974, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32651668

RESUMO

KEY MESSAGE: Catalytically active indica SSIIa allele in high amylose rice with down-regulated japonica SBEIIb can increase starch content and modify the starch structure and properties without changing its amylose content. Rice (Oryza sativa) genotypes with inactive starch synthase IIa (SSIIa) with recessive variants of starch branching enzyme IIb (SBEIIb) exhibit a range of alterations in grain phenotype, starch granule morphology, starch granule bound proteins, starch structure, and functional properties. However, the interactions between the two enzymes have not been thoroughly investigated yet. We analysed recombinant rice lines having down-regulated SBEIIb expression (SBEIIbDR) with either indica or japonica type SSIIa (SSIIaind or SSIIajap). In SBEIIbDR rice starch granules, the increased abundance of two protein bands (SSI and SSIIa) was found with eight additional protein bands not generally associated with starch granules. The amount of SSIIa was higher in SSIIaindSBEIIbDR than SSIIajapSBEIIbDR, which indicated that indica type SSIIa, possibly in the monomer form, was extensively involved in starch biosynthesis in the SBEIIbDR endosperm. Furthermore, SSIIaindSBEIIbDR grains had higher total starch content and higher starch swelling power than SSIIajapSBEIIbDR lines, but the amylopectin gelatinization temperatures and enthalpy and the apparent amylose content remained similar. In summary, this work suggests that SSIIaind can partly compensate for the alteration of starch synthesis resulting from the SBEIIb down-regulation in japonica background without reducing its amylose content. The study provides insight into the starch structural and textural improvements of high amylose starch.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/genética , Amilose/química , Oryza/genética , Proteínas de Plantas/genética , Sintase do Amido/genética , Amido/química , Alelos , Cruzamentos Genéticos , Regulação para Baixo , Grão Comestível/genética , Endosperma/química , Regulação da Expressão Gênica de Plantas , Genótipo , Oryza/enzimologia , Plantas Geneticamente Modificadas/enzimologia
20.
Transgenic Res ; 29(4): 429-442, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32691287

RESUMO

Four Dendrobium Sonia 'Earsakul' lines were generated by insertion of one, two or three antisense copies of a Carica papaya gene encoding 1-aminocyclopropane-1-carboxylic acid oxidase (CpACO). Whole vegetative plants of the transgenic lines showed about 50% of the basal ethylene production rate, while the increase in ethylene production in floral buds during opening and open flowers prior to visible senescence was delayed. Detailed analysis of more than 100 parameters in flowering plants showed no effect of antisense ACO on plant morphology and coloration, except for shorter length and width of some of the sepals and petals. In intact plants the water-soaking of floral buds as well as bud abscission were delayed by ACO antisense, as was the time to senescence of open flowers. Pollen viability and pollen tube growth were not affected in the transgenic lines. In cut inflorescences placed in water, bud yellowing, bud water soaking, and bud abscission were considerably delayed by the antisense construct, while the life span of open flowers were increased and abscission of open flowers were delayed. It is concluded that the reduction of ACO activity affected the shape of some petals/sepals and delayed the abortion in floral buds, and the senescence and abscission of open flowers.


Assuntos
Aminoácido Oxirredutases/antagonistas & inibidores , Elementos Antissenso (Genética) , Senescência Celular , Dendrobium/enzimologia , Flores/anatomia & histologia , Flores/fisiologia , Regulação Enzimológica da Expressão Gênica , Aminoácido Oxirredutases/genética , DNA de Plantas/genética , Dendrobium/genética , Dendrobium/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
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