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1.
Plant Cell Rep ; 40(8): 1301-1303, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34274991

RESUMO

KEY MESSAGE: Interactions of phytohormone signaling pathways and their crosstalk with the different intermediates of cell signaling cascades regulate the molecular stress responses in plants.


Assuntos
Reguladores de Crescimento de Plantas/metabolismo , Fenômenos Fisiológicos Vegetais , Estresse Fisiológico , Cálcio/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais
2.
J Plant Physiol ; 264: 153472, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315028

RESUMO

Citrus fruit are generally confronted with various fungal diseases that cause fruit deterioration and economic loss. Salicylic acid (SA), a plant hormone, is an important signal molecule required for stimulating the disease resistance of plants. However, there has been limited information about the molecular mechanism of SA biosynthesis involving biotic stress response in citrus fruit. In the present study, an R2R3 MYB transcription factor (CsMYB96) was identified to mediate SA signaling in response to fungal diseases. The transient overexpression assay revealed that CsMYB96 contributed to the strong tolerance of citrus fruit to Penicillium italicum along with an increase in SA content; meanwhile, CsMYB96 conferred resistance to Botrytis cinerea in Arabidopsis plants. Further metabolomic profiling of stable transgenic Arabidopsis revealed that CsMYB96 participated in the regulation of various metabolism pathways and enhanced the accumulation of phenolic acids. RNA-seq analysis confirmed that overexpression of CsMYB96 activated the expression of genes involved in plant-pathogen interaction, phenylpropanoid biosynthesis, and SA signaling. Besides, CsMBY96 directly activated the transcription of calmodulin binding protein 60g (CsCBP60g), a predominant transcription factor required for the activation of SA signaling. In summary, our results reveal that CsMYB96 promotes SA biosynthesis and the accumulation of defense metabolites to enhance the fungal pathogen resistance of citrus fruit and Arabidopsis and provide new insights into the regulation of disease response.


Assuntos
Citrus sinensis/imunologia , Resistência à Doença , Frutas/microbiologia , Doenças das Plantas/imunologia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Ácido Salicílico/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis , Botrytis , Citrus sinensis/metabolismo , Citrus sinensis/microbiologia , Frutas/imunologia , Frutas/metabolismo , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas
3.
Int J Mol Sci ; 22(14)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34298928

RESUMO

Salt stress seriously restricts crop yield and quality, leading to an urgent need to understand its effects on plants and the mechanism of plant responses. Although phytohormones are crucial for plant responses to salt stress, the role of phytohormone signal transduction in the salt stress responses of stress-resistant species such as Sophora alopecuroides has not been reported. Herein, we combined transcriptome and metabolome analyses to evaluate expression changes of key genes and metabolites associated with plant hormone signal transduction in S. alopecuroides roots under salt stress for 0 h to 72 h. Auxin, cytokinin, brassinosteroid, and gibberellin signals were predominantly involved in regulating S. alopecuroides growth and recovery under salt stress. Ethylene and jasmonic acid signals may negatively regulate the response of S. alopecuroides to salt stress. Abscisic acid and salicylic acid are significantly upregulated under salt stress, and their signals may positively regulate the plant response to salt stress. Additionally, salicylic acid (SA) might regulate the balance between plant growth and resistance by preventing reduction in growth-promoting hormones and maintaining high levels of abscisic acid (ABA). This study provides insight into the mechanism of salt stress response in S. alopecuroides and the corresponding role of plant hormones, which is beneficial for crop resistance breeding.


Assuntos
Estresse Salino/genética , Transdução de Sinais/genética , Sophora/genética , Ácido Abscísico/metabolismo , Brassinosteroides/metabolismo , Citocininas/genética , Etilenos/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Ácidos Indolacéticos/metabolismo , Melhoramento Vegetal/métodos , Reguladores de Crescimento de Plantas/genética , Proteínas de Plantas/genética , Ácido Salicílico/metabolismo , Tolerância ao Sal/genética , Sophora/metabolismo , Estresse Fisiológico/genética , Transcriptoma/genética , Regulação para Cima/genética
4.
BMC Plant Biol ; 21(1): 306, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193042

RESUMO

BACKGROUND: Outbreaks of insect pests in paddy fields cause heavy losses in global rice yield annually, a threat projected to be aggravated by ongoing climate warming. Although significant progress has been made in the screening and cloning of insect resistance genes in rice germplasm and their introgression into modern cultivars, improved rice resistance is only effective against either chewing or phloem-feeding insects. RESULTS: In this study, the results from standard and modified seedbox screening, settlement preference and honeydew excretion tests consistently showed that Qingliu, a previously known leaffolder-resistant rice variety, is also moderately resistant to brown planthopper (BPH). High-throughput RNA sequencing showed a higher number of differentially expressed genes (DEGs) at the infestation site, with 2720 DEGs in leaves vs 181 DEGs in sheaths for leaffolder herbivory and 450 DEGs in sheaths vs 212 DEGs in leaves for BPH infestation. The leaf-specific transcriptome revealed that Qingliu responds to leaffolder feeding by activating jasmonic acid biosynthesis genes and genes regulating the shikimate and phenylpropanoid pathways that are essential for the biosynthesis of salicylic acid, melatonin, flavonoids and lignin defensive compounds. The sheath-specific transcriptome revealed that Qingliu responds to BPH infestation by inducing salicylic acid-responsive genes and those controlling cellular signaling cascades. Taken together these genes could play a role in triggering defense mechanisms such as cell wall modifications and cuticular wax formation. CONCLUSIONS: This study highlighted the key defensive responses of a rarely observed rice variety Qingliu that has resistance to attacks by two different feeding guilds of herbivores. The leaffolders are leaf-feeder while the BPHs are phloem feeders, consequently Qingliu is considered to have dual resistance. Although the defense responses of Qingliu to both insect pest types appear largely dissimilar, the phenylpropanoid pathway (or more specifically phenylalanine ammonia-lyase genes) could be a convergent upstream pathway. However, this possibility requires further studies. This information is valuable for breeding programs aiming to generate broad spectrum insect resistance in rice cultivars.


Assuntos
Herbivoria/fisiologia , Oryza/genética , Oryza/parasitologia , Floema/parasitologia , Folhas de Planta/parasitologia , Transcriptoma/genética , Animais , Parede Celular/metabolismo , Ciclopentanos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Hemípteros/fisiologia , Metabolismo dos Lipídeos , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Ácido Salicílico/metabolismo , Ácido Chiquímico/metabolismo , Transcrição Genética
5.
Plant Cell Rep ; 40(8): 1415-1427, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34109470

RESUMO

KEY MESSAGE: Foliar application of SA cross-talks and induce endogenous nitric oxide and reactive oxygen species to improve innate immunity and vigor of tomato plant against Fusarium oxysporum stress. The present investigation was aimed to demonstrate the efficacy of salicylic acid (SA), as a powerful elicitor or plant growth regulator (PGR) and its cross-talk with nitric oxide (NO) in tomato against the biotic stress caused by wilt pathogen, Fusarium oxysporum f. sp. lycopersici. Different defense-related enzymes and gene expression, phenol, flavonoid, and phenolic acid content along with NO generation and other physiological characters have been estimated after foliar application of SA. Total chlorophyll content was steadily maintained and the amount of death of cells was negligible after 72 h of SA treatment. Significant reduction of disease incidence was also recorded in SA treated sets. Simultaneously, NO generation was drastically improved at this stage, which has been justified by both spectrophotometrically and microscopically. A direct correlation between reactive oxygen species (ROS) generation and NO has been established. Production of defense enzymes, gene expressions, different phenolic acids was positively influenced by SA treatment. However, tomato plants treated with SA along with NO synthase (NOS) inhibitor or NO scavenger significantly reduce all those parameters tested. On the other hand, NO donor-treated plants showed the same inductive effect like SA. Furthermore, SA treated seeds of tomato also showed improved physiological parameters like higher seedling vigor index, shoot and root length, mean trichome density, etc. It is speculated that the cross-talk between SA and endogenous NO have tremendous ability to improve defense responses and growth of the tomato plant. It can be utilized in future sustainable agriculture for bimodal action.


Assuntos
Fusarium/patogenicidade , Lycopersicon esculentum/imunologia , Lycopersicon esculentum/microbiologia , Óxido Nítrico/metabolismo , Ácido Salicílico/metabolismo , Morte Celular/efeitos dos fármacos , Enzimas/metabolismo , Flavonoides/análise , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Interações Hospedeiro-Patógeno/fisiologia , Lignina/metabolismo , Lycopersicon esculentum/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Fenóis/análise , Fenóis/metabolismo , Células Vegetais/efeitos dos fármacos , Células Vegetais/microbiologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ácido Salicílico/farmacologia , Plântula/efeitos dos fármacos , Plântula/imunologia , Plântula/microbiologia
6.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070465

RESUMO

Environmental or abiotic stresses are a common threat that remains a constant and common challenge to all plants. These threats whether singular or in combination can have devastating effects on plants. As a semiaquatic plant, rice succumbs to the same threats. Here we systematically look into the involvement of salicylic acid (SA) in the regulation of abiotic stress in rice. Studies have shown that the level of endogenous salicylic acid (SA) is high in rice compared to any other plant species. The reason behind this elevated level and the contribution of this molecule towards abiotic stress management and other underlying mechanisms remains poorly understood in rice. In this review we will address various abiotic stresses that affect the biochemistry and physiology of rice and the role played by SA in its regulation. Further, this review will elucidate the potential mechanisms that control SA-mediated stress tolerance in rice, leading to future prospects and direction for investigation.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/metabolismo , Ácido Salicílico/metabolismo , Estresse Fisiológico/fisiologia , Resposta ao Choque Frio/fisiologia , Secas , Regulação da Expressão Gênica de Plantas/genética , Resposta ao Choque Térmico/fisiologia , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Metais/metabolismo , Metais/toxicidade , Oryza/enzimologia , Reguladores de Crescimento de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/fisiologia
7.
Int J Mol Sci ; 22(9)2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-34066536

RESUMO

Plant food production is severely affected by fungi; to cope with this problem, farmers use synthetic fungicides. However, the need to reduce fungicide application has led to a search for alternatives, such as biostimulants. Rare-earth elements (REEs) are widely used as biostimulants, but their mode of action and their potential as an alternative to synthetic fungicides have not been fully studied. Here, the biostimulant effect of gadolinium (Gd) is explored using the plant-pathosystem Arabidopsis thaliana-Botrytis cinerea. We determine that Gd induces local, systemic, and long-lasting plant defense responses to B. cinerea, without affecting fungal development. The physiological changes induced by Gd have been related to its structural resemblance to calcium. However, our results show that the calcium-induced defense response is not sufficient to protect plants against B. cinerea, compared to Gd. Furthermore, a genome-wide transcriptomic analysis shows that Gd induces plant defenses and modifies early and late defense responses. However, the resistance to B. cinerea is dependent on JA/ET-induced responses. These data support the conclusion that Gd can be used as a biocontrol agent for B. cinerea. These results are a valuable tool to uncover the molecular mechanisms induced by REEs.


Assuntos
Arabidopsis/imunologia , Arabidopsis/microbiologia , Botrytis/fisiologia , Ciclopentanos/metabolismo , Etilenos/metabolismo , Gadolínio/farmacologia , Oxilipinas/metabolismo , Substâncias Protetoras/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Botrytis/efeitos dos fármacos , Botrytis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética
8.
Int J Mol Sci ; 22(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34071930

RESUMO

APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors play important roles in plant development and stress response. Although AP2/ERF genes have been extensively investigated in model plants such as Arabidopsis thaliana, little is known about their role in biotic stress response in perennial fruit tree crops such as apple (Malus × domestica). Here, we investigated the role of MdERF100 in powdery mildew resistance in apple. MdERF100 localized to the nucleus but showed no transcriptional activation activity. The heterologous expression of MdERF100 in Arabidopsis not only enhanced powdery mildew resistance but also increased reactive oxygen species (ROS) accumulation and cell death. Furthermore, MdERF100-overexpressing Arabidopsis plants exhibited differential expressions of genes involved in jasmonic acid (JA) and salicylic acid (SA) signaling when infected with the powdery mildew pathogen. Additionally, yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that MdERF100 physically interacts with the basic helix-loop-helix (bHLH) protein MdbHLH92. These results suggest that MdERF100 mediates powdery mildew resistance by regulating the JA and SA signaling pathways, and MdbHLH92 is involved in plant defense against powdery mildew. Overall, this study enhances our understanding of the role of MdERF genes in disease resistance, and provides novel insights into the molecular mechanisms of powdery mildew resistance in apple.


Assuntos
Arabidopsis/genética , Resistência à Doença/genética , Expressão Gênica , Malus/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Transporte Ativo do Núcleo Celular , Sequência de Aminoácidos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Fenótipo , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/metabolismo , Fatores de Transcrição/metabolismo
9.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069912

RESUMO

Cell wall invertase (CWIN) activity and the expression of the corresponding gene were previously observed to be significantly elevated in a Cu-tolerant population of Elsholtzia haichowensis relative to a non-tolerant population under copper stress. To understand the differences in CWIN gene regulation between the two populations, their CWIN promoter ß-glucuronidase (GUS) reporter vectors were constructed. GUS activity was measured in transgenic Arabidopsis in response to copper, sugar, and phytohormone treatments. Under the copper treatment, only the activity of the CWIN promoter from the Cu-tolerant population was slightly increased. Glucose and fructose significantly induced the activity of CWIN promoters from both populations. Among the phytohormone treatments, only salicylic acid induced significantly higher (p < 0.05) activity of the Cu-tolerant CWIN promoter relative to the non-tolerant promoters. Analysis of 5'-deletion constructs revealed that a 270-bp promoter fragment was required for SA induction of the promoter from the Cu-tolerant population. Comparison of this region in the two CWIN promoters revealed that it had 10 mutation sites and contained CAAT-box and W-box cis-elements in the Cu-tolerant promoter only. This work provides insights into the regulatory role of SA in CWIN gene expression and offers an explanation for differences in CWIN expression between E. haichowensis populations.


Assuntos
Parede Celular/genética , Lamiaceae/genética , beta-Frutofuranosidase/genética , Arabidopsis/genética , Parede Celular/metabolismo , Cobre/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Lamiaceae/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas/genética , Ácido Salicílico/metabolismo , beta-Frutofuranosidase/metabolismo
10.
Plant Cell ; 33(3): 735-749, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33955489

RESUMO

The tradeoff between growth and defense is a critical aspect of plant immunity. Therefore, the plant immune response needs to be tightly regulated. Salicylic acid (SA) is an important plant hormone regulating defense against biotrophic pathogens. Recently, N-hydroxy-pipecolic acid (NHP) was identified as another regulator for plant innate immunity and systemic acquired resistance (SAR). Although the biosynthetic pathway leading to NHP formation is already been identified, how NHP is further metabolized is unclear. Here, we present UGT76B1 as a uridine diphosphate-dependent glycosyltransferase (UGT) that modifies NHP by catalyzing the formation of 1-O-glucosyl-pipecolic acid in Arabidopsis thaliana. Analysis of T-DNA and clustered regularly interspaced short palindromic repeats (CRISPR) knock-out mutant lines of UGT76B1 by targeted and nontargeted ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) underlined NHP and SA as endogenous substrates of this enzyme in response to Pseudomonas infection and UV treatment. ugt76b1 mutant plants have a dwarf phenotype and constitutive defense response which can be suppressed by loss of function of the NHP biosynthetic enzyme FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1). This suggests that elevated accumulation of NHP contributes to the enhanced disease resistance in ugt76b1. Externally applied NHP can move to distal tissue in ugt76b1 mutant plants. Although glycosylation is not required for the long-distance movement of NHP during SAR, it is crucial to balance growth and defense.


Assuntos
Proteínas de Arabidopsis/metabolismo , Glicosiltransferases/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Regulação da Expressão Gênica de Plantas , Glicosiltransferases/genética , Ácidos Pipecólicos/metabolismo , Imunidade Vegetal/genética , Imunidade Vegetal/fisiologia , Pseudomonas syringae/patogenicidade , Ácido Salicílico/metabolismo
11.
AAPS PharmSciTech ; 22(5): 164, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34041632

RESUMO

Psoriasis is a life-threatening autoimmune inflammatory skin disease, triggered by T lymphocyte. Recently, the drugs most commonly used for the treatment of psoriasis include methotrexate (MTX), cyclosporine (CsA), acitretin, dexamethasone, and salicylic acid. However, conventional formulations due to poor absorptive capacity, inconsistent drug release characteristics, poor capability of selective targeting, poor retention of drug molecules in target tissue, and unintended skin reactions restrict the clinical efficacy of drugs. Advances in topical nanocarriers allow the development of prominent drug delivery platforms can be employed to address the critical issues associated with conventional formulations. Advances in nanocarriers design, nano-dimensional configuration, and surface functionalization allow formulation scientists to develop formulations for a more effective treatment of psoriasis. Moreover, interventions in the size distribution, shape, agglomeration/aggregation potential, and surface chemistry are the significant aspects need to be critically evaluated for better therapeutic results. This review attempted to explore the opportunities and challenges of current revelations in the nano carrier-based topical drug delivery approach used for the treatment of psoriasis.


Assuntos
Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos/tendências , Nanocápsulas/administração & dosagem , Psoríase/tratamento farmacológico , Administração Cutânea , Animais , Ciclosporina/administração & dosagem , Ciclosporina/metabolismo , Portadores de Fármacos/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Liberação Controlada de Fármacos/fisiologia , Humanos , Lipossomos/administração & dosagem , Lipossomos/metabolismo , Metotrexato/administração & dosagem , Metotrexato/metabolismo , Psoríase/metabolismo , Ácido Salicílico/administração & dosagem , Ácido Salicílico/metabolismo
12.
Int J Mol Sci ; 22(9)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946839

RESUMO

Hormone signaling plays a pivotal role in plant-microbe interactions. There are three major phytohormones in plant defense: salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). The activation and trade-off of signaling between these three hormones likely determines the strength of plant defense in response to pathogens. Here, we describe the allocation of hormonal signaling in Brassica napus against the fungal pathogen Leptosphaeria maculans. Three B. napus genotypes (Westar, Surpass400, and 01-23-2-1) were inoculated with two L. maculans isolates (H75 8-1 and H77 7-2), subsequently exhibiting three levels of resistance: susceptible, intermediate, and resistant. Quantitative analyses suggest that the early activation of some SA-responsive genes, including WRKY70 and NPR1, contribute to an effective defense against L. maculans. The co-expression among factors responding to SA/ET/JA was also observed in the late stage of infection. The results of conjugated SA measurement also support that early SA activation plays a crucial role in durable resistance. Our results demonstrate the relationship between the onset patterns of certain hormone regulators and the effectiveness of the defense of B. napus against L. maculans.


Assuntos
Brassica napus/fisiologia , Ciclopentanos/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno/fisiologia , Leptosphaeria/crescimento & desenvolvimento , Oxilipinas/metabolismo , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Brassica napus/genética , Brassica napus/microbiologia , Cotilédone/metabolismo , Cotilédone/microbiologia , Resistência à Doença , Genes de Plantas , Genótipo , Interações Hospedeiro-Patógeno/genética , Hifas/ultraestrutura , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Transdução de Sinais , Fatores de Transcrição/fisiologia
13.
Genes (Basel) ; 12(5)2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922119

RESUMO

Sandalwood (Santalum album L.) heartwood-derived essential oil contains a high content of sesquiterpenoids that are economically highly valued and widely used in the fragrance industry. Sesquiterpenoids are biosynthesized via the mevalonate acid and methylerythritol phosphate (MEP) pathways, which are also the sources of precursors for photosynthetic pigments. 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) is a secondary rate-limiting enzyme in the MEP pathway. In this paper, the 1416-bp open reading frame of SaDXR and its 897-bp promoter region, which contains putative conserved cis-elements involved in stress responsiveness (HSE and TC-rich repeats), hormone signaling (abscisic acid, gibberellin and salicylic acid) and light responsiveness, were cloned from 7-year-old S. album trees. A bioinformatics analysis suggested that SaDXR encodes a functional and conserved DXR protein. SaDXR was widely expressed in multiple tissues, including roots, twigs, stem sapwood, leaves, flowers, fruit and stem heartwood, displaying significantly higher levels in tissues with photosynthetic pigments, like twigs, leaves and flowers. SaDXR mRNA expression increased in etiolated seedlings exposed to light, and the content of chlorophylls and carotenoids was enhanced in all 35S::SaDXR transgenic Arabidopsis thaliana lines, consistent with the SaDXR expression level. SaDXR was also stimulated by MeJA and H2O2 in seedling roots. α-Santalol content decreased in response to fosmidomycin, a DXR inhibitor. These results suggest that SaDXR plays an important role in the biosynthesis of photosynthetic pigments, shifting the flux to sandalwood-specific sesquiterpenoids.


Assuntos
Aldose-Cetose Isomerases/genética , Santalum/genética , Ácido Abscísico/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Clonagem Molecular/métodos , Flores/genética , Regulação da Expressão Gênica de Plantas/genética , Giberelinas/metabolismo , Complexos Multienzimáticos/genética , Folhas de Planta/genética , Raízes de Plantas/genética , Ácido Salicílico/metabolismo , Santalum/metabolismo , Homologia de Sequência de Aminoácidos
14.
Plant Physiol ; 185(3): 876-891, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33793924

RESUMO

The hormone salicylic acid (SA) plays crucial roles in plant defense, stress responses, and in the regulation of plant growth and development. Whereas the biosynthetic pathways and biological functions of SA have been extensively studied, SA catabolism is less well understood. In this study, we report the identification and functional characterization of an FAD/NADH-dependent SA 1-hydroxylase from tomato (Solanum lycopersicum; SlSA1H), which catalyzes the oxidative decarboxylation of SA to catechol. Transcript levels of SlSA1H were highest in stems and its expression was correlated with the formation of the methylated catechol derivatives guaiacol and veratrole. Consistent with a role in SA catabolism, SlSA1H RNAi plants accumulated lower amounts of guaiacol and failed to produce any veratrole. Two O-methyltransferases involved in the conversion of catechol to guaiacol and guaiacol to veratrole were also functionally characterized. Subcellular localization analyses revealed the cytosolic localization of this degradation pathway. Phylogenetic analysis and functional characterization of SA1H homologs from other species indicated that this type of FAD/NADH-dependent SA 1-hydroxylases evolved recently within the Solanaceae family.


Assuntos
Oxigenases de Função Mista/metabolismo , Ácido Salicílico/metabolismo , Catecóis/metabolismo , Regulação da Expressão Gênica de Plantas , Guaiacol/metabolismo , Lycopersicon esculentum/enzimologia , Lycopersicon esculentum/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Proteína O-Metiltransferase/metabolismo
15.
Int J Mol Sci ; 22(6)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802058

RESUMO

Citrus Huanglongbing (HLB) disease or citrus greening is caused by Candidatus Liberibacter asiaticus (Las) and is the most devastating disease in the global citrus industry. Salicylic acid (SA) plays a central role in regulating plant defenses against pathogenic attack. SA methyltransferase (SAMT) modulates SA homeostasis by converting SA to methyl salicylate (MeSA). Here, we report on the functions of the citrus SAMT (CsSAMT1) gene from HLB-susceptible Wanjincheng orange (Citrus sinensis (L.) Osbeck) in plant defenses against Las infection. The CsSAMT1 cDNA was expressed in yeast. Using in vitro enzyme assays, yeast expressing CsSAMT1 was confirmed to specifically catalyze the formation of MeSA using SA as a substrate. Transgenic Wanjincheng orange plants overexpressing CsSAMT1 had significantly increased levels of SA and MeSA compared to wild-type controls. HLB resistance was evaluated for two years and showed that transgenic plants displayed significantly alleviated symptoms including a lack of chlorosis, low bacterial counts, reduced hyperplasia of the phloem cells, and lower levels of starch and callose compared to wild-type plants. These data confirmed that CsSAMT1 overexpression confers an enhanced tolerance to Las in citrus fruits. RNA-seq analysis revealed that CsSAMT1 overexpression significantly upregulated the citrus defense response by enhancing the transcription of disease resistance genes. This study provides insight for improving host resistance to HLB by manipulation of SA signaling in citrus fruits.


Assuntos
Citrus sinensis/genética , Resistência à Doença/genética , Metiltransferases/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Citrus sinensis/microbiologia , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Liberibacter/fisiologia , Metiltransferases/metabolismo , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , RNA-Seq/métodos , Ácido Salicílico/metabolismo , Homologia de Sequência de Aminoácidos
16.
Nat Commun ; 12(1): 2317, 2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33875651

RESUMO

Plant immunity frequently incurs growth penalties, which known as the trade-off between immunity and growth. Heterosis, the phenotypic superiority of a hybrid over its parents, has been demonstrated for many traits but rarely for disease resistance. Here, we report that the central circadian oscillator, CCA1, confers heterosis for bacterial defense in hybrids without growth vigor costs, and it even significantly enhances the growth heterosis of hybrids under pathogen infection. The genetic perturbation of CCA1 abrogated heterosis for both defense and growth in hybrids. Upon pathogen attack, the expression of CCA1 in F1 hybrids is precisely modulated at different time points during the day by its rhythmic histone modifications. Before dawn of the first infection day, epigenetic activation of CCA1 promotes an elevation of salicylic acid accumulation in hybrids, enabling heterosis for defense. During the middle of every infection day, diurnal epigenetic repression of CCA1 leads to rhythmically increased chlorophyll synthesis and starch metabolism in hybrids, effectively eliminating the immunity-growth heterosis trade-offs in hybrids.


Assuntos
Arabidopsis/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Vigor Híbrido/genética , Hibridização Genética/genética , Arabidopsis/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Bactérias/crescimento & desenvolvimento , Clorofila/metabolismo , Epigênese Genética/genética , Plantas Geneticamente Modificadas , Ácido Salicílico/metabolismo , Amido/metabolismo , Fatores de Transcrição/genética
17.
Plant Cell Rep ; 40(8): 1305-1329, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33751168

RESUMO

Phytohormones are ubiquitously involved in plant biological processes and regulate cellular signaling pertaining to unheralded environmental cues, such as salinity, drought, extreme temperature and nutrient deprivation. The association of phytohormones to nearly all the fundamental biological processes epitomizes the phytohormone syndicate as a candidate target for consideration during engineering stress endurance in agronomically important crops. The drought stress response is essentially driven by phytohormones and their intricate network of crosstalk, which leads to transcriptional reprogramming. This review is focused on the pivotal role of phytohormones in water deficit responses, including their manipulation for mitigating the effect of the stressor. We have also discussed the inherent complexity of existing crosstalk accrued among them during the progression of drought stress, which instigates the tolerance response. Therefore, in this review, we have highlighted the role and regulatory aspects of various phytohormones, namely abscisic acid, auxin, gibberellic acid, cytokinin, brassinosteroid, jasmonic acid, salicylic acid, ethylene and strigolactone, with emphasis on drought stress tolerance.


Assuntos
Secas , Reguladores de Crescimento de Plantas/metabolismo , Fenômenos Fisiológicos Vegetais , Ácido Abscísico/metabolismo , Brassinosteroides/metabolismo , Citocininas/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Ácidos Indolacéticos/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais , Estresse Fisiológico
18.
Biochem Biophys Res Commun ; 551: 161-167, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33740623

RESUMO

Physiological oxygen concentration (physioxia) ranges from 1 to 8% in human tissues while many researchers cultivate mammalian cells under an atmospheric concentration of 21% (hyperoxia). Oxygen is one of the significant gases which functions in human cells including energy production in mitochondria, metabolism in peroxidase, and transcription of various genes in company with HIF (Hypoxia-inducible factors) in the nucleus. Thus, mammalian cell culture should be deliberated on the oxygen concentration to mimic in vivo physiology. Here, we studied if the cultivation of human skin cells under physiological conditions could affect skin significant genes in barrier functions and dermal matrix formation. We further examined that some representative active ingredients in dermatology such as glycolic acid, gluconolactone, and salicylic acid work in different ways depending on the oxygen concentration. Taken together, we present the importance of oxygen concentration in skin cell culture for proper screening of novel ingredients as well as the mechanistic study of skin cell regulation.


Assuntos
Hidroxiácidos/farmacologia , Oxigênio/farmacologia , Pele , Linhagem Celular , Colágeno Tipo I/genética , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Gluconatos/metabolismo , Glicolatos/metabolismo , Humanos , Queratina-1/genética , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Lactonas/metabolismo , Metaloproteinase 1 da Matriz/genética , Oxigênio/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , Proteínas S100/genética , Ácido Salicílico/metabolismo , Pele/citologia , Pele/efeitos dos fármacos , Pele/metabolismo
19.
Int J Mol Sci ; 22(5)2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33670954

RESUMO

Fusarium verticillioides causes multiple diseases of Zea mays (maize) including ear and seedling rots, contaminates seeds and seed products worldwide with toxic chemicals called fumonisins. The role of fumonisins in disease is unclear because, although they are not required for ear rot, they are required for seedling diseases. Disease symptoms may be due to the ability of fumonisins to inhibit ceramide synthase activity, the expected cause of lipids (fatty acids, oxylipins, and sphingolipids) alteration in infected plants. In this study, we explored the impact of fumonisins on fatty acid, oxylipin, and sphingolipid levels in planta and how these changes affect F. verticillioides growth in maize. The identity and levels of principal fatty acids, oxylipins, and over 50 sphingolipids were evaluated by chromatography followed by mass spectrometry in maize infected with an F. verticillioides fumonisin-producing wild-type strain and a fumonisin-deficient mutant, after different periods of growth. Plant hormones associated with defense responses, i.e., salicylic and jasmonic acid, were also evaluated. We suggest that fumonisins produced by F. verticillioides alter maize lipid metabolism, which help switch fungal growth from a relatively harmless endophyte to a destructive necrotroph.


Assuntos
Fumonisinas/toxicidade , Fusarium/química , Germinação , Metabolismo dos Lipídeos/efeitos dos fármacos , Micoses/metabolismo , Doenças das Plantas/microbiologia , Zea mays/efeitos dos fármacos , Ciclopentanos/análise , Ciclopentanos/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Fumonisinas/farmacologia , Micotoxinas/toxicidade , Oxilipinas/análise , Oxilipinas/metabolismo , Ácido Salicílico/análise , Ácido Salicílico/metabolismo , Esfingolipídeos/análise , Esfingolipídeos/metabolismo , Zea mays/química , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
20.
BMC Plant Biol ; 21(1): 72, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33530947

RESUMO

BACKGROUND: APETALA2/ethylene responsive factor (AP2/ERF) transcription factors are a plant-specific family of transcription factors and one of the largest families of transcription factors. Ethylene response factors (ERF) regulate plant growth, development, and responses to biotic and abiotic stress. In a previous study, the ERF2 gene was significantly upregulated in both resistant and susceptible tomato cultivars in response to Stemphylium lycopersici. The main purpose of this study was to systematically analyze the ERF family and to explore the mechanism of ERF2 in tomato plants resisting pathogen infection by the Virus-induced Gene Silencing technique. RESULTS: In this experiment, 134 ERF genes were explored and subjected to bioinformatic analysis and divided into twelve groups. The spatiotemporal expression characteristics of ERF transcription factor gene family in tomato were diverse. Combined with RNA-seq, we found that the expression of 18 ERF transcription factors increased after inoculation with S. lycopersici. In ERF2-silenced plants, the susceptible phenotype was observed after inoculation with S. lycopersici. The hypersensitive response and ROS production were decreased in the ERF2-silenced plants. Physiological analyses showed that the superoxide dismutase, peroxidase and catalase activities were lower in ERF2-silenced plants than in control plants, and the SA and JA contents were lower in ERF2-silenced plants than in control plants after inoculation with S. lycopersici. Furthermore, the results indicated that ERF2 may directly or indirectly regulate Pto, PR1b1 and PR-P2 expression and enhance tomato resistance. CONCLUSIONS: In this study, we identified and analyzed members of the tomato ERF family by bioinformatics methods and classified, described and analyzed these genes. Subsequently, we used VIGS technology to significantly reduce the expression of ERF2 in tomatoes. The results showed that ERF2 had a positive effect on tomato resistance to S. lycopersici. Interestingly, ERF2 played a key role in multiple SA, JA and ROS signaling pathways to confer resistance to invasion by S. lycopersici. In addition, ERF2 may directly or indirectly regulate Pto, PR1b1 and PR-P2 expression and enhance tomato resistance to S. lycopersici. In summary, this study provides gene resources for breeding for disease resistance in tomato.


Assuntos
Ascomicetos/fisiologia , Resistência à Doença/genética , Genoma de Planta , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Família Multigênica , Doenças das Plantas/genética , Proteínas de Plantas/genética , Motivos de Aminoácidos , Catalase/metabolismo , Cromossomos de Plantas/genética , Sequência Conservada , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Especificidade de Órgãos/genética , Oxilipinas/metabolismo , Peroxidase/metabolismo , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo , Fatores de Transcrição/metabolismo
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