RESUMEN

Plant glucanases and chitinases are defense proteins that participate in pathogenesis; however, very little is known about the glucanase (GLUC) and chitinase (CHIT) gene families in mango. Some mango cultivars are of great economic importance and can be affected by anthracnose, a postharvest disease caused by fungi of the genus Colletotrichum spp. This study identified and characterized 23 putative glucanases and 16 chitinases in the mango genome cv. Tommy Atkins. We used phylogenetic analyses to classify the glucanases into three subclasses (A, B, and C) and the chitinases into four classes (I, II, IV, and V). Information on the salicylic, jasmonic acid, and ethylene pathways was obtained by analyzing the cis-elements of the GLUC and CHIT class I and IV gene promoters. The expression profile of GLUC, CHIT class I, and CHIT class IV genes in mango cv. Ataulfo inoculated with two Colletotrichum spp. revealed different profile expression related to these fungi's level of virulence. In general, this study provides the basis for the functional validation of these target genes with which the regulatory mechanisms used by glucanases and chitinases as defense proteins in mango can be elucidated.

Asunto(s)

Quitinasas , Colletotrichum , Regulación de la Expresión Génica de las Plantas , Mangifera , Filogenia , Enfermedades de las Plantas , Colletotrichum/patogenicidad , Colletotrichum/genética , Mangifera/microbiología , Mangifera/genética , Quitinasas/genética , Quitinasas/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oxilipinas/metabolismo , Ciclopentanos/metabolismo , Perfilación de la Expresión Génica

RESUMEN

YABBY genes encode specific TFs of seed plants involved in development and formation of leaves, flowers, and fruit. In the present work, genome-wide and expression analyses of the YABBY gene family were performed in six species of the Fragaria genus: Fragaria × ananassa, F. daltoniana, F. nilgerrensis, F. pentaphylla, F. viridis, and F. vesca. The chromosomal location, synteny pattern, gene structure, and phylogenetic analyses were carried out. By combining RNA-seq data and RT-qPCR analysis we explored specific expression of YABBYs in F. × ananassa and F. vesca. We also analysed the promoter regions of FaYABBYs and performed MeJA application to F. × ananassa fruit to observe effects on gene expression. We identified and characterized 25 YABBY genes in F. × ananassa and six in each of the other five species, which belong to FIL/YAB3 (YABBY1), YAB2 (YABBY2), YAB5 (YABBY5), CRC, and INO clades previously described. Division of the YABBY1 clade into YABBY1.1 and YABBY1.2 subclades is reported. We observed differential expression according to tissue, where some FaYABBYs are expressed mainly in leaves and flowers and to a minor extent during fruit development of F. × ananassa. Specifically, the FaINO genes contain jasmonate-responsive cis-acting elements in their promoters which may be functional since FaINOs are upregulated in F. × ananassa fruit under MeJA treatment. This study suggests that YABBY TFs play an important role in the development- and environment-associated responses of the Fragaria genus.

Asunto(s)

Ciclopentanos , Diploidia , Fragaria , Regulación de la Expresión Génica de las Plantas , Oxilipinas , Filogenia , Proteínas de Plantas , Factores de Transcripción , Fragaria/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ciclopentanos/metabolismo , Ciclopentanos/farmacología , Oxilipinas/farmacología , Oxilipinas/metabolismo , Frutas/genética , Frutas/crecimiento & desarrollo , Poliploidía , Acetatos/farmacología , Regiones Promotoras Genéticas/genética , Sintenía , Familia de Multigenes

RESUMEN

Phospholipase C (PLC) plays a key role in lipid signaling during plant development and stress responses. PLC activation is one of the earliest responses during pathogen perception. Arabidopsis thaliana contains seven PLC encoding genes (AtPLC1 to AtPLC7) and two pseudogenes (AtPLC8 and AtPLC9), being AtPLC2 the most abundant isoform with constitutive expression in all plant organs. PLC has been linked to plant defense signaling, in particular to the production of reactive oxygen species (ROS). Previously, we demonstrated that AtPLC2 is involved in ROS production via the NADPH oxidase isoforms RBOHD activation during stomata plant immunity. Here we studied the role of AtPLC2 on plant resistance against the necrotrophic fungus Botrytis cinerea, a broad host-range and serious agricultural pathogen. We show that the AtPLC2-silenced (amiR PLC2) or null mutant (plc2-1) plants developed smaller B. cinerea lesions. Moreover, plc2-1 showed less ROS production and an intensified SA-dependent signaling upon infection, indicating that B. cinerea uses AtPLC2-triggered responses for a successful proliferation. Therefore, AtPLC2 is a susceptibility (S) gene that facilitates B. cinerea infection and proliferation.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/microbiología , Fosfoinositido Fosfolipasa C/genética , Fosfoinositido Fosfolipasa C/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Botrytis/metabolismo , Fosfatidilinositoles , Proliferación Celular , Enfermedades de las Plantas/microbiología , Regulación de la Expresión Génica de las Plantas , Oxilipinas/metabolismo , Ciclopentanos/metabolismo

RESUMEN

MAIN CONCLUSION: CRISPR/Cas9-mediated Phospholipase C2 knock-out tomato plants are more resistant to Botrytis cinerea than wild-type plants, with less ROS and an increase and reduction of (JA) and (SA)-response marker genes, respectively. Genome-editing technologies allow non-transgenic site-specific mutagenesis of crops, offering a viable alternative to traditional breeding methods. In this study we used CRISPR/Cas9 to inactivate the tomato Phospholipase C2 gene (SlPLC2). Plant PLC activation is one of the earliest responses triggered by different pathogens regulating plant responses that, depending on the plant-pathogen interaction, result in plant resistance or susceptibility. The tomato (Solanum lycopersicum) PLC gene family has six members, named from SlPLC1 to SlPLC6. We previously showed that SlPLC2 transcript levels increased upon xylanase infiltration (fungal elicitor) and that SlPLC2 participates in plant susceptibility to Botrytis cinerea. An efficient strategy to control diseases caused by pathogens is to disable susceptibility genes that facilitate infection. We obtained tomato SlPLC2-knock-out lines with decreased ROS production upon B. cinerea challenge. Since this fungus requires ROS-induced cell death to proliferate, SlPLC2-knock-out plants showed an enhanced resistance with smaller necrotic areas and reduced pathogen proliferation. Thus, we obtained SlPLC2 loss-of-function tomato lines more resistant to B. cinerea by means of CRISPR/Cas9 genome editing technology.

Asunto(s)

Solanum lycopersicum , Fosfolipasas de Tipo C , Fosfolipasas de Tipo C/metabolismo , Solanum lycopersicum/genética , Sistemas CRISPR-Cas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Oxilipinas/metabolismo , Fitomejoramiento , Botrytis/metabolismo , Fosfolipasas/genética , Fosfolipasas/metabolismo , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas

RESUMEN

The present work aims to evaluate the roles of methyl jasmonate (MeJA) in the formation of volatile organic compounds (VOC) from grape tomatoes during ripening. Fruits were treated with MeJA, ethylene, 1-MCP (1-methylcyclopropene), and MeJA+1-MCP, with analyses of the VOC and levels of the gene transcripts for the enzymes lipoxygenase (LOX), alcohol dehydrogenase (ADH), and hydroperoxide lyase (HPL). An intimate relationship between MeJA and ethylene in aroma formation was detected, mainly among the VOC from the carotenoid pathway. Expression of the fatty acid transcripts, LOXC, ADH, and HPL pathway genes, was reduced by 1-MCP, even when associated with MeJA. In ripe tomato, MeJA increased most of the volatile C6 compounds, except 1-hexanol. The MeJA+1-MCP treatment followed most of the increases in volatile C6 compounds that were increased by MeJA alone, which evidenced some ethylene-independent mechanism in the production of the volatile C6 compounds. In ripe tomato, MeJA and MeJA+1-MCP increased the levels of 6-methyl-5-hepten-2-one, which is derived from lycopene, evidencing an ethylene-independent biosynthetic process.

Asunto(s)

Solanum lycopersicum , Vitis , Compuestos Orgánicos Volátiles , Frutas/metabolismo , Solanum lycopersicum/genética , Vitis/metabolismo , Compuestos Orgánicos Volátiles/metabolismo , Etilenos/metabolismo , Oxilipinas/farmacología , Oxilipinas/metabolismo , Ciclopentanos/farmacología , Ciclopentanos/metabolismo , Acetatos/farmacología , Acetatos/metabolismo , Regulación de la Expresión Génica de las Plantas

RESUMEN

Plants being sessile organisms are exposed to various biotic and abiotic factors, thus causing stress. The Pseudomonas aeruginosa bacterium is an opportunistic pathogen for animals, insects, and plants. Direct exposure of Arabidopsis thaliana to the P. aeruginosa PAO1 strain induces plant death by producing a wide variety of virulence factors, which are regulated mainly by quorum sensing systems. Besides virulence factors, P. aeruginosa PAO1 also produces cyclodipeptides (CDPs), which possess auxin-like activity and promote plant growth through activation of the target of the rapamycin (AtTOR) pathway. On the other hand, plant defense mechanisms are regulated through the production of phytohormones, such as salicylic acid (SA) and jasmonic acid (JA), which are induced in response to pathogen-associated molecular patterns (PAMPs), activating defense genes associated with SA and JA such as PATHOGENESIS-RELATED-1 (PR-1) and LIPOXYGENASE2 (LOX2), respectively. PR proteins are suggested to play critical roles in coordinating the Systemic Acquired Resistance (SAR). In contrast, LOX proteins (LOX2, LOX3, and LOX4) have been associated with the production of JA by producing its precursors, oxylipins. The activation of defense mechanisms involves signaling cascades such as Mitogen-Activated Protein Kinases (MAPKs) or the TOR pathway as a switch for re-directing energy towards defense or growth. In this work, we challenged A. thaliana (wild type, mpk6 or mpk3 mutants, and overexpressing TOR) seedlings with P. aeruginosa PAO1 strains to identify the role of bacterial CDPs in the plant immune response. Results showed that the pre-exposure of these Arabidopsis seedlings to CDPs significantly reduced plant infection of the pathogenic P. aeruginosa PAO1 strains, indicating that plants that over-express AtTOR or lack MPK3/MPK6 protein-kinases are more susceptible to the pathogenic effects. In addition, CDPs induced the GUS activity only in the LOX2::GUS plants, indicative of JA-signaling activation. Our findings indicate that the CDPs are molecules that trigger SA-independent and JA-dependent defense responses in A. thaliana; hence, bacterial CDPs may be considered elicitors of the Arabidopsis immune response to pathogens.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Animales , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Inmunidad , Oxilipinas/metabolismo , Desarrollo de la Planta , Enfermedades de las Plantas/microbiología , Pseudomonas aeruginosa , Ácido Salicílico/metabolismo , Factores de Virulencia/metabolismo , Factores de Virulencia/farmacología

RESUMEN

Lung cancer is currently the leading cause of cancer death worldwide; it is often diagnosed at an advanced stage and bears poor prognosis. It has been shown that diet is an important environmental factor that contributes to the risk and mortality of several types of cancers. Intake of ω-3 and ω-6 PUFAs plays an important role in cancer risk and progression. Current Western populations have high consumption of ω-6 PUFAs with a ratio of ω-6/ω-3 PUFAs at 15:1 to 16.7:1 This high consumption of ω-6 PUFAs is related to increased cancer risk and progression. However, whether a diet rich in ω-6 PUFAs can contribute to tumor aggressiveness has not been well investigated. We used a murine model of pulmonary squamous cell carcinoma to study the aggressiveness of tumors in mice fed with a diet rich in ω-6 PUFAs and its relationship with oxylipins. Our results shown that the mice fed a diet rich in ω-6 showed a marked increase in proliferation, angiogenesis and pro-inflammatory markers and decreased expression of pro-apoptotic proteins in their tumors. Oxylipin profiling revealed an upregulation of various pro-tumoral oxylipins including PGs, HETEs, DiHETrEs and HODEs. These results demonstrate for the first time that high intake of ω-6 PUFAs in the diet enhances the malignancy of tumor cells by histological changes on tumor dedifferentiation and increases cell proliferation, angiogenesis, pro-inflammatory oxylipins and molecular aggressiveness targets such as NF-κB p65, YY1, COX-2 and TGF-ß.

Asunto(s)

Ácidos Grasos Omega-3 , Neoplasias Pulmonares , Animales , Dieta , Ácidos Grasos Omega-3/metabolismo , Ácidos Grasos Omega-3/farmacología , Ácidos Grasos Omega-6/metabolismo , Ácidos Grasos Omega-6/farmacología , Ratones , Oxilipinas/metabolismo

RESUMEN

Lipokines are bioactive compounds, derived from adipose tissue depots, that control several molecular signaling pathways. Recently, 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME), an oxylipin, has gained prominence in the scientific literature. An increase in circulating 12,13-diHOME has been associated with improved metabolic health, and the action of this molecule appears to be mediated by brown adipose tissue (BAT). Scientific evidence indicates that the increase in serum levels of 12,13-diHOME caused by stimuli such as physical exercise and exposure to cold may favor the absorption of fatty acids by brown adipose tissue and stimulate the browning process in white adipose tissue (WAT). Thus, strategies capable of increasing 12,13-diHOME levels may be promising for the prevention and treatment of obesity and metabolic diseases. This review explores the relationship of 12,13-diHOME with brown adipose tissue and its role in the metabolic health context, as well as the signaling pathways involved between 12,13-diHOME and BAT.

Asunto(s)

Tejido Adiposo Pardo/metabolismo , Enfermedades Metabólicas/tratamiento farmacológico , Enfermedades Metabólicas/metabolismo , Ácidos Oléicos/metabolismo , Tejido Adiposo Blanco/metabolismo , Humanos , Terapia Molecular Dirigida , Ácidos Oléicos/sangre , Ácidos Oléicos/farmacología , Oxilipinas/metabolismo

RESUMEN

Plant expansins are structural cell wall-loosening proteins implicated in several developmental processes and responses to environmental constraints and pathogen infection. To date, there is limited information about the biological function of expansins-like B (EXLBs), one of the smallest and less-studied subfamilies of plant expansins. In the present study, we conducted a functional analysis of the wild Arachis AdEXLB8 gene in transgenic tobacco (Nicotiana tabacum) plants to clarify its putative role in mediating defense responses to abiotic and biotic stresses. First, its cell wall localization was confirmed in plants expressing an AdEXLB8:eGFP fusion protein, while nanomechanical assays indicated cell wall reorganization and reassembly due to AdEXLB8 overexpression without compromising the phenotype. We further demonstrated that AdEXLB8 increased tolerance not only to isolated abiotic (drought) and biotic (Sclerotinia sclerotiorum and Meloidogyne incognita) stresses but also to their combination. The jasmonate and abscisic acid signaling pathways were clearly favored in transgenic plants, showing an activated antioxidative defense system. In addition to modifications in the biomechanical properties of the cell wall, we propose that AdEXLB8 overexpression interferes with phytohormone dynamics leading to a defense primed state, which culminates in plant defense responses against isolated and combined abiotic and biotic stresses.

Asunto(s)

Arachis/genética , Nicotiana/fisiología , Proteínas de Plantas/genética , Estrés Fisiológico/genética , Ácido Abscísico/metabolismo , Animales , Ascomicetos/patogenicidad , Fenómenos Biomecánicos , Pared Celular/genética , Pared Celular/metabolismo , Ciclopentanos/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas , Oxilipinas/metabolismo , Células Vegetales/metabolismo , Hojas de la Planta/fisiología , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Nicotiana/citología , Nicotiana/genética , Nicotiana/microbiología , Tylenchoidea/patogenicidad

RESUMEN

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.

Asunto(s)

Arabidopsis/inmunología , Arabidopsis/microbiología , Botrytis/fisiología , Ciclopentanos/metabolismo , Etilenos/metabolismo , Gadolinio/farmacología , Oxilipinas/metabolismo , Sustancias Protectoras/farmacología , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Botrytis/efectos de los fármacos , Botrytis/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Especies Reactivas de Oxígeno/metabolismo , Ácido Salicílico/metabolismo , Estrés Fisiológico/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , Activación Transcripcional/genética

RESUMEN

Soil salinity is one of the most limiting stresses for crop productivity and quality worldwide. In this sense, jasmonates (JAs) have emerged as phytohormones that play essential roles in mediating plant response to abiotic stresses, including salt stress. Here, we reviewed the mechanisms underlying the activation and response of the JA-biosynthesis and JA-signaling pathways under saline conditions in Arabidopsis and several crops. In this sense, molecular components of JA-signaling such as MYC2 transcription factor and JASMONATE ZIM-DOMAIN (JAZ) repressors are key players for the JA-associated response. Moreover, we review the antagonist and synergistic effects between JA and other hormones such as abscisic acid (ABA). From an applied point of view, several reports have shown that exogenous JA applications increase the antioxidant response in plants to alleviate salt stress. Finally, we discuss the latest advances in genomic techniques for the improvement of crop tolerance to salt stress with a focus on jasmonates.

Asunto(s)

Adaptación Fisiológica/genética , Ciclopentanos/metabolismo , Genómica , Oxilipinas/metabolismo , Plantas/genética , Estrés Salino/genética , Tolerancia a la Sal/genética

RESUMEN

BACKGROUND: Jasmonic acid (JA) is a signal transducer molecule that plays an important role in plant development and stress response; it can also efficiently stimulate secondary metabolism in plant cells. RESULTS: RNA-Seq technology was applied to identify differentially expressed genes and study the time course of gene expression in Rhazya stricta in response to JA. Of more than 288 million total reads, approximately 27% were mapped to genes in the reference genome. Genes involved during the secondary metabolite pathways were up- or downregulated when treated with JA in R. stricta. Functional annotation and pathway analysis of all up- and downregulated genes identified many biological processes and molecular functions. Jasmonic acid biosynthetic, cell wall organization, and chlorophyll metabolic processes were upregulated at days 2, 6, and 12, respectively. Similarly, the molecular functions of calcium-transporting ATPase activity, ADP binding, and protein kinase activity were also upregulated at days 2, 6, and 12, respectively. Time-dependent transcriptional gene expression analysis showed that JA can induce signaling in the phenylpropanoid and aromatic acid pathways. These pathways are responsible for the production of secondary metabolites, which are essential for the development and environmental defense mechanism of R. stricta during stress conditions. CONCLUSIONS: Our results suggested that genes involved in flavonoid biosynthesis and aromatic acid synthesis pathways were upregulated during JA stress. However, monoterpenoid indole alkaloid (MIA) was unaffected by JA treatment. Hence, we can postulate that JA plays an important role in R. stricta during plant development and environmental stress conditions.

Asunto(s)

Ciclopentanos/metabolismo , Apocynaceae/genética , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Estrés Fisiológico , Flavonoides/biosíntesis , Secuencia de Bases , Expresión Génica , Ambiente , Transcriptoma

RESUMEN

Farnesyl pyrophosphate synthase (FPS) is a key enzyme that catalyzes the formation of farnesyl pyrophosphate, the main initiator for rubber chain initiation in Hevea brasiliensis Muell. Arg. The transcriptional regulatory mechanisms of the FPS gene still not well understood. Here, a WRKY transcription factor designated HbWRKY27 was obtained by screening the latex cDNA library applied the HbFPS1 promoter as bait. HbWRKY27 interacted with the HbFPS1 promoter was further identified by individual Y1H and EMSA assays. HbWRKY27 belongs to group IIe WRKY subfamily which contains a typical WRKY domain and C-X5-CX23-HXH motif. HbWRKY27 was localized to the nucleus. HbWRKY27 predominantly accumulated in latex. HbWRKY27 was up-regulated in latex by ethrel, salicylic acid, abscisic acid, and methyl jasmonate treatment. Transient expression of HbWRKY27 led to increasing the activity of the HbFPS1 promoter in tobacco plant, suggesting that HbWRKY27 positively regulates the HbFPS1 expression. Taken together, an upstream transcription factor of the key natural rubber biosynthesis gene HbFPS1 was identified and this study will provide novel transcriptional regulatory mechanisms of the FPS gene in Hevea brasiliensis.

Asunto(s)

Hevea/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Acetatos/metabolismo , Secuencia de Aminoácidos , Núcleo Celular/genética , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Genes de Plantas/genética , Hevea/metabolismo , Látex/metabolismo , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/genética , Regiones Promotoras Genéticas/genética , Goma/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Regulación hacia Arriba/genética

RESUMEN

Diatraea saccharalis constitutes a threat to the sugarcane productivity, and obtaining borer tolerant cultivars is an alternative method of control. Although there are studies about the relationship between the interaction of D. saccharalis with sugarcane, little is known about the molecular and genomic basis of defense mechanisms that confer tolerance to sugarcane cultivars. Here, we analyzed the transcriptional profile of two sugarcane cultivars in response to borer attack, RB867515 and SP80-3280, which are considered tolerant and sensitive to the borer attack, respectively. A sugarcane genome and transcriptome were used for read mapping. Differentially expressed transcripts and genes were identified and termed to as DETs and DEGs, according to the sugarcane database adopted. A total of 745 DETs and 416 DEGs were identified (log2|ratio| > 0.81; FDR corrected P value ≤ 0.01) after borer infestation. Following annotation of up- and down-regulated DETs and DEGs by similarity searches, the sugarcane cultivars demonstrated an up-regulation of jasmonic acid (JA), ethylene (ET), and defense protein genes, as well as a down-regulation of pathways involved in photosynthesis and energy metabolism. The expression analysis also highlighted that RB867515 cultivar is possibly more transcriptionally activated after 12 h from infestation than SP80-3280, which could imply in quicker responses by probably triggering more defense-related genes and mediating metabolic pathways to cope with borer attack.

Asunto(s)

Grano Comestible/genética , Lepidópteros/metabolismo , Saccharum/genética , Transcripción Genética , Animales , Ciclopentanos/metabolismo , Grano Comestible/metabolismo , Grano Comestible/parasitología , Larva/genética , Larva/parasitología , Lepidópteros/patogenicidad , Oxilipinas/metabolismo , Saccharum/parasitología

RESUMEN

The plant hormones salicylic acid (SA) and jasmonic acid (JA) regulate defense mechanisms capable of overcoming different plant stress conditions and constitute distinct but interconnected signaling pathways. Interestingly, several other molecules are reported to trigger stress-specific defense responses to biotic and abiotic stresses. In this study, we investigated the effect of 14 elicitors against diverse but pivotal types of abiotic (drought) and biotic (the chewing insect Ascia monuste, the hemibiotrophic bacterium Pseudomonas syringae DC 3000 and the necrotrophic fungus Alternaria alternata) stresses on broccoli and Arabidopsis. Among the main findings, broccoli pre-treated with SA and chitosan showed the highest drought stress recovery in a dose-dependent manner. Several molecules led to increased drought tolerance over a period of three weeks. The enhanced drought tolerance after triggering the SA pathway was associated with stomata control. Moreover, methyl jasmonate (MeJA) reduced A. monuste insect development and plant damage, but unexpectedly, other elicitors increased both parameters. GUS reporter assays indicated expression of the SA-dependent PR1 gene in plants treated with nine elicitors, whereas the JA-dependent LOX2 gene was only expressed upon MeJA treatment. Overall, elicitors capable of tackling drought and biotrophic pathogens mainly triggered the SA pathway, but adversely also induced systemic susceptibility to chewing insects. These findings provide directions for potential future in-depth characterization and utilization of elicitors and induced resistance in plant protection.

Asunto(s)

Arabidopsis/inmunología , Brassica/inmunología , Resistencia a la Enfermedad , Enfermedades de las Plantas/inmunología , Acetatos/metabolismo , Alternaria/patogenicidad , Animales , Arabidopsis/microbiología , Arabidopsis/parasitología , Brassica/microbiología , Brassica/parasitología , Mariposas Diurnas/patogenicidad , Ciclopentanos/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas/inmunología , Oxilipinas/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitología , Proteínas de Plantas/metabolismo , Pseudomonas syringae/patogenicidad , Ácido Salicílico/metabolismo

RESUMEN

Expansins are encoded by some phytopathogenic bacteria and evidence indicates that they act as virulence factors for host infection. Here we analysed the expression of exl1 by Pectobacterium brasiliense and Pectobacterium atrosepticum. In both, exl1 gene appears to be under quorum sensing control, and protein Exl1 can be observed in culture medium and during plant infection. Expression of exl1 correlates with pathogen virulence, where symptoms are reduced in a Δexl1 mutant strain of P. atrosepticum. As well as Δexl1 exhibiting less maceration of potato plants, fewer bacteria are observed at distance from the inoculation site. However, bacteria infiltrated into the plant tissue are as virulent as the wild type, suggesting that this is due to alterations in the initial invasion of the tissue. Additionally, swarming from colonies grown on MacConkey soft agar was delayed in the mutant in comparison to the wild type. We found that Exl1 acts on the plant tissue, probably by remodelling of a cell wall component or altering the barrier properties of the cell wall inducing a plant defence response, which results in the production of ROS and the induction of marker genes of the JA, ET and SA signalling pathways in Arabidopsis thaliana. Exl1 inactive mutants fail to trigger such responses. This defence response is protective against Pectobacterium brasiliense and Botrytis cinerea in more than one plant species.

Asunto(s)

Arabidopsis/citología , Pectobacterium/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Factores de Virulencia/metabolismo , Arabidopsis/inmunología , Arabidopsis/microbiología , Ciclopentanos/metabolismo , Etilenos/metabolismo , Regulación Bacteriana de la Expresión Génica , Interacciones Huésped-Patógeno , Oxilipinas/metabolismo , Pectobacterium/citología , Pectobacterium/genética , Pectobacterium/fisiología , Percepción de Quorum , Ácido Salicílico/metabolismo , Virulencia , Factores de Virulencia/genética

RESUMEN

The biotrophic fungus Phakopsora pachyrhizi is currently the major pathogen affecting soybean production worldwide. It has already been suggested for the non-host interaction between P. pachyrhizi and Arabidopsis thaliana that the fungus in early infection induces jasmonic acid (JA) pathway to the detriment of the salicylic acid (SA) pathway as a mechanism to the establishment of infection. In this study, we verified that this mechanism might also be occurring during the compatible interaction in soybean (Glycine max L. Merril). It was demonstrated that P. pachyrhizi triggers a JA pathway during the early and late stages of infection in a susceptible soybean cultivar. The expression of the GmbZIP89 was induced in a biphasic profile, similarly to other JA responsive genes, which indicates a new marker gene for this signaling pathway. Additionally, plants silenced for GmbZIP89 (iGmZIP89) by the virus-induced gene silencing (VIGS) approach present lower severity of infection and higher expression of pathogenesis related protein 1 (PR1). The lower disease severity showed that the iGmbZIP89 plants became more resistant to infection. These data corroborate the hypothesis that the GmbZIP89 may be a resistance negative regulator. In conclusion, we demonstrated that P. pachyrhizi mimics a necrotrophic fungus and activates the JA/ET pathway in soybean. It is possible to suppose that its direct penetration on epidermal cells or fungal effectors may modulate the expression of target genes aiming the activation of the JA pathway and inhibition of SA defense.

Asunto(s)

Ciclopentanos , Glycine max , Interacciones Huésped-Patógeno , Oxilipinas , Phakopsora pachyrhizi , Transducción de Señal , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Interacciones Huésped-Patógeno/fisiología , Oxilipinas/metabolismo , Phakopsora pachyrhizi/fisiología , Enfermedades de las Plantas/microbiología , Glycine max/microbiología

RESUMEN

INTRODUCTION: Vitis labrusca L. grapes are largely cultivated in Brazil, but the tropical climate negatively affects the phenols content, especially anthocyanin. According to the projections of the incoming climatic changes, the climate of several viticulture zone might change to tropical. Therefore, researches are focusing on increasing grape phenols content; with methyl jasmonate application (MeJa) is considered a good alternative. OBJECTIVES: The aim was to investigate with an untargeted approach the metabolic changes caused by the MeJa pre-harvest application on two Vitis labrusca L. cultivars grapes, both of them grown in two Brazilian regions. METHODS: Isabel Precoce and Concord grapes cultivated under subtropical climate, in the south and southeast of Brazil, received MeJa pre-harvest treatment. Grape metabolome was extracted and analyzed with a MS based metabolomics protocol by UPLC-HRMS-QTOF. RESULTS: Unsupervised data analysis revealed a clear separation between the two regions and the two cultivars, while supervised data analysis revealed biomarkers between the MeJa treatment group and the control group. Among the metabolites positively affected by MeJa were (a) flavonoids with a high degree of methylation at the B-ring (malvidin and peonidin derivatives and isorhamentin) for Isabel Precoce grapes; (b) glucosides of hydroxycinnamates, gallocatechin, epigallocatechin and cis-piceid for Concord grapes; and (c) hydroxycinnamates esters with tartaric acid, and procyanidins for the Southeast region grapes. CONCLUSION: These results suggest that MeJa can be used as elicitor to secondary metabolism in grapes grown even under subtropical climate, affecting phenolic biosynthesis.

Asunto(s)

Acetatos/análisis , Ciclopentanos/análisis , Oxilipinas/análisis , Fenoles/análisis , Vitis/química , Acetatos/metabolismo , Brasil , Cromatografía Líquida de Alta Presión , Ciclopentanos/metabolismo , Espectrometría de Masas , Metabolómica , Oxilipinas/metabolismo , Fenoles/metabolismo , Vitis/metabolismo

RESUMEN

Plants produce species-specific herbivore-induced plant volatiles (HIPVs) after damage. We tested the hypothesis that herbivore-specific HIPVs prime neighboring plants to induce defenses specific to the priming herbivore. Since Manduca sexta (specialist) and Heliothis virescens (generalist) herbivory induced unique HIPV profiles in Nicotiana benthamiana, we used these HIPVs to prime receiver plants for defense responses to simulated herbivory (mechanical wounding and herbivore regurgitant application). Jasmonic acid (JA) accumulations and emitted volatile profiles were monitored as representative defense responses since JA is the major plant hormone involved in wound and defense signaling and HIPVs have been implicated as signals in tritrophic interactions. Herbivore species-specific HIPVs primed neighboring plants, which produced 2 to 4 times more volatiles and JA after simulated herbivory when compared to similarly treated constitutive volatile-exposed plants. However, HIPV-exposed plants accumulated similar amounts of volatiles and JA independent of the combination of priming or challenging herbivore. Furthermore, volatile profiles emitted by primed plants depended only on the challenging herbivore species but not on the species-specific HIPV profile of damaged emitter plants. This suggests that feeding by either herbivore species primed neighboring plants for increased HIPV emissions specific to the subsequently attacking herbivore and is probably controlled by JA.

Asunto(s)

Herbivoria/fisiología , Nicotiana/inmunología , Nicotiana/metabolismo , Compuestos Orgánicos Volátiles/metabolismo , Animales , Ciclopentanos/metabolismo , Manduca/fisiología , Mariposas Nocturnas/fisiología , Oxilipinas/metabolismo , Hojas de la Planta/metabolismo , Nicotiana/parasitología

RESUMEN

OBJECTIVES: To determine the production of 9-hydroxyoctadecadienoic acid and 13-hydroxyoctadecadienoic acid during cardiopulmonary bypass in infants and children undergoing cardiac surgery, evaluate their relationship with increase in cell-free plasma hemoglobin, provide evidence of bioactivity through markers of inflammation and vasoactivity (WBC count, milrinone use, vasoactive-inotropic score), and examine their association with overall clinical burden (ICU/hospital length of stay and mechanical ventilation duration). DESIGN: Prospective observational study. SETTING: Twelve-bed cardiac ICU in a university-affiliated children's hospital. PATIENTS: Children were prospectively enrolled during their preoperative clinic appointments with the following criteria: greater than 1 month to less than 18 years old, procedures requiring cardiopulmonary bypass INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS: Plasma was collected at the start and end of cardiopulmonary bypass in 34 patients. 9-hydroxyoctadecadienoic acid, 13-hydroxyoctadecadienoic acid, plasma hemoglobin, and WBC increased. 9:13-hydroxyoctadecadienoic acid at the start of cardiopulmonary bypass was associated with vasoactive-inotropic score at 2-24 hours postcardiopulmonary bypass (R = 0.25; p < 0.01), milrinone use (R = 0.17; p < 0.05), and WBC (R = 0.12; p < 0.05). 9:13-hydroxyoctadecadienoic acid at the end of cardiopulmonary bypass was associated with vasoactive-inotropic score at 2-24 hours (R = 0.17; p < 0.05), 24-48 hours postcardiopulmonary bypass (R = 0.12; p < 0.05), and milrinone use (R = 0.19; p < 0.05). 9:13-hydroxyoctadecadienoic acid at the start and end of cardiopulmonary bypass were associated with the changes in plasma hemoglobin (R = 0.21 and R = 0.23; p < 0.01). The changes in plasma hemoglobin was associated with milrinone use (R = 0.36; p < 0.001) and vasoactive-inotropic score less than 2 hours (R = 0.22; p < 0.01), 2-24 hours (R = 0.24; p < 0.01), and 24-48 hours (R = 0.48; p < 0.001) postcardiopulmonary bypass. Cardiopulmonary bypass duration, 9:13-hydroxyoctadecadienoic acid at start of cardiopulmonary bypass, and plasma hemoglobin may be risk factors for high vasoactive-inotropic score. Cardiopulmonary bypass duration, changes in plasma hemoglobin, 9:13-hydroxyoctadecadienoic acid, and vasoactive-inotropic score correlate with ICU and hospital length of stay and/mechanical ventilation days. CONCLUSIONS: In low-risk pediatric patients undergoing cardiopulmonary bypass, 9:13-hydroxyoctadecadienoic acid was associated with changes in plasma hemoglobin, vasoactive-inotropic score, and WBC count, and may be a risk factor for high vasoactive-inotropic score, indicating possible inflammatory and vasoactive effects. Further studies are warranted to delineate the role of hydroxyoctadecadienoic acids and plasma hemoglobin in cardiopulmonary bypass-related dysfunction and to explore hydroxyoctadecadienoic acid production as a potential therapeutic target.

Asunto(s)

Puente Cardiopulmonar/métodos , Ácidos Grasos Insaturados/sangre , Cardiopatías Congénitas/cirugía , Ácidos Linoleicos/sangre , Oxilipinas/sangre , Biomarcadores/sangre , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/métodos , Puente Cardiopulmonar/efectos adversos , Niño , Preescolar , Ácidos Grasos Insaturados/metabolismo , Femenino , Cardiopatías Congénitas/tratamiento farmacológico , Hemoglobinas/análisis , Humanos , Lactante , Unidades de Cuidados Intensivos , Tiempo de Internación , Recuento de Leucocitos , Ácidos Linoleicos/metabolismo , Masculino , Milrinona/uso terapéutico , Oxilipinas/metabolismo , Estudios Prospectivos , Respiración Artificial , Factores de Riesgo , Vasodilatadores/uso terapéutico