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 GénicaRESUMEN
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 MultigenesRESUMEN
Yellow pitahaya is a tropical fruit that has gained popularity in recent years. Natural elicitors are compounds that can stimulate the resistance and quality of fruits. The objective of this study was to evaluate the effects of natural elicitors, methyl salicylate (MeSa), methyl jasmonate (JaMe), salicylic acid (SA) and oxalic acid (OA) at concentrations of 0.1 mM (MeSa and JaMe) and 5 mM (SA and OA), applied to the yellow pitahaya fruits under greenhouse conditions. After full blossom, four applications were made with a frequency of 15 days. At the time of harvest and after storage, the following variables were evaluated: firmness (whole fruit), total soluble solids (TSS), total acidity (TA), phenolics and carotenoids (in the pulp), while phenolics, carotenoids, macronutrients and micronutrients were determined in the peel. The results showed MeSa advanced the fruit maturation, according to higher TSS, lower TA and firmness than MeJa-treated fruits, for which a delayed ripening process was shown. All treatments induced a higher polyphenolic concentration during storage. Regarding the alternative use of the peel as a by-product, the application of natural elicitors significantly increased the content of polyphenols, carotenoids, macronutrients and micronutrients in the peel, especially MeSa, which can be used as a bioactive compound in the food industry. In conclusion, the results indicate that natural elicitors can be an alternative to improve the quality and shelf life of yellow pitahaya fruits.
Asunto(s)
Acetatos , Cactaceae , Carotenoides , Ciclopentanos , Almacenamiento de Alimentos , Frutas , Oxilipinas , Ácido Salicílico , Frutas/química , Frutas/efectos de los fármacos , Frutas/metabolismo , Frutas/crecimiento & desarrollo , Oxilipinas/farmacología , Ciclopentanos/farmacología , Ciclopentanos/metabolismo , Acetatos/farmacología , Carotenoides/metabolismo , Almacenamiento de Alimentos/métodos , Cactaceae/química , Cactaceae/crecimiento & desarrollo , Cactaceae/metabolismo , Ácido Salicílico/farmacología , Salicilatos/farmacología , Salicilatos/metabolismo , Fenoles/análisis , Ácido Oxálico/metabolismoRESUMEN
Soybean (Glycine max ) is the world's most widely grown seed legume. One of the most important pests that decrease seed quality and reduce yield of soybean crops is the southern green stink bug (Nezara viridula ). Insect damage triggers accumulation of defensive compounds such as protease inhibitors (PIs), isoflavonoids and reactive oxygen species, which are regulated by the lipoxygenase (LOX)-regulated jasmonic acid (JA) to stop insect feeding. This study identified and characterised the role of LOX isoforms in the modulation of chemical defences in seeds of field-grown soybean that decreased digestive enzyme activities of N. viridula after insect attack. Stink bugs attack increased LOX 1 and LOX 2 expression, and activities of LOX 1 and LOX 3 isoenzymes in developing soybean seeds. In addition, stink bug damage and methyl jasmonate application induced expression and activity of both cysteine PIs and trypsin PIs in developing soybean seeds, suggesting that herbivory induced JA in soybean seeds. High PI activity levels in attacked seeds decreased cysteine proteases and α-amylases activities in the gut of stink bugs that fed on field-grown soybean. We demonstrated that LOX isoforms of seeds are concomitantly induced with JA-regulated PIs by stink bugs attack, and these PIs inhibit the activity of insect digestive enzymes. To our knowledge, this is the first study to investigate the participation of LOX in modulating JA-regulated defences against stink bugs in seeds of field-grown soybean, and our results suggest that soybean PIs may inhibit α-amylase activity in the gut of N. viridula .
Asunto(s)
Ciclopentanos , Glycine max , Heterópteros , Oxilipinas , Animales , Lipooxigenasas , Semillas , Heterópteros/fisiología , Isoformas de Proteínas , Inhibidores Enzimáticos , Receptores Depuradores de Clase ERESUMEN
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/metabolismoRESUMEN
Co-infestations by herbivores, a common situation found in natural settings, can distinctly affect induced plant defenses compared to single infestations. Related tritrophic interactions might be affected through the emission of changed blends of herbivore-induced plant volatiles (HIPVs). In a previous study, we observed that the infestation by red spider mite (Oligonychus ilicis) on coffee plants facilitated the infestation by white mealybug (Planococcus minor), whereas the reverse sequence of infestation did not occur. Here, we examined the involvement of the jasmonate and salicylate pathways in the plant-mediated asymmetrical facilitation between red spider mites and white mealybugs as well as the effect of multiple herbivory on attractiveness to the predatory mite Euseius concordis and the ladybug Cryptolaemus montrouzieri. Both mite and mealybug herbivory led to the accumulation of JA-Ile, JA, and cis-OPDA in plants, although the catabolic reactions of JA-Ile were specifically regulated by each herbivore. Infestation by mites or mealybugs induced the release of novel volatiles by coffee plants, which selectively attracted their respective predators. Even though the co-infestation by mites and mealybugs resulted in a stronger accumulation of JA-Ile, JA and SA than the single infestation treatments, the volatile emission was similar to that of mite-infested or mealybug-infested plants. However, multiple infestation had a negative impact on the attractiveness of HIPVs to the predators, making them less attractive to the predatory mite and a repellent to the ladybug. We discuss the potential underlying mechanisms of the susceptibility induced by mites, and the effect of multiple infestation on each predator.
Asunto(s)
Coffea , Tetranychidae , Animales , Herbivoria , Café , Ciclopentanos/metabolismoRESUMEN
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 PlantasRESUMEN
The mechanism of Diels-Alder reactions between cyclopentadiene and several cyanoethylenes was studied by means of Density Functional Theory calculations using QTAIM and IQA (Interacting Quantum Atoms) analyses along complete IRC paths. Each geometry from the IRC had its wavefunction computed and the topology of the electronic density for it was then evaluated. By means of IQA, the global energetic profile was partitioned among the various atoms in the molecule, providing insight into what atoms are the main ones responsible for the magnitude of the energy barriers. The (a)synchronicity of the reaction mechanisms featuring non-symmetrically substituted dienophiles was characterized, from QTAIM, by the electron densities and Laplacians over the LCP's as well as by the different atomic energy barriers obtained from IQA. The magnitude of the atomic barrier nicely explains the (a)synchronicity of the reaction mechanisms, and the degree of (a)synchronicity is nicely revealed by the difference between the earlier and later bond breaking and bond formations. The main conclusion is that important energetic and electronic changes are occurring before and after the position of the transition state structure, mainly for those asynchronous mechanisms, and although these provide essential insight into the reaction mechanism, most studies cannot assess this kind of information because they are focusing solely on reactants, transition states, and products. We advocate that the additional computational effort required for such analyses is more than compensated by the great amount of useful information it provides.
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Ciclopentanos , Teoría Cuántica , Modelos Moleculares , Reacción de Cicloadición , Ciclopentanos/química , ElectrónicaRESUMEN
Phyllanthus acuminatus has been studied for its vast medical and industrial potential. Phytochemical investigations reveal that the genus is a rich source of lignans, flavonoids, phenolics, terpenoids, and other metabolites. However, the phytochemical profile elucidation of this species still needs further research. The use of eliciting compounds such as salicylic acid and methyl jasmonate has managed to increase the production of secondary metabolites in plant cell cultures. Hairy roots of Phyllanthus acuminatus were produced in 250 mL flasks with a 16 h light/8 h darkness photoperiod under diffused light with a culture time of four weeks. The elicitors salicylic acid and methyl jasmonate were tested in 50 µM and 200 µM concentrations. Non-targeted analysis was done for the different treatments using HR-MS. Identified metabolites were grouped in phenylpropanoids, phenols, and mucic acids, and statistical analysis of relative concentrations was achieved. A significant change in phenols' relative concentrations appeared in the elicitations with salicylic acid. Because of the elicitation treatment, specific compounds increased their concentrations, some of which have known pharmacological effects and are used in treating chronic diseases. The best elicitation treatment was salicylic acid 50 µM as it increased by more than 100% the general content of phenols and phenylpropanoid derivates and triplicates the concentration of mucic acid derivates in treated hairy root extracts. The application of non-targeted analysis showed interesting changes in phytochemical concentration due to elicitation in Phyllanthus acuminatus hairy roots.
Asunto(s)
Acetatos , Ciclopentanos , Oxilipinas , Fenoles , Phyllanthus , Azúcares Ácidos , Espectrometría de Masas , Ácido Salicílico/farmacología , Fitoquímicos/farmacologíaRESUMEN
The acid-promoted cyclization of all-trans linearly conjugated dienones and dienals constitutes a synthetic strategy for the construction of 2-cyclopentenones.
Asunto(s)
Ácidos , Ciclopentanos , Ciclización , Catálisis , EstereoisomerismoRESUMEN
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/farmacologíaRESUMEN
Enhancement of plant defense by exogenous elicitors is a promising tool for integrated pest management strategy. In the present study, cotton plants were treated with different concentrations (0, 0.01, 0.1, and 1.0 mM) of the natural plant defense elicitor, jasmonic acid (JA), and defense-related indicators in the plants were then determined. The cotton bollworm larvae were fed with JA-treated cotton leaves and larvae performances were discussed in terms of larvae relative growth rate (RGR), larval duration, pupal mass, humoral immunity, and activities of a target enzyme, three detoxification enzymes and two metabolic enzymes. Research results showed that JA treatment increased the contents of gossypol and H2O2, and decreased that of the total soluble carbohydrates, and 0.1 mM JA was more powerful in the induction of defense-related parameters. As a consequence, cotton bollworm larvae reared on JA-treated cotton leaves showed slower RGR, prolonged larvae duration, and decreased pupal mass. In addition, when larvae were fed with JA-treated cotton leaves, activities of phenoloxidae (an indicator of humoral immunity) and acetylcholinesterase (AchE, a target enzyme), alkaline phosphatases (ALP), acidic phosphatase (ACP), and three detoxification enzymes, carboxylesterase (CarE), glutathione S-transferase (GST), and cytochrome P450 (P450), were all reduced compared to the control. Taken together, the results suggest that JA can be an alternative agent for pest management by delaying insect growth and inhibiting immune defense and detoxification capacity of the cotton bollworm, which may reduce the use of synthetic pesticides.
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Gossypium , Mariposas Nocturnas , Acetilcolinesterasa/metabolismo , Animales , Ciclopentanos , Sistema Enzimático del Citocromo P-450/metabolismo , Peróxido de Hidrógeno/metabolismo , Inmunidad Humoral , Larva , Oxilipinas , Hojas de la Planta , PupaRESUMEN
Trichoderma atroviride is a root-colonizing fungus that confers multiple benefits to plants. In plants, small RNA (sRNA)-mediated gene silencing (sRNA-MGS) plays pivotal roles in growth, development, and pathogen attack. Here, we explored the role of core components of Arabidopsis thaliana sRNA-MGS pathways during its interaction with Trichoderma. Upon interaction with Trichoderma, sRNA-MGS-related genes paralleled the expression of Arabidopsis defense-related genes, linked to salicylic acid (SA) and jasmonic acid (JA) pathways. SA- and JA-related genes were primed by Trichoderma in leaves after the application of the well-known pathogen-associated molecular patterns flg22 and chitin, respectively. Defense-related genes were primed in roots as well, but to different extents and behaviors. Phenotypical characterization of mutants in AGO genes and components of the RNA-dependent DNA methylation (RdDM) pathway revealed that different sets of sRNA-MGS-related genes are essential for (i) the induction of systemic acquired resistance against Botrytis cinerea, (ii) the activation of the expression of plant defense-related genes, and (iii) root colonization by Trichoderma. Additionally, plant growth induced by Trichoderma depends on functional RdDM. Profiling of DNA methylation and histone N-tail modification patterns at the Arabidopsis Nitrile-Specifier Protein-4 (NSP4) locus, which is responsive to Trichoderma, showed altered epigenetic modifications in RdDM mutants. Furthermore, NSP4 is required for the induction of systemic acquired resistance against Botrytis and avoidance of enhanced root colonization by Trichoderma. Together, our results indicate that RdDM is essential in Arabidopsis to establish a beneficial relationship with Trichoderma. We propose that DNA methylation and histone modifications are required for plant priming by the beneficial fungus against B. cinerea.
Asunto(s)
Arabidopsis/genética , Arabidopsis/metabolismo , Resistencia a la Enfermedad/genética , Silenciador del Gen , Hypocreales/genética , Nitrilos/metabolismo , ARN/metabolismo , Proteínas de Arabidopsis/metabolismo , Botrytis , Ciclopentanos , Regulación de la Expresión Génica de las Plantas , Hypocreales/metabolismo , Oxilipinas , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Raíces de Plantas/metabolismo , Ácido Salicílico/metabolismo , Trichoderma/genética , Trichoderma/metabolismoRESUMEN
BACKGROUND: Andean lupin (Lupinus mutabilis Sweet) is an important leguminous crop from South America with a high protein content. In Ecuador, lupin yields are severely affected by the infestation of Delia platura larvae on germinating seeds. The application of elicitor molecules with activity against herbivorous insects to control D. platura infestation constitutes an unexplored and promising alternative for chemical insecticides. In this study, methyl jasmonate (MeJA), hexanoic acid, menadione sodium bisulfite, and DL-ß-aminobutyric acid were evaluated for their ability to induce resistance against D. platura in three commercial lupin cultivars. RESULTS: Only seeds pretreated with MeJA significantly impaired insect performance during choice and no-choice assays. Additionally, fitness indicators such as seed germination and growth were not affected by MeJA treatment. To investigate the molecular mechanisms behind the MeJA-mediated resistance, RT-qPCR assays were performed. First, RT-qPCR reference genes were validated, showing that LmUBC was the most stable reference gene. Next, expression analysis over time revealed that MeJA application up-regulated the activity of the jasmonic acid biosynthetic genes LmLOX2 and LmAOS, together with other jasmonate-related defense genes, such as LmTPS1, LmTPS4, LmPI2, LmMBL, LmL/ODC, LmCSD1, and LmPOD. CONCLUSION: This study indicates that MeJA can be used as an environmentally friendly elicitor molecule to protect Andean lupin from D. platura attack without fitness cost. MeJA application induces plant defense responses to insects in Andean lupin that may be modulated by the onset of terpenoid biosynthesis, proteinase inhibitors, lectins, polyamines, and antioxidative enzymes. © 2021 Society of Chemical Industry.
Asunto(s)
Dípteros , Lupinus , Acetatos/farmacología , Animales , Ciclopentanos/farmacología , Regulación de la Expresión Génica de las Plantas , Oxilipinas/farmacología , SemillasRESUMEN
N,N-dimethyl-hexadecylamine (DMHDA) is released as part of volatile blends emitted by plant probiotic bacteria and affects root architecture, defense and nutrition of plants. Here, we investigated the changes in gene expression of transcription factors responsible of maintenance of the root stem cell niche and jasmonic acid signaling in Arabidopsis seedlings in response to this volatile. Concentrations of DMHDA that repress primary root growth were found to alter cell size and division augmenting cell tissue layers in the meristem and causing root widening. DMHDA triggered the division of quiescent center cells, which correlated with repression of SHORT ROOT (SHR), SCARECROW (SCR), and PLETHORA 1 (PLT1) proteins and induction of WUSCHEL-RELATED HOMEOBOX 5 (WOX5) transcription factor. Interestingly, an activation of the expression of the jasmonic acid-related reporter genes JAZ1/TIFY10A-GFP and JAZ10pro::JAZ10-GFP suggests that the halted growth of the primary root inversely correlated with expression patterns underlying the defense reaction, which may be of adaptive importance to protect roots against biotic stress. Our data help to unravel the gene expression signatures upon sensing of a highly active bacterial volatile in Arabidopsis seedlings.
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Proteínas de Arabidopsis , Arabidopsis , Aminas , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ciclopentanos , Expresión Génica , Regulación de la Expresión Génica de las Plantas , Hidrocarburos , Oxilipinas , Raíces de Plantas/metabolismo , Nicho de Células MadreRESUMEN
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/patogenicidadRESUMEN
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/genéticaRESUMEN
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.
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Adaptación Fisiológica/genética , Ciclopentanos/metabolismo , Genómica , Oxilipinas/metabolismo , Plantas/genética , Estrés Salino/genética , Tolerancia a la Sal/genéticaRESUMEN
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.
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Ciclopentanos/metabolismo , Apocynaceae/genética , Oxilipinas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Estrés Fisiológico , Flavonoides/biosíntesis , Secuencia de Bases , Expresión Génica , Ambiente , TranscriptomaRESUMEN
Two new penta- and tetrasubstituted cyclopentenones, named phaseocyclopentenones A and B (1 and 2), together with guignardone A (3), were isolated from Macrophomina phaseolina cultures. The phytopathogenic fungus was isolated from infected soybean tissues showing charcoal rot symptoms in Argentina. Charcoal rot is a devastating disease considering that soybean is one of the main legumes cultivated in the world. Phaseocyclopentenones A and B were characterized by 1D and 2D 1H and 13C NMR spectroscopic and HRESIMS spectrometric data and chemical methods as 4-benzoyl-3,4,5-trihydroxy-2-phenylcyclopent-2-enone and 3,5-dihydroxy-2,4-diphenylcyclopent-2-enone, respectively. The relative configuration of phaseocyclopentenones A and B was assigned by 1H and NOESY NMR methods, while their absolute configurations were assigned by electronic circular dichroism methods. When assayed on a nonhost plant (Solanum lycopersicum L.) by the leaf puncture assay, phaseocyclopentenones A and B and guignardone A showed phytotoxic activity, while only 1 and 2 were toxic when tested on cuttings of the same plant. No phytotoxicity or antifungal activity was detected for the three compounds on the host plant soybean (Glycine max L.) and against some of its fungal pathogens, namely, Cercospora nicotianae and Colletotrichum truncatum, also isolated from infected soybean plants in Argentina.