RESUMEN
Ethylene response factor (ERF) is a class of plant-specific transcription factors that play an important role in plant growth, development, and stress response. However, the underlying mechanism of strawberry ERFs in pathogenic responses against Botrytis cinerea (B. cinerea) remains largely unclear. In this study, we isolated FaERF2, a nucleus-localized ERF transcription factor from Fragaria x ananassa. Transiently overexpressing FaERF2 in strawberry fruits significantly enhances their resistant ability to B. cinerea, while silencing FaERF2 in strawberry fruits enhances their susceptibility to B. cinerea. In addition, we found that FaERF2 could directly bind to the cis-acting element GCC box in the promoters of two ß-1,3-glucanase genes, FaBG-1 and FaBG-2, and activate their expression. Finally, both strawberry fruits transient expression followed by B. cinerea inoculation assays and recombinant protein incubation tests collectively substantiated the inhibitory effect of FaBG-1 and FaBG-2 on B. cinerea mycelium growth. These results revealed the molecular regulation mechanism of FaERF2 in response to B. cinerea and laid foundations for creating disease-resistance strawberry cultivar through genome editing approach.
Asunto(s)
Botrytis , Resistencia a la Enfermedad , Fragaria , Enfermedades de las Plantas , Proteínas de Plantas , Botrytis/fisiología , Fragaria/genética , Fragaria/microbiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Resistencia a la Enfermedad/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regulación de la Expresión Génica de las Plantas , Glucano 1,3-beta-Glucosidasa/metabolismo , Glucano 1,3-beta-Glucosidasa/genéticaRESUMEN
Fusarium head blight (FHB) is a devastating fungal disease affecting different cereals, particularly wheat, and poses a serious threat to global wheat production. Chitinases and ß-glucanases are two important proteins involved in lysing fungal cell walls by targeting essential macromolecular components, including chitin and ß-glucan micro fibrils. In our experiment, a transgenic wheat (Triticum aestivum) was generated by introducing chitinase and glucanase genes using Biolistic technique and Recombinant pBI121 plasmid (pBI-ChiGlu (-)). This plasmid contained chitinase and glucanase genes as well as nptII gene as a selectable marker. The expression of chitinase and glucanase was individually controlled by CaMV35S promoter and Nos terminator. Immature embryo explants from five Iranian cultivars (Arta, Moghan, Sisun, Gascogen and A-Line) were excised from seeds and cultured on callus induction medium to generate embryonic calluses. Embryogenic calluses with light cream color and brittle texture were selected and bombarded using gold nanoparticles coated with the recombinant pBI-ChiGlu plasmid. Bombarded calluses initially were transferred to selective callus induction medium, and later, they were transfferd to selective regeneration medium. The selective agent was kanamycin at a concentration of 25 mg/l in both media. Among five studied cultivars, A-Line showed the highest transformation percentage (4.8%), followed by the Sisun, Gascogen and Arta in descending order. PCR and Southern blot analysis confirmed the integration of genes into the genome of wheat cultivars. Furthermore, in an in-vitro assay, the growth of Fusarium graminearum was significantly inhibited by using 200 µg of leaf protein extract from transgenic plants. According to our results, the transgenic plants (T1) showed the resistance against Fusarium when were compared to the non-transgenic plants. All transgenic plants showed normal fertility and no abnormal response was observed in their growth and development.
Asunto(s)
Quitinasas , Resistencia a la Enfermedad , Fusarium , Enfermedades de las Plantas , Triticum , Quitinasas/genética , Quitinasas/metabolismo , Resistencia a la Enfermedad/genética , Fusarium/genética , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/metabolismo , Irán , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Triticum/genética , Triticum/metabolismo , Triticum/microbiologíaRESUMEN
BACKGROUND: Many phytopathogens secrete a large number of cell wall degrading enzymes (CWDEs) to decompose host cell walls in order to penetrate the host, obtain nutrients and accelerate colonization. There is a wide variety of CWDEs produced by plant pathogens, including glycoside hydrolases (GHs), which determine the virulence, pathogenicity, and host specificity of phytopathogens. The specific molecular mechanisms by which pathogens suppress host immunity remain obscure. RESULT: In this study, we found that CgEC124 encodes a glycosyl hydrolase with a signal peptide and a conserved Glyco_hydro_cc domain which belongs to glycoside hydrolase 128 family. The expression of CgEC124 was significantly induced in the early stage of Colletotrichum graminicola infection, especially at 12 hpi. Furthermore, CgEC124 positively regulated the pathogenicity, but it did not impact the vegetative growth of mycelia. Ecotopic transient expression of CgEC124 decreased the disease resistance and callose deposition in maize. Moreover, CgEC124 exhibited the ß-1,3-glucanase activity and suppresses glucan-induced ROS burst in maize leaves. CONCLUSIONS: Our results indicate that CgEC124 is required for full virulence of C. graminicola but not for vegetative growth. CgEC124 increases maize susceptibility by inhibiting host reactive oxygen species burst as well as callose deposition. Meanwhile, our data suggests that CgEC124 explores its ß-1,3-glucanase activity to prevent induction of host defenses.
Asunto(s)
Colletotrichum , Enfermedades de las Plantas , Inmunidad de la Planta , Zea mays , Colletotrichum/patogenicidad , Resistencia a la Enfermedad , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Glucano 1,3-beta-Glucosidasa/metabolismo , Glucano 1,3-beta-Glucosidasa/genética , Glucanos/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Especies Reactivas de Oxígeno/metabolismo , Zea mays/inmunología , Zea mays/microbiologíaRESUMEN
Laminaripentaose (L5)-producing ß-1,3-glucanases can preferentially cleave the triple-helix curdlan into ß-1,3-glucooligosaccharides, especially L5. In this study, a newly identified member of the glycoside hydrolase family 64, ß-1,3-glucanase from Streptomyces pratensis (SpGlu64A), was functionally and structurally characterized. SpGlu64A shared highest identity (30%) with a ß-1,3-glucanase from Streptomyces matensis. The purified SpGlu64A showed maximal activity at pH 7.5 and 50 °C, and exhibited strict substrate specificity toward curdlan (83.1 U·mg-1). It efficiently hydrolyzed curdlan to produce L5 as the end product. The overall structure of SpGlu64A consisted of a barrel domain and a mixed (α/ß) domain, which formed an unusually wide groove with a crescent-like structure. In the two complex structures (SpGlu64A-L3 and SpGlu64A-L4), two oligosaccharide chains were captured and the triple-helical structure was relatively compatible with the wide groove, which suggested the possibility of binding to the triple-helical ß-1,3-glucan. A catalytic framework (ß6-ß9-ß10) and the steric hindrance formed by the side chains of residues Y161, N163, and H393 in the catalytic groove were predicted to complete the exotype-like cleavage manner. On the basis of the structure, a fusion protein with the CBM56 domain (SpGlu64A-CBM) and a mutant (Y161F; by site-directed mutation) were obtained, with 1.2- and 1.7-fold increases in specific activity, respectively. Moreover, the combined expression of SpGlu64A-CBM and -Y161F improved the enzyme activity by 2.63-fold. The study will not only be helpful in understanding the reaction mechanism of ß-1,3-glucanases but will also provide a basis for further enzyme engineering.
Asunto(s)
Oligosacáridos , Streptomyces , beta-Glucanos , Streptomyces/enzimología , Streptomyces/genética , Especificidad por Sustrato , beta-Glucanos/metabolismo , Oligosacáridos/metabolismo , Oligosacáridos/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Modelos Moleculares , Glucano 1,3-beta-Glucosidasa/metabolismo , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/química , Secuencia de Aminoácidos , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/metabolismo , Glicósido Hidrolasas/química , Dominio Catalítico , Cristalografía por Rayos X , Hidrólisis , Concentración de Iones de Hidrógeno , CinéticaRESUMEN
Chitooligosaccharides (CHOS) with multiple biological activities are usually produced through enzymatic hydrolysis of chitosan or chitin. However, purification and recycling of the enzyme have largely limited the advancement of CHOS bioproduction. Here, we engineered a novel enzyme by fusing the native chitosanase Csn75 with a carbohydrate-binding module (CBM) that can specifically bind to curdlan. The recombinase Csn75-CBM was successfully expressed by Pichia pastoris and allowed one-step purification and immobilization in the chitosanase immobilized curdlan packed-bed reactor (CICPR), where a maximum adsorption capacity of 39.59 mg enzyme/g curdlan was achieved. CHOS with degrees of polymerization of 2-5 (a hydrolysis yield of 97.75%), 3-6 (75.45%), and 3-7 (73.2%) were continuously produced by adjusting the ratio of enzyme and chitosan or the flow rate of chitosan. Moreover, the CICPR exhibited good stability and reusability after several cycles. The recombinase Csn75-CBM has greatly improved the efficiency of the bioproduction of CHOS.
Asunto(s)
Quitosano/síntesis química , Enzimas Inmovilizadas/química , Glucano 1,3-beta-Glucosidasa/química , Glicósido Hidrolasas/química , Oligosacáridos/síntesis química , Aspergillus fumigatus/enzimología , Bacillus/enzimología , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Enzimas Inmovilizadas/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Glucano 1,3-beta-Glucosidasa/genética , Glicósido Hidrolasas/genética , Mutación , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Dominios Proteicos/genética , Ingeniería de Proteínas , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , beta-GlucanosRESUMEN
Curdlan is a bacterial, water-insoluble, linear homopolysaccharide that has been widely used in the food industry. In this study, genome information of strain CGMCC 11546, a UV-induced high-yield mutant of the model curdlan-producing strain Agrobacterium sp. ATCC 31749, was used to investigate the molecular mechanism of curdlan biosynthesis. The maximum curdlan yield of 47.97 ± 0.57 g/L was obtained from strain CGMCC 11546 by using optimal media containing 60 g/L sucrose, 6 g/L yeast, 2 g/L KH2PO4, 0.4 g/L MgSO4·7H2O, 2 g/L CaCO3, 0.1 g/L FeSO4·7H2O, 0.04 g/L MnSO4, and 0.02 g/L ZnCl2 at 30 °C and 280 rpm after 96 h of fermentation. The gel strength of curdlan was improved by 41 % by knocking out the ß-1,3-glucanase genes exoK and exsH of strain CGMCC 11546. Furthermore, the application of curdlan from the ΔexoK-exsH strain in noodles significantly improved the eating quality of both raw and cooked noodles.
Asunto(s)
Agrobacterium/enzimología , Agrobacterium/genética , Genoma Bacteriano , Polisacáridos Bacterianos/metabolismo , beta-Glucanos/metabolismo , Agrobacterium/efectos de la radiación , Proteínas Bacterianas/genética , Medios de Cultivo/química , Suplementos Dietéticos , Fermentación , Calidad de los Alimentos , Geles/química , Eliminación de Gen , Glucano 1,3-beta-Glucosidasa/genética , Peso Molecular , Organismos Modificados Genéticamente , Rayos Ultravioleta , Secuenciación Completa del Genoma/métodosRESUMEN
We determined whether heat and chemical treatments could reduce the decay of kiwifruit caused by Botrytis cinerea during postharvest storage. Kiwifruits were treated with 5 g/L (w/v) potassium sorbate (PS), with a 48 °C hot water treatment (HT), and with a combined treatment (HT + PS). Mycelial growth of B. cinerea and the postharvest quality of 'XuXiang' kiwifruits were evaluated. HT + PS significantly inhibited mycelial growth, germ tube growth, and spore germination of B. cinerea. This treatment also reduced the incidence of gray mold in kiwifruit postharvest, and enhanced activities of defense-related enzymes in kiwifruit tissues. Compared with the control, all treatments resulted in lower malondialdehyde (MDA) contents and higher total phenolic contents in kiwifruits. HT + PS also increased the activities of chitinase and ß-1,3-glucanase and the transcript levels of their encoding genes. HT + PS can improve kiwifruit quality and reduce decay during postharvest storage.
Asunto(s)
Actinidia/microbiología , Botrytis/efectos de los fármacos , Ácido Sórbico/farmacología , Actinidia/química , Actinidia/enzimología , Botrytis/genética , Quitinasas/genética , Quitinasas/metabolismo , ADN de Hongos/metabolismo , Calidad de los Alimentos , Frutas/química , Frutas/enzimología , Frutas/microbiología , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/metabolismo , Calor , Malondialdehído/metabolismo , Fenoles/metabolismoRESUMEN
The enzymes from hyperthermophilic microorganisms populating volcanic sites represent interesting cases of protein adaptation and biotransformations under conditions where conventional enzymes quickly denature. The difficulties in cultivating extremophiles severely limit access to this class of biocatalysts. To circumvent this problem, we embarked on the exploration of the biodiversity of the solfatara Pisciarelli, Agnano (Naples, Italy), to discover hyperthermophilic carbohydrate-active enzymes (CAZymes) and to characterize the entire set of such enzymes in this environment (CAZome). Here, we report the results of the metagenomic analysis of two mud/water pools that greatly differ in both temperature and pH (T = 85 °C and pH 5.5; T = 92 °C and pH 1.5, for Pool1 and Pool2, respectively). DNA deep sequencing and following in silico analysis led to 14 934 and 17 652 complete ORFs in Pool1 and Pool2, respectively. They exclusively belonged to archaeal cells and viruses with great genera variance within the phylum Crenarchaeota, which reflected the difference in temperature and pH of the two Pools. Surprisingly, 30% and 62% of all of the reads obtained from Pool1 and 2, respectively, had no match in nucleotide databanks. Genes associated with carbohydrate metabolism were 15% and 16% of the total in the two Pools, with 278 and 308 putative CAZymes in Pool1 and 2, corresponding to ~ 2.0% of all ORFs. Biochemical characterization of two CAZymes of a previously unknown archaeon revealed a novel subfamily GH5_19 ß-mannanase/ß-1,3-glucanase whose hemicellulose specificity correlates with the vegetation surrounding the sampling site, and a novel NAD+ -dependent GH109 with a previously unreported ß-N-acetylglucosaminide/ß-glucoside specificity. DATABASES: The sequencing reads are available in the NCBI Sequence Read Archive (SRA) database under the accession numbers SRR7545549 (Pool1) and SRR7545550 (Pool2). The sequences of GH5_Pool2 and GH109_Pool2 are available in GenBank database under the accession numbers MK869723 and MK86972, respectively. The environmental data relative to Pool1 and Pool2 (NCBI BioProject PRJNA481947) are available in the Biosamples database under the accession numbers SAMN09692669 (Pool1) and SAMN09692670 (Pool2).
Asunto(s)
Proteínas Bacterianas/genética , Ambientes Extremos , Glucano 1,3-beta-Glucosidasa/genética , Metagenómica , beta-Manosidasa/genética , Proteínas Bacterianas/metabolismo , Crenarchaeota/enzimología , Glucano 1,3-beta-Glucosidasa/metabolismo , Concentración de Iones de Hidrógeno , Temperatura , beta-Manosidasa/metabolismoRESUMEN
Phytophthora is considered one of the most destructive genus for many agricultural plant species worldwide, with a strong environmental and economic impact. Phytophthora cinnamomi is a highly aggressive Phytophthora species associated with the forest decline and responsible for the ink disease in chestnut trees (Castanea sativa Miller), a culture which is extremely important in Europe. This pathogenicity occurs due to the action of several enzymes like the hydrolysis of 1,3-ß-glucans at specific sites by the enzyme endo-1,3-ß-D-glucosidase. The aim of this work to analyze the heterologous expression in two microorganisms, Escherichia coli and Pichia pastoris, of an endo-1,3-ß-D-glucosidase encoded by the gene ENDO1 (AM259651) from P. cinnamomi. Different plasmids were used to clone the gene on each organism and the real-time quantitative polymerase chain reaction was used to determine its level of expression. Homologous expression was also analyzed during growth in different carbon sources (glucose, cellulose, and sawdust) and time-course experiments were used for endo-1,3-ß-D-glucosidase production. The highest expression of the endo-1,3-ß-D-glucosidase gene occurred in glucose after 8 h of induction. In vivo infection of C. sativa by P. cinnamomi revealed an increase in endo-1,3-ß-D-glucosidase expression after 12 h. At 24 h its expression decreased and at 48 h there was again a slight increase in expression, and more experiments in order to further explain this fact are underway.
Asunto(s)
Glucano Endo-1,3-beta-D-Glucosidasa/genética , Phytophthora/genética , Clonación Molecular/métodos , Glucano 1,3-beta-Glucosidasa/genética , Glucano Endo-1,3-beta-D-Glucosidasa/metabolismo , Glucosidasas/genética , Glucosidasas/metabolismo , Phytophthora/metabolismo , Enfermedades de las Plantas , Reacción en Cadena en Tiempo Real de la Polimerasa/métodosRESUMEN
The use of biopolymers as elicitors in controlling plant diseases is gaining momentum world-wide due to their eco-friendly and non-toxic nature. In the present study, we have used an algal biopolymer (sodium alginate) and tested its applicability as an elicitor in inducing resistance factors against Alternaria solani, which causes early blight disease in Solanum lycopersicum (tomato plant). We have pre-treated tomato plants with different concentrations of sodium alginate (0.2%, 0.4%, and 0.6%) before A. solani infection. We found that sodium alginate has effectively controlled the growth of A. solani. In addition, a significant increase in the expression levels of SOD was observed in response to pathogen infection. The increased protease inhibitors activity further suggest that sodium alginate restrict the development of A. solani infection symptoms in tomato leaves. This corroborates well with the cell death analysis wherein increased sodium alginate pre-treatment results in decreased cell death. Also, the expression profile analyses reveal the induction of genes only in sodium alginate-pretreated tomato leaves, which are implicated in plant defense mechanism. Taken together, our results suggest that sodium alginate can be used as an elicitor to induce resistance against A. solani in tomato plants.
Asunto(s)
Alginatos/farmacología , Alternaria/inmunología , Resistencia a la Enfermedad/efectos de los fármacos , Enfermedades de las Plantas/prevención & control , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/genética , Solanum lycopersicum/efectos de los fármacos , Alternaria/patogenicidad , Antioxidantes/farmacología , Muerte Celular/efectos de los fármacos , Quitinasas/genética , Quitinasas/inmunología , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/inmunología , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/inmunología , Solanum lycopersicum/genética , Solanum lycopersicum/inmunología , Solanum lycopersicum/microbiología , Células Vegetales/efectos de los fármacos , Células Vegetales/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Proteínas de Plantas/inmunología , Inhibidores de Proteasas/inmunología , Inhibidores de Proteasas/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/inmunologíaAsunto(s)
Citrus/microbiología , Glucano 1,3-beta-Glucosidasa/genética , Phytophthora/patogenicidad , Enfermedades de las Plantas/genética , Trichoderma/enzimología , Agrobacterium , Citrus/genética , Resistencia a la Enfermedad , Enfermedades de las Plantas/microbiología , Plantas Modificadas Genéticamente , Trichoderma/genéticaRESUMEN
Plants are continuously challenged by pathogens, affecting most staple crops compromising food security. They have evolved different mechanisms to counterattack pathogen infection, including the accumulation of pathogenesis-related (PR) proteins. These proteins have been implicated in active defense, and their overexpression has led to enhanced resistance in nuclear transgenic plants, although in many cases constitutive expression resulted in lesion-mimic phenotypes. We decided to evaluate plastid transformation as an alternative to overcome limitations observed for nuclear transgenic technologies. The advantages include the possibilities to express polycistronic RNAs, to obtain higher protein expression levels, and the impeded gene flow due to the maternal inheritance of the plastome. We transformed Nicotiana tabacum plastids to co-express the tobacco PR proteins AP24 and ß-1,3-glucanase. Transplastomic tobacco lines were characterized and subsequently challenged with Rhizoctonia solani, Peronospora hyoscyami f.sp. tabacina and Phytophthora nicotianae. Results showed that transplastomic plants expressing AP24 and ß-1,3-glucanase are resistant to R. solani in greenhouse conditions and, furthermore, they are protected against P.hyoscyami f.sp. tabacina and P. nicotianae in field conditions under high inoculum pressure. Our results suggest that plastid co- expression of PR proteins AP24 and ß-1,3-glucanase resulted in enhanced resistance against filamentous pathogens.
Asunto(s)
Bioensayo , Resistencia a la Enfermedad/genética , Glucano 1,3-beta-Glucosidasa/genética , Nicotiana/genética , Nicotiana/microbiología , Serina Endopeptidasas/genética , Ambiente Controlado , Expresión Génica , Fenotipo , Plantas Modificadas Genéticamente , Nicotiana/inmunologíaRESUMEN
The aim of this work was to evaluate the possibility of control of wilt disease caused by Fusarium andiyazi through chitosan (CS) and chitosan nanoparticles (CNPs). In the present study, the expression pattern of pathogenesis-related (PR) proteins genes such as PR-1, PR-2 (ß-1,3-glucanase), PR-8 (chitinase), and PR-10 was analyzed using real-time RT-PCR. In vitro studies showed that among different concentrations (0.1-5.0â¯mg/ml), 5.0â¯mg/ml concentration of CS and CNPs produced maximum inhibition of radial mycelial growth, 54.8% and 73.81%, respectively. Also, upregulated expression of ß-1,3-glucanase, chitinase, PR-1 and PR-10 genes were recorded with 1.48, 1.15, 1.15, and 1.41, fold expression in 24 hpi, respectively, in plants inoculated with CNPs. The most significant up-regulation was observed in transcript profile of SOD that showed 4.5-foldexpression, at 48 hpi. Therefore, our results confirmed that CS and CNPs induced up-regulation of PR-proteins and antioxidant genes might play a significant role for successful biocontrol.
Asunto(s)
Quitosano/farmacología , Fusarium/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas , Nanopartículas/química , Proteínas de Plantas/genética , Solanum lycopersicum/efectos de los fármacos , Quitinasas/genética , Quitinasas/inmunología , Quitosano/química , Activación Enzimática/efectos de los fármacos , Fusarium/crecimiento & desarrollo , Fusarium/patogenicidad , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/inmunología , Interacciones Huésped-Patógeno , Solanum lycopersicum/genética , Solanum lycopersicum/inmunología , Solanum lycopersicum/microbiología , Micelio/efectos de los fármacos , Micelio/crecimiento & desarrollo , Micelio/patogenicidad , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/agonistas , Proteínas de Plantas/inmunología , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/inmunología , Superóxido Dismutasa/genética , Superóxido Dismutasa/inmunologíaRESUMEN
Aluminum (Al) toxicity is a primary limiting factor for crop production in acid soils. Callose deposition, an early indicator and likely a contributor to Al toxicity, is induced rapidly in plant roots under Al stress. SbGlu1, encoding a ß-1,3-glucanase for callose degradation, showed important roles in sorghum Al resistance, yet its regulatory mechanisms remain unclear. The STOP1 transcription factors mediate Al signal transduction in various plants. Here, we identified their homolog in sweet sorghum, SbSTOP1, transcriptionally activated the expression of SbGlu1. Moreover, the DNA sequence recognized by SbSTOP1 on the promoter of SbGlu1 lacked the reported cis-acting element. Complementation lines of Atstop1 with SbSTOP1 revealed enhanced transcription levels of SbGlu1 homologous gene and reduced callose accumulation in Arabidopsis. These results indicate, for the first time, that SbSTOP1 is involved in the modulation of callose deposition under Al stress via transcriptional regulation of a ß-1,3-glucanase gene.
Asunto(s)
Aluminio/toxicidad , Glucano 1,3-beta-Glucosidasa/genética , Glucanos/metabolismo , Proteínas de Plantas/metabolismo , Sorghum/efectos de los fármacos , Sorghum/fisiología , Transcripción Genética/efectos de los fármacos , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Arabidopsis/fisiología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Células HEK293 , Humanos , Regiones Promotoras Genéticas/genética , Sorghum/genética , Sorghum/metabolismoRESUMEN
Both plants and animals must contend with changes in their environment. The ability to respond appropriately to these changes often underlies the ability of the individual to survive. In plants, an early response to environmental stress is an alteration in plasmodesmatal permeability with accompanying changes in cell to cell signaling. However, the ways in which plasmodesmata are modified, the molecular players involved in this regulation, and the biological significance of these responses are not well understood. Here, we examine the effects of nutrient scarcity and excess on plasmodesmata-mediated transport in the Arabidopsis thaliana root and identify two CALLOSE SYNTHASES and two ß-1,3-GLUCANASES as key regulators of these processes. Our results suggest that modification of plasmodesmata-mediated signaling underlies the ability of the plant to maintain root growth and properly partition nutrients when grown under conditions of excess nutrients.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiología , Glucanos/metabolismo , Metales Pesados/toxicidad , Arabidopsis/efectos de los fármacos , Proteínas de Arabidopsis/genética , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/metabolismo , Glucosiltransferasas/genética , Glucosiltransferasas/metabolismo , Permeabilidad/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/fisiología , Plasmodesmos/efectos de los fármacos , Plasmodesmos/metabolismoRESUMEN
ß-1,3-glucan plays a role in Candida biofilm formation and survival of biofilm-forming Candida to stresses. In this study, we evaluated the antibiofilm activity of ß-1,3-glucanase, which can degrade poly-ß(1â3)-glucose of Candida albicans biofilms. Biofilm was dispersed by 55.96%. ß-1,3-glucanase had no effect on Candida planktonic growth as well as adhesion. ß-1,3-glucanase markedly enhanced the antifungal susceptibility of fluconazole and amphotericin B. The examination using confocal laser scanning microscopy and scanning electron microscope confirmed the antibiofilm activity of ß-1,3-glucanase. Our findings demonstrate that ß-1,3-glucanase may be useful as an antibiofilm agent.
Asunto(s)
Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Candida albicans/fisiología , Farmacorresistencia Fúngica , Glucano 1,3-beta-Glucosidasa/metabolismo , Biopelículas/crecimiento & desarrollo , Candida albicans/ultraestructura , Glucano 1,3-beta-Glucosidasa/genética , Pruebas de Sensibilidad Microbiana , FenotipoRESUMEN
The antifungal properties and the induction of resistance by ε-poly-l-lysine (ε-PL) were examined to reveal its potential in protecting tomato plants against Botrytis cinerea. As presented herein, ε-PL at 1200mg/L was found to have optimal in vitro antifungal activities, achieving an inhibition rate of 94.96%. In first-year field tests, ε-PL (1200mg/L) had a control effect of up to 79.07% against tomato grey mould. Similar results were obtained in the second year. In greenhouse experiments, ε-PL was observed to effectively reduce leaf infection, with an observed control rate at 89.22%. To define the molecular-genetic mechanisms, we compared the gene expression under four different conditions: sterile water sprayed plants (Control), Botrytis-infected plants (Inf), ε-PL-treated plants (ε-PL) and ε-PL-treated+infected plants (ε-PL+Inf). Quantitative PCR analysis at 36h after inoculation revealed that ε-PL+Inf plants exhibited significant expression and priming of several key Botrytis-induced genes in tomato. The results indicate that ε-PL promoted plant capacity of tomato to activate defense mechanisms upon pathogen attack. In total, these findings revealed that ε-PL should be an excellent biocontrol agent candidate that combined direct antifungal activity against B. cinerea and plant resistance capacity.
Asunto(s)
Agentes de Control Biológico/farmacología , Botrytis/fisiología , Resistencia a la Enfermedad/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Enfermedades de las Plantas/prevención & control , Polilisina/farmacología , Solanum lycopersicum/efectos de los fármacos , Botrytis/efectos de los fármacos , Botrytis/crecimiento & desarrollo , Quitinasas/genética , Resistencia a la Enfermedad/genética , Glucano 1,3-beta-Glucosidasa/genética , Solanum lycopersicum/genética , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genéticaRESUMEN
BH0236 from Bacillus halodurans is a multimodular ß-1,3-glucanase comprising an N-terminal family 81 glycoside hydrolase catalytic module, an internal family 6 carbohydrate-binding module (CBM) that binds the nonreducing end of ß-1,3-glucan chains, and an uncharacterized C-terminal module classified into CBM family 56. Here, we determined that this latter CBM, BhCBM56, bound the soluble ß-1,3-glucan laminarin with a dissociation constant (Kd ) of â¼26 µm and displayed higher affinity for insoluble ß-1,3-glucans with Kd values of â¼2-10 µm but lacked affinity for ß-1,3-glucooligosaccharides. The X-ray crystal structure of BhCBM56 and NMR-derived chemical shift mapping of the binding site revealed a ß-sandwich fold, with the face of one ß-sheet possessing the ß-1,3-glucan-binding surface. On the basis of the functional and structural properties of BhCBM56, we propose that it binds a quaternary polysaccharide structure, most likely the triple helix adopted by polymerized ß-1,3-glucans. Consistent with the BhCBM56 and BhCBM6/56 binding profiles, deletion of the CBM56 from BH0236 decreased activity of the enzyme on the insoluble ß-1,3-glucan curdlan but not on soluble laminarin; additional deletion of the CBM6 also did not affect laminarin degradation but further decreased curdlan hydrolysis. The pseudo-atomic solution structure of BH0236 determined by small-angle X-ray scattering revealed structural insights into the nature of avid binding by the BhCBM6/56 pair and how the orientation of the active site in the catalytic module factors into recognition and degradation of ß-1,3-glucans. Our findings reinforce the notion that catalytic modules and their cognate CBMs have complementary specificities, including targeting of polysaccharide quaternary structure.
Asunto(s)
Bacillus/enzimología , Proteínas Bacterianas/química , Glucano 1,3-beta-Glucosidasa/química , Bacillus/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Sitios de Unión , Cristalografía por Rayos X , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/metabolismo , Polisacáridos/química , Polisacáridos/metabolismo , Estructura Secundaria de ProteínaRESUMEN
We investigated cell growth and activity of intra- and extracellular chitinase, ß-1,3-glucanase, and chitin deacetylase with SDS-PAGE by incubating W. anomalus EG2 in PDB and YPD media for 24h in presence of different concentrations (0%, 0.1%, 0.3%, and 0.5%) of colloidal chitin. Maximum cell growth was observed in both PDB and YPD media without colloidal chitin. In the absence of colloidal chitin, maximum extracellular ß-1,3-glucanase activity of 32.96 and 47.28 units/mL was reported at 18h in PDB medium and 6h in YPD medium, respectively. In addition, extracellular chitinase was unaffected by various concentrations of carboxymethyl chitin in both PDB and YPD media. In the absence of colloidal chitin, maximum intracellular chitinase activity was indicated to be 9.82 and 9.86 units/mg protein in PDB and YPD media, respectively. Maximum intracellular ß-1,3-glucanase activity reported was 17.34 units/mg protein in PDB medium containing 0.5% colloidal chitin and 15.0 units/mg protein in YPD medium containing 0.3% colloidal chitin. Five major isozymes, GN1, GN2, GN3, GN4, and GN5, of intracellular ß-1,3-glucanase were detected with glucan-containing high polymer complex as a substrate with or without colloidal chitin.
Asunto(s)
Quitina/análogos & derivados , Quitinasas/genética , Quitinasas/metabolismo , Glucano 1,3-beta-Glucosidasa/genética , Glucano 1,3-beta-Glucosidasa/metabolismo , Glucanos/farmacología , Pichia/enzimología , Quitina/farmacología , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/enzimología , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Glucanos/química , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/enzimología , Pichia/citología , Pichia/efectos de los fármacos , Pichia/genéticaRESUMEN
Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to fungal disease red rot caused by Colletotrichum falcatum Went. The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery. We report development of red rot resistant transgenic sugarcane through expression of ß-1,3-glucanase gene from Trichoderma spp. The transgene integration and its expression were confirmed by quantitative reverse transcription-PCR in first clonal generation raised from T0 plants revealing up to 4.4-fold higher expression, in comparison to non-transgenic sugarcane. Bioassay of transgenic plants with two virulent C. falcatum pathotypes, Cf 08 and Cf 09 causing red rot disease demonstrated that some plants were resistant to Cf 08 and moderately resistant to Cf 09. The electron micrographs of sucrose storing stalk parenchyma cells from these plants displayed characteristic sucrose-filled cells inhibiting Cf 08 hyphae and lysis of Cf 09 hyphae; in contrast, the cells of susceptible plants were sucrose depleted and prone to both the pathotypes. The transgene expression was up-regulated (up to 2.0-fold in leaves and 5.0-fold in roots) after infection, as compared to before infection in resistant plants. The transgene was successfully transmitted to second clonal generation raised from resistant transgenic plants. ß-1,3-glucanase protein structural model revealed that active sites Glutamate 628 and Aspartate 569 of the catalytic domain acted as proton donor and nucleophile having role in cleaving ß-1,3-glycosidic bonds and pathogen hyphal lysis.