Silicon as resistance inducer to control black apphid Aphis craccivora Koch, 1854 in cowpea beans [Vigna unguiculata (L)] Walp

The black aphid Aphis craccivora (Koch, 1854) stands out between the bugs considered cowpea pests. The objective of this study was to evaluate the effects of silicon application on the resistance induction of cowpea plants to the black aphid A. craccivora. The experiment was conducted in the Entomology Laboratory of the Phytosanitary sector of the Centro de Ciências Agrárias at the Universidade Federal do Piauí. The effects of the application of silicon on biological aspects were evaluated using a completely randomized design, with four treatments and 40 repetitions, being: silicon in soil (T1), silicon in soil + leaf (T2), silicone leaf (T3), and control (T4). The following biological variables were evaluated: generation period, reproductive period, fecundity, and daily average of nymphs per female. The silicon and lignin contents were also evaluated in the plants. The silicic acid was applied in a 1% solution around the stem of the plants (soil), 15 days after emergence, by diluting 2 g of the product in 200 mL of water. However, the leaf application was carried out with sprayer five days after application in soil. The non-preference of A. craccivora on bean was also evaluated. The evaluations were performed after 24, 48 and 72 hours of infestation by counting nymphs at 24, 48 and 72 hours and adults at each leaf session. The application of silicon promotes the reduction of the production of nymphs, interfering in the biological aspects of A. craccivora, and has potential to be used in a cowpea pest management program in cowpea.

Effects of exogenous IBA and fungal elicitor on growth of in vitro roots culture of Dysosma versipellis and production of podophyllotoxin / 中国中药杂志

Using the White as basic medium, the effects of the exogenous IBA and endophytic fungal elicitor on the growth of in vitro roots cultures of Dysosma versipellis and production of podophyllotoxin were investigated in this study. The results showed that the IBA and the endophytic fungus Zasmidium syzygii elicitor could increase the content of podophyllotoxin of in vitro roots of D. versipellis after 3 weeks. The White medium added with 3 mg·L~(-1) IBA induced the highest increase of podophyllotoxin(1 830.86 μg·g~(-1)), which was 2.07 folds greater than the control, and followed by 1.5 mg·L~(-1) IBA, fungal elicitor, 1 mg·L~(-1) IBA, 0.5 mg·L~(-1) IBA and 4.5 mg·L~(-1) IBA, which was 1.82, 1.71, 1.63, 1.43 and 1.1 folds greater than the control, respectively. The results also showed that the growth of roots was certain positively correlated with the change of IBA concentration. Therefore, 3 mg·L~(-1) IBA was the most suitable for the production of podophyllotoxin in the in vitro roots of D. versipellis, and the stimulating effect of Z. syzygii fungal elicitor was between 1.5 mg·L~(-1) and 1 mg·L~(-1) IBA, which was a potential natural elicitor to induce the accumulation of podophyllotoxin in future production.

Influence of elicitors on effective constituents and expression of key metabolic enzyme genes in hairy roots of Atropa belladonna / 中草药

Objective To improve the yield of the effective medicinal ingredients of Atropa belladonna, to provide economic and efficient method for the actual production of A. belladonna, therefore to provide a basic reference for the related research on the mechanism of secondary metabolism of medicinal plants. Methods In this study, the influences of four kinds of elicitors, including methyl jasmonate (MJ), AgNO3, salicylic acid (SA), yeast extract (YE), on the accumulation of active components and the expression level of key metabolic enzyme genes, including putrescine N-methyl transferase (pmt), tropinone reductase-I (trI), and hyoscyamine-6-β-hydroxylase (h6h), were studied in hairy roots of A. belladonna. 0.5 g fresh hairy roots of A. belladonna were cultivated in B5 liquid medium. 12 d later, these mediums were replaced with the new medium containing one kind of four elicitors. Hairy roots were taken samples after 2 d to mensurate the fresh weight, dry weight, the content of tropane alkaloids, some physiological indexes, and three key genes expression level. Results MJ inhibited the growth and tropane alkaloids accumulation of hairy roots. The gene expression level of pmt and trI also decreased compared with control group (CK). The contents of tropane alkaloids and the expression level of pmt, trI and h6h were all increased compared with CK by the treatment of AgNO3, while the growth of hairy rootswas inhibited; SA contributed to the increased content of hyoscyamine, but with no obvious influence on growth of hairy roots. As to YE, the content of tropane alkaloids and the expression level of pmt, trI, h6h were all increased correspondingly. Further more, YE was benefit for the growth of hairy roots. Conclusion Elicitors had selective influence on growth and tropane alkaloids accumulation in hairy roots of A. belladonna. The best elicitor on accumulation of tropane alkaloids was AgNO3. YE could effectively improve of the growth of hairy and contents of tropane alkaloids. This study concluded that these elicitors influence the secondary metabolism of A. belladonna by regulating and controlling the expression level of some genes of key metabolic Enzyme, which could provide an effective method to enhance the medicinal composition in the culture of hairy roots of A. belladonna.

Real-time fluorescent quantitative PCR detection of key enzyme genes expression of alkaloid biosynthesis promoted by endophytic fungal elicitor in Sophora alopecuroides / 中草药

Objective To establish a method of detecting the expression of Lysine decarboxylase (LDC) -a key enzyme for the synthesis of alkaloid in the host promoted by the endophytic fungal elicitor of Sophora alopecuroides by using real-time fluorescence quantitative PCR (qRT-PCR). Methods Target gene primers QLDC-F/QLDC-R and reference gene primers Lectin-F/Lectin-R were designed according to LDC and Lectin gene sequences of S. alopecuroids; Five-fold gradient dilution of cDNA was used as the standard sample for the construction of the standard curve of target gene and the reference gene. Reaction system and reaction conditions of qRT-PCR were optimized, and the sensitivity of semi-quantitative PCR and qRT-PCR were analyzed and compared. Under different eliciting time of endophytic fungal elicitors NDZKDF13 of S. alopecuroides, the content of oxymatrine in the host was determined by HPLC, the expression of LDC gene was detected by qRT-PCR, and the relationship between LDC gene expression and the accumulation of OMA was analyzed. Results The results of qRT-PCR were better when the cDNA content in the system was 200 ng/μL and the annealing temperature was 61 ℃. The standard curve of the target gene and the reference gene was constructed, in which the cycle threshold and template concentration showed a good linear relationship, the amplification efficiency was above 99%, and the sensitivity was 25 times that of semi-quantitative PCR. Under the induction effect of endophytic fungal elicitor NDZKDF13, expression of host LDC gene reached the peak on the 6th day, which was 25.58 times that of the control. The increase of OMA content lagged the change of the LDC gene expression and reached the highest amount on the 9th day after the induction. Conclusion The qRT-PCR technique was successfully applied to the functional gene research of S. alopecuroides. Through the optimization of various conditions, a platform for accurate and simple detection of functional gene expression in S. alopecuroides was established.

Antimicrobial activity of Agaricus brasiliensis on Plasmopara viticola and its effect on the induction of resistance to the control of downy mildew on Isabel Precoce / Atividade antimicrobiana de Agaricus brasiliensis sobre Plasmopara viticola e seu efeito na indução de resistência para o controle de míldio em videiras Isabel Precoce

Agaricus brasiliensis include bioactive compounds that can act as antibiotics, bacteriostatic, fungistatic and nematostatic substances. In this sense, this study aimed to evaluate the effect of a single application of aqueous mycelial suspension (AMS) of A. brasiliensis in control of downy mildew (Plasmopara viticola) and resistance induction in 'Isabel Precoce' grapevines under greenhouse conditions. Treatments consisted of three doses of 1%, 5%, 10%, 15% and 20% AMS A. brasiliensis, as well as treatment with acibenzolar-S-methyl (ASM). The variables analyzed were: sporangiospore germination, disease severity, represented by the area under the disease progress curve (AUDPC), catalase enzyme activity, peroxidase and polyphenol. The 10%, 15% and 20% doses of AMS caused approximately 80% reduction in germination of P. viticola sporangiospores. The treatments did not show significant effects in reducing both the AUDPC of mildew and polyphenol oxidase enzyme activity. The A. brasiliensis aqueous mycelial suspension showed a fungitoxic effect on the germination of sporangiopores; however, it was not enough to reduce the severity of mildew in the 'Isabel Precoce' grapevines, even when acting on the catalase and peroxidase enzymes. Thus, experiments should be performed to verify the viability of the reproductive structures of the pathogen externalized in the vines when treated with A. brasiliensis AMS.(AU)

Agaricus brasiliensis possui compostos bioativos que apresentam atividade antimicrobiana e induz mecanismos de defesa em plantas contra patógenos. O objetivo deste trabalho foi avaliar a aplicação da suspensão miceliada aquosa de A. brasiliensis no controle do míldio (Plasmopara viticola) e indução de resistência em videiras Isabel Precoce. Os tratamentos foram: 0, 1, 5, 10, 15 e 20% da suspensão miceliada aquosa de A. brasiliensis, além do tratamento com acibenzolar-S-metil. As variáveis analisadas foram: germinação de esporangiósporos; severidade da doença, representada pela área abaixo da curva de progresso da doença; atividade da enzima catalase; peroxidase e polifenoloxidase. As doses 10, 15 e 20% de suspensão miceliada aquosa de A. brasiliensis proporcionaram redução de aproximadamente 80% na germinação dos esporangiósporos de P. viticola. Os tratamentos não apresentaram efeitos significativos na redução da área abaixo da curva de progresso da doença do míldio e na atividade da enzima polifenoloxidase. A dose de 10% da suspensão miceliada aquosa de A. brasiliensis reduziu a atividade de catalase e induziu a atividade da peroxidase. A suspensão miceliada aquosa de A. brasiliensis apresentou efeito fungitóxico na germinação de esporangióporos, entretanto não foi suficiente para reduzir a severidade do míldio da videira Isabel Precoce, mesmo atuando na atividade das enzimas catalase e peroxidase. Assim, experimentos deverão ser realizados para verificar a viabilidade das estruturas reprodutivas do patógeno exteriorizadas nas videiras quando tratadas com suspensão miceliada aquosa de A. brasiliensis.(AU)

Extraction and characterisation of proteins from a Malaysian Isolate of Magnaporthe grisea

Aims@#Rice blast, a disease caused by the fungus Magnaporthe grisea is one of the serious diseases of rice in the world. The main objective of this study is to isolate and characterise the proteins extracted from the rice blast fungus, M. grisea 7.6. @*Methodology and results@#Through comparative 2-D analyses of the crude protein extracts obtained from this fungus, we were able to identify 88 protein spots through MALDI-TOF. These proteins were then classified into 8 functional groups through the Pfam and KEGG databases into hypothetical, transferases, energy and carbon metabolism, oxidoreductases, molecular chaperone, hydrolases, structural organisation and kinases. The individual protein’s functions were then identified and their possible role in pathogenesis, virulence and proliferation of M. grisea 7.6 were predicted. @*Conclusion, significance and impact of study@#Through the assays conducted, we were able to identify some proteins and pathways that could be targeted in developing fungicides and used in future mutagenesis studies.

Yeast extract elicitation increases vinblastine and vincristine yield in protoplast derived tissues and plantlets in Catharanthus roseus

Abstract Catharanthus roseus (L.) G. Don, Apocynaceae, is an immensely important medicinal plant, produces a variety of anticancerous compounds. The yield of two most investigated alkaloids vinblastine and vincristine is unfortunately very low. A vast array of technologies including elicitation have recently been used to enrich Catharanthus alkaloid in culture. Yeast extract is a biotic elicitor, the polysaccharide and the peptide moiety have been recognized as a signalling element in enriching secondary metabolites. In this study, the yeast extract elicitation on vinblastine and vincristine was studied in various protoplast derived tissues and plantlets. Four different yeast extract treatments (T1 = 0.5 g/l, T2 = 1.0 g/l, T3 = 1.5 g/l and T4 = 2.0 g/l) were prepared and used. The alkaloid was quantified and a comparative account of yield were presented by the use of High performance thin layer chromatography. The yeast extract amendment in medium improved vinblastine and vincristine yield in cultivating tissues, maximum being in germinating embryos and in in vitro raised leaf. The highest yield was in T3 (1.5 mg/l) in which 22.74% vinblastine and 48.49% vincristine enrichment was noted in germinating embryos; the enhancement was however, treatment-specific. Antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase activities were investigated as addition of yeast extract caused cellular stress and had enriched level of alkaloids.

Application of plant tissue culture in field of Chinese medicine resources / 中国中药杂志

Plant tissue culture technology has been widely used in the field of traditional Chinese medicine(TCM) resources with its unique advantages, playing an important role in the protection of TCM resources. In this review, some applications of plant tissue culture were summarized, including production of active compounds by using plant tissue culture, genetic diversity analysis, Dao-di herbs, elicitor application, biosynthesis and transgenic plants. Through the above researches will promote the further development of plant tissue culture technology, making it play a greater role in the field of TCM resources.

Aplicação exógena de quitosana no sistema antioxidante de jaborandi / Exogenous chitosan application on antioxidant systems of jaborandi

A aplicação de eliciadores em plantas é utilizada em estudos de fisiologia para compreensão dos mecanismos de defesa ao ataque de herbívoros ou infecção por patógenos. Em virtude disso, foi avaliado o efeito do eliciador exógeno quitosana no sistema antioxidante enzimático de jaborandi (Piper mollicomum Kunth). Foram avaliadas as atividades das enzimas ascorbato peroxidase (APX), catalase (CAT) e superóxido dismutase (SOD) e as concentrações de peróxido de hidrogênio (H2O2) e malonaldeído (MDA), ambas análises para verificar a peroxidação lipídica. O delineamento experimental utilizado foi o de blocos casualizados (DBC), constituído de um fatorial (5x2) composto pelos controles sem quitosana (plantas sem pulverização e plantas pulverizadas apenas com o solvente de diluição da quitosana) e concentrações de quitosana (2,5; 5,0 e 10,0 g L-1) em dois estádios de desenvolvimento foliar (em desenvolvimento e completamente expandida). Nas folhas completamente expandidas, o sistema antioxidante foi mais ativo. A CAT teve maior participação no sequestro de radicais livres, induzido pela aplicação da quitosana em ambos os estádios de desenvolvimento foliar. A APX foi induzida somente nas folhas completamente expandidas e na maior concentração de quitosana. O método do MDA foi melhor para evidenciar a diferença nos teores de peróxido de hidrogênio, em função do estresse induzido pela quitosana. De acordo com os resultados obtidos neste ensaio, pode-se sugerir que, nas plantas de jaborandi, as enzimas antioxidativas são requisitadas em resposta ao eliciador em questão, a quitosana, compondo, assim, o mecanismo de defesa dessas plantas.

Elicitors are used in plant physiology studies for comprehension of defense mechanisms against herbivore attach and pathogen infections. For this reason, the exogenous chitosan effect was tested as an elicitor on Jaborandi (Piper mollicomum Kunth). Thus, it was evaluated the elicitor effect in the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) ,ascorbate peroxidase (APX),hydrogen peroxide (H2O2) and malonaldehyde (MDA) concentrations to estimate the lipid peroxidation. The experimental design was in randomized blocks in a factorial 5x2, being 2 controls (plants without pulverization and plants sprayed only with a diluting solvent chitosan) and 3 chitosan concentrations (2.5; 5.0 and 10.0 g L-1) in 2 leaf development stage (in development and fully expanded). At the fully expanded leaves, the antioxidant system presented higher active. The CAT had greater involvement in the kidnapping of free radicals induced by the application of chitosan in both leaf stages of development. The APX was induced only in fully expanded leaves and the highest concentration of chitosan. The MDA method was better to highlight the difference in hydrogen peroxide content as a function of stress induced by chitosan. According to the results of this test, it can be suggested that the plants Jaborandi antioxidant enzymes are required in response to the elicitor in question, chitosan, thus composing the defense mechanism of these plants.

Cloning and expression analysis of a tyrosine decarboxylase gene from Rehmannia glutinosa / 中国中药杂志

Tyrosine decarboxylase (TyrDC) is an important enzyme in the secondary metabolism of several plant species, and was hypothesized to play a key role in the biosynthesis of phenylethanoid glycosides. Based on the transcriptome data, we cloned the full-length cDNA (GenBank accession NO. KU640395) of RgTyDC gene from Rehmannia glutinosa, and then performed bioinformatic analysis of the sequence. Further, we detected the expression pattern in different organs and hair roots treated with four elicitors by qRT-PCR. The results showed that the full length of RgTyDC cDNA was 1 530 bp encoding 509 amino acids. The molecular weight of the putative RgTyDC protein was about 56.6 kDa and the theoretical isoelectric point was 6.25. The RgTyDC indicated the highest homology with Sesamum indicum SiTyDC and Erythranthe guttata EgTyDC, both of them were reached 88%. RgTyDC highly expressed in R. glutinosa leaf, especially in senescing leaf, and rarely expressed in tuberous root. After the treatment of SA and MeJA, the relative expression level of RgTyDC mRNA was substantially increased. The results provide a foundation for exploring the molecular function of RgTyDC involved in phenylethanoid glycosides biosynthesis.

Phenylalanine enhances Quercetin content in In vitro cultures of Abutilon indicum L.

Flavonoids have aroused considerable interest because of their potential beneficial effect on human health. Quercetin is one of the most abundant natural flavonoids present in medicinal plants. In the present study, a comparative phytochemical analysis of bioactive compounds from leaf and leaf derived callus of Abutilon indicum L. was carried out. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) analysis of methanolic extract of Abutilon leaf revealed the presence of quercetin. To test the effect of precursor in enhancing flavonoid content, in vitro studies were conducted by supplementing phenylalanine to actively growing callus cultures of Abutilon. More than threefold increase in quercetin content was obtained in elicitor induced callus compared to control.

Differential accumulation of defense-related isoflavonoids inhypocotyls/roots of common bean (Phaseolus vulgaris L. ) cultivars treatedwith salicylic acid and structurally related compounds / Acumulación diferencial de isoflavonoides relacionados con la defensa en hipocótilos/raíces de variedades deporoto (Phaseolus vulgaris L. ) tratados con ácido salicílico y compuestos estructuralmente relacionados

Hypocotyls/roots of four (anthracnose-resistant: ICA Quimbaya and CORPOICA 106; anthracnose-susceptible: Cargamanto Rojo and Cargamanto Mocho) common bean cultivars treated with salicylic acid (SA) as elicitor, were analyzed to determine the capacity for synthesizing defense-related isoflavonoids. Time-course and dose-response studies indicated that the maximum levels of isoflavonoids, occurred at 1.45 mM SA and between 96 and 144 h post-induction. Overall, anthracnose-resistant cultivars produced the defense-related isoflavonoids to superior amounts than the susceptible ones. Additionally, crude isoflavonoid extracts from SA-treated tissues cvs. ICA Quimbaya and Cargamanto Rojo displayed higher inhibitory effect against C. lindemuthianum than those from water-treated tissues. A comparison of the isoflavonoid-eliciting activity of a series of structurally-related compounds to SA revealed that isoflavonoid production may be differentially controlled. Acetyl-salicylic acid showed the best isoflavonoid-inducing effect. Results might be useful for crop protection programs through the selecting of common bean cultivars with better prospects of disease resistance, and the development of better isoflavonoid-eliciting agents.

Los hipocótilos/raíces de cuatro variedades de poroto (resistente a antracnosis: ICA Quimbaya y CORPOICA 106; susceptible a antracnosis: Cargamanto Rojo y Cargamanto Mocho) tratados con ácido salicílico (AS) como elicitor, se analizaron para determinar la capacidad para sintetizar isoflavonoides relacionados con la defensa. Los estudios en el curso del tiempo y dosis-respuesta indicaron que los niveles máximos de isoflavonoides, ocurrieron a una concentración de AS de 1.45 mM y entre 96 y 144 h post-inducción. En general, las variedades resistentes a la antracnosis produjeron los isoflavonoides relacionados con la defensa en cantidades superiores en comparación con las variedades susceptibles. Adicionalmente, los extractos de isoflavonoides crudos provenientes de tejidos tratados con AS var. ICA Quimbaya y Cargamanto Rojo desplegaron un efecto inhibitorio contra C. lindemuthianum mayor que aquellos resultantes de tejidos tratados con agua. Una comparación de la actividad inductora de isoflavonoides de una serie de compuestos estructuralmente relacionados con el AS reveló que la producción de isoflavonoides puede ser controlada diferencialmente. El ácido acetilsalicílico mostró el mejor efecto inductor de isoflavonoides. Los resultados pueden ser útiles para los programas de protección a cultivos a través de la selección de variedades con mejores perspectivas de resistencia a enfermedades, y el desarrollo de mejores agentes elicitores de isoflavonoides.

Signal transduction of atractylodin biosynthesis in Atractylodes lancea cell induced by endophytic fungal elicitor mediated with nitric oxide followed by salicylic acid / 中草药

Objective: To investigate the signal molecules and signal transduction involved in endophytic fungal elicitor-induced atractylodin biosynthesis and the effect of an endophytic fungal elicitor on the key enzyme activity in Atractylodes lancea. Methods: Content changes of nitric oxide (NO), salicylic acid (SA), and atractylodin were detected under the endophytic fungal elicitor treatment by plant cell suspension culture technology. Results: The endophytic fungal elicitor remarkably promoted NO burst and the biosynthesis of SA and atractyodin by activating nitric oxide synthase (NOS), phenylalanine ammonia lyase (PAL), and acetyl coenzyme A carboxylase (ACC), respectively. NOS inhibitor PBITU could inhibit the NO and SA accumulation and the atractyodin biosynthesis induced by the elicitor. And atractyodin biosynthesis could also be triggered by exogenous NO or SA. The results indicated that NO and SA were the necessary signal molecules and NO burst was mediated by NOS induced by endophytic fungal elicitor. NO quencher cPITO could effectively remove NO burst in A. lancea cell induced by endophytic fungal elicitor and notably inhibit the biosynthesis promotion of SA and atractyodin in A. lancea cell induced by endophytic fungal elicitor. Exogenous SNP could reverse the cPITO inhibition on the activity of PAL and ACC and the synthesis of SA and atractylodin. This suggested that NO was an upstream signal molecule mediated endophytic fungal elicitor to accelerate the biosynthesis of SA and atractyodin. Conclusion: Endophytic fungal elicitor mediated through NO followed by SA could promote atractyodin biosynthesis by activating ACC in A. lancea.

Polyamine-mediated triterpenoid synthesis in suspension cells of Betula platyphylla induced by fungal elicitor / 中草药

Objective: To clarify whether polyamine-mediated triterpenoid synthesis in birch (Betula platyphylla) suspension cells induced by fungal elicitor. Methods: Fungal elicitor (40 μg/mL), putrescine (Put, 1 mmol/L), and D-arginine (D-Arg, 2 mmol/L) were added to the eight-day-old suspension cell culture, the content changes of triterpenoid and free polyamines were analyzed by chemical colorimetry and HPLC. The effect of polyamine on triterpenoid synthesis in B. platyphylla suspension cells induced by fungal elicitor was analyzed by pharmacology and restoration experiment. Results: After the treatment of fungal elicitor or Put, the contents and yields of free polyamines and triterpenoid were increased. Among of them, the triterpenoid content was the highest after 24 h treatment, the increasing rates were 68.54% and 30.34%, respectively. The triterpenoid content was increased by the cotreatment of fungal elicitor and Put, but the increasing degree of yield was lower than that by the treatment of fungal elicitor alone. Compared with the fungal elicitor alone, the cotreatment of fungal elicitor and D-Arg decreased the triterpenoid content by 40.57% in the highest degree of decreasing after 24 h treatment. In restoration experiment, with the treatment time prolonging, the effect of fungal elicitor, Put, or cotreatment of fungal elicitor and D-Arg on triterpenoid synthesis was decreasing to the control level finally. Conclusion: Polyamine could mediate the triterpenoid synthesis in cells of B. platyphylla induced by fungal elicitor.

Enhancement of beta-Glucan Content in the Cultivation of Cauliflower Mushroom (Sparassis latifolia) by Elicitation

The effectiveness of three kinds of enzymes (chitinase, beta-glucuronidase, and lysing enzyme complex), employed as elicitors to enhance the beta-glucan content in the sawdust-based cultivation of cauliflower mushroom (Sparassis latifolia), was examined. The elicitors were applied to the cauliflower mushroom after primordium formation, by spraying the enzyme solutions at three different levels on the sawdust-based medium. Mycelial growth was fully accomplished by the treatments, but the metabolic process during the growth of fruiting bodies was affected. The application of a lysing enzyme resulted in an increase in the beta-glucan concentration by up to 31% compared to that of the control. However, the treatment resulted in a decrease in mushroom yield, which necessitated the need to evaluate its economic efficiency. Although we still need to develop a more efficient way for using elicitors to enhance functional metabolites in mushroom cultivation, the results indicate that the elicitation technique can be applied in the cultivation of medicinal/edible mushrooms.

Interaction between putrescine and hydrogen peroxide on regulating triterpenoid production in Betula platyphylla / 中草药

Objective: To analyze the interaction between putrescine (Put) and hydrogen peroxide (H2O2) on the regulation of triterpenoid production in Betula platyphylla suspension cell culture. Methods: Put (1 mmol/L), H2O2 (0.1 mmol/L), and fungal elicitors (40 μg/mL) were added into the eight-day-old B. platyphylla suspension cell culture, and the changes of triterpenoid content, polyamine content, and H2O2 fluorescence intensity were analyzed by chemical colorimetry, HPLC, and fluorescence microscopy, respectively. Results: Put (1 mmol/L) increased the H2O2 fluorescence intensity and triterpenoid content in B. platyphylla suspension cell culture. H2O2 (0.1 mmol/L) promoted the triterpenoid production, inhibited the production of spermidine (Spd) and spermine (Spm), and had no effectt on Put content. Under the treatment of 1 mmol/L Put and 0.1 mmol/L H2O2, H2O2 fluorescence intensity and polyamine (PAs) content were between its separated treatment, and triterpenoid content was significantly higher than its separated treatment. Comparing with the fungal elicitor, fungal elicitor and H2O2 scavenger catalase (CAT) induced an increase of 0.62% and 16.05% in Put and Spd content, respectively, while no effect on Spm content. Fungal elicitor and PAs synthesis inhibitor D-arginine (D-arg) decreased the H2O2 fluorescence intensity. Under the treatment of fungal elicitor, the fluorescence intensity of CAT and D-arg, H2O2 and the contents of PAs and triterpenoid were lower than those of fungal elicitor and CAT or D-arg, but triterpenoid content was still higher than that of the control. Conclusion: This can be inferred that the interaction between Put and H2O2 regulates the triterpenoid production in birch suspension cell culture.

Effect of elicitors on the contents of secondary metabolites in thymus / 中国药学杂志

OBJECTIVE: To investigate the effect of elicitors on secondary metabolites accumulation at different proliferation stages of thyme. METHODS: The thyme was induced by jasmonic acid methyl ester, salicylic acid and chitosan respectively after being culture on 1/2 MS basal medium for 20, 30 and 40 d, and secondary metabolites were extracted and examined by GC-MS. RESULTS: Forty-six compounds were identified in the solution. It was found through comparison of 12 compounds with contents more than 1% that three inducers significantly increased the contents of aromatic compounds represented by thymol, oxidation terpenoids and terpenes compounds represented by benzene, 1-methyl-3-(1-methylethyl) and 1,4-cyclohexadiene 1-methyl-4-(1-methylethyl). CONCLUSION: The secondary metabolites of thyme are affected significantly by elicitors.

Induction of systemic resistance in different varieties of Solanum tuberosum by pure and crude elicitor treatment.

A 10 kD elicitor protein (infestin) produced by Phytopthora infestans was purified and its efficacy for induction of systemic resistance in resistant and susceptible varieties of Solanum tuberosum was studied. Culture filtrates from P. infestans with and without purified elicitor (infestin) were used as elicitors to understand the effect of purified elicitor (infestin) on development of systemic resistance. Culture filtrate and purified elicitor (infestin) were found to induce hypersensitive reaction on the leaves of resistant varieties, but not on susceptible varieties after 48 h. Culture filtrate devoid of purified elicitor (infestin) did not induce any necrotic spots even on resistant variety. Purified elicitor (infestin) was found to induce glucose oxidase, NADPH oxidase, superoxide dismutase, glutathione reductase, catalase and peroxidase enzymes in resistant S. tuberosum plants, however the induction of these enzymes was low in susceptible varieties. The oxidative enzymes were found to induce earlier than antioxidative enzymes and there was negative correlation between these two groups of enzymes. Levels of salicylic acid, phenylalanine ammonia lyase (PAL), -1, 3 glucanase and chitinase activities were also found higher in resistant than in susceptible varieties. It was observed that purified elicitor (infestin) was superior to crude culture filtrate, but was not capable of inducing systemic resistance in susceptible varieties.

Elevated yield of Monacolin K in Monascus purpureus by fungal elicitor and mutagenesis of UV and LiCl

In China, Monascus spp., a traditional fungus used in fermentation, is used as a natural food additive. Monascus spp. can produce a secondary metabolite, monacolin K namely, which is proven to be a cholesterol-lowering and hypotensive agent. Hence, recently, many researchers have begun focusing on how to increase the production of monacolin K by Monascus purpureus. In the present study, we investigated the effect of the fungal elicitor and the mutagenesis of UV & LiCl on the amount of monacolin K produced by Monascus purpureus. The fugal elicitor, Sporobolomyces huaxiensis, was isolated from tea leaves and its filtrate was added into the culture filtrate of Monascus purpureus during growth to induct the production of monacolin K. The results showed that the highest amount of monacolin K produced by the liquid fermentation was 446.92 mg/mL, which was produced after the fungal elicitor was added to the culture filtrate of Monascus purpureus on the day 4; this amount was approximately 6 times greater than that of the control culture filtrate, whereas the highest amount of monacolin K produced by the mutated strain was 3 times greater than the control culture after the irradiation of UV light in the presence of 1.0 % LiCl in the medium.

Elicitores de péptidos antimicrobianos: estrategia potencial contra infecciones / Antimicrobial peptide elicitors: a potential strategy against infections

Los inconvenientes del tratamiento con antibióticos, como el surgimiento de cepas multirresistentes y las reacciones adversas, han llevado a la búsqueda de alternativas. El conocimiento de las rutas de activación de la respuesta inmune innata y sus interacciones con las rutas de señalización de la respuesta inmune adaptativa podría llevar a tratamientos basados en elicitores de péptidos antimicrobianos, sustancias inocuas que producen la sobreexpresión de genes de la respuesta inmune innata, más efectivos, rápidos y seguros para combatir las infecciones, que siguen siendo un problema de salud pública mundial.

The drawbacks associated with antibiotic-based treatment of infectious diseases including an increase in multidrug-resistant strains and adverse reactions have lead to the search of antimicrobial peptide elicitors (APE), harmless substances that boost an overexpression of innate immunity genes. Knowledge on innate immunity activation pathways and their interactions with adaptive immunity would lead to more effective, faster and safer APE-based treatments to battle infections which still are a common public health problem worldwide.