Elicitor Research Articles

Effect of Elicitors treated callus of Baliospermum montanum (Willd.) Muell. Arg. on cell cycle arrest and apoptosis in HEP-2 and PC-3 cells

Effect of Elicitors treated callus of Baliospermum montanum (Willd.) Muell. Arg. on cell cycle arrest and apoptosis in HEP-2 and PC-3 cells

Effect of Carbon Source, Auxin and Elicitor on the Growth and Synthesis of Secondary Metabolites of Adventitious Roots of Cajanus cajan(Linn.) Millsp.

Effect of Carbon Source, Auxin and Elicitor on the Growth and Synthesis of Secondary Metabolites of Adventitious Roots of Cajanus cajan(Linn.) Millsp.

CONTROL OF FIRE BLIGHT INFECTIONS WITH SYNTHETIC PEPTIDES THAT ELICIT PLANT DEFENSE RESPONSES

Antimicrobial peptides (AMPs) are reliable compounds to develop strategies for integrated plant disease management. These peptides can act directly against the pathogens and/or induce plant defense responses. In this work, 33 sequences including linear and cyclic peptides, linear and cyclic peptidotriazoles, and cyclic lipopeptides were tested for induction of plant defense. A first screening was carried out with BY2 tobacco cell cultures by determining the alkalinization and production of hydrogen peroxide. Peptides BP13, BP100, BP143 and BPC200W were slightly positive in these assays and were tested by RT-qPCR for expression of 10 defense-related genes in tomato, which are representative of the jasmonic acid, salicylic acid and ethylene pathways. BP13 and BPC200W induced overexpression of several genes that are also overexpressed by reference plant defense peptide elicitors. Plant assays with potted pear plants in the greenhouse confirmed the effect of peptides BP13 and BPC200W in controlling Erwinia amylovora infections, putatively through plant defense induction.

English

English

Response surface modeling of natural alizarin production in hairy root cultures of Rubia tinctorum L. upon elicitation with fungal mycelia

The roots of Rubia tinctorum L., the common madder contain natural red dye known as alizarin. In the current study, central composite design of response surface methodology was employed for modeling of fungal elicitor treatment on natural alizarin production in uniform hairy root cultures of common madder in liquid 1/2 B5 medium. Upon fungal elicitation assay, using two fungal mycelia elicitors ( Aspergillus niger and Bipolaris maydis ) at three different times (0, 12 and 24h), the production of alizarin was determined. According to the results, after 24h; modeling and optimization conditions, including combination of 2 % of both elicitors for alizarin production equal to 10.0 mg.g -1 DW was evaluated. Optimal process parameters have been determined by using a high desirability value of 1.00 in Design-Expert ® software. Our results, altogether, offer a promising method regarding to the improvement of the alizarin production, as a pivotal natural dye in industrial applications.

Inducing resistance in cotton against Colletotrichum gossypii var. cephalosporioides with essential oils

This study aimed to evaluate the potential of essential oils of rosemary ( Rosmarinus officinalis ), baccharis ( Baccharis trimera ), lemon grass ( Cymbopogon citratus ), basil ( Ocimum basilicum ) and eucalyptus ( Corymbia citriodora ) in inducing resistance in cotton plants against C. gossypii var. cephalosporioides . The inductive effect of the essential oils was evaluated in plants growing in pots in the environment, which were treated with 1% essential oil at 47 days of age. 24 hours after elicitor treatment the plants were inoculated with a suspension of 1.5 x 10 5 conidia mL -1 of C. gossypii var. cephalosporioides . Five evaluations were performed disease and calculated the area under the disease progress curve. All essential oils showed potential for inducing resistance against cotton C. gossypii var. cephalosporioides .

Corrigendum: Muropeptides in Pseudomonas aeruginosa and their Role as Elicitors of β‐Lactam‐Antibiotic Resistance

Corrigendum: Muropeptides in <i>Pseudomonas aeruginosa</i> and their Role as Elicitors of β‐Lactam‐Antibiotic Resistance

Berichtigung: Muropeptides in Pseudomonas aeruginosa and their Role as Elicitors of β‐Lactam‐Antibiotic Resistance

Berichtigung: Muropeptides in <i>Pseudomonas aeruginosa</i> and their Role as Elicitors of β‐Lactam‐Antibiotic Resistance

The specifics of elicitor effect on Triticum aestivum macromorphogenesis under simultaneous lesion by Septoria tritici and Puccinia recondita

Phytopathogenic fungi interrupt the macromorphogenesis of wheat (Triticum aestivum) but biotic elicitors stimulate the nonspecific tolerance, growth and development of plant stems. It is shown that oxalic acid as a biotic elicitor and donor of nitric oxide signal molecule (sodium nitroprusside) stimulate stem growth in height and last leaves length, as well as grain quantity and productivity both in cv. ‘Poliska 90’ and cv. ‘Stolychna’ under Septoria tritici and Puccinia recondita infection in field trials. It is detected that the degree of infected leaf area decreased in both treated cultivars under Saari-Prescott scale. Cv. ‘Poliska 90’ is more sensitive to both fungal pathogens than cv. ‘Stolychna’, but elicitor influence on its architectonics was no less than on cv. ‘Stolychna’.

Elicitor applications to cell suspension culture for production of phenolic compounds in grapevine.

In this study, the effects of cadmium sulphate (CdSO 4 ), fleuresans irradiation, methyl jasmonate (MeJA) and sucrose treatments on the production of phenolic compounds in grapevine cell suspension cultures initiated from callus from petiole tissues of Vitis vinifera L. cvs. Gamay, Kalecik karasi and Okuzgozu were investigated. As the elicitors of CdSO 4 (0, 1 and 1.5 mM), MeJA (0 and 10 μM) and sucrose (0, 0.20 and 0.25 M) were applied. Cell suspensions were exposed to visible light (10,000 lux) for fleuresans irradiation or cultured in dark constantly. Total phenolics, total flavanols, total flavonols and anthocyanin were determined spectrophotometrically while trans-r esveratrol was quantified by HPLC. CdSO 4 at 1.5 mM concentration and MeJA at 10 μM concentration yielded the highest phenolic productions in all cultivars. Especially, Kalecik Karasitreated with CdSO 4 at 1.5 mM had the highest total phenolic (3.144 mg g -1 ), anthocyanin (1.672 CV g -1 ) and trans -resveratrol (3.650 μg g -1 ) contents. MeJA application at 10 μM provided the trans resveratrol accumulation as high as 11.681 μg g -1 in Okuzgozu. 0.20 M sucrose concentration resulted in the highest total phenolics (4.215 mg g -1 ) and trans -resveratrol (7.550 μg g -1 ) in Kalecik Karasi cultures while the most anthocyanin accumulation (2.024 CV g -1 ) was achieved from Gamay. Darkness had strongly increased trans -resveratrol content in all cultivars, whereas total phenolics and anthocyanin synthesis were induced by light. Elicitor applications of CdSO 4 , MeJA, sucrose and fleuresans irradiation can be an efficient approach for the production of phenolics in grapevines.

Expression profiling of malate dehydrogenase, superoxide dismutase and polygalacturonase-inhibiting protein in common bean in response to host and non-host pathogens.

The expression of malate dehydrogenase, superoxide dismutase and polygalacturonase- inhibiting protein was investigated in common bean plants inoculated with Xanthomonas hortorum pv. pelargonii as a non-host pathogen and X. axonopodis pv. phaseoli as a host pathogen. In comparison with inoculated plants with a host pathogen, more expression of malate dehydrogenase and superoxide dismutase was observed in treatments of non-host pathogen. The maximum expression of the genes was recorded 48 h post inoculation. Malate dehydrogenase and superoxide dismutase play crucial roles in incompatible plant-pathogen interaction. No significant difference was detected in expression of polygalacturonase-inhibiting protein in inoculated plants with host or non-host pathogen compared to control in any time points. In the absence of polygalacturonase that acts as an elicitor, polygalacturonase-inhibiting protein are not expressed.

The role of polyamine to increasing growth of plant: As a key factor in health crisis

Context: There is an increasing concern over predications that the world population will reach 8 billion in the next 25 years. Currently, many regions in Africa and Asia are experiencing a food crisis that is contributing to hunger, malnutrition and starvation. So each way to increasing yielding plant is a key factor to respond this demand. There are several elicitor to reach this target. Polyamines (PAS) are lightweight molecular that are present in all living organisms. PAS are necessary for the growth of prokaryotes and eukaryotes. Putrescine (Put), spermidine (Spd) and spermine (Spm) are the major PAS in plants. In plant cells, Put (diamine) is synthesized from ornithine and arginine by ornithine decarboxylase and arginine decarboxylase, respectively. With regard to the significance of the flower and oilseed of safflower, this research has been done on Put and its effect on the growth and development of safflower. Discussion :This experiment included three separate plans (A, B, C) and each plan has two different culture mediums that were called 'a' and 'b'. Finding and Conclusion: In this work, we found that maximum shoot regeneration belonged to Put A4 and Put A2 (Plan A). Also, the third plan has a significant reduction rather than first and second plan regarding rooting. According to data, the group with the highest shoot regeneration (A plan-Put A4) had maximum peroxidase activity also and the treatments of B plan with the lowest shoot regeneration had lowest enzyme activity.

Salicylic Acid, Phosphorous Acid and Fungicide Sumi 8 Effects on Polyphenol Oxidases Activities and Cassava Resistance to Anthracnose

In Côte d’Ivoire, cassava contributes enormously to improve food security of population by increasing national production and financial resources of vulnerable households. But, plant is attacked by several diseases including anthracnose. This study was done to improve its resistance to anthracnose by stimulating its natural defense following treatment plants with salicylic acid, phosphorous acid and fungicide Sumi 8 as elicitors. Polyphenol oxidases were chosen as resistance marker. Results showed that in the three cultivars (yacé, TMS30572 and I88/00158), yacé was more susceptible to anthracnose (p<0.05; F = 6.83). After treatments, cassava resistance against anthracnose has been improved. Polyphenol oxidases activities were more stimulated in presence of elicitor’s phosphorous acid and salicylic acid. Native-PAGE of polyphenol oxidases revealed 11 isoenzymes including 7 new isoenzymes detected in elicited plants, treated plants contaminated or uncontaminated by Colletotrichum gloeosporioïdes, pathogen of anthracnose. Recent isoenzymes were specific for each cultivar. Their appearance was correlated with plant resistance to C. gloeosporioïdes. In these plants, in particular those germinated directly in elicitation medium, anthracnose symptoms were lessened. These elicitors were thus induced and/or stimulated cassava defense especially polyphenol oxidases activities.

PATHOGEN-INDUCED EXPRESSION OF HARPINPSS INCREASES RESISTANCE IN TOBACCO AGAINST FUSARIUM OXYSPORUM f. sp. NICOTIANAE

HarpinPss (encoded by the hrpZ gene), a proteinaceous elicitor produced by Pseudomonas syringae pv. syringae, induces cell death in plants through hypersensitive response (HR). With an aim to generate transgenic tobacco resistant to fungal diseases, hrpZ was expressed in a secretable form, tagged with the signal peptide (SP) of PR1a, under the constitutive 35S promoter (P35S) or pathogen-inducible promoters (PIPs) like phenylalanine ammonia lyase (PAL), osmotin (OSM), and hypersensitive-related (HSR) promoters. The constitutive expression of the secretable form of hrpZ did not permit regeneration of transformed cells due to harpinPss-induced cell death. Transformants were recovered at a low frequency (2-6%) from leaf discs infected with Agrobacterium harbouring the SP-hrpZ driven by PIPs due to wound-induced leaky expression of harpinPss. The transgenic lines were confirmed by PCR using transgene-specific primers for SP-hrpZ. The expression of hrpZ under PIPs in transgenic lines was confirmed by Western blotting after challenging the leaves with Fusarium oxysporum f. sp. nicotianae. RT-PCR analysis also confirmed the expression of SP-hrpZ driven by PIPs in transgenic tobacco upon infection with F. oxysporum f. sp. nicotianae. The expression of harpinPss in these transgenic lines was accompanied by expression of defense-response genes such as PR1, PR2, PR3, HSR and HIN1. Transgenic tobacco plants showed enhanced resistance to F. oxysporum f. sp. nicotianae. Our findings suggest the potential use of an elicitor gene (hrpZ), driven by PIPs (PAL, OSM, and HSR) for the development of resistant plants.

A genetic screen of chitosan-resistant mutant in Arabidopsis thaliana

Forward genetic approach is a powerful tool to elucidate plant response to elicitors. Chitosan, the biodegradable polymer deacetylated form of chitin, plays a role as an elicitor in many plants. To discover the chitosan response mechanism, we achieved a screening for the EMS-mutagenized Arabidopsis population with chitosan-resistant characters that has not been previously reported. At the seedling stage, high dosage of chitosan reduced plant growth both shoot and root systems. Mutant phenotype is characterized by the larger plant size and/or longer root length compared with wild-type plant on 80 mg/L chitosan supplemented plates. Mutants also showed leaf defect phenotypes such as leaf shape and leaf coloration. A number of the putative mutants were sterile, with no flowers or showed early senescence before completion of their life cycles. At least 5 chitosan-insensitive mutant lines showed the larger shoots or longer root length comparing to wild type in chitosan treated condition. The genetic inheritance analysis with L er background crosses showed heterosis phenotype, interfering the growth-related trait of chitosan-resistant characters. To avoid the heterosis interference, the mutants were crossed with Col background. To identify the mutant population with a single recessive mutated gene, F 2 progeny of each cross was evaluated. Only three mutant lines, 106A, 129A and 161A showed the potential to contain the single recessive mutated genes involving in chitosan response. However, the 129A line did not showed the consistent chitosan-insensitive phenotype after the repeated phenotyping of the M 3 population. Therefore, only 106A and 161A will be used for further chitosan-responsive gene characterization as the next step.

Leucine zipper-like motifs of HrpZPss are not essential to induce hypersensitive response in tobacco.

Harpins are heat-stable, glycine-rich proteins secreted by several Gram-negative phytopathogenic bacteria, involved in the induction of hypersensitive response in non-host plants. HrpZPss is highly heat stable, exists as a polydispersed, multimeric protein in nature and the functional significance for its existence in many oligomeric forms, remains still unclear. It was suggested that the leucine zipper-like motifs (LZMs) may take part in the formation of oligomeric aggregates, which may be responsible for HR elicitation by harpins and for their high thermal stability. To test the involvement of LZMs in HR elicitation and induction of defense responses, we have generated deletion mutants with or without LZMs and analysed their ability to induce HR, and/or activate the defense responses. The deletion mutant HrpZMM1, with no LZM also elicited HR as well as defense responses in tobacco suggesting the LZMs are not essential for elicitor activity of HrpZPss. However, the ability to elicit defense responses may be linked with the ability to induce HR.

Effect of biotic elicitors on secondary metabolite production in cell suspensions of Hypericum triquetrifolium Turra.

Many experiments were designed to induce and increase the production of some secondary metabolites in tissue cultures of Hypericum triquetrifolium Turra using some biotechnological approaches. Callus was initiated on leaf discs cultured on MS medium supplemented with thidazirion (TDZ) at the concentrations 1.0, 1.25, 1.5, 2.0, or 2.5 mgL -1 and indole-3-acetic acid (IAA) at 0.5 mgL -1 ; callus was also initiated on stem explants on MS medium supplemented with 1.25 mgL -1 6-benzyl-aminopurine (BAP) and 0.5 mgL -1 of IAA. HPLC was used to determine the type and quantity of secondary metabolites in comparison with standards. Phytochemical accumulation in suspension cultures derived from leaf (LCs), stem (SCs) and root (RCs) were investigated. Fungal extracts of Aspergillus niger , Fusarium oxysporum and commercial yeast were added to a liquid MS medium at 0.1, 0.25, 0.5 or 0.75 mgL -1 . Data showed that the yield of p-OH-benzoic acid and chlorgenic acid in LCs treated with 0.5 mgL -1 yeast extract increased significantly compared with the control. Caffeic acid and tannic acid decreased in LCs significantly after elicitation with all biotic elicitors, but catechin accumulation in LCs increased significantly, when A. niger extract was added at all concentrations. Rutin, hypersoid and quercitin production in SCs increased significantly when treated with the fungal elicitors ; A. niger , F. oxysporum and yeast extracts. Chlorgenic decreased significantly in SCs, after the addition of all biotic elicitors at different concentrations.

The non-traditional growth regulator pectimorf is an elicitor of defense responses and protects Arabidopsis against Botrytis cinerea

Pectimorf is a non-traditional growth regulator produced in Cuba by partial enzymatic degradation of the cell wall of citrus fruit rinds. It is mainly composed of oligogalacturonides (OGs) and is currently used for in vitro micropropagation of different crops. Since OGs are known to elicit plant defense responses and are able to protect plants against fungal infection, we have investigated whether Pectimorf also has elicitor properties in Arabidopsis thaliana. The activity of Pectimorf was similar to that observed with similar doses of OGs in different bioassays (induction of gene expression, elicitation of oxidative burst, activation of MAP kinases). Furthermore, Pectimorf pre-treatments increased resistance of Arabidopsis leaves against infection by Botrytis cinerea. Pectimorf, as previously observed with OGs, also showed antagonistic effects with exogenous auxin. Taken together, these data indicate that Pectimorf is a potent elicitor of plant innate immunity and may be used as an inexpensive natural product to protect crops against diseases.

The contribution of Trichoderma to balancing the costs of plant growth and defense.

Trichoderma is a fungal genus of cosmopolitan distribution and high biotechnological value, with several species currently used as biological control agents. Additionally, the enzyme systems of the fungus are widely applied in industry. Species of Trichoderma protect plants against the attack of soil-borne plant pathogens by competing for nutrients and inhibiting or killing plant pathogenic fungi and oomycetes, through the production of antibiotics and/or hydrolytic enzymes. In addition to the role of Trichoderma spp. as biocontrol agents, they have other beneficial effects on plants, including the stimulation of plant defenses and the promotion of plant growth. In this review, we focus on the complex plant defense signaling network that allows the recognition of fungi as non-hostile microbes, including microbial-associated molecular patterns (MAMPs), damage-associated molecular patterns (DAMPs) and secreted elicitors. We also examine how fungal interactions with plant receptors can activate induced resistance by priming and balancing plant defense and growth responses. Our observations are integrated into a model describing Trichoderma-plant hormone signaling network interactions.

A new concept for production and scaling up of bioactive compounds from Egyptian date palm (Zaghlool) cultivar using bioreactor

A promising and successful protocol for enhancement and production of total phenolic and peroxides compounds from Egyptian date palm cultivar Zaghlool cells in stirred tank reactor was established. The influence of cell culture cultivation in combination with Aspergillus niger extract, and methyl-jasmonate elicitors incorporation in the feeding medium on cell growth patterns and production of active compounds was investigated. The maximum value of cell growth parameters and the highest content of bioactive compounds were obtained from elicitation of modified MS-medium with Aspergillus niger extract at 0.1% in combination with methyl-jasmonate (100 µM), as compared with other concentrations after 10 days of cultivation. The chemical analyses of phenolic and peroxidase compounds were spectrophotometrically performed.