The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex ...The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill and Colletotrichum dematium (Pers.) Grove). Among these three elicitors, V. dahliae had the highest inducing efficiency, but none of them manifests any noticeable effects on the cell growth of the hairy root cultures. The artemisinin content of the hairy root cultures treated with V. dahliae elicitor was 1.12 mg/g DW, which was 45% higher than the control (0.77 mg/g DW). The results showed that elicitation was dependent on the elicitor concentration, the incubation period and the physiological stage at which the hairy root cultures were treated. In addition, the authors found that for V. dahliae , the optimum concentration was 0.4 mg carbohydrate per millilitre medium, the strongest response of A. annua hairy root cultures to the elicitation was at the late exponential growth stage, and the highest artemisinin content of the hairy root cultures was on the 4th day post treatment.展开更多
To optimize the technique of rapid propagation of Dendrobium hybrida seedlings and to explore a hormone-free tissue culture method for D.hybrida,six kinds of mycorrhizal fungi which were isolated from the wild orchids...To optimize the technique of rapid propagation of Dendrobium hybrida seedlings and to explore a hormone-free tissue culture method for D.hybrida,six kinds of mycorrhizal fungi which were isolated from the wild orchids were made into fungal elicitors.These fungal elicitors were added into the DE medium with concentrations of 40,60 and 80 ml/L,respectively.After a 90-d culturing,the effects of fungal elicitors on the growth of D.hybrida cultivar ‘088＇ tissue culture seedlings were studied.The results showed that treatment 13（T13） extremely significantly increased the fresh weight,but other treatment groups had no significant effects.In addition,T1,T5,T9,T11 and T13 extremely significantly influenced the contents of chlorophyll a and chlorophyll a ＋ b.However,T1 and T11 had extremely significantly effect on the content of chlorophyll b.Combining the effects on fresh weight and chlorophyll content,it could be concluded T13（40 ml/L of Y05） has promoting effects on the growth of D.hybrida tissue culture seedlings.展开更多
Callus cultures of Origanum vulgare L. were established from leaf discus on Murashige and Skoog （MS） medium containing different levels of growth regulators, i.e., 2,4-Dichlorophenoxyacetic acid （2,4-D）, Naphthale...Callus cultures of Origanum vulgare L. were established from leaf discus on Murashige and Skoog （MS） medium containing different levels of growth regulators, i.e., 2,4-Dichlorophenoxyacetic acid （2,4-D）, Naphthalene acetic acid （NAA）, Benzyl Adenine （BA） and Kinetin （Kn） and incubated under dark condition. Callus tissues were employed to study the influence of abiotic elicitors on the production of thymol. Constant weights of callus （300 mg） were cultured on accumulation medium treated separately with each one of elicitors used （50 g/L sucrose, 200 mg/L NaC1 and 50 or 100 mg/L proline）. The fresh and dry weights of callus were recorded after six weeks. The result indicated that maximum production of fresh and dry callus weight were 1,014 mg and 46.20 mg respectively achieved at 0.5 mg/L 2,4-D and 3 mg/L BA adding to the medium. Dry callus tissues were extracted with 70% methanol and analyzed by HPLC to determine the concentrations of thymol. The addition of abiotic elicitors to MS medium caused significant reduction in fresh weight of callus compared with control treatment. The concentration of thymol in the callus cultured on control treatment was 146.6 ppm. The data showed that 50 or 100 mg/L proline produced the highest yield of thymol 181.48 ppm and 174.58 ppm respectively, followed by sucrose 162.9 ppm, whereas the treatment with NaCI caused reduction in thymol concentration to percentage of 50.56% compared with the control.展开更多
In this study, using Taxus cuspidata as a raw material, we obtained stable high-yielding cell lines by subculturing and quantified paclitaxel content using ultra- sonic extraction combined with TLC-UV spectrophotom- e...In this study, using Taxus cuspidata as a raw material, we obtained stable high-yielding cell lines by subculturing and quantified paclitaxel content using ultra- sonic extraction combined with TLC-UV spectrophotom- etry. In single factor and multiple factors tests to optimize design and study the effects of elicitors, precursors, and metabolic inhibitors on paclitaxel production by Taxus cuspidata cells, paclitaxel production reached 4.32 mg/L when 100 μmol/L methyl jasmonate, 20 mg/L salicylic acid, 400 mg/L phenylalanine and 2 mg/L gibberellin （GA3） were added to the culture medium of suspension cells. When adding metabolic adjustment factors on the 7th day of culture, extra- and intracellular paclitaxel production was the highest at 4.855 mg/L, paclitaxel release rate was 10.48 %, fresh mass and paclitaxel production of cell increased, respectively, by 6.08 and 11.57 %. By controlling the anabolism of paclitaxel, paclitaxel yield was significantly improved.展开更多
The Northeast region is the main producer of guava in Brazil,generating employment and income.However,water availability means that producer’s resort to using water with high salinity,which harms plant development,es...The Northeast region is the main producer of guava in Brazil,generating employment and income.However,water availability means that producer’s resort to using water with high salinity,which harms plant development,especially during the seedling formation phase.The adoption of techniques that mitigate the deleterious effect of salinity is increasingly necessary,such as the use of elicitors such as ascorbic acid.The purpose of this study was to analyze the morphophysiology of guava seedlings under saline and ascorbic acid levels.The study was carried out by applying treatments composed of five saline levels(SL=0.3;1.3;2.3;3.3 and 4.3 dS m^(-1))and four levels of ascorbic acid—AA(0,200,400,and 600 mg L^(-1)),in a 5×4 factorial arrangement,adopting a randomized block design.Gas exchange and growth of guava seedlings are limited from 0.3 dS m^(-1).Using 400 mg L^(-1)of AA reduces damage from salinity on stomatal conductance,transpiration,and net assimilation rate up to the estimated SL of 1.80 dS m^(-1).In contrast,AA level 412 mg L^(-1)increased instantaneous water use efficiency up to the salinity of 2.3 dS m^(-1).AA level of 600 mg L^(-1)attenuated salt stress effects on leaf area and height/stem diameter ratio up to SL of 2.05 dS m^(-1).The number of leaves and the absolute and relative growth rates were stimulated by AA under the lowest saline level.展开更多
Salt stress is one of the most harmful environmental stresses in recent times and represents a significant threat to food security. Soil salinization is caused by spontaneous natural processes of mineral dissolution a...Salt stress is one of the most harmful environmental stresses in recent times and represents a significant threat to food security. Soil salinization is caused by spontaneous natural processes of mineral dissolution and human activities such as inappropriate irrigation practices. Natural geological progressions like weathering of rocks, arid climate, and higher evaporation, as well as anthropogenic activities, including the use of brackish water for irrigation, and poor tillage operations, are the foremost causes of soil salinization. Typical characteristics of saline soils are salt stress, high pH, and lack of organic carbon, as well as low availability of nutrients. Disruption of precipitation patterns as well as high average annual temperatures due to climate change additionally negatively affects the process of soil salinization. Productivity and ability to support crop growth are reduced on saline soil. Salinity-induced stress reduces plant growth by modulating the antioxidative system and nutrient orchestration. The aim of this work is to show that the mentioned problems can be alleviated in several ways such as the addition of biochar, exogenous application of several elicitors, seed priming, etc. Research has shown that the addition of biochar can significantly improve the recovery of saline soil. The addition of biochar has no significant effect on soil pH, while the cation exchange capacity of the soil increased by 17%, and the electrical conductivity of the saturated paste extract decreased by 13.2% (depends on the initial salinity and the type of biochar raw material). Moreover, biochar enriched with silicon increases the resistance of bananas to salt stress. In addition, exogenous application of several elicitors helps plants to alleviate stress by inducing stress-related physicochemical and molecular changes (selenium, sulfur, silicon, salicylic acid). Finally, seed priming showed positive effects on metabolomics, proteomics and growth of plants subjected to abiotic stress. Priming usually involves immersing the seed in a solution for a period of time to induce physiological and metabolic progression prior to germination.展开更多
Highly ameliorated phytochemicals from plants are recognized to have numerous beneficial effects on human health.However,obtaining secondary metabolites directly from wild plants is posing a great threat to endangered...Highly ameliorated phytochemicals from plants are recognized to have numerous beneficial effects on human health.However,obtaining secondary metabolites directly from wild plants is posing a great threat to endangered plant species due to their over exploitation.Moreover,due to complicated structure and stereospecificity chemical synthesis of these compounds is a troublesome procedure.As a result,sustainable and ecofriendly in vitro strategy has been adopted for phytochemicals production.But,lack of fully differentiated cells lowers down cultured cells productivity.Consequently,for enhancing yield of metabolites produced by cultured plant cells a variety of methodologies has been followed one such approach includes elicitation of culture medium that provoke stress responses in plants enhancing synthesis and storage of bioactive compounds.Nevertheless,for conclusive breakthrough in synthesizing bioactive compounds at commercial level in-depth knowledge regarding metabolic responses to elicitation in plant cell cultures is needed.However,technological advancement has led to development of molecular based approaches like metabolic engineering and synthetic biology which can serve as promising path for phytochemicals synthesis.This review article deals with classification,stimulating effect of elicitors on cultured cells,parameters of elicitors and action mechanism in plants,modern approaches like metabolic engineering for future advances.展开更多
Lignans are a prominent group of phenolic compounds ubiquitously present in the plant kingdom,playing a critical role in both plant physiology and human health.Structurally they are characterized by the dimerization o...Lignans are a prominent group of phenolic compounds ubiquitously present in the plant kingdom,playing a critical role in both plant physiology and human health.Structurally they are characterized by the dimerization of two phenylpropane units to attain diverse chemical configurations that contribute to their wide range of biological activities.In plants,lignans function primarily as defense molecules,protecting against pathogens,herbivores,and environmental stressors.These compounds also participate in plant growth regulation and lignification processes.From a nutritional and medicinal perspective,lignans are valued for their significant health benefits.They act as phytoestrogens,which can modulate estrogen receptors in humans,thereby offering protective effects against hormone-related diseases such as breast cancer and menopausal symptoms.Additionally,lignans possess potent antioxidant and anti-inflammatory properties,contributing to cardiovascular health and cancer prevention.This review aims to provide a comprehensive overview of the importance of lignans in plants,highlighting their chemical diversity,health-promoting properties and stress adaptation.By synthesizing recent research findings,this review underscores the significance of lignans in enhancing plant resilience under stress and human health.It explores their potential applications in the food and pharmaceutical industries.Besides,it will also focus on the widely used method for enhancing the production of these high-value secondary metabolites in plant cell cultures to meet their requirement in pharmaceutical industries.展开更多
The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (la...The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.展开更多
The effectiveness ofpostharvest β-aminobutyric acid （BABA） treatment was studied for inducing resistance against dry rot caused by Fusarium sulphureum in tubers and slices of two potato cultivars （resistant cultiv...The effectiveness ofpostharvest β-aminobutyric acid （BABA） treatment was studied for inducing resistance against dry rot caused by Fusarium sulphureum in tubers and slices of two potato cultivars （resistant cultivar Shepody and susceptible cultivar Xindaping）. The results showed that BABA at 100 mmol L-1 significantly reduced lesion diameter in inoculated both tubers and slices. The chemical at 100 mmol L-1 showed an effective reduction in infection ability ofF. sulphureum inoculated 48 and 72 h after treatment in slices of resistant cultivar, and 72 and 96 h in susceptible ones. BABA increased the activitives of peroxidase （POD）, polyphenoloxidase （PPO） and phenylalanine ammonialyase （PAL）, and accumulated the contents of lignin, flavonoids and phenolics in slices. The resistant cultivar had a stronger resistant response than the susceptible one. These findings suggest that the BABA treatment can induce the resistance in potato tubers, however, the inducing degree depends on the original level of resistance present in each cultivar.展开更多
In order to reveal the signaling pathways triggered by elicitor in plant-microbe interactions, the mechanisms of hypersensitive necrosis responses in Nicotiana tabacum L. cv. Gexin III induced by palmin were studied a...In order to reveal the signaling pathways triggered by elicitor in plant-microbe interactions, the mechanisms of hypersensitive necrosis responses in Nicotiana tabacum L. cv. Gexin III induced by palmin were studied at molecular and cellular level. The burst of superoxide, intercellular diffusion of hydrogen peroxide and process of cell death induced by palmin were investigated in tobacco plants by biochemical methods and Confocal microscopy. The results showed that a large amount of O-2(.-) was rapidly generated in tobacco cell elicited by palmin as a result of activation of NADPH oxidase, and the O-2(.-) was dismutated into H2O2 immediately by superoxide dismutase (SOD). Accumulation and intercellular diffusion of H2O2 were shown to be a trigger for hypersensitive cell death; and Ca2+ and some specific protein kinase were also shown to be involved in the activation of oxidative burst in tobacco cell induced by palmin.展开更多
NAD(P)H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C. A. Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Col-letotrichum lagera...NAD(P)H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C. A. Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Col-letotrichum lagerarium. In addition, Cle induced an oxidative burst and enhanced the synthesis of saponin, activity of phenylalanine ammonialyase (PAL) , accumulation of chalcone synthase (CHS) and the transcription of a hydroxyproline-rich glycoprotein gene ( hrgp ) . Pre-treatments with DPI and quinacrine (two inhibitors of mammalian neutrophil plasma membrane NADPH oxidase) for 30 min prior to Cle addition blocked the NAD(P)H oxidase activity induced by Cle. These inhibitors also inhibited the release of H2C2, the synthesis of saponin, PAL activity and CHS accumulation. Our data revealed homology between plasma membrane NAD(P)H oxidases of mammalian neutrophil cells and ginseng suspension cells. They also indicated that deactivated NAD(P)H oxidases catalysed the release of H2O2 and that H2O2 was functioning as a second messenger stimulating PAL activity, saponin synthesis and hrgp transcription. Elevations of Ca2 + and protein phos-phorylation/dephosphorylation were required for this defense process. We propose that NAD(P)H oxidases mediate the processes of Cle-induced defense responses in ginseng suspensions, and postulate the existence of a signalling cascade including extracellular Cle stimulation, activation of plasma membrane NAD(P)H oxidases, release of H2O2, and the intracellular responses of metabolism and gene transcription in ginseng suspension cells.展开更多
Endogenous elicitor, termed cellulase-degraded cell wall (CDW), was prepared from the cell wall of suspension-cultured ginseng (Panax ginseng C.A. Meyer) cells via cellulase degradation. CDW activated the NADPH oxidas...Endogenous elicitor, termed cellulase-degraded cell wall (CDW), was prepared from the cell wall of suspension-cultured ginseng (Panax ginseng C.A. Meyer) cells via cellulase degradation. CDW activated the NADPH oxidase activity of isolated plasma membranes and stimulated in vivo H2O2 generation in ginseng cell suspensions. CDW also increased the activity of phenylalanine ammonia lyase (PAL), expression of a P. ginseng squalene epoxidase (sqe) gene and saponin synthesis. NADPH oxidase inhibitors inhibited both in vitro NADPH oxidase activity and in vivo H2O2 generation. Induction of PAL activity, saponin synthesis and sqe gene expression were all inhibited by such inhibitor treatments and reduced by incubation with catalase and HA scavengers. These data indicate that activation of NADPH oxidase and generation of H2O2 are essential signalling events mediating defence responses induced by the endogenous elicitor(s) present in CDW.展开更多
The process of ripening involves physiological and biochemical events that become a concern during postharvest storage.We have documented different approaches for the preservation and maintenance of fruit quality duri...The process of ripening involves physiological and biochemical events that become a concern during postharvest storage.We have documented different approaches for the preservation and maintenance of fruit quality during the postharvest period that are biocompatible and fully safe for consumption.Chemical residues that sustain sensory characteristics,such as color,flavor,aroma,and texture,are considered.In fruit ripening,both physical and chemical elicitors are described that regulate ethylene biosynthesis or its signaling for gene expression.The key regulatory enzymes,such as ACC synthase and ACC oxidase,for ethylene biosynthesis,are important for both climacteric and non-climacteric fruits.Anti-oxidizing genes that retain sensory characteristics are concerns in this respect.Chemical elicitors,including chitosan,polyamine,phenolics,lipopolysaccharide,silver derivatives,and nanocomposites,are described.Gas pressure,light wavelengths,relative humidity,cooling,and other environmental factors are important for improved postharvest storage.These elicitors maintain redox status by inhibiting the generation of reactive oxygen species(ROS)or their lysis.Growth regulators,including abscisic acid,auxin,brassinosteroids,jasmonic acid,and salicylic acid,are important for the regulation of ripening.Mechanical injuries,ionic imbalances,temperature variations,and tissue dehydration can occur irrespective of ripening cate-gories.The use of synthetic physiochemically active compounds is discussed in terms of physiological,metabolic,cellular,and molecular functions.Ethylene-induced autocatalytic processes,antioxidant cascades,epigenetic regulation,and homeodomain gene expression are discussed.Sugar–acid metabolism,dissolution of the cell wall,and direct or indirect production of secondary metabolites related to postharvest storage are mentioned regarding chilling storage.Elicitors and agrochemicals that trigger plant defense to increase secondary metabolite production are discussed for reducing fruit senescence during postharvest storage.展开更多
The drug L-DOPA has been widely used against Parkinson's disease and is extracted from plants.Due to the increasing demand of this drug,new plant sources need to be discovered in addition to the existing sources.T...The drug L-DOPA has been widely used against Parkinson's disease and is extracted from plants.Due to the increasing demand of this drug,new plant sources need to be discovered in addition to the existing sources.The paper embodies results on Mucuna monosperma,which can be a promising candidate for L-DOPA.The seed powder of this plant contains 5.48%of(dry weight)the drug and when the seeds were soaked in distilled water,content was increased to 6.58%.Different elicitors when added,enhanced the drug level in seed up to 11.8%.The possible rationale behind this increase was confirmed by increase in tyrosinase activity in the seeds.Presence of L-DOPA was confirmed using various analytical techniques as HPLC,HPTLC and NMR.The work demonstrates a potential candidate plant as a source for L-DOPA when a novel method was adopted as described here.展开更多
Leaf discs of five cultivars of sugarcane exhibiting different degree of susceptibility to leaf scald were used to measure β-1,3 glucanase activity before and after experimental infection with Xanthomonas albilineans...Leaf discs of five cultivars of sugarcane exhibiting different degree of susceptibility to leaf scald were used to measure β-1,3 glucanase activity before and after experimental infection with Xanthomonas albilineans. Leaf discs were permeabilized with iso-propanol to facilitate the uptake of the enzyme substrate by intact tissues and to improve the enzyme assay. Bacterial infection significantly enhances β-1,3 glucanase activity of sensitive cultivars whereas significantly decreased that of the resistant one. Low concentrations of salicylate increase the hydrolase activity whereas jasmonic acid do not act as an elicitor of the enzyme and β-1,3 glucanase, such as laminarin, significantly inhibits the production of β-1,3 glucanase. Thus, the enzyme must be considered as a sensitivity factor induced by the pathogen.展开更多
Callus cultures of Hyoscyamus niger L. were initiated from leaf segments cultured on Murashige and Skoog （MS） medium supplemented with 0.5 mg/L Benzyl Adenine （BA） and 0, 1, 2 and 3 mg/L Naphthalene acetic acid （...Callus cultures of Hyoscyamus niger L. were initiated from leaf segments cultured on Murashige and Skoog （MS） medium supplemented with 0.5 mg/L Benzyl Adenine （BA） and 0, 1, 2 and 3 mg/L Naphthalene acetic acid （ NAA ）. Half of cultures were incubated under light of 16 hr/day, while the other half was incubated under complete darkness. The incubation temperature was 25 ± 1 ℃in both incubation conditions. The fresh and dry weight of the produced callus was obtained after six weeks of incubation. Callus produced were recultured on medium that gave the highest production of callus. Constant weight （300 mg） of callus was cultured in each of these medium supplemented with abiotic elicitor of 50 g/L sucrose, 200 mg/L NaCI, 50 or 100 mg/L proline and 2 mg/L BA each one added separately and incubated under complete darkness. The fresh and dry weights of callus were measured after six weeks. HPLC was used to determine the tropane alkaloids （Hyoscyamine and Scopolamine）. The results showed that the significant highest average of fresh and dry weight of callus （112 and 89.6 mg） achieved using the medium contained 0.5 mg/L BA and 2 mg/L NAA under dark condition. The amount of fresh and dry weight of callus produced under dark condition was significantly higher than that produced under light condition, with increase in percentage of 51.3 and 37.62% respectively. The addition of abiotic elicitors caused reduction in both fresh and dry weight of callus, therefore the highest fresh weight average was 1,727 mg using 100 mg/L proline. The results indicated that addition of 50 or 100 mg/L proline led to increase in Hyoscyamine concentration of 58.03 and 21.37% respectively compared with the control. While other abiotic elicitors were found to cause reduction in Hyoscyamine concentration. Percentage of Scopolamine concentration were increased to 129.03, 166.94, 205.51 and 149.20% after addition of sucrose （50 g/L）, NaC1 （200 mg/L） and proline （50 or 100 mg/L） respectively compared with the control.展开更多
Induced resistance was studied in muskmelons （cv. Yindi） inoculated Trichothecium roseum with postharvest 1,2,3- benzothiadiazole-7-carbothioic acid S-methyl ester （ASM） （100 mg L^-1） or harpin （50 mg L^-1） tr...Induced resistance was studied in muskmelons （cv. Yindi） inoculated Trichothecium roseum with postharvest 1,2,3- benzothiadiazole-7-carbothioic acid S-methyl ester （ASM） （100 mg L^-1） or harpin （50 mg L^-1） treatment. Both ASM and harpin significantly reduced lesion diameter in inoculated fruit. Lesion diameter was limited in the treated and untreated halves of the same fruit, indicating that the local and systemic resistance was induced. Inhibiting efficacy of elicitors lasted 7 and 5 days in the treated and untreated halves. The resistance increased by the chemicals was associated with the activation of peroxidase （POD） and chitinase （CHT）. The elicitors induced a significantly and progressively increasing activity of POD and CHT in the treated and untreated halves, and the activation lasted at least 5 days. The activities of POD isoenzymes increased in the treated fruit. However, no new enzyme band was found in the treated and untreated halves.展开更多
文摘The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill and Colletotrichum dematium (Pers.) Grove). Among these three elicitors, V. dahliae had the highest inducing efficiency, but none of them manifests any noticeable effects on the cell growth of the hairy root cultures. The artemisinin content of the hairy root cultures treated with V. dahliae elicitor was 1.12 mg/g DW, which was 45% higher than the control (0.77 mg/g DW). The results showed that elicitation was dependent on the elicitor concentration, the incubation period and the physiological stage at which the hairy root cultures were treated. In addition, the authors found that for V. dahliae , the optimum concentration was 0.4 mg carbohydrate per millilitre medium, the strongest response of A. annua hairy root cultures to the elicitation was at the late exponential growth stage, and the highest artemisinin content of the hairy root cultures was on the 4th day post treatment.
基金Supported by National Nonprofit Institute Research Grant of CATAS-TCGRI(1630032014027)Special Fund for Agro-scientific Research in the Public Interest(201203071)Special Project for Scientific and Technological Achievements Demonstration and Promotion in Hainan Province(SQ2013CGSF0006)~~
文摘To optimize the technique of rapid propagation of Dendrobium hybrida seedlings and to explore a hormone-free tissue culture method for D.hybrida,six kinds of mycorrhizal fungi which were isolated from the wild orchids were made into fungal elicitors.These fungal elicitors were added into the DE medium with concentrations of 40,60 and 80 ml/L,respectively.After a 90-d culturing,the effects of fungal elicitors on the growth of D.hybrida cultivar ‘088＇ tissue culture seedlings were studied.The results showed that treatment 13（T13） extremely significantly increased the fresh weight,but other treatment groups had no significant effects.In addition,T1,T5,T9,T11 and T13 extremely significantly influenced the contents of chlorophyll a and chlorophyll a ＋ b.However,T1 and T11 had extremely significantly effect on the content of chlorophyll b.Combining the effects on fresh weight and chlorophyll content,it could be concluded T13（40 ml/L of Y05） has promoting effects on the growth of D.hybrida tissue culture seedlings.
文摘Callus cultures of Origanum vulgare L. were established from leaf discus on Murashige and Skoog （MS） medium containing different levels of growth regulators, i.e., 2,4-Dichlorophenoxyacetic acid （2,4-D）, Naphthalene acetic acid （NAA）, Benzyl Adenine （BA） and Kinetin （Kn） and incubated under dark condition. Callus tissues were employed to study the influence of abiotic elicitors on the production of thymol. Constant weights of callus （300 mg） were cultured on accumulation medium treated separately with each one of elicitors used （50 g/L sucrose, 200 mg/L NaC1 and 50 or 100 mg/L proline）. The fresh and dry weights of callus were recorded after six weeks. The result indicated that maximum production of fresh and dry callus weight were 1,014 mg and 46.20 mg respectively achieved at 0.5 mg/L 2,4-D and 3 mg/L BA adding to the medium. Dry callus tissues were extracted with 70% methanol and analyzed by HPLC to determine the concentrations of thymol. The addition of abiotic elicitors to MS medium caused significant reduction in fresh weight of callus compared with control treatment. The concentration of thymol in the callus cultured on control treatment was 146.6 ppm. The data showed that 50 or 100 mg/L proline produced the highest yield of thymol 181.48 ppm and 174.58 ppm respectively, followed by sucrose 162.9 ppm, whereas the treatment with NaCI caused reduction in thymol concentration to percentage of 50.56% compared with the control.
基金supported by development plan project during ‘‘the 12th Five Year Plan’’ Nation Science and Technology in rural area(No.2012AA10A506-04 and No.2013AA103005-04)Changchun City science and technology development program(No.2014174)Changchun City science and technology support program(No.2014NK002)
文摘In this study, using Taxus cuspidata as a raw material, we obtained stable high-yielding cell lines by subculturing and quantified paclitaxel content using ultra- sonic extraction combined with TLC-UV spectrophotom- etry. In single factor and multiple factors tests to optimize design and study the effects of elicitors, precursors, and metabolic inhibitors on paclitaxel production by Taxus cuspidata cells, paclitaxel production reached 4.32 mg/L when 100 μmol/L methyl jasmonate, 20 mg/L salicylic acid, 400 mg/L phenylalanine and 2 mg/L gibberellin （GA3） were added to the culture medium of suspension cells. When adding metabolic adjustment factors on the 7th day of culture, extra- and intracellular paclitaxel production was the highest at 4.855 mg/L, paclitaxel release rate was 10.48 %, fresh mass and paclitaxel production of cell increased, respectively, by 6.08 and 11.57 %. By controlling the anabolism of paclitaxel, paclitaxel yield was significantly improved.
基金supported by CNPq(National Council for Scientific and Technological Development—Processo:151057/2024-9),CAPES(Coordination for the Improvement of Higher Education Personnel)financial code—001,and UFCG(Universidade Federal de Campina Grande).
文摘The Northeast region is the main producer of guava in Brazil,generating employment and income.However,water availability means that producer’s resort to using water with high salinity,which harms plant development,especially during the seedling formation phase.The adoption of techniques that mitigate the deleterious effect of salinity is increasingly necessary,such as the use of elicitors such as ascorbic acid.The purpose of this study was to analyze the morphophysiology of guava seedlings under saline and ascorbic acid levels.The study was carried out by applying treatments composed of five saline levels(SL=0.3;1.3;2.3;3.3 and 4.3 dS m^(-1))and four levels of ascorbic acid—AA(0,200,400,and 600 mg L^(-1)),in a 5×4 factorial arrangement,adopting a randomized block design.Gas exchange and growth of guava seedlings are limited from 0.3 dS m^(-1).Using 400 mg L^(-1)of AA reduces damage from salinity on stomatal conductance,transpiration,and net assimilation rate up to the estimated SL of 1.80 dS m^(-1).In contrast,AA level 412 mg L^(-1)increased instantaneous water use efficiency up to the salinity of 2.3 dS m^(-1).AA level of 600 mg L^(-1)attenuated salt stress effects on leaf area and height/stem diameter ratio up to SL of 2.05 dS m^(-1).The number of leaves and the absolute and relative growth rates were stimulated by AA under the lowest saline level.
文摘Salt stress is one of the most harmful environmental stresses in recent times and represents a significant threat to food security. Soil salinization is caused by spontaneous natural processes of mineral dissolution and human activities such as inappropriate irrigation practices. Natural geological progressions like weathering of rocks, arid climate, and higher evaporation, as well as anthropogenic activities, including the use of brackish water for irrigation, and poor tillage operations, are the foremost causes of soil salinization. Typical characteristics of saline soils are salt stress, high pH, and lack of organic carbon, as well as low availability of nutrients. Disruption of precipitation patterns as well as high average annual temperatures due to climate change additionally negatively affects the process of soil salinization. Productivity and ability to support crop growth are reduced on saline soil. Salinity-induced stress reduces plant growth by modulating the antioxidative system and nutrient orchestration. The aim of this work is to show that the mentioned problems can be alleviated in several ways such as the addition of biochar, exogenous application of several elicitors, seed priming, etc. Research has shown that the addition of biochar can significantly improve the recovery of saline soil. The addition of biochar has no significant effect on soil pH, while the cation exchange capacity of the soil increased by 17%, and the electrical conductivity of the saturated paste extract decreased by 13.2% (depends on the initial salinity and the type of biochar raw material). Moreover, biochar enriched with silicon increases the resistance of bananas to salt stress. In addition, exogenous application of several elicitors helps plants to alleviate stress by inducing stress-related physicochemical and molecular changes (selenium, sulfur, silicon, salicylic acid). Finally, seed priming showed positive effects on metabolomics, proteomics and growth of plants subjected to abiotic stress. Priming usually involves immersing the seed in a solution for a period of time to induce physiological and metabolic progression prior to germination.
文摘Highly ameliorated phytochemicals from plants are recognized to have numerous beneficial effects on human health.However,obtaining secondary metabolites directly from wild plants is posing a great threat to endangered plant species due to their over exploitation.Moreover,due to complicated structure and stereospecificity chemical synthesis of these compounds is a troublesome procedure.As a result,sustainable and ecofriendly in vitro strategy has been adopted for phytochemicals production.But,lack of fully differentiated cells lowers down cultured cells productivity.Consequently,for enhancing yield of metabolites produced by cultured plant cells a variety of methodologies has been followed one such approach includes elicitation of culture medium that provoke stress responses in plants enhancing synthesis and storage of bioactive compounds.Nevertheless,for conclusive breakthrough in synthesizing bioactive compounds at commercial level in-depth knowledge regarding metabolic responses to elicitation in plant cell cultures is needed.However,technological advancement has led to development of molecular based approaches like metabolic engineering and synthetic biology which can serve as promising path for phytochemicals synthesis.This review article deals with classification,stimulating effect of elicitors on cultured cells,parameters of elicitors and action mechanism in plants,modern approaches like metabolic engineering for future advances.
基金Ragini Singh is very thankful to the Jamia Hamdard University Grants Commission,India for research grant No.162000681.
文摘Lignans are a prominent group of phenolic compounds ubiquitously present in the plant kingdom,playing a critical role in both plant physiology and human health.Structurally they are characterized by the dimerization of two phenylpropane units to attain diverse chemical configurations that contribute to their wide range of biological activities.In plants,lignans function primarily as defense molecules,protecting against pathogens,herbivores,and environmental stressors.These compounds also participate in plant growth regulation and lignification processes.From a nutritional and medicinal perspective,lignans are valued for their significant health benefits.They act as phytoestrogens,which can modulate estrogen receptors in humans,thereby offering protective effects against hormone-related diseases such as breast cancer and menopausal symptoms.Additionally,lignans possess potent antioxidant and anti-inflammatory properties,contributing to cardiovascular health and cancer prevention.This review aims to provide a comprehensive overview of the importance of lignans in plants,highlighting their chemical diversity,health-promoting properties and stress adaptation.By synthesizing recent research findings,this review underscores the significance of lignans in enhancing plant resilience under stress and human health.It explores their potential applications in the food and pharmaceutical industries.Besides,it will also focus on the widely used method for enhancing the production of these high-value secondary metabolites in plant cell cultures to meet their requirement in pharmaceutical industries.
文摘The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.
基金supported by the Gansu Agricultural Bio-Technology Foundation, China (GNSW-2005-08)the R&D Special Funds for Public Welfare Indus-try (Agriculture) of Ministry of Agriculture of China(NYHYZX07-6)
文摘The effectiveness ofpostharvest β-aminobutyric acid （BABA） treatment was studied for inducing resistance against dry rot caused by Fusarium sulphureum in tubers and slices of two potato cultivars （resistant cultivar Shepody and susceptible cultivar Xindaping）. The results showed that BABA at 100 mmol L-1 significantly reduced lesion diameter in inoculated both tubers and slices. The chemical at 100 mmol L-1 showed an effective reduction in infection ability ofF. sulphureum inoculated 48 and 72 h after treatment in slices of resistant cultivar, and 72 and 96 h in susceptible ones. BABA increased the activitives of peroxidase （POD）, polyphenoloxidase （PPO） and phenylalanine ammonialyase （PAL）, and accumulated the contents of lignin, flavonoids and phenolics in slices. The resistant cultivar had a stronger resistant response than the susceptible one. These findings suggest that the BABA treatment can induce the resistance in potato tubers, however, the inducing degree depends on the original level of resistance present in each cultivar.
文摘In order to reveal the signaling pathways triggered by elicitor in plant-microbe interactions, the mechanisms of hypersensitive necrosis responses in Nicotiana tabacum L. cv. Gexin III induced by palmin were studied at molecular and cellular level. The burst of superoxide, intercellular diffusion of hydrogen peroxide and process of cell death induced by palmin were investigated in tobacco plants by biochemical methods and Confocal microscopy. The results showed that a large amount of O-2(.-) was rapidly generated in tobacco cell elicited by palmin as a result of activation of NADPH oxidase, and the O-2(.-) was dismutated into H2O2 immediately by superoxide dismutase (SOD). Accumulation and intercellular diffusion of H2O2 were shown to be a trigger for hypersensitive cell death; and Ca2+ and some specific protein kinase were also shown to be involved in the activation of oxidative burst in tobacco cell induced by palmin.
文摘NAD(P)H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C. A. Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Col-letotrichum lagerarium. In addition, Cle induced an oxidative burst and enhanced the synthesis of saponin, activity of phenylalanine ammonialyase (PAL) , accumulation of chalcone synthase (CHS) and the transcription of a hydroxyproline-rich glycoprotein gene ( hrgp ) . Pre-treatments with DPI and quinacrine (two inhibitors of mammalian neutrophil plasma membrane NADPH oxidase) for 30 min prior to Cle addition blocked the NAD(P)H oxidase activity induced by Cle. These inhibitors also inhibited the release of H2C2, the synthesis of saponin, PAL activity and CHS accumulation. Our data revealed homology between plasma membrane NAD(P)H oxidases of mammalian neutrophil cells and ginseng suspension cells. They also indicated that deactivated NAD(P)H oxidases catalysed the release of H2O2 and that H2O2 was functioning as a second messenger stimulating PAL activity, saponin synthesis and hrgp transcription. Elevations of Ca2 + and protein phos-phorylation/dephosphorylation were required for this defense process. We propose that NAD(P)H oxidases mediate the processes of Cle-induced defense responses in ginseng suspensions, and postulate the existence of a signalling cascade including extracellular Cle stimulation, activation of plasma membrane NAD(P)H oxidases, release of H2O2, and the intracellular responses of metabolism and gene transcription in ginseng suspension cells.
文摘Endogenous elicitor, termed cellulase-degraded cell wall (CDW), was prepared from the cell wall of suspension-cultured ginseng (Panax ginseng C.A. Meyer) cells via cellulase degradation. CDW activated the NADPH oxidase activity of isolated plasma membranes and stimulated in vivo H2O2 generation in ginseng cell suspensions. CDW also increased the activity of phenylalanine ammonia lyase (PAL), expression of a P. ginseng squalene epoxidase (sqe) gene and saponin synthesis. NADPH oxidase inhibitors inhibited both in vitro NADPH oxidase activity and in vivo H2O2 generation. Induction of PAL activity, saponin synthesis and sqe gene expression were all inhibited by such inhibitor treatments and reduced by incubation with catalase and HA scavengers. These data indicate that activation of NADPH oxidase and generation of H2O2 are essential signalling events mediating defence responses induced by the endogenous elicitor(s) present in CDW.
文摘The process of ripening involves physiological and biochemical events that become a concern during postharvest storage.We have documented different approaches for the preservation and maintenance of fruit quality during the postharvest period that are biocompatible and fully safe for consumption.Chemical residues that sustain sensory characteristics,such as color,flavor,aroma,and texture,are considered.In fruit ripening,both physical and chemical elicitors are described that regulate ethylene biosynthesis or its signaling for gene expression.The key regulatory enzymes,such as ACC synthase and ACC oxidase,for ethylene biosynthesis,are important for both climacteric and non-climacteric fruits.Anti-oxidizing genes that retain sensory characteristics are concerns in this respect.Chemical elicitors,including chitosan,polyamine,phenolics,lipopolysaccharide,silver derivatives,and nanocomposites,are described.Gas pressure,light wavelengths,relative humidity,cooling,and other environmental factors are important for improved postharvest storage.These elicitors maintain redox status by inhibiting the generation of reactive oxygen species(ROS)or their lysis.Growth regulators,including abscisic acid,auxin,brassinosteroids,jasmonic acid,and salicylic acid,are important for the regulation of ripening.Mechanical injuries,ionic imbalances,temperature variations,and tissue dehydration can occur irrespective of ripening cate-gories.The use of synthetic physiochemically active compounds is discussed in terms of physiological,metabolic,cellular,and molecular functions.Ethylene-induced autocatalytic processes,antioxidant cascades,epigenetic regulation,and homeodomain gene expression are discussed.Sugar–acid metabolism,dissolution of the cell wall,and direct or indirect production of secondary metabolites related to postharvest storage are mentioned regarding chilling storage.Elicitors and agrochemicals that trigger plant defense to increase secondary metabolite production are discussed for reducing fruit senescence during postharvest storage.
文摘The drug L-DOPA has been widely used against Parkinson's disease and is extracted from plants.Due to the increasing demand of this drug,new plant sources need to be discovered in addition to the existing sources.The paper embodies results on Mucuna monosperma,which can be a promising candidate for L-DOPA.The seed powder of this plant contains 5.48%of(dry weight)the drug and when the seeds were soaked in distilled water,content was increased to 6.58%.Different elicitors when added,enhanced the drug level in seed up to 11.8%.The possible rationale behind this increase was confirmed by increase in tyrosinase activity in the seeds.Presence of L-DOPA was confirmed using various analytical techniques as HPLC,HPTLC and NMR.The work demonstrates a potential candidate plant as a source for L-DOPA when a novel method was adopted as described here.
文摘Leaf discs of five cultivars of sugarcane exhibiting different degree of susceptibility to leaf scald were used to measure β-1,3 glucanase activity before and after experimental infection with Xanthomonas albilineans. Leaf discs were permeabilized with iso-propanol to facilitate the uptake of the enzyme substrate by intact tissues and to improve the enzyme assay. Bacterial infection significantly enhances β-1,3 glucanase activity of sensitive cultivars whereas significantly decreased that of the resistant one. Low concentrations of salicylate increase the hydrolase activity whereas jasmonic acid do not act as an elicitor of the enzyme and β-1,3 glucanase, such as laminarin, significantly inhibits the production of β-1,3 glucanase. Thus, the enzyme must be considered as a sensitivity factor induced by the pathogen.
文摘Callus cultures of Hyoscyamus niger L. were initiated from leaf segments cultured on Murashige and Skoog （MS） medium supplemented with 0.5 mg/L Benzyl Adenine （BA） and 0, 1, 2 and 3 mg/L Naphthalene acetic acid （ NAA ）. Half of cultures were incubated under light of 16 hr/day, while the other half was incubated under complete darkness. The incubation temperature was 25 ± 1 ℃in both incubation conditions. The fresh and dry weight of the produced callus was obtained after six weeks of incubation. Callus produced were recultured on medium that gave the highest production of callus. Constant weight （300 mg） of callus was cultured in each of these medium supplemented with abiotic elicitor of 50 g/L sucrose, 200 mg/L NaCI, 50 or 100 mg/L proline and 2 mg/L BA each one added separately and incubated under complete darkness. The fresh and dry weights of callus were measured after six weeks. HPLC was used to determine the tropane alkaloids （Hyoscyamine and Scopolamine）. The results showed that the significant highest average of fresh and dry weight of callus （112 and 89.6 mg） achieved using the medium contained 0.5 mg/L BA and 2 mg/L NAA under dark condition. The amount of fresh and dry weight of callus produced under dark condition was significantly higher than that produced under light condition, with increase in percentage of 51.3 and 37.62% respectively. The addition of abiotic elicitors caused reduction in both fresh and dry weight of callus, therefore the highest fresh weight average was 1,727 mg using 100 mg/L proline. The results indicated that addition of 50 or 100 mg/L proline led to increase in Hyoscyamine concentration of 58.03 and 21.37% respectively compared with the control. While other abiotic elicitors were found to cause reduction in Hyoscyamine concentration. Percentage of Scopolamine concentration were increased to 129.03, 166.94, 205.51 and 149.20% after addition of sucrose （50 g/L）, NaC1 （200 mg/L） and proline （50 or 100 mg/L） respectively compared with the control.
文摘Induced resistance was studied in muskmelons （cv. Yindi） inoculated Trichothecium roseum with postharvest 1,2,3- benzothiadiazole-7-carbothioic acid S-methyl ester （ASM） （100 mg L^-1） or harpin （50 mg L^-1） treatment. Both ASM and harpin significantly reduced lesion diameter in inoculated fruit. Lesion diameter was limited in the treated and untreated halves of the same fruit, indicating that the local and systemic resistance was induced. Inhibiting efficacy of elicitors lasted 7 and 5 days in the treated and untreated halves. The resistance increased by the chemicals was associated with the activation of peroxidase （POD） and chitinase （CHT）. The elicitors induced a significantly and progressively increasing activity of POD and CHT in the treated and untreated halves, and the activation lasted at least 5 days. The activities of POD isoenzymes increased in the treated fruit. However, no new enzyme band was found in the treated and untreated halves.
