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Afgekia mahidolae is a rare plant species that possesses antioxidant, antimicrobial, and wound healing properties. This study aimed to establish the in vitro culture of A. mahidolae and investigate the effects of elicitors on their phenolic and flavonoid production, including the antioxidant activities. The established callus was prepared in the form of cell suspension cultures to determine the effect of elicitors. After elicitation for 3 days, A. mahidolae cell suspension cultures treated by 5 µM salicylic acid or 100 mg/L yeast extract exhibited significantly higher levels of total phenolic and total flavonoid content than untreated cultures, which correlated to the antioxidant activities. In addition, the profiles of phenolic and flavonoid compounds in the callus and intact leaves of A. mahidolae were determined by LC-MS, which showed different phytochemicals. The findings of this study may encourage more sustainable development of A. mahidolae cultivation. [ABSTRACT FROM AUTHOR]

In the drought conditions of the last few decades, the use of novel scientific methods to increase the growth and production of effective substances of the medicinal and aromatic plants has been essential. This study was done to investigate the effect of foliar application of salicylic acid and proline on the growth traits and essential oil content of Dracocephalum kotschyi Boiss. (Lamiaceae family) under water deficit conditions at the Research Farm of the Research Center of Agricultural and Natural Resources of Chaharmahal va Bakhtiari Province, Iran during the two crop years of 2017-2019. The experiment was performed as a factorial in a CRBD with three replications. Experimental factors included irrigation treatment at two levels of normal irrigation (non-stress, irrigation after draining 30% of F.C.) and deficit irrigation regime (irrigation after draining 50% of F.C.), and three levels of foliar application (control, salicylic acid 1 mM, and proline 1 mM). The essential oil from the aerial parts of the herb at early flowering stage was extracted by water distillation. According to the results, the highest content of chlorophyll a, b, and total (0.96, 0.45, and 1.39 mg/g, respectively) were observed in water deficit irrigation treatment. Also, application of water deficit stress increased the proline content by 70% compared to the control while it did not show a significant effect on the morphological traits of plant height, stem diameter, and plant dry weight. Salicylic acid as a defense factor reduced the negative effects of deficit irrigation conditions on the essential oil, proline, and chlorophylls a, b, and total contents. The highest and lowest contents of essential oils were obtained in foliar-application of proline (1.12 mL/100 g dry matter) and control (0.84 mL/100 g dry matter), respectively. In conclusion, the foliar-spraying of salicylic acid in conditions of deficit irrigation is recommended to reduce the negative effects of stress and increase the content of D. kotschyi essential oil. [ABSTRACT FROM AUTHOR]

An approach to overcome drought stress is using growth-promoting bacteria. This study was carried out to investigate the effect of Azospirillum growth-promoting bacteria under drought stress on yield and biochemical characteristics of Nigella sativa L. in the crop year 2019-2020 in Servak village of Yasouj province in Kohgiluyeh and Boyer-Ahmad province. The experiment was performed as a factorial split plot in a randomized complete block design with three replications. The main factor was irrigation in three levels (irrigation after using 30% soil moisture (control), irrigation after using 60% soil moisture, and irrigation after using 90% soil moisture) and the sub-factor of Azospirillum growthpromoting bacteria in two levels (no inoculation and inoculation of seeds with bacteria). Results showed that inoculation of growth-promoting bacteria increased yield and carbohydrate under moderate stress conditions. In high stress conditions, carotenoid and malondialdehyde had significant changes. Chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids had significant changes under both moderate and severe stress. On the other hand, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids had significant changes in both moderate and high stress. The highest concentrations of total chlorophyll (1.01 mg / g fresh weight) and carotenoids (0.77 mg / g fresh weight) were observed in irrigation after consuming 30% soil moisture and inoculation with bacteria. The highest yield (1072 kg / ha) was observed under consuming 30% soil moisture and bacteria. Measuring the rate of plant growth is suggested at different stages to determine the effect of stress in each period to get a perfect interpretation of the effect of stress on the plant. [ABSTRACT FROM AUTHOR]

Cell death-inducing proteins (CDIPs) play important roles in the infection of Botrytis cinerea, a broad host-range necrotrophic phytopathogen. Here, we show that the secreted protein BcCDI1 (Cell Death Inducing 1) can cause necrosis in tobacco leaves and at the same time elicit plant defense. The transcription of Bccdi1 was induced at the infection stage. Deletion or overexpression of Bccdi1 resulted in no notable change in disease lesion on bean, tobacco, and Arabidopsis leaves, indicating that Bccdi1 has no effect on the final outcome of B. cinerea infection. Furthermore, the plant receptor-like kinases BAK1 and SOBIR1 are required to transduce the cell death-promoting signal induced by BcCDI1. These findings suggest that BcCDI1 is possibly recognized by plant receptors and then induces plant cell death. [ABSTRACT FROM AUTHOR]

Summary: Vitellogenins (Vgs) are critical for the development and fecundity of insects. As such, these essential proteins can be used by plants to reliably sense the presence of insects.We addressed this with a combination of molecular and chemical analyses, genetic transformation, bioactivity tests, and insect performance assays.The small N‐terminal subunit of Vgs of the planthopper Nilaparvata lugens (NlVgN) was found to trigger strong defense responses in rice when it enters the plants during feeding or oviposition by the insect. The defenses induced by NlVgN not only decreased the hatching rate of N. lugens eggs, but also induced volatile emissions in plants, which rendered them attractive to a common egg parasitoid. VgN of other planthoppers triggered the same defenses in rice. We further show that VgN deposited during planthopper feeding compared with during oviposition induces a somewhat different response, probably to target the appropriate developmental stage of the insect.We also confirm that NlVgN is essential for planthopper growth, development, and fecundity. This study demonstrates that VgN in planthopper eggs and saliva acts as a reliable and unavoidable elicitor of plant defenses. Its importance for insect performance precludes evolutionary adaptions to prevent detection by rice plants. [ABSTRACT FROM AUTHOR]

Sweet peppers are consumed worldwide, and traditional uses have sparked interest in their applications as dietary antioxidants, which can be enhanced in plants using elicitors. These are endowed with phytochemicals with potential health benefits such as antioxidants, bioavailability, and bioaccessibility. The trend in metabolomics shows us chemical fingerprints linking metabolomics, innovative analytical form, and bioinformatics tools. The objective was to evaluate the impact of multiple stress interactions, elicitor concentrations, and electrical conductivity on the concentration of secondary metabolites to relate their response to metabolic pathways through the foliar application of a cocktail of said elicitors in pepper crops under greenhouse conditions. The extracts were analyzed by spectrophotometry and gas chromatography, and it was shown that the PCA analysis identified phenolic compounds and low molecular weight metabolites, confirming this as a metabolomic fingerprint in the hierarchical analysis. These compounds were also integrated by simultaneous gene and metabolite simulants to obtain effect information on different metabolic pathways. Showing changes in metabolite levels at T6 (36 mM H2O2 and 3.6 dS/m) and T7 (0.1 mM SA and 3.6 dS/m) but showing statistically significant changes at T5 (3.6 dS/m) and T8 (0.1 mM SA, 36 mM H2O2, and 3.6 dS/m) compared to T1 (32 dS/m) or control. Six pathways changed significantly (p < 0.05) in stress-induced treatments: aminoacyl t-RNA and valine-leucine-isoleucine biosynthesis, and alanine-aspartate-glutamate metabolism, glycoxylate-dicarboxylate cycle, arginine-proline, and citrate. This research provided a complete profile for the characterization of metabolomic fingerprint of bell pepper under multiple stress conditions. [ABSTRACT FROM AUTHOR]

Nanoparticles are emerging as a cutting-edge technology to improve crop agricultural input efficiency and reduce biotic and abiotic stresses. In viticulture, nanoparticles hold promise for the sustainable application of an elicitor (methyl jasmonate, MeJ), allowing a considerable dosage reduction. Herein, the influence of the foliar application of free MeJ (10 mM) and MeJ nanoformulation (ACP-MeJ, 1 mM MeJ) on Tempranillo grape amino acids content over two vintages (2019 and 2020) was evaluated. While both MeJ treatments provided a significant increase of the amino nitrogen and yeast assimilable nitrogen in the must in 2019, there were no significant differences on these parameters in 2020. In 2019, MeJ treatment enhanced the synthesis of most of the amino acids included in this study, while ACP-MeJ promoted the formation of six amino acids. Hence, the content of total amino acids, with and without proline, was higher after applying MeJ than in the control musts. However, these values were higher for control must than for MeJ samples in 2020. The multivariable analysis confirmed that the vintage factor had a more prominent effect on the overall parameters of the musts. This strong influence of the vintage could be related to the higher rainfall in 2020. [ABSTRACT FROM AUTHOR]

Alginates extracted from two Moroccan brown seaweeds and their derivatives were investigated for their ability to induce phenolic metabolism in the roots and leaves of tomato seedlings. Sodium alginates (ALSM and ALCM) were extracted from the brown seaweeds Sargassum muticum and Cystoseira myriophylloides, respectively. Low-molecular-weight alginates (OASM and OACM) were obtained after radical hydrolysis of the native alginates. Elicitation was carried out by foliar spraying 20 mL of aqueous solutions (1 g/L) on 45-day-old tomato seedlings. Elicitor capacities were evaluated by monitoring phenylalanine ammonia-lyase (PAL) activity, polyphenols, and lignin production in the roots and leaves after 0, 12, 24, 48, and 72 h of treatment. The molecular weights (Mw) of the different fractions were 202 kDa for ALSM, 76 kDa for ALCM, 19 kDa for OACM, and 3 kDa for OASM. FTIR analysis revealed that the structures of OACM and OASM did not change after oxidative degradation of the native alginates. These molecules showed their differential capacity to induce natural defenses in tomato seedlings by increasing PAL activity and through the accumulation of polyphenol and lignin content in the leaves and roots. The oxidative alginates (OASM and OACM) exhibited an effective induction of the key enzyme of phenolic metabolism (PAL) compared to the alginate polymers (ALSM and ALCM). These results suggest that low-molecular-weight alginates may be good candidates for stimulating the natural defenses of plants. [ABSTRACT FROM AUTHOR]

Fruit losses and wastage are mainly due to postharvest diseases; their control is reduced with pesticides. The excessive use of synthetic fungicides has caused harmful effects on human health and the environment, so it is therefore necessary to reduce their use. The development of new innocuous strategies has led to the use of compounds of natural or biological origin with the capacity to induce the plant defense system, which improves the fruit's response against future pathogen attacks in addition to reducing the incidence of postharvest diseases. These compounds are known as "elicitors". Although the use of molecular tools such as RT-qPCR or the measurement of the enzymatic activity of molecular markers makes it possible to determine the activation of the plant defense system in response to the application of an elicitor compound, in recent years, omics technologies such as the transcriptome, proteome, or metabolome have provided new and interesting information that helps to elucidate the molecular aspects involved in the activation of the plant defense system in response to the application of elicitors. This review summarizes recent advances in molecular aspects, highlighting the contribution of omics technologies to a better understanding of fruit defense mechanisms induced by different elicitors. [ABSTRACT FROM AUTHOR]

Melatonin (N-acetyl-5-methoxytryptamine) is involved in multiple functions in plants. However, its role in some metabolic pathways and exogenous application's effect on fruits is still unclear. Furthermore, the effects of pre-storage melatonin treatment on sensory traits and consumer acceptance of cherries have yet to be studied. For this reason, the early sweet cherry cultivar 'Samba' harvested at the commercial ripening stage was treated with different melatonin concentrations (0.1, 0.3, and 0.5 mmol L−1) and stored for 21 days under controlled cold temperature and humidity. The standard quality, respiration rate, postharvest aptitude, sensory quality, phenols, and antioxidant systems (non-enzymatic and enzymatic) were analysed at 14 and 21 days of storage. Postharvest treatment with melatonin 0.5 mmol L−1 improved firmness and reduced weight loss and non-commercial fruit percentage while increasing respiration rate, lipophilic antioxidant activity, and ascorbate peroxidase enzyme activity. Furthermore, the treated cherries showed better sensory qualities, such as uniformity of colour and skin colour, as well as being sourer and showing better consumer acceptance and liking after 14 days of storage. Therefore, we conclude that the 0.5 mmol L−1 concentration is effective on the standard, sensory, and bioactive quality of early sweet cherries and can be considered an eco-friendly tool for maintaining the postharvest quality of early cherries. [ABSTRACT FROM AUTHOR]

Introduction: The anti-tumor vindoline and catharanthine alkaloids are naturally existed in Catharanthus roseus (C. roseus), an ornamental plant in many tropical countries. Plant-specific TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play important roles in various plant developmental processes. However, the roles of C. roseus TCPs (CrTCPs) in terpenoid indole alkaloid (TIA) biosynthesis are largely unknown. Methods: Here, a total of 15 CrTCP genes were identified in the newly updated C. roseus genome and were grouped into three major classes (P-type, C-type and CYC/TB1). Results: Gene structure and protein motif analyses showed that CrTCPs have diverse intron-exon patterns and protein motif distributions. A number of stress responsive cis-elements were identified in promoter regions of CrTCPs. Expression analysis showed that three CrTCP genes (CrTCP2, CrTCP4, and CrTCP7) were expressed specifically in leaves and four CrTCP genes (CrTCP13, CrTCP8, CrTCP6, and CrTCP10) were expressed specifically in flowers. HPLC analysis showed that the contents of three classic TIAs, vindoline, catharanthine and ajmalicine, were significantly increased by ultraviolet-B (UV-B) and methyl jasmonate (MeJA) in leaves. By analyzing the expression patterns under UV-B radiation and MeJA application with qRT-PCR, a number of CrTCP and TIA biosynthesis-related genes were identified to be responsive to UV-B and MeJA treatments. Interestingly, two TCP binding elements (GGNCCCAC and GTGGNCCC) were identified in several TIA biosynthesis-related genes, suggesting that they were potential target genes of CrTCPs. Discussion: These results suggest that CrTCPs are involved in the regulation of the biosynthesis of TIAs, and provide a basis for further functional identification of CrTCPs. [ABSTRACT FROM AUTHOR]

During the last few decades, endophytes have attracted increased attention due to their ability to produce a plethora of bioactive secondary metabolites. These compounds not only help the endophytes to outcompete other plant-associated microbes or pathogens through quorum sensing, but also enable them to surmount the plant immune system. However, only a very few studies have described the interlink between various biochemical and molecular factors of host-microbe interactions involved in the production of these pharmacological metabolites. The peculiar mechanisms by which endophytes modulate plant physiology and metabolism through elicitors, as well as how they use transitional compounds of primary and secondary metabolism as nutrients and precursors for the synthesis of new compounds or enhancing existing metabolites, are still less understood. This study thus attempts to address the aspects of synthesis of such metabolites used in therapeutics by the endophytes in the light of their ecological significance, adaptation, and intercommunity interactions. Our study explores how endophytes adapt to the specific host environment, especially in medicinal plants that produce metabolites with pharmacological potential and simultaneously modulate host gene expression for the biosynthesis of these metabolites. We also discuss the differential interactions of fungal and bacterial endophytes with their hosts. [ABSTRACT FROM AUTHOR]

The use of abiotic and biotic elicitors for increasing the accumulation of pharmaceutical active ingredients in plant tissues has gained an increasing interest worldwide. This study was intented to provide promoting accumulation of camphor and phenolic compound using cadmium chloride (CdCl2) and silver nitrate (AgNO3) in cell culture of Achillea gypsicola. Growing cells from 8-day-old cultures were treated with three concentrations (5, 25 and 50 µM) of CdCl2 and AgNO3, along with the control. The quantification of camphor and phenolic compound were performed using Headspace-GC-MS and spectrophotometer, respectively. The content of camphor and phenolic compound, cell number and cell dry weight were significantly affected by increasing doses of AgNO3 and CdCl2. The highest significant change in camphor content was observed in cell treated with 25 µM CdCl2 and AgNO3 with a 6.88 and 6.32 fold increase, respectively. The application of 50 µM AgNO3 and CdCl2, however, resulted in a rapid decine in all attributes studied, implying that culture of A. gypsicola is susceptible to elicitation by high concentrations of these elicitors. In conclusion, using AgNO3 and CdCl2 elicitors in cultured tissues of A. gypsicola would be of great importance to enhanced production of desired bioactive compounds of medicinal importance. [ABSTRACT FROM AUTHOR]

The induction of natural defense mechanisms in plants is considered to be one of the most important strategies used in integrated pest management (IPM). Plant immune inducers could reduce the use of chemicals for plant protection and their harmful impacts on the environment. Planticine® is a natural plant defense biostimulant based on oligomers of α(1→4)-linked D-galacturonic acids, which are biodegradable and nontoxic. The aim of this study was to define the molecular basis of Planticine's biological activity and the efficacy of its use as a natural plant resistance inducer in greenhouse conditions. Three independent experiments with foliar application of Planticine® were carried out. The first experiment in a climatic chamber (control environment, no pest pressure) subjected the leaves to RNA-seq analysis, and the second and third experiments in greenhouse conditions focused on efficacy after a pest infestation. The result was the RNA sequencing of six transcriptome libraries of tomatoes treated with Planticine® and untreated plants; a total of 3089 genes were found to be differentially expressed genes (DEGs); among them, 1760 and 1329 were up-regulated and down-regulated, respectively. DEG analysis indicated its involvement in such metabolic pathways and processes as plant-pathogen interaction, plant hormone signal transduction, MAPK signaling pathway, photosynthesis, and regulation of transcription. We detected up-regulated gene-encoded elicitor and effector recognition receptors (ELRR and ERR), mitogen-activated protein kinase (MAPKs) genes, and transcription factors (TFs), i.e., WRKY, ERF, MYB, NAC, bZIP, pathogenesis-related proteins (PRPs), and resistance-related metabolite (RRMs) genes. In the greenhouse trials, foliar application of Planticine® proved to be effective in reducing the infestation of tomato leaves by the biotrophic pathogen powdery mildew and in reducing feeding by thrips, which are insect herbivores. Prophylactic and intervention use of Planticine® at low infestation levels allows the activation of plant defense mechanisms. [ABSTRACT FROM AUTHOR]

Amaranth has many interesting features, both nutritional and otherwise, that make it attractive as a food crop. Plants grown in greenhouses have higher yields but lower nutritional value compared to those grown in open fields. This prompted an interest in studying viable elicitors for the production of amaranth. Small hydrogen peroxide (H2O2) concentrations for foliar spraying from 0 to 18 mM have been used in greenhouse amaranth cultivation. The objective of this work was to evaluate the effect of foliar application of H2O2 megadoses on growth parameters, total phenolic compounds, condensed tannins, anthocyanins, and the antioxidant capacity of leaves and seeds of amaranth grown in a greenhouse setting. The seed of the Amaranthus hypochondriacus L. species was used. The concentrations of H2O2 analyzed were 0, 125, 250 and 400 mM, with 11 applications throughout the growing cycle. The variable data were subjected to an analysis of variance (ANOVA), followed by a Tukey's post hoc test (95% CI, p < 0.05). The results on chlorophyll, growth parameters and proximal chemical analysis showed no statistical difference between the control group versus the treatment groups. A greater number of favorable changes in the different variables studied were observed with the 125 mM H2O2 treatment, including the increase in antioxidant capacity measured by FRAP. The seed showed a considerable increase in TFC with all treatments and responded better to the 250 mM H2O2 treatment in the case of DPPH (an increase of 30%) and TPC (an increase of 44%). A 28% increase in anthocyanin content was observed with the treatment of 400 mM H2O2. The use of H2O2 may be an appropriate strategy to enhance the production of antioxidant compounds in amaranth without affecting growth or its basic proximal chemical composition. More studies are required in this regard. [ABSTRACT FROM AUTHOR]

Pueraria tuberosa contains a wide range of bioactive compounds, including polyphenols, alkaloids, and phytosterols, which make it valuable to the pharmaceutical and food industries. Elicitor compounds trigger the defense mechanisms in plants and are widely used to increase the yield of bioactive molecules in in vitro cultures. The present study was conducted to evaluate the effects of different concentrations of biotic elicitors such as yeast extract (YE), pectin (PEC), and alginate (ALG) on growth, antioxidant activity, and metabolite accumulation in in vitro propagated shoots of P. tuberosa. The elicitors applied to shoot cultures of P. tuberosa significantly increased biomass (shoot number, fresh weight, and dry weight), and metabolites such as protein, carbohydrates, chlorophyll, total phenol (TP), and total flavonoid (TF) contents, as well as antioxidant activity compared to untreated control. Biomass, TP, and TF contents, as well as antioxidant activity, were most significant in cultures treated with 100 mg/L PEC. In contrast, chlorophyll, protein, and carbohydrate increased most in cultures treated with 200 mg/L ALG. Application of 100 mg/L of PEC led to the accumulation of high amounts of isoflavonoids including puerarin (220.69 μg/g), daidzin (2935.55 μg/g), genistin (5612 μg/g), daidzein (479.81 μg/g), and biochanin-A (111.511 μg/g) as analyzed by high-performance liquid chromatography (HPLC). Total isoflavonoids content of 100 mg/L PEC treated shoots was obtained as 9359.56 μg/g, 1.68-fold higher than in vitro propagated shoots without elicitors (5573.13 μg/g) and 2.77-fold higher than shoots of the mother plant (3380.17 μg/g). The elicitor concentrations were optimized as 200 mg/L YE, 100 mg/L PEC, and 200 mg/L ALG. Overall, this study showed that the application of different biotic elicitors resulted in better growth, antioxidant activity, and accumulation of metabolites in P. tuberosa, which could lead to obtaining phytopharmaceutical advantages in the future. [ABSTRACT FROM AUTHOR]

Methyl jasmonate (MeJ) is an elicitor that, when applied in the vineyard, can improve grape quality. There are several studies about the MeJ influence on red grape varieties; however, to our knowledge, there is little information about white grape varieties, specifically Tempranillo Blanco. Therefore, the aim of this work is to evaluate the effect of MeJ foliar treatments, carried out at veraison and post-veraison, on the aromatic, phenolic and nitrogen composition of Tempranillo Blanco grapes. The results showed that grape volatile compounds content increased after MeJ application, especially terpenoids, C13 norisoprenoids, benzenoids and alcohols, and, in general, mainly at post-veraison. Regarding phenolic and nitrogen compounds, their concentrations were enhanced after MeJ treatments, regardless of application time. Consequently, MeJ treatment improved grape volatile, phenolic and nitrogen composition, particularly when this elicitor was applied post-veraison. Therefore, this is a good and easy tool to modulate white grape quality. [ABSTRACT FROM AUTHOR]

The biological approach for synthesizing nanoparticles (NPs) using plant extracts is an efficient alternative to conventional physicochemical methods. Galegine, isolated from Galega (Galega officinalis L.), has anti-diabetic properties. In the present study, silver nanoparticles (AgNPs) loaded onto urea-based periodic mesoporous organosilica (AgNPs/Ur-PMO) were bio-synthesized using G. officinalis leaf extract. The synthesized NPs were characterized and confirmed via analysis methods. Different concentrations of biosynthesized AgNPs/Ur-PMO nanoparticles (0, 1, 5, 10, and 20 mg L−1) were used as elicitors in cell suspension culture (CSC) of G. officinalis. The callus cells from hypocotyl explants were treated at their logarithmic growth phase (8th d) and were collected at time intervals of 24, 72, 120, and 168 h. The viability and growth of cells were reduced (by 17% and 35%, respectively) at higher concentrations and longer treatments of AgNPs/Ur-PMO; however, the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were increased (1.23 and 3.01 fold, respectively in comparison with the control average). The highest total phenolic (2.43 mg g−1 dry weight) and flavonoid (2.22 mg g−1 dry weight) contents were obtained 168 h after treatment with 10 mg L−1 AgNPs/Ur-PMO. An increasing tendency in the antioxidant enzyme activities was also observed in all the elicitor concentrations. Treatment with AgNPs/Ur-PMO (in particular 5 mg L−1 for 120 h) significantly enhanced the galegine content (up to 17.42 mg g−1) about 1.80 fold compared with the control. The results suggest that AgNPs/Ur-PMO can be used as an effective elicitor for enhancing galegine production in the CSC of G. officinalis. Key points: • The green biosynthesis of AgNPs/Ur-PMO was done using G. officinalis leaf extract • Its toxicity as an elicitor increased with increasing concentration and treatment time • AgNPs/Ur-PMO significantly increased the antioxidant capacity and galegine content [ABSTRACT FROM AUTHOR]

Fusarium wilt of banana, especially Tropical Race 4 (TR4) is a major factor restricting banana production. Developing a resistant cultivar and inducing plant defenses by elicitor application are currently two of the best options to control this disease. Isotianil is a monocarboxylic acid amide that has been used as a fungicide to control rice blast and could potentially induce systemic acquired resistance in plants. To determine the control effect of elicitor isotianil on TR4 in different resistant cultivars, a greenhouse pot experiment was conducted and its results showed that isotianil could significantly alleviate the symptoms of TR4, provide enhanced disease control on the cultivars 'Baxi' and 'Yunjiao No.1' with control effect 50.14% and 56.14%, respectively. We compared the infection processes in 'Baxi' (susceptible cultivars) and 'Yunjiao No.1' (resistant cultivars) two cultivars inoculated with pathogen TR4. The results showed that TR4 hyphae could rapidly penetrate the cortex into the root vascular bundle for colonization, and the colonization capacity in 'Baxi' was significantly higher than that in 'Yunjiao No.1'. The accumulation of a large number of starch grains was observed in corms cells, and further analysis showed that the starch content in 'Yunjiao No. 1' as resistant cultivar was significantly higher than that in 'Baxi' as susceptible cultivar, and isotianil application could significantly increase the starch content in 'Baxi'. Besides, a mass of tyloses were observed in the roots and corms and these tyloses increased after application with isotianil. Furthermore, the total starch and tyloses contents and the control effect in the corms of 'Yunjiao No.1' was higher than that in the 'Baxi'. Moreover, the expression levels of key genes for plant resistance induction and starch synthesis were analyzed, and the results suggested that these genes were significantly upregulated at different time points after the application of isotianil. These results suggest that there are significant differences between cultivars in response to TR4 invasion and plant reactions with respect to starch accumulation, tyloses formation and the expression of plant resistance induction and starch synthesis related genes. Results also indicate that isotianil application may contribute to disease control by inducing host plant defense against TR4 infection and could be potentially used together with resistant cultivar as integrated approach to manage this destructive disease. Further research under field conditions should be included in the next phases of study. [ABSTRACT FROM AUTHOR]

Oviposition by herbivorous insects can stimulate plants to produce a certain degree of resistance. Compared to research on resistance to insect feeding, research on oviposition resistance is still in its infancy in China and most results are from overseas. To promote domestic research in this field, this paper reviews various aspects of oviposition-induced plant resistance, including the elicitor, structural defense, chemical defense, defensive gene expression and indirect defense. The future direction of research on oviposition-induced resistance is also discussed. Identifying and understanding the elicitor mechanism should be the first step in research in this area. Structural defense occurs mainly through changes in the plant cell wall structure, growth of the oviposition site, tissue necrosis and hypersensitivity. Chemical defenses includes the production of volatiles that deter further egg deposition on a chosen plant or neighboring plants. It also includes changes in nutrients and secondary metabolites in the leaves of affected plants that increase larval mortality. At the molecular level, oviposition can induce the synthesis of defensive proteins and the up-regulation of genes associated with resistance. Studies of related pathways mainly focus on the transduction pathways of signal molecules, such as JA, SA and ethylene. Ecological or indirect defense is mainly induced by transmitting information via the release of volatiles between plants, thereby promoting a tertiary trophic relationship that protects plants in the same location. There has been a relatively large amount of research conducted on the release of volatile compounds by plants to attract natural enemies, such as predators and parasitic wasps for indirect defense. Currently, research on oviposition induced resistance is still mainly theoretical, and there are few products or techniques available for the control of agriculture or forestry pests. Induced plant resistance is, however, likely to be an important way of controlling pests in the future, and further research on plant defensive mechanisms is, therefore, essential to provide a theoretical basis for this. [ABSTRACT FROM AUTHOR]

ABSTRACT Brazil is one of the largest cashew producers in the world, and its Northeast region stands out. However, cashew growth and development are negatively affected by irrigation with brackish water in its production. In this context, strategies have been employed to alleviate salt stress effects on plants. Among the strategies, the exogenous application of elicitor substances, such as salicylic acid, has stood out. Given the above, the objective of the present study was to evaluate the effect of foliar application of salicylic acid as an attenuator of salt stress on the morphophysiology of early dwarf cashew. The study was carried out in a greenhouse, in a randomized block design, in a 5 × 4 factorial arrangement, with five levels of electrical conductivity of the irrigation water - ECw (0.4, 1.2, 2.0, 2.8, and 3.6 dS m-1) and four concentrations of salicylic acid - SA (0, 1, 2, and 3 mM), with three replicates and one plant per plot. Irrigation with water of electrical conductivity above 0.4 dS m-1 negatively affected the leaf relative water content, gas exchange, photosynthetic pigments, and growth of plants. Salicylic acid at a concentration of 1 mM attenuated the effects of salt stress on electrolyte leakage, relative water content, gas exchange, synthesis of photosynthetic pigments, and growth of early dwarf cashew irrigated using water with ECw of up to 3.6 dS m-1, at 210 days after transplanting.

Spain is one of the main contributors to global pomegranate production. Pomegranate presents a challenge for preservation at suboptimal temperatures. Preserving this fruit for an extended period is challenging due to its susceptibility to chilling injury (CI). For this reason, we have examined different postharvest treatments to extend the pomegranate shelf life and their potential impact on reducing CI. For this reason, two postharvest treatments have been applied: 1-Methylcyclopropene (1000 nL L−1 1-MCP) and methyl jasmonate vapors (0.01 mM MeJA), a natural elicitor found in many plant organs that induces a wide range of physiological processes, including the activation of defense mechanisms against stress. Following the application of these treatments and subsequent fruit storage at 2 °C for 90 days, maintenance of firmness and membrane integrity was observed. Additionally, a positive synergic effect was observed in these quality traits when combining both substances (1-MCP + MeJA), especially with regard to delaying weight loss, the external color evolution, and total polyphenol accumulation. On the other hand, MeJA treatment alone or in combination with 1-MCP also increased the anthocyanin content in arils, thereby enhancing the fruit quality. In general, the best results were observed when these two different technologies were applied as a combined treatment, especially in terms of maintaining quality traits such as fruit firmness and total acidity and reducing weight loss and CI. This is the first time that these two substances have been tested together in any fruit species, and their simultaneous application in the same container represents an innovative approach that could be an interesting tool for commercial purposes.

Plant response to pathogen challenge involves recognition by specific receptors of conserved molecular patterns associated with pathogenic organisms. Understanding a wider range of pathogen detection pathways in different plant species is valuable for identification and development of pathogen-resistant plant material. Xylella fastidiosa is an important bacterial pathogen of several agricultural crops including table and wine grapes. Although some pathogen recognition pathways have been identified for X. fastidiosa in host plants, there are likely several other molecular interactions that could be exploited to increase plant resistance to this pathogen. This study identified a conserved bacterial cold shock protein component (Xfcsp20) as an elicitor of reactive oxygen species production by Vitis vinifera plant tissue, an indication of pathogen recognition response. Characterization of Xfcsp20 as an elicitor of an oxidative burst in grapevine hosts of X. fastidiosa will be useful to continued work in the areas of bacterial-plant interactions and plant resistance. [Figure: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Chlamydomonas reinhardtii is a eukaryotic, unicellular photosynthetic organism and a potential algal platform for producing biomass and recombinant proteins for industrial use. Ionizing radiation is a potent genotoxic and mutagenic agent used for algal mutation breeding that induces various DNA damage and repair responses. In this study, however, we explored the counterintuitive bioeffects of ionizing radiation, such as X- and γ-rays, and its potential as an elicitor to facilitate batch or fed-batch cultivation of Chlamydomonas cells. A certain dose range of X- and γ-rays was shown to stimulate the growth and metabolite production of Chlamydomonas cells. X- or γ-irradiation with relatively low doses below 10 Gy substantially increased chlorophyll, protein, starch, and lipid content as well as growth and photosynthetic activity in Chlamydomonas cells without inducing apoptotic cell death. Transcriptome analysis demonstrated the radiation-induced changes in DNA damage response (DDR) and various metabolic pathways with the dose-dependent expression of some DDR genes, such as CrRPA30, CrFEN1, CrKU, CrRAD51, CrOASTL2, CrGST2, and CrRPA70A. However, the overall transcriptomic changes were not causally associated with growth stimulation and/or enhanced metabolic activities. Nevertheless, the radiation-induced growth stimulation was strongly enhanced by repetitive X-irradiation and/or subsequent cultivation with an inorganic carbon source, i.e., NaHCO3, but was significantly inhibited by treatment of ascorbic acid, a scavenger of reactive oxygen species (ROS). The optimal dose range of X-irradiation for growth stimulation differed by genotype and radiation sensitivity. Here, we suggest that ionizing radiation within a certain dose range determined by genotype-dependent radiation sensitivity could induce growth stimulation and enhance metabolic activities, including photosynthesis, chlorophyll, protein, starch, and lipid synthesis in Chlamydomonas cells via ROS signaling. The counterintuitive benefits of a genotoxic and abiotic stress factor, i.e., ionizing radiation, in a unicellular algal organism, i.e., Chlamydomonas, may be explained by epigenetic stress memory or priming effects associated with ROS-mediated metabolic remodeling. [ABSTRACT FROM AUTHOR]

The plant defence inducer Actigard® (acibenzolar-S-methyl [ASM]) is applied before flowering and after fruit harvest to control bacterial canker in kiwifruit caused by Pseudomonas syringae pv. actinidiae. Pre-flowering application of ASM is known to upregulate defence gene expression; however, the effect of postharvest ASM on defence gene expression in the vine is unknown. In this study, the expression of eight "defence marker" genes was measured in the leaves of Actinidia chinensis var. chinensis, "Zesy002," and Actinidia chinensis var. deliciosa, "Hayward," vines after postharvest treatment with ASM and/or copper. There were two orchards per cultivar with harvest dates approximately three weeks apart for investigating potential changes in responsiveness to ASM during the harvest period. In all trials, postharvest ASM induced the expression of salicylic-acid-pathway defence genes PR1, PR2, PR5, BAD, DMR6, NIMIN2, and WRKY70. Gene upregulation was the greatest at 1 day and 7 days after treatment and declined to the control level after 3 weeks. In "Zesy002", the ASM-induced response was greater at the early harvest site than at the late harvest site. This decline was concomitant with leaf yellowing and a reduction in RNA yield. Effects of postharvest ASM on gene expression did not persist into the following spring, nor were vines conditioned to respond more strongly to pre-flowering ASM application. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish the hairy root (HR) culture of Plantago major to evaluate the accumulation of apigenin, catalpol and gallic acid after elicitation and investigate the biological activity of its methanolic extraction. The highest transformation frequency was obtained by Agrobacterium rhizogenes strain A4, 0.5 mg/L 6-Benzylaminopurine in pre-cultivation medium, 150 µM acetosyringone in co-cultivation medium (1/2 MS), and immersion method for inoculation of leaf explants. The production of apigenin, catalpol and gallic acid compounds were significantly affected by treatment of 1.18 mM AgNO3 at 24 h which yielded 4.30, 8.24 and 2.89-fold increase, respectively. The assessment of anti-bacterial activity showed that the methanolic extracts of the HRs elicited with 1.18 mM AgNO3 were significantly active against Proteus vulgaris (PTCC 1182) (MIC = 25 mg/mL and MBC = 25 mg/mL). Furthermore, the MTT assay revealed that the methanolic extracts of the HRs were cytotoxic on the SW-480 cell (IC50=337.56 ± 1.82 µg/mL). [ABSTRACT FROM AUTHOR]

When attacked by herbivores, plants produce electrical signals which can activate the synthesis of the defense mediator jasmonate. These wound-induced membrane potential changes can occur in response to elicitors that are released from damaged plant cells. We list plant-derived elicitors of membrane depolarization. These compounds include the amino acid l -glutamate (Glu), a potential ligand for GLUTAMATE RECEPTOR-LIKE (GLR) proteins that play roles in herbivore-activated electrical signaling. How are membrane depolarization elicitors dispersed in wounded plants? In analogy with widespread turgor-driven cell and organ movements, we propose osmoelectric siphon mechanisms for elicitor transport. These mechanisms are based on membrane depolarization leading to cell water shedding into the apoplast followed by membrane repolarization and water uptake. We discuss two related mechanisms likely to occur in response to small wounds and large wounds that trigger leaf-to-leaf electrical signal propagation. To reduce jasmonate pathway activation, a feeding insect must cut through tissues cleanly. If their mandibles become worn, the herbivore is converted into a robust plant defense activator. Our models may therefore help to explain why numerous plants produce abrasives which can blunt herbivore mouthparts. Finally, if verified, the models we propose may be generalizable for cell to cell transport of water and pathogen-derived regulators. [ABSTRACT FROM AUTHOR]

Valinomycin is a cyclodepsipeptide antibiotic with a broad spectrum of biological activities, such as antiviral, antitumor, and antifungal activities. However, the low yield of valinomycin often limits its applications in medicine, agriculture, and industry. In our previous report, Streptomyces sp. ZJUT-IFE-354 was identified as a high-yielding strain of valinomycin. In this study, Plackett–Burman design (PBD) and response surface methodology (RSM) were used to optimize components of medium. The optimal medium contained 31 g/L glucose, 22 g/L soybean meal, and 1.6 g/L K2HPO4·3H2O, which could generate 262.47 ± 4.28 mg/L of valinomycin. Then, the culture conditions were optimized by a one-factor-at-a-time (OFAT) approach. The optimal conditions for the strain included a seed age of 24 h, an inoculum size of 8% (v/v), an incubation temperature of 28 °C, an initial pH of 7.2, an elicitor of 0.1% Bacillus cereus feeding at 24 h cultivation, and the feeding of 0.6% L-valine at 36 h cultivation. The final valinomycin production increased to 457.23 ± 9.52 mg/L, which was the highest yield ever reported. It highlights that RSM and OFAT may be efficient methods to enhance valinomycin production by Streptomyces sp. ZJUT-IFE-354. [ABSTRACT FROM AUTHOR]

A so-called priming defense is activated only when a plant suffers from heavy pathogenic invasion, thus avoiding excessive energy and material costs under low pathogen loads. In our previous studies, we demonstrated that elicitors, such as β-aminobutyric acid (BABA), methyl jasmonate (MeJA) or benzothiadiazole (BTH), can induce the priming of a defense response against fungal infections in postharvest peach fruit. Interestingly, the defense priming was accompanied by increased soluble sugar accumulation. In this study, we aimed to elucidate the mechanism underlying the increase in sugar contents in primed peach fruit. We identified a group IIa WRKY transcription factor, PpWRKY40, from Prunus persica. Using yeast one-hybrid assays, electrophoretic mobility shift assays and dual-luciferase reporter assays, we show that PpWRKY40 is a transcriptional activator of the sucrose synthesis-related genes sucrose synthase (PpSS1) and sucrose-phosphate synthase (PpSPS3). Induction of defense priming with BABA, MeJA or BTH upregulated PpWRKY40 expression and promoted the transcript levels of PpSS1 and PpSPS3 and their enzymatic activities in postharvest peach fruit, resulting in the enhancement of sucrose synthesis. Moreover, the activities of sorbitol catabolizing enzymes—S6PDH, NAD+-SDH, NADP+-SDH—increased in the peach fruit treated with the defense priming elicitors, indicating that sorbitol was converted into glucose and fructose. Induction of defense priming also improved the sensory quality and antioxidant levels of fruit. In summary, the three defense priming elicitors improved the soluble sugar accumulation and overall quality in postharvest peach by upregulating the PpWRKY40 gene and increasing sorbitol catabolism. [ABSTRACT FROM AUTHOR]

Hypericum perforatum L., is a sprawling, leafy herb that grows in open, disturbed areas, known as St. John's wort, has a variety of secondary metabolites that can be used for medicinal and therapeutic purposes. Heavy metals have become the most dangerous pollutants in the environment. The effect of cadmium chloride, lead nitrate, silver nitrate, methyl jasmonate, and salicylic acid was studied on several morphometric and biochemical features of St. John's wort simultaneously using the Taguchi statistical method. The results showed cadmium chloride and lead nitrate reduced the morphometric and biochemical properties of St. John's wort while salicylic acid compensated for the adverse effects of heavy metals. Simultaneously, use of salicylic acid and silver nitrate with cadmium chloride and lead nitrate reduced the toxic effects of these metals on morphometric properties. Methyl jasmonate improved growth characteristics at low levels and inhibited at higher levels. Also, according to the results, salicylic acid could reduce the effects of heavy metals on the biochemical properties, while silver nitrate acts like heavy metals, especially at higher levels. Salicylic acid reduced the harmful effects of these heavy metals and at all levels was able to create a better induction effect on St. John's wort. These elicitors mainly changed the adverse effects of heavy metals by strengthening the pathways of the antioxidant system in St. John's wort. The research assumptions were validated, which suggests that the Taguchi method could be considered in an optimum culture of medicinal plants under different treatments such as heavy metals and elicitors. [ABSTRACT FROM AUTHOR]

The rapid and mass production of secondary metabolites through chemical methods is mostly expensive, difficult, or impossible. Considering the economic importance of these metabolites and their small production in medicinal plants, some methods such as the cultivation of hairy roots and the use of biotic and abiotic stimuli have been suggested to increase these metabolites. The accumulation of the tropane alkaloid atropine in Atropa belladonna L. is of great importance in the pharmaceutical industry. In this research, transgenic hairy roots of A. belladonna was produced using an A7 strain of Agrobacterium rhizogenes. The transformation of hairy roots was confirmed by PCR test. The results of the PCR test showed the correctness of the amplification of the bp780 fragment for the rolB gene in hairy roots. In addition, the effect of different concentrations (0, 125, 250, and 500 μM) of salicylic acid in two times of 24 and 48 hours on the amount of atropine content, the plant growth rate and the activity of antioxidant enzymes of A. belladonna hairy roots was investigated. The data statistically analyzed using factorial experiment based on a completely random design with three replications. The results of the analysis of variance showed significant effect of salicylic acid on all the traits (P<0.01). The effect of time was significant for the amount of atropine and ascorbate peroxidase (APX). The salicylic acid by time interaction effects were significant for the amount of atropine, catalase (CAT), and guaiacol peroxidase (GPX) (P<0.01, 0.05). The results showed that by increasing salicylic acid concentrations the growth of hairy roots significantly decrease compared to the control and the lowest values of fresh and dry weight of the hairy roots (2.79 and 0.148 g) were obtained in 500 μM of salicylic acid compared to the control (6.76 and 0.273 g). However, based on GC/MS analysis, the highest amount of atropine (11 times more than the control) was obtained in the 250 μM salicylic acid in a period of 24 hours. The highest catalase and guaiacol peroxidase activities were obtained at concentrations of 250 and 125μM salicylic acid for 24 hours, respectively. The highest level of ascorbate peroxidase enzyme activity was obtained at the concentration of 250 μM salicylic acid compared to the control. It was concluded that the salicylic acid stimulant at low concentrations is useful for cell signaling and stimulating the production of secondary metabolites, but at high concentrations, it disrupts the growth of hairy roots. [ABSTRACT FROM AUTHOR]

γ-Aminobutyric acid (GABA) occurs naturally at a low concentration in fruits, but can be increased following several stress events, playing a physiological effect. Lemon trees were preharvest treated with GABA at three concentrations (10, 50, and 100 mM) during two consecutive seasons (2019–2020 and 2020–2021). Fruit growth (diameter) and crop yield (kg tree−1 and number of fruits tree−1) and quality traits were evaluated at harvest. Results showed that treatments were effective at increasing lemon size (a 5% higher) and yield, especially for GABA at 100 mM, for the two assayed seasons. Thus, yield was increased between 13 and 18% with respect to the control trees for the two harvest dates. With respect to the quality traits, GABA treatments did not impact any negative effects on the quality attributes, since the total soluble solids (7–8° Brix), total acidity (5–6 g 100 g−1), and fruit firmness (13–14 N mm−1) were similar to the control fruits. Therefore, GABA applied as preharvest treatment could be considered as a potent tool to enhance the yield of lemon fruits. [ABSTRACT FROM AUTHOR]

Ricinus communis is a species distributed worldwide. Its seeds are used to produce castor oil, which can be used for the production of biofuels; yield improvement can be achieved with elicitors that are substances of biological origin that can induce increased productivity of primary and secondary metabolism, when applied to plants. Salicylic acid (SA) is a natural constituent of plants, and applied exogenously acts as an elicitor. The aim of this work is to evaluate the oil content of castor bean plants elicitated with 900, 600, 300, and 100 µM of salicylic acid and its emissions derived from biodiesel made with the oil in blends (0, 10 and 20%) with commercial fuel in a 296 cc diesel cycle engine; elicitation was foliar sprayed. The oil content increased 39% when 900 µM SA was applied compared to control, and the evaluation of emissions showed the maximum reduction with 20% of Ricinus communis biodiesel (RCB) in all different RPM rates. Otherwise, the use of SA could be a method to increase oil content in castor plants as there is no difference in emission reduction derived from the SA application compared to control. [ABSTRACT FROM AUTHOR]

The roots of Pyrenacantha volubilis contain camptothecin (CPT), a high-value bioactive compound possessing anticancer and anti-HIV properties. Isolated root cultures of P. volubilis established in half MS media fortified with 0.3 mgL-1 indole-3-acetic acid and 0.2 mgL-1 indole-3-butyric acid and transferred to light conditions resulted in induction of green roots which obtained a maximum biomass content of 1.09 ± 0.03 g fresh weight with a growth index of 2.07 ± 0.02 in 60 days. The chlorophyll and camptothecin content of the roots was found to increase throughout the culture period attaining a maximum total chlorophyll content of 2.97 ± 0.004 mgg-1 fresh weight in 60 days and CPT content of 2.59 ± 0.02 mgg-1dry weight in 50 days. In the elicitation studies, the green roots treated with 200 mgL-1 yeast extract yielded a maximum camptothecin content of 5.3 ± 0.40 mgg-1 dry weight in 7 days of incubation, which was a 1.94 fold increase in camptothecin content than the control cultures. The thin layer chromatography, high performance liquid chromatography, and liquid chromatography-mass spectroscopy analysis further confirmed the presence of camptothecin (2.17 ± 0.04 mgg-1DW) in the 30 day old in vitro root samples. The overall results suggest the feasibility of green root cultures of P. volubilis as an efficient system for sustainable in vitro production of camptothecin provided further scaling up experiments in bio reactors are imperative. • In vitro green root culture system of Pyrenacantha volubilis was established for camptothecin production. • Root cultures subjected to elicitation yielded a maximum camptothecin content of 5.3 ± 0.40 mgg-1 DW. • Root cultures can be used as an alternative source for camptothecin production instead of conventional sources. [ABSTRACT FROM AUTHOR]

Copyright of Horticulture / Kertgazdaság is the property of Herman Otto Intezet Nonprofit Kft. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agriculture & Nature / Kahramanmaraş Sütçü İmam Üniversitesi Tarım & Doğa Dergisi is the property of Kahramanmaras Sutcu Imam Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An experiment was conducted to evaluate the effect of different levels of chitosan and salicylic acid on morphological traits of the medicinal plant Galega officinalis L. in field conditions in a completely randomized design with three replications in 2017 in the research farm of Islamic Azad University, Miyaneh Branch. The treatments included foliar application with four levels of salicylic acid (0.5, 1, 2, and 3 mM/l), foliar application with four levels of chitosan (0.2, 0.4, 0.6, and 0.8 g/l) and foliar application with distilled water (the control). The results showed that foliar application of biological stimulants had a significant impact on all evaluated traits, except plant height and leaf dry weight. By increasing the concentration of chitosan and salicylic acid, the fresh and dry weight of the stem have decreased so that the highest values in the two traits have belonged to the treatments of chitosan 0.4 and 0.2 g/l and 1 and 0.5 mM/l salicylic acid. Maximum number of internodes (with a numerical mean of 4.80), root length in chitosan treatment (0.4 g/l), and the highest number of leaf (at a concentration of 0.6 g/l chitosan) has been observed. In the study of leaf and root characteristics, chitosan with concentrations of 0.2 and 0.4 g/l and in inflorescence characteristics, salicylic acid with concentrations of 2 and 3 mM/l have been more effective. In general, the use of concentrations of 0.4 and 0.2 g/l chitosan have had a more optimal effect on the morphological traits of the medicinal plant Galega officinalis L., making it ultimately recommended thanks to its positive effect on most of the plant's growth characteristics due to its rapid absorption to achieve the desired yield in a sustainable agricultural path. [ABSTRACT FROM AUTHOR]

Feverfew is an herb used to treat different diseases such as migraine headaches. Due to the economic aspect of its metabolites in the pharmaceutical industry, establishing new approaches to produce the compounds on a large scale is essential. To investigate the effects of stimulators on parthenolide synthesis, feverfew plants were treated with different elicitors, including methyl jasmonate, salicylic acid, NaCl, aluminum oxide, and magnesium aluminate spinel nanoparticles. The expression of genes, E-beta-caryophyllene synthase, Germacrene A synthase, and Costunolide Synthase in the metabolite biosynthesis pathway was examined using qRT-PCR. In addition, parthenolide content, total flavonoids, and polyphenols antioxidant activity were evaluated by HPLC and spectrophotometry. Our results indicated that methyl jasmonate and salicylic acid were more effective on the final concentration of parthenolide, but magnesium aluminate spinel affected the genes' expression, positively. The results show that the elicitors can be used to increase the metabolite in the plant, commercially. [ABSTRACT FROM AUTHOR]

Tobacco mosaic virus is the etiological agent of one of the most critical diseases limiting chili pepper production. Various practices have been used to manage the disease, e.g., the use of resistant varieties and interference with the vector through chemical control. However, these practices are not helpful once the virus has been established in the plant. There is still no effective method for the sustainable management of the disease; therefore, exploring new options is required. Currently, some studies have reported the activity of TiO2 NPs against viruses in plants, although not against TMV in chili pepper. The present work aims to determine a possible direct action of TiO2 NPs against TMV and if there is a relationship between the amount of virus and symptoms. The application of TiO2 NPs at 150 μg/mL in infected pepper plants reduced symptoms and viral load and improved the morphological characteristics compared to the control. Incubation of 150 µg/mL TiO2 NPs with the virus for 6 and 8 h before infection decreased viral concentration significantly after infection compared to the control. In this work, it is reported, for the first time, that the use of TiO2 NPs is a novel practice for the control of TMV in chili pepper. [ABSTRACT FROM AUTHOR]

Abstract Systemic necrosis, induced by plant virus-derived elicitors, is considered as one of the most severe symptoms. It has never been reported that the elicitors encoded by wheat yellow mosaic virus (WYMV) can induce systemic necrosis in plant. In this study, we discovered that the WYMV-encoded 14K protein localized to the endoplasmic reticulum (ER) membrane and triggered a necrotic symptom in Nicotiana benthamiana at 5 days post-infiltration (dpi). Meanwhile, overexpression of WYMV 14K suppressed the replication of tobacco rattle virus (TRV) and potato virus X (PVX). Additionally, deletion of the transmembrane domain and substitution of two non-conserved regions in 14K resulted in the loss of the ability of this protein to induce systemic necrosis. Moreover, the 14K homologous proteins of other bymoviruses failed to induce systemic necrosis. Our results, for the first time, reveal that WYMV 14K induces systemic necrosis and suppresses the replication of other viruses.

Although microbial pathogens utilize various strategies to evade plant immunity, host plants have evolved powerful defense mechanisms that can be activated in preparation for threat by infective organisms. Here, we identified one 24 kDa alkyl hydroperoxide reductase C (AhpC) from the culture supernatant of Ralstonia solanacearum strain FQY-4 (denoted RsAhpC) in the presence of host roots. RsAhpC contributes to H 2 O 2 detoxification and the pathogenicity of R. solanacearum. However, the introduction of RsAhpC into the apoplast could activate immune defense, leading to suppression of pathogen colonization in both Nicotiana benthamiana and the Honghua Dajinyuan (HD) cultivar of N. tabacum. Consequently, overexpression of RsAhpC in the HD cultivar enhanced the resistance of tobacco to bacterial wilt disease caused by FQY-4. Overall, this study provides insight into the arms race between pathogens and their plant hosts. Specifically, it is firstly reported that plants can sense pathogen-derived AhpC to activate defenses, in addition to the role of AhpC in pathogen ROS detoxification. Therefore, the macromolecule AhpC produced by Ralstonia solanacearum has the ability to enhance plant defense as an elicitor, which provides a practical strategy for disease resistance breeding. [ABSTRACT FROM AUTHOR]

The demand for economically valuable terpenoid-derived compounds, especially those extracted from patchouli plants, is experiencing exponential growth. These compounds are potentially applied in a wide range of industrial sectors including food manufacturing, perfumeries, and pharmaceuticals. Nevertheless, there is a need for further development in patchouli plant cultivation to align with market demands. Therefore, employing robust in vitro -based propagation methods could offer significant advantages. Furthermore, this technique is also used for plant metabolites enhancement. This strategy applies the methyl jasmonate (MeJA) elicitor to boost the production of secondary metabolites. In Indonesia, patchouli var. Sidikalang is extensively cultivated in many areas. This study aims to evaluate the effect of naphtaleneacetic acid (NAA) and 6-benzylamino purine (BAP) to increase plant growth via in vitro culture. Furthermore, we also investigate the effect of MeJA on the metabolite profiles and on the AACT gene expression. Our findings revealed that the combination of 2.5 µM of BAP and 0.25 µM of NAA resulted in optimal growth and high rate of organogenesis across all growth parameters. Our data also successfully identified 50 dominant compounds, each with varying percentage areas. Notably, patchouli alcohol emerged as the primary compound in the tricyclic sesquiterpene group, consistently present in all treatment groups. Furthermore, the expression of the PatAACT gene significantly increased by 7.42-fold after treatment with MeJA at 100 µM and by 2,9-fold after treatment with MeJA at 300 µM, compared to the control. Altogether, our findings might offer new insight in P. cablin propagation and new strategy for patchouli-derived metabolites using exogenous MeJA. [ABSTRACT FROM AUTHOR]

In the present study, the phytochemical content and the antioxidant activity in the inflorescences of the monoecious hemp cultivar Codimono grown in southern Italy were assessed, and their elicitation was induced by foliar spray application of 50 mg/L and 250 mg/L of chitosan (CHT) at three different molecular weights (low, CHT L; medium, CHT M; high CHT H). The analysis of the phytochemical profile confirmed that cannabinoids were the most abundant class (54.2%), followed by flavonoids (40.3%), tocopherols (2.2%), phenolic acids (1.9%), and carotenoids (1.4%). Cannabinoids were represented almost exclusively by cannabidiol, whereas cannabigerol and Δ9-tetrahydrocannabinol were detected at very low levels (the latter was below the legal limit of 0.3%). The most abundant flavonoids were orientin and vitexin, whereas tocopherols were mainly represented by α-tocopherol. The antioxidant activity was found to be positively correlated with flavonoids and tocopherols. Statistical analysis revealed that the CHT treatments significantly affected the phytochemical content and the antioxidant activity of hemp inflorescences. Notably, a significant increase in the total phenolic content (from +36% to +69%), the α-tocopherol (from +45% to +75%) and β+γ-tocopherol (from +35% to +82%) contents, and the ABTS radical scavenging activity (from +12% to +28%) was induced by all the CHT treatments. In addition, treatments with CHT 50 solutions induced an increase in the total flavonoid content (from +12% to +27%), as well as in the vitexin (from +17% to +20%) and orientin (from +20% to +30%) contents. Treatment with CHT 50 L almost always resulted in the greatest increases. Overall, our findings indicated that CHT could be used as a low-cost and environmentally safe elicitor to improve the health benefits and the economic value of hemp inflorescences, thus promoting their employment in the food, pharmaceutical, nutraceutical, and cosmetic supply chains.