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This study investigated the potential benefits of utilizing salicylic acid (SA) and magnetic field (MF) as elicitors to increase mycelia mass and triterpenoids content in the liquid fermentation of Morchella eximia, an abundant edible and medicinal fungus. The results showed that SA and MF could increase mycelia mass and triterpenoids content, and the combination of the two (MF intensity 2.5 mT, SA concentration 200 mmol/L) had the most significant promotion effect on them. This was supported by transcriptome analysis results, which indicated that the upregulation of mvaK2, ERG3, ERG26, SOAT, EBP, and ERG1 genes involved in terpenoid backbone biosynthesis and steroid biosynthesis pathways, particularly those related to squalene biosynthesis, contributed to the increased triterpenoids content in M. eximia induced by the MF+SA combination. The findings provided insights into the potential mechanisms underlying the improvement of triterpenoids production in M. eximia and offered a theoretical basis for enhancing triterpenoids production in edible and medicinal fungi using chemical and physical elicitors. [ABSTRACT FROM AUTHOR]

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a destructive disease that causes significant yield losses in wheat production worldwide, including in Egypt. The use of biocontrol agents is among the best eco-friendly management strategies to control this disease, as they are more sustainable and environmentally friendly than traditional chemical control methods. In a comparative analysis, antioxidant enzyme activity and various management approaches were compared with two bacterial biocontrol agents, Bacillus subtilis and Pseudomonas putida. This study showed the remarkable efficacy of endophytic bacteria, B. subtilis and P. putida, in mitigating wheat stripe rust infection across three wheat varieties, namely Misr1, Gimmeiza11, and Sids12. B. subtilis exhibited superior performance compared to P. putida, resulting in infection types of 1 and 2.66, respectively, following inoculation. The highest reduction rate was observed with Tilit fungicide (500 ppm), followed by B. subtilis and Salicylic acid (1000 ppm), respectively. Variations in wheat varieties' response to Pst infection were observed, with Misr1 exhibiting the lowest infection and Sids12 showing high susceptibility. Among the tested inducers, Salicylic acid demonstrated the greatest reduction in disease infection, followed by Indole acetic acid, while Oxalic acid exhibited the lowest decrease. Additionally, the study evaluated the activities of five antioxidant enzymes, including Catalase, Ascorbate peroxidase (APX), glutathione reductase (GR), Superoxide dismutase (SOD), and peroxidase (POX), in the wheat-stripe rust interaction under different integrated management approaches. The wheat variety Misr1 treated with Tilit (500 ppm), B. subtilis, Salicylic acid, Montoro (500 ppm), and P. putida exhibited the highest increase in all enzymatic activities. These findings provide valuable insights into the effectiveness of B. subtilis and P. putida as biocontrol agents for wheat stripe rust control in Egypt, emphasizing their potential role in sustainable, integrated, and environmentally friendly management practices. [ABSTRACT FROM AUTHOR]

Natural astaxanthin, a super antioxidant and colorant, is widely applied in the nutrition, cosmetics, pharmaceuticals, food and feed industries. Haematococcus pluvialis is the predominant commercial source of astaxanthin and is being intensively studied to maximize its astaxanthin content and yield. Low productivity and high cost remain the two major drawbacks to the large-scale production of H. pluvialis. Chemical inducers combined with stressful conditions constitute an effective joint strategy to promote increases in the astaxanthin yield of H. pluvialis. This review summarizes the effects of three classes of chemical inducer-regulated reactive oxygen species (ROS), namely, ROS-stimulating, ROS-alleviating and non-influencing ROS, on astaxanthin accumulation, and analyses the underlying mechanisms through which ROS signalling stimulate astaxanthin biosynthesis and modulate stress tolerance in H. pluvialis. Chemical inducers can regulate ROS signalling to elevate astaxanthin enrichment in H. pluvialis under stressful environments, and during this process, carbon redistribution, the antioxidant system, hormone flux or other signalling pathways are modulated. This review will provide a feasible biotechnology for enhancing the economic production of astaxanthin from H. pluvialis through supplementation with food-grade and economical chemical inducers. Furthermore, large-scale optimization and economic feasibility analyses should be conducted in accordance with the current strategy. • Chemical inducers combined with abiotic stress are a useful strategy for astaxanthin enrichment in H. pluvialis. • Stress-induced ROS are indispensable for the successful use of chemical inducers in astaxanthin production. • Chemical inducers can regulate ROS signalling or provide precursors to stimulate astaxanthin accumulation. • Suitable chemical inducers matching abiotic stress is feasible for commercial astaxanthin by H. pluvialis. [ABSTRACT FROM AUTHOR]

Damping-off and root-rot diseases of lupine are considered the main problem in lupine production in Egypt. In this study, the effect of two bioagents i.e., Trichoderma harzianum and Bacillus megaterium, two chemical inducers i.e., salicylic and citric acid, and mycorrhizal fungus compared to the fungicide Topsin-M70 were tested in vitro, greenhouse and field conditions against Fusarium exysporium, F. Solani, and Rhizoctonia solani are the causes of root rot and damping-off of lupine plants. All of the tests were done in vitro. The tested linear growth of bacteria was significantly slowed by bioagents of the three pathogenic fungi, B. megaterium. The most significant reduction was induced by T. harzianum, which was followed by T. harzianum. Sowing lupine in the seeds soil artificially inoculated with any of the three pathogenic fungi with a large increase in fresh and dry weight. The incidence of pre-and post-emergence damping-off was significantly reduced compared to the control treatment. B.megaterium and Topsin-M70 exhibited the highest percentages of survived plants. In general, in all the tested bio-agents, chemical inducers, the mycorrhizal fungus, and Topsin-M70 under field circumstances, the incidence of damping-off was dramatically reduced. The data obtained revealed all the tested treatments. Peroxidase, polyphenol oxidase, and chitinase enzymes, which play critical roles in plant metabolism, saw a significant increase inactivity, defense mechanisms that work against pathogens infection.

Damping-off and root-rot diseases of lupine are considered the main problem in lupine production in Egypt. In this study, the effect of two bioagents i.e., Trichoderma harzianum and Bacillus megaterium, two chemical inducers i.e., salicylic and citric acid, and mycorrhizal fungus compared to the fungicide Topsin-M70 were tested in vitro, greenhouse and field conditions against Fusarium exysporium, F. Solani, and Rhizoctonia solani are the causes of root rot and damping-off of lupine plants. All of the tests were done in vitro. The tested linear growth of bacteria was significantly slowed by bioagents of the three pathogenic fungi, B. megaterium. The most significant reduction was induced by T. harzianum, which was followed by T. harzianum. Sowing lupine in the seeds soil artificially inoculated with any of the three pathogenic fungi with a large increase in fresh and dry weight. The incidence of pre-and post-emergence damping-off was significantly reduced compared to the control treatment. B.megaterium and Topsin-M70 exhibited the highest percentages of survived plants. In general, in all the tested bio-agents, chemical inducers, the mycorrhizal fungus, and Topsin-M70 under field circumstances, the incidence of damping-off was dramatically reduced. The data obtained revealed all the tested treatments. Peroxidase, polyphenol oxidase, and chitinase enzymes, which play critical roles in plant metabolism, saw a significant increase inactivity, defense mechanisms that work against pathogens infection. [ABSTRACT FROM AUTHOR]

Abstract Background Erythroleukemia is caused by the uncontrolled multiplication of immature erythroid progenitor cells which fail to differentiate into erythrocytes. By directly targeting this class of malignant cells, the induction of terminal erythroid differentiation represents a vital therapeutic strategy for this disease. Erythroid differentiation involves the execution of a well-orchestrated gene expression program in which epigenetic enzymes play critical roles. In order to identify novel epigenetic mediators of differentiation, this study explores the effects of multiple, highly specific, epigenetic enzyme inhibitors, in murine and human erythroleukemia cell lines. Results We used a group of compounds designed to uniquely target the following epigenetic enzymes: G9a/GLP, EZH1/2, SMYD2, PRMT3, WDR5, SETD7, SUV420H1 and DOT1L. The majority of the probes had a negative impact on both cell proliferation and differentiation. On the contrary, one of the compounds, A-366, demonstrated the opposite effect by promoting erythroid differentiation of both cell models. A-366 is a selective inhibitor of the G9a methyltransferase and the chromatin reader Spindlin1. Investigation of the molecular mechanism of action revealed that A-366 forced cells to exit from the cell cycle, a fact that favored erythroid differentiation. Further analysis led to the identification of a group of genes that mediate the A-366 effects and include CDK2, CDK4 and CDK6. Conclusions A-366, a selective inhibitor of G9a and Spindlin1, demonstrates a compelling role in the erythroid maturation process by promoting differentiation, a fact that is highly beneficial for patients suffering from erythroleukemia. In conclusion, this data calls for further investigation towards the delivery of epigenetic drugs and especially A-366 in hematopoietic disorders.

Introduction: Bacterial ghosts (BGs), known as the empty cell envelope of gram-negative bacteria lacking cytoplasmic content yet retaining all unaltered morphological and structural features of their living counterparts, are widely studied and used as the platform for the production of the vaccines as well as the transporting drug and gene delivery. However, the study related to the creation of BGs based on gene expression is still limited because of the difference in cell wall structure between microorganisms. Therefore, in the current study, for the aims to determine chemicals combination and minimum inhibition concentration (MIC) to optimize BGs production. Material and method: Salmonella choleraesuis strain was collected from NAVETCO company. The study used critical concentrations from chemical combination to convert salmonella cells to BGs. Chemicals combination and MIC, temperature, shaking speed were optimized using Plakett- Burman matrix and response surface methodology. Cell structure was determined by using a scanning electron microscope, experimental mice were vaccinated and challenged with virulence to determine immune responses of bacterial ghost. Results: The appropriate chemicals for the production of BGs biomass were NaOH 3.125 mg/ml; SDS 1.15 mg/ml, H2O2 8.79 µl/ml, ethanol. The observation of morphology, BGs have remained the structure and shape, which were like the living microbial cells. Conclusions: The conditions of BGs production have been identified to produce large amounts of bacterial ghost biomass to further application in vaccine production and pharma.

Yellowing, extreme leaf distortion, and mosaic are all symptoms of the Papaya ring spot virus (PRSV). The objective of this research is to evaluate the effects of cinnamon, clove, garlic, fennel, ginger and chamomile extracts and some chemical inducers such as calcium chloride, nitric acid, pectin, oxalic acid, potassium chloride, tannic acid, disodium phosphate, P- Amino butyric acid (BABA), indole butyric acid (IPA) and salicylic acid on PRSV disease development in cucumber plants. Treatment with inducers decreased the severity and titer of PRSV under greenhouse conditions. In this regard, the cinnamon extract showed the best outcomes. Under field conditions, similar findings were obtained. Chemical and biotic treatments followed by PRSV inoculation resulted in potentiated induction of POD gene. In conclusion, utilizing inducers could be useful in practice because it could provide an easy, environmentally friendly, and economically acceptable method of protecting cucumber plants from PRSV while also reducing pollution from agricultural chemicals. [ABSTRACT FROM AUTHOR]

Abstract Background Fragile sites are the chromosomal regions that are susceptible to breakage, and their frequency varies among the human population. Based on the frequency of fragile site induction, they are categorized as common and rare fragile sites. Common fragile sites are sensitive to replication stress and often rearranged in cancer. Rare fragile sites are the archetypal trinucleotide repeats. Fragile sites are known to be involved in chromosomal rearrangements in tumors. Human miRNA genes are also present at fragile sites. A better understanding of genes and miRNAs lying in the fragile site regions and their association with disease progression is required. Result HumCFS is a manually curated database of human chromosomal fragile sites. HumCFS provides useful information on fragile sites such as coordinates on the chromosome, cytoband, their chemical inducers and frequency of fragile site (rare or common), genes and miRNAs lying in fragile sites. Protein coding genes in the fragile sites were identified by mapping the coordinates of fragile sites with human genome Ensembl (GRCh38/hg38). Genes present in fragile sites were further mapped to DisGenNET database, to understand their possible link with human diseases. Human miRNAs from miRBase was also mapped on fragile site coordinates. In brief, HumCFS provides useful information about 125 human chromosomal fragile sites and their association with 4921 human protein-coding genes and 917 human miRNA’s. Conclusion User-friendly web-interface of HumCFS and hyper-linking with other resources will help researchers to search for genes, miRNAs efficiently and to intersect the relationship among them. For easy data retrieval and analysis, we have integrated standard web-based tools, such as JBrowse, BLAST etc. Also, the user can download the data in various file formats such as text files, gff3 files and Bed-format files which can be used on UCSC browser. Database URL: http://webs.iiitd.edu.in/raghava/humcfs/

Natural products are considered to be the lifeline treatment for several diseases where their structural complexity makes them a source of potential lead molecules. As a producer of antibiotics, food colorants, enzymes, and nutritious food, fungi are beneficial to humans. Fungi, as a source of novel natural products, draw attention of scientists. However, redundant isolation of metabolite retards the rate of discovery. So, apart from the standard conditions for the production of secondary metabolites, certain induction strategies are used to trigger biosynthetic genes in fungi. Advancement in the computational tools helps in connecting gene clusters and their metabolite production. Therefore, modern analytical tools and the genomic era in hand leads to the identification of manifold of cryptic metabolites. The cryptic biosynthetic gene cluster (BGC) has become a treasure hunt for new metabolites representing biosynthetic pathways, regulatory mechanisms, and other factors. This review includes the use of chemical inducers/epigenetic modifiers and co-culture (species interaction) techniques to induce these BGCs. Furthermore, it cites a detailed representation of molecules isolated using these strategies. Since the induction occurs on the genomic molecular DNA and histones, this together brings a significant exploration of the biosynthetic pathways. Graphical Abstract [ABSTRACT FROM AUTHOR]

Background: Erythroleukemia is caused by the uncontrolled multiplication of immature erythroid progenitor cells which fail to differentiate into erythrocytes. By directly targeting this class of malignant cells, the induction of terminal erythroid differentiation represents a vital therapeutic strategy for this disease. Erythroid differentiation involves the execution of a well-orchestrated gene expression program in which epigenetic enzymes play critical roles. In order to identify novel epigenetic mediators of differentiation, this study explores the effects of multiple, highly specific, epigenetic enzyme inhibitors, in murine and human erythroleukemia cell lines. Results: We used a group of compounds designed to uniquely target the following epigenetic enzymes: G9a/GLP, EZH1/2, SMYD2, PRMT3, WDR5, SETD7, SUV420H1 and DOT1L. The majority of the probes had a negative impact on both cell proliferation and differentiation. On the contrary, one of the compounds, A-366, demonstrated the opposite effect by promoting erythroid differentiation of both cell models. A-366 is a selective inhibitor of the G9a methyltransferase and the chromatin reader Spindlin1. Investigation of the molecular mechanism of action revealed that A-366 forced cells to exit from the cell cycle, a fact that favored erythroid differentiation. Further analysis led to the identification of a group of genes that mediate the A-366 effects and include CDK2, CDK4 and CDK6. Conclusions: A-366, a selective inhibitor of G9a and Spindlin1, demonstrates a compelling role in the erythroid maturation process by promoting differentiation, a fact that is highly beneficial for patients suffering from erythroleukemia. In conclusion, this data calls for further investigation towards the delivery of epigenetic drugs and especially A-366 in hematopoietic disorders. [ABSTRACT FROM AUTHOR]

Chilli (Capsicum annuum), cultivated as spicy crop and has played a vital role in the maintenance of human body. Chilli veinal mottle virus (ChiVMV) is one of the most destructive and fast spreadable disease by vector and mechanically worldwide. The present study confirms the mechanical inoculation of ChiVMV in host plant by leaf inoculation method. Reducing agent carbon tetrachloride (CCl4) and chloroform (CHCl) with ratio 5% and 2.5% reduced the infectivity and longevity of crude virus sap by mixing with them. The exogenous application of chemical inducer (Salicylic acid SA) and botanicals (Eucalyptus and Mint) reduced the disease incidence and severity of ChiVMV in greenhouse study and these were ecofriendly in nature. Salicylic Acid decreased severity (28%) followed by Eucalyptus (11.05%) and Mint (9.66%). The final chlorophyll contents study of healthy and diseased leaf was done with spectrophotometer by using different wavelength absorbance (645nm, 663nm, 652nm and 490nm), the healthy leaf of chilli plant shows more a, b and total chlorophyll as compared to diseased leaves. [ABSTRACT FROM AUTHOR]

Abstract Plant defense against their pathogens can be induced by a complex network of different inducers. The present study investigates the synergistic effect of Trichoderma harzianum, exogenous salicylic acid (SA) and methyl jasmonate (MeJA) over the response and regulation of the antioxidant defense mechanisms and lipid peroxidation in tomato plants against Fusarium wilt disease. In the present work, tomato plants were infected by Fusarium oxysporum f. sp. lycopersici 3 days after inoculated with T. harzianum and/or sprayed daily for 3 days with chemical inducers (SA and MeJA). Plants were analysed at 0, 24, 48, 72 and 96 h after inoculation with Fusarium oxysporum f. sp. lycopersici. Infection of tomato plants by pathogen led to strong reduction in the dry weight of roots and shoots with the enhanced concentration of H2O2 and varying degree of lipid peroxidation. Concurrently, exogenous SA, when applied with pathogen greatly enhanced H2O2 content as well as activities of antioxidant enzymes except catalase (CAT) and ascorbate peroxidase (APx). The pathogen challenged plants pretreated with T. harzianum and MeJA together exhibited less lipid peroxidation and as well as the elevated level of ascorbic acid and enhanced activities of antioxidant enzymes. All applied treatments protected tomato seedlings against Fusarium wilt disease but the percentage of protection was found higher in plants pretreated with the combination of T. harzianum and chemical inducers.

BACKGROUND Great efforts have been made to identify grasses that are resistant to spittlebugs (Hemiptera: Cercopidae). However, the time required to develop and launch new cultivars is relatively long. The employment of resistance inducers is a current strategy that may be useful for the control of insect pests. This analysis evaluates the feasibility of using the chemical inducers silicon and nitric oxide to increase spittlebug resistance based on changes in forage grass vegetative characteristics and the biological traits of Mahanarva spectabilis (Distant, 1909). RESULTS: Mahanarva spectabilis nymphs and adults can cause significant damage to forage grasses. Furthermore, silicon and nitric oxide inducers were not sufficient to lessen this damage by positively influencing the growth and development of forage grasses. These inducers did not negatively alter the biological parameters of M. spectabilis or diminish its population. However, phenolic compound concentrations increased when forage grasses were treated with silicon or attacked by adult insects, but this parameter was not useful to predict spittlebug resistance. This fact suggests that the physiological and biochemical changes caused by silicon should be further studied. CONCLUSION: The current analysis demonstrated that application of the chemical inducers silicon and nitric oxide is currently not a viable strategy for the effective and economic management of M. spectabilis on Brachiaria ruziziensis, Pennisetum purpureum and Digitaria sp. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Six cultivars of peanut i.e. Giza 5, Giza 6, R92, Ismailia 1, Gregory and Virginia. were evaluated for their susceptibility to the natural infection by Cercospora leaf spot during two successive growing seasons of 2016 and 2017. Generally, Ismailia 1, followed by R92 were the most resistant tested cvs., for the disease and produced the highest pod yield in both seasons. However, Gregory, followed by Virginia were the most susceptible ones recording the highest percentages of disease incidence and severity in tested both seasons. Induction of disease resistance was carried out using salicylic acid, nicotinic acid, butyric acid, ascorbic acid and bion which were applied at three concentrations, i.e. 2, 4 and 8 mM. The obtained results proved that bion and salicylic acid at 8 mM followed by ascorbic acid at the same conc., were the most effective inducers for minimizing disease incidence as well as disease severity and consequently increased the produced pod yield during both investigated seasons . Four plant growth regulators namely indole butaric acid (IBA), naphthalene acetic acid (NAA), gibberellic acid (GA3) and baclobtrazole were applied at three concentrations, i.e. 50, 100 and 200 ppm proved that naphthalene acetic acid and indole butaric acid at 200 ppm were the most effective inducers for minimizing disease incidence as well as severity and consequently increased the prodced pod yield during both investigated seasons. Four sulfate mineral salts i.e., copper sulphate (CuSo4), zinc sulphate (ZnSo4), magnesium sulphate (MgSo4) and manganese sulphate (MnSo4) at three concentrations, i.e. 1, 2 and 4mM, were tested. Copper sulphate followed by magnesium sulphate gave the lowest percentages of disease incidene and severity without significant differences in between and consequently increased the produced pod yield. The effect of five silicate salts, i.e. calcium silicate (CaSio3), magnesium silicate (MgSio3), potassium silicate (K2Sio3) aluminum silicate (Al2Sio3) and seal- matreax (commercial compound) at four concentrations, i.e. 200, 400, 800 and1600 ppm were evaluated. Generally, calcium silicate followed by potassium silicate gave the lowest percentage of disease incidence and severity and increased the produced pod yield.Thus, there is a correlation between induced resistance and some biochemical changes in peanut leaf tissues including phenol contents (free, conjugate and total phenols) and oxidative enzyme activities, i.e., peroxidase and polyphenoloxidase. [ABSTRACT FROM AUTHOR]

Pine wilt disease (PWD) is the most destructive disease threatening pine worldwide. The disease is mainly caused by the pine wood nematode, Bursaphelenchus xylophilus, which is vectored by pine sawyer longhorn‐beetles, Monochamus spp. This study aimed to select resistance‐inducing pine endophytic bacteria for management of PWD. To set up a defence‐related genes expression pattern for screening, four chemical inducers (salicylic acid, γ‐aminobutyric acid (GABA), β‐aminobutyric acid and α‐aminobutyric acid) were tested in vitro on pine calli and in vivo on pine seedlings. Treatment with GABA had the greatest reduction in PWD severity on pine seedlings. The pattern of defence‐related gene expression in calli treated with GABA was used to select potential resistance‐inducing bacterial strains. In addition, 92 bacterial strains were isolated from pine tree needles and stems and were tested for expression of defence‐related genes in pine calli in vitro. Among the tested strains, 13 showed a similar pattern to GABA treatment in at least four tested defence‐related genes and were selected for the seedling assay. From the seedling assay, three bacterial strains (16YSM‐E48, 16YSM‐P180 and 16YSM‐P39) showed significant reduction in PWD severity compared to the untreated control. Moreover, among the selected strains, cell‐free culture supernatant of strain 16YSM‐P180 significantly reduced PWD severity in inoculated pine seedlings. The selected strains were identified based on the 16S rRNA sequence as Pseudomonas putida 16YSM‐E48, Curtobacterium pusillum 16YSM‐P180 and Stenotrophomonas rhizophila 16YSM‐P39. These selected strains are suggested as potential alternatives for management of PWD by induction of systemic resistance. [ABSTRACT FROM AUTHOR]

Highlights • Systemic acquired resistance (SAR) induces broad spectrum resistance at the whole plant level. • SAR involves the generation of phloem mobile signals. • A chemically diverse set of SAR inducers have been identified, many are mobile, but only a few function within the time frame of SAR signal movement. • Phloem loading routes for three of the SAR inducers are known. • Most of the known SAR inducers function in a cooperative pathway comprising two parallel branches. Abstract Plants respond to biotic stress by inducing a variety of responses, which not only protect against the immediate diseases but also provide immunity from future infections. One example is systemic acquired resistance (SAR), which provides long-lasting and broad-spectrum protection at the whole plant level. The induction of SAR prepares the plant for a more robust response to subsequent infections from related and unrelated pathogens. SAR involves the rapid generation of signals at the primary site of infection, which are transported to the systemic parts of the plant presumably via the phloem. SAR signal generation and perception requires an intact cuticle, a waxy layer covering all aerial parts of the plant. A chemically diverse set of SAR inducers has already been identified, including hormones (salicylic acid, methyl salicylate), primary/secondary metabolites (nitric oxide, reactive oxygen species, glycerol-3-phosphate, azelaic acid, pipecolic acid, dihyroabetinal), fatty acid/lipid derivatives (18 carbon unsaturated fatty acids, galactolipids), and proteins (DIR1-Defective in Induced Resistance 1, AZI1-Azelaic acid Induced 1). Some of these are demonstrably mobile and the phloem loading routes for three of these SAR inducers is known. Here we discuss the recent findings related to synthesis, transport, and the relationship between these various SAR inducers. [ABSTRACT FROM AUTHOR]

Botrytis fabae is one of the most important fungal pathogens attacking the leaves and the stem of faba bean Viciafaba L. and causes severe yield losses. This study was carried out to evaluate the effect of four chemical inducers (salicylic, citric, ascorbic and oxalic acids) and one fungicide (Carbendazim) against B. fabae in field and glasshouse conditions. Under field conditions for two seasons and glasshouse experiments, plants treated with salicylic acid showed substantial and significant decrease in the disease severity on the leaves and the stem compared with the control and the fungicide. Salicylic acid was highly effective and controlled the disease better than Carbendazim which provided only partial protection. In vitro, the inhibition of fungal growth was investigated and showed that salicylic acid was the best inhibitor of fungal growth (48%) followed by oxalic (39%), ascorbic (33%) and citric (10%) acids 6 days after incubation. An important increase of total phenols was recorded in treatment by salicylic acid in the healthy and infected leaves of faba bean 12, 24, 48, 72, 96 and 120 hours after inoculation. These promising results on the control of the main fungal disease damaging faba bean in Tunisia and other regions will have an important impact on faba bean production.

The effect of DL-β-aminobutyric acid (BABA), benzothiadiazole (BTH), indoleacetic acid (IAA) and salicylic acid (SA) on induced systemic resistance was investigated in moderately susceptible and susceptible wheat genotypes Tamuz-2 and AL-8/70 against Puccinia striiformis f. sp. tritici. Resistance was characterized by reduced infection of yellow rust disease (Yrd). Changes in peroxidase, phenylalanine ammonia-lyase activities and in total phenolic compound content demonstrated that the resistance to Puccinia striiformis can be induced by BABA, BTH, IAA and SA in these two wheat genotypes. Further studies are needed before a practical method using many analogue compounds, such as potassium phosphate and biotic agent for Yrd resistance in wheat is developed.

The comparative suppressive potential of some organic acids known as resistance inducing chemicals viz., salicylic acid (SA) and its two derivatives; acetylsalicylic acid (ASA) and 3,5-dinitrosalicylic acid (DNSA), along with Lascorbic acid (AA), oxalic acid (OA) and citric acid (CA) for managing Meloidogyne incognita infecting tomato plants was investigated under greenhouse conditions. The results showed that all tested organic acids as well as the application methods significantly reduced tomato root galls and 2nd stage juvenile numbers in soil compared with control. Except DNSA and AA, foliar application of tested organic acids was more effective in reducing nematode galls than soil drench application. Foliar application of ASA caused superior effect in the reduction of J2 in soil (100 %) followed by AA (89.44 %), OA (88.25 %) and SA (70.69 %). CA (96.52 %) was tended to be the most effective chemicals in reducing J2 in soil when applied as soil drench. All treatments enhanced shoot and root length of tomato as well as shoot weight compared with the untreated check. Only SA and DNSA significantly increased the root weights. DNSA enhanced the growth indices of tomato plant when used as foliar spray more than soil drenching and opposite trend was observed for OA. These chemical activators have potential to suppress M. incognita infection through the stimulation of tomato tolerance. [ABSTRACT FROM AUTHOR]

Plant defense against their pathogens can be induced by a complex network of different inducers. The present study investigates the synergistic effect of Trichoderma harzianum, exogenous salicylic acid (SA) and methyl jasmonate (MeJA) over the response and regulation of the antioxidant defense mechanisms and lipid peroxidation in tomato plants against Fusarium wilt disease. In the present work, tomato plants were infected by Fusarium oxysporum f. sp. lycopersici 3 days after inoculated with T. harzianum and/or sprayed daily for 3 days with chemical inducers (SA and MeJA). Plants were analysed at 0, 24, 48, 72 and 96 h after inoculation with Fusarium oxysporum f. sp. lycopersici. Infection of tomato plants by pathogen led to strong reduction in the dry weight of roots and shoots with the enhanced concentration of HO and varying degree of lipid peroxidation. Concurrently, exogenous SA, when applied with pathogen greatly enhanced HO content as well as activities of antioxidant enzymes except catalase (CAT) and ascorbate peroxidase (APx). The pathogen challenged plants pretreated with T. harzianum and MeJA together exhibited less lipid peroxidation and as well as the elevated level of ascorbic acid and enhanced activities of antioxidant enzymes. All applied treatments protected tomato seedlings against Fusarium wilt disease but the percentage of protection was found higher in plants pretreated with the combination of T. harzianum and chemical inducers. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate certain of bioagents (Trichoderma harzianum, T. hamatum, T. viride and ESRU bioformulation) and chemical inducers (salicylic acid and potassium silicate) on suppression of coriander stem rot disease caused by Sclerotinia sclerotiorum. The highest antagonistic bioagent was T. viride which reduced the mycelial growth to 3.9 cm in relation to control, being (9.0 cm). Moreover, five concentrations of each of salicylic acid and potassium silicate (0, 100, 250, 500 and 750 ppm) were evaluated against the growth and formation of sclerotia of the causal fungus in vitro and in a greenhouse. Salicylic acid completely inhibited both parameters at 250 and 500 ppm., respectively. Meanwhile, potassium silicates gave the same effect at 750 ppm. Under greenhouse conditions, spraying of coriander plants challenged with the causal fungus with any of the tested inducers and the bioagents lead to a critical reduction in the disease severity in relation to the control. Potassium silicate and salicylic acid as well as T. viride and ESRU formulation were the most efficient treatments, being 18.52, 22.22, 29.63 and 33.33%, respectively. Moreover, the effect of the tested inducers as a soil drench integrated with the bioagents as foliar spray was performed. Potassium silicate integrated with T. viride was the most effective treatment. Two season field experiments (2015-2016 and 2016-2017) showed that potassium silicate as soil drench integrated with T. viride as foliar spray was highly effective in reducing the percentage of dead plants and the area under the disease progress curve as well as increasing the weight of 100 seeds during the two seasons. An increase in the activity of polyphenoloxidase, peroxidase and phenylalanine ammonia lyase was recorded in the leaves sprayed with potassium silicate followed by those sprayed with salicylic acid then T. viride and the ESRU formulation. [ABSTRACT FROM AUTHOR]

This study was completed to assess the efficacy of certain chemical inducers (potassium dihydrogen phosphate, potassium monohydrogen phosphate, oxalic acid, salicylic acid, sodium salicylate, ferrous sulfate and magnesium sulfate) compare to flusilazole fungicide against Sphaerotheca fuliginea, the causative fungus of powdery mildew of cucumber under greenhouse conditions. The impact of these elicitors on some biochemical and growth characters of cucumber was also examined. The data demonstrated that the flusilazole was the best treatment against powdery mildew followed by salicylic acid, potassium dihydrogen phosphate, magnesium sulfate, ferrous sulfate, oxalic acid and potassium monohydrogen phosphate, respectively. Marked raise in the measured biochemical parameters (chlorophyll content, peroxidase and polyphenoloxidase) of treated cucumber compare to untreated control. Growth and yield characters (plant height, number of fruits/plant and yield/plant) of cucumber were remarkably increased in cucumber treated with examined elicitors compare to untreated control. The examined chemical inducers could be counted as stand by for control powdery mildew of cucumber. [ABSTRACT FROM AUTHOR]

This study was aimed to determine the efficacy of certain chemical inducers on incidence of charcoal rot disease caused by Macrophomina phaseolina (Tassi) in okra okra (Abelmoschus esculentus (L.) under greenhouse and field conditions. Pathogenicity of 12 isolates of Macrophomina phaseolina was carried out on okra under greenhouse conditions. These isolates capable to infect okra plants caused charcoal rot on the basil stem with various degrees of diseases severity. Isolate No. 3 caused the highest charcoal rot severity (70.15%) followed by isolate No. 6 (58.69%). The positive effect of four inducer chemicals, i.e salicylic and ascorbic acids at concentrations 50, 100, 200 ppm; Benzothiadiazole, Bion at 200, 400, 800 ppm and humic acid at 500, 1000, 2000 ppm on the induction of systemic resistance in okra against charcoal rot disease and its effect on growth parameters and green fruit yield components were studied. In vitro, all tested chemical inducers able to suppress growth of M. phaseolina. The highest decrease in linear growth of M. phaseolina was noticed with Bion at concentration 800 ppm (66.96%). Under greenhouse conditions, all the tested chemical inducers significantly decreased charcoal rot severity at all concentrations compared with control. The reduction of charcoal rot in okra was enhanced by increasing chemical inducers concentration. Ascorbic acid was the most effective chemical inducers as they greatly retarded charcoal rot caused by M. phaseolina especially at the higher concentration (200 ppm). While, salicylic acid at 50 ppm recorded the lowest protection of charcoal rot severity. Under field conditions, the percentages of charcoal rot severity were significantly reduced due to soaking the seeds before sowing in any of chemical inducers in both trial seasons (2013 and 2014). The most effective inducer was humic acid at 2000 ppm (84.44 and 85.65% reduction of charcoal rot severity), followed by ascorbic acid at 200 ppm (79.79 and 79.28% reduction of charcoal rot severity) in the first and the second growing seasons, respectively. Also, these treatments significantly increased growth parameters i.e. plant height and number of branches plant-1 as well as, green fruit yield parameters i.e. number of green fruit plant-1; weight of green fruit plant-1 (gm); and total green fruits (ton/acre). Generally, humic acid gave the best results in all growth and green fruit yield parameters under field conditions especially at higher concentration (2000 ppm). [ABSTRACT FROM AUTHOR]

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Nrf2 (NF-E2-related factor 2) is a master regulator of cellular responses against environmental stresses. Nrf2 induces the expression of detoxification and antioxidant enzymes, and Keap1 (Kelch-like ECH-associated protein 1), an adaptor subunit of Cullin 3-based E3 ubiquitin ligase, regulates Nrf2 activity. Keap1 also acts as a sensor for oxidative and electrophilic stresses. Keap1 retains multiple sensor cysteine residues that detect various stress stimuli. Increasing attention has been paid to the roles that Nrf2 plays in the protection of our bodies against drug toxicity and stress-induced diseases. On the other hand, Nrf2 is found to promote both oncogenesis and cancer cell resistance against chemotherapeutic drugs. Thus, although Nrf2 acts to protect our body from deleterious stresses, cancer cells hijack the Nrf2 activity to support their malignant growth. Nrf2 has emerged as a new therapeutic target, and both inducers and inhibitors of Nrf2 are awaited. Studies challenging the molecular basis of the Keap1–Nrf2 system functions are now critically important to improve translational studies of the system. Indeed, recent studies identified cross talk between Nrf2 and other signaling pathways, which provides new insights into the mechanisms by which the Keap1–Nrf2 system serves as a potent regulator of our health and disease. [ABSTRACT FROM AUTHOR]

Acibenzolar-S-Methyl (ASM) is a functional analog of salicylic acid (SA) that activates local and systemic acquired resistance (SAR) responses in plants against a wide variety of pathogens. Iris yellow spot virus (IYSV) is an economically important tospovirus of onion that causes severe economic losses to both bulb and seed crops. IYSV resistant onion cultivars are not available to date and there are limited control options. To explore the possibility of utilizing SAR as a control option, we first used two different hosts of IYSV, Datura stramonium and Nicotiana benthamiana, to study the ability of ASM in triggering SAR against IYSV infection. Quantitative descriptors based on both symptom expression and relative levels of IYSV nucleoprotein and viral small RNA were developed and used to determine the SAR in ASM- and buffer-treated plants. A significant reduction in virus levels in ASM-treated plants was noticed by ELISA and PCR. The level of SAR response was also assessed by measuring the IYSV lesion size and number on the inoculated leaves of ASM-treated plants. ASM-treated plants showed reduced symptoms compared to buffer-treated plants. This study could be useful in potentially developing novel SAR-based options for virus management. [ABSTRACT FROM AUTHOR]

The evolving understanding of plant signaling pathways has promoted the possibility of using chemical inducers as an effective tactic for crop protection. In this study, under greenhouse conditions, we conducted a growth assay of Spodoptera littoralis (Boisduval) larvae on tomato plants treated with BTH ( S-methyl benzo [1, 2, 3] thiadiazole 7 carbothioate) as a salicylic acid mimic, PDJ (propyl [1 RS, 2 RS]-[3-oxo-2-pentylcyclopentyl] acetate) as a jasmonic acid-mimic or both chemicals as a combined treatment. The larval body weight of S. littoralis was drastically reduced with each chemical compared to control plants, and there was a significant synergistic interaction. Overall, the total weight gain of surviving larvae fed on treated plants was distinctly tenfold less than for those fed on control plants. Moreover, incorporating the chemical inducers in artificial diets had no direct or toxic impact on the larval body weight of S. littoralis under laboratory conditions. Larval survival rates were significantly lower (35-40 %) on treated plants with either combined or independent inducers' treatments compared with control plants after 15-day feeding. In contrast, incorporating the chemical inducers in artificial diets had no direct effect on larval survival rates under laboratory conditions. The applied concentrations of BTH and PDJ had no detectable phytotoxicity to tomato plants. Our results demonstrate that BTH and PDJ can act synergistically when applied to tomato to reduce the performance of S. littoralis. These findings stress that the application of chemical inducers could provide an environment-friendly tactic to help manage insect pests and thereby play multiple roles in improving the overall plant resistance to herbivore pests. [ABSTRACT FROM AUTHOR]

Systemic acquired resistance (SAR) induced by five different phytohormones (plant growth regulators); salicylic acid (SA), abscisic acid (ABA), indole 3-butyric acid (IBA), indoleacetic acid (IAA) and naphthaleneacetic acid (NAA) was investigated against Puccinia striiformis f. sp. tritici (pst) in the Egyptian susceptible wheat genotype Sids-12. Seedlings were sprayed with three different concentrations of each phytohormones and inoculated by uredospore of pst then evaluated against the germination. Results indicated that, all the five chemical inducers were able to inhibit spore germination and showed highly significant differences among treatments, while, ABA and NAA recorded the lowest germination and the highest inhibition percentages at the low concentration (50 μg/ml). Also, all treatments reduced infection type values and numbers of pustules/leaf compared with control (untreated treatment). ABA treatment at concentration of 50 μg/ml was capable to induce complete protection for the susceptible wheat cultivar, Sids-12 by significant reduction of infection type (0) compared with control. On the other side, relative gene expression of two pathogenesis-related (PR) protein genes; the antifungal protein (PR-1) and the endochitinase (PR-4) were evaluated for the treated seedlings in all treatments at three different time points comparing with untreated plants and the resistant wheat genotype Misr-3. Results showed up-regulation of gene expressions in all treatments for the two tested genes at the three time points (1, 2 and 7 days after inoculation) comparing with control and most of treatments comparing with the resistant genotype Misr-3. This over expression of PR protein genes might be definitive in activation of the host defense mechanism against Pst and playing the important role of resistance induced by chemical inducers as phytohormones in wheat. Also, it was found that ABA treatment was more efficient in inducing the resistance to wheat stripe rust disease than other chemical inducers. The obtained results indicated that phytohormones as inducers can be used to management stripe rust disease in wheat. • Systemic acquired resistance is one of the most important plant defense mechanisms gives immunity against the secondary infections from expression for specific genes as a result of response to pathogens or chemical inducer effects. • Five plant growth regulators (phytohormones) as chemical inducers were investigated to induce systemic acquired resistance against pst in the Egyptian susceptible wheat genotype Sids-12. • Results showed up-regulation of gene expressions in most treatments for PR-1 and PR-4 genes after inoculation comparing with control and the resistant genotype Misr-3. • This over expression of PR protein genes might be definitive in activation of the host defense mechanism against Pst and playing the important role of resistance induced by chemical inducers in wheat. • Phytohormones as inducers can be used to management stripe rust disease in wheat especially ABA treatment was more efficient in the resistance than other chemical inducers. [ABSTRACT FROM AUTHOR]

Background Inducible promoters are widely spread genetic tools for triggering, tuning and optimizing the expression of recombinant genes in engineered biological systems. Most of them are controlled by the addition of a specific exogenous chemical inducer that indirectly regulates the promoter transcription rate in a concentration-dependent fashion. In order to have a robust and predictable degree of control on promoter activity, the degradation rate of such chemicals should be considered in many applications like recombinant protein production. Results In this work, we use whole-cell biosensors to assess the half-life of three commonly used chemical inducers for recombinant Escherichia coli: Isopropyl β-D-1-thiogalactopyranoside (IPTG), anhydrotetracycline (ATc) and N-(3-oxohexanoyl)-L-homoserine lactone (HSL). A factorial study was conducted to investigate the conditions that significantly contribute to the decay rate of these inducers. Temperature has been found to be the major factor affecting ATc, while medium and pH have been found to highly affect HSL. Finally, no significant degradation was observed for IPTG among the tested conditions. Conclusions We have quantified the decay rate of IPTG, ATc and HSL in many conditions, some of which were not previously tested in the literature, and the main effects affecting their degradation were identified via a statistics-based framework. Whole-cell biosensors were successfully used to conduct this study, yielding reproducible measurements via simple multiwell-compatible assays. The knowledge of inducer degradation rate in several contexts has to be considered in the rational design of synthetic biological systems for improving the predictability of induction effects, especially for prolonged experiments. [ABSTRACT FROM AUTHOR]

The role of six inducing resistance chemicals (IRCs), i.e. ascorbic acid, oxalic acid, sodium salicylate, di-basic potassium phosphate, salicylic acid and benzothiadiazole (BTH) compared to the fungicide (Tilt) was tested against the wheat leaf rust caused by Puccinia triticina in two wheat cultivars Giza 139 and Giza 168 under greenhouse and field conditions in 2011/12 growing season in Sharkia Governorate, Egypt. All treatments and the fungicide significantly decreased disease severity (%), electrolyte leakage and suppressed the disease symptoms as compared to the control treatment in both cultivars. Reactive oxygen species (ROS) such as superoxide (O2-) and hydrogen peroxide (H2O2) levels were decreased significantly as a result of chemical inducers treatments as compared to the control and fungicide treatments. Consequently, antioxidant enzymes, catalase (CAT) and dehydroascorbate reductase (DHAR) activities were significantly increased in the infected wheat leaves treated with IRCs as compared to the control and fungicides treatments. The fungicide was not affecting significantly on ROS levels and antioxidant activities, indicating its direct toxic effect on the pathogen. These results suggest that IRCs up-regulated the antioxidant enzymes, CAT and DHAR which can play an important role in suppressing wheat leaf rust pathogen. This was confirmed by the low levels of ROS such as O2- and H2O2. [ABSTRACT FROM AUTHOR]

Abstract: The infection of the feline T-lymphocyte cell line FeT-J with the feline immunodeficiency virus (FIV) Petaluma strain led to the establishment of nonvirus-producing cells. One clone (C15) obtained by limiting dilution was found to express FIV in response to chemical inducers of retroviruses. The chemical treatment of C15 cells led to not only FIV protein synthesis but also an augmentation of viral production. Examination of the C15 cell derivatives obtained by recloning revealed that 10–40% of treated cells constitutively expressed FIV antigens, whereas 100% with expressed FIV antigen in response to the inducer. Chemical induction resulted in more than a 100-fold increase in infectious viral production. The results suggest that a majority of FeT-J cells that are infected with FIV exist in a non-productive state. Establishing a cell line that can be non-productively infected by FIV may help determine the mechanisms of FIV latency. [Copyright &y& Elsevier]

Abstract: The recent urgency to develop new vaccines for emerging and re-emerging diseases, such as pandemic influenza, has necessitated the use of cell substrates not previously used in the manufacture of licensed vaccines. A major safety concern in the use of novel cell substrates is the presence of potential adventitious agents, such as latent and occult viruses, that may not be detected by currently used conventional assays. In cases where the novel cell substrate is known to be tumorigenic, there are additional safety issues related to tumorigenicity of intact cells and oncogenicity of residual cellular DNA. We have developed a strategy for evaluating vaccine cell substrates for the presence of latent/occult viruses, including endogenous retroviruses, latent RNA viruses and oncogenic DNA viruses, by optimizing conditions for chemical induction of viruses and using a combination of broad and specific assays to enable detection of known and novel viruses. [Copyright &y& Elsevier]

The effect of chemicals on the induction of systemic resistance in blackgram (Vigna mungo) against urdbean leaf crinkle virus (ULCV) was studied. Pre-inoculation spraying of blackgram plants with resistance-inducing chemicals, namely salicylic acid and benzothiadiazole at 100 ppm concentration was found to be effective in reducing ULCV infection and increasing the incubation period of the virus under controlled conditions. The treatment of blackgram plants with salicylic acid and benzothiadiazole significantly increased the phenylalanine ammonialyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO) activities. New isoforms of peroxidase and polyphenol oxidase were also induced by these treatments. A two-fold increase in accumulation of total phenol was observed in plants treated with salicylic acid and benzothiadiazole. [ABSTRACT FROM AUTHOR]

Abstract: The mussel Mytilus edulis settlement and distribution was studied on plastic panels with manipulated flow regime (faired, bluff, split and angled) with or without water soluble metabolites of the green alga Cladophora rupestris. The panels were exposed vertically on a device (hydrovane) that ensures their constant orientation in the current during the peak of larval settlement at 1 m depth. In order to investigate larval distribution on the panels, half of them were coated with a silicone vacuum grease that prevents larvae from de-attachment. This grease was not toxic and did not attract or repel larvae. Low densities of larvae on the un-greased plates compared to the greased ones suggested that some of larvae left the substratum. The blue mussel larvae initially settled in regions of reduced shear velocity and then redistribute to the regions of high shear velocity. The presence of the alga increased the density of blue mussel larvae and changed their distribution on the panels. Overall, our results demonstrated that larval recruitment of M. edulis is an active process affected both by boundary-layer hydrodynamics and algal waterborne compounds. [Copyright &y& Elsevier]

Size selectivity of aqueous pores in Vicia leaf cuticles was investigated by measuring the penetration of calcium salts into the abaxial surface of detached leaves. Molecular weights of salts ranged from 111 g mol−1 to 755 g mol−1. Penetration in light at 20°C and 100% humidity was a first order process and rate constants of penetration ranged from 0.39 h−1 (CaCl2) to 0.058 h−1 (Ca-lactobionate). Penetration was a first order process in the dark as well, but the rate constants were smaller by a factor of 1.82. Plotting logarithmatised rate constants versus anhydrous molecular weights resulted in straight lines both in light and in the dark. The slopes per hour were very similar and the average slope was −1.2×10−3 mol g−1. Hence, size selectivity was not affected by stomatal opening, and in light or darkness permeability of Vicia cuticles decreased by a factor of 2.9 when molecular weight increased from 100 g mol−1 to 500 g mol−1. Silver nitrate was preferentially precipitated as silver chloride in guard cells, glandular trichomes and at the base of trichomes. It was concluded that these precipitates mark the location of aqueous pores in Vicia leaf cuticles. The size selectivity of aqueous pores in Vicia leaf cuticles is small compared to that observed in poplar leaf cuticles, in which permeability decreased by a factor of 7–13 for the same range of molecular weights. It is also much smaller than size selectivity of the lipophilic pathway in cuticles. These findings suggest that active ingredients of pesticides, growth regulators and chemical inducers with high molecular weights penetrate leaves at higher rates when formulated as ions. [ABSTRACT FROM AUTHOR]

A recombinant gene coding for an antibody-targeted urokinase-type plasminogen activator was constructed for the purpose of enhancing the thrombolytic specificity of urokinase. The recombinant gene was cloned into prokaryotic expression vector pTrcHisA, and transformed intoEscherichia colistrain Rosetta (DE3). Less than 4mg of the desired protein/l could be obtained in the form of inclusion bodies. Of various inducers and enhancers of stress responses, the heat-shock enhances, streptomycin, the osmotic stress inducers,d-arabinose and sucrose, and the cold-shock enhancer, tetracycline, simulated the expression of the antibody-targeted plasminogen activator by 2- 5-fold. [ABSTRACT FROM AUTHOR]

Despite the remarkable progress achieved in the treatment of leukemias over the last several years, many problems (multidrug resistance [MDR], cellular heterogeneity, heterogeneous molecular abnormalities, karyotypic instability, and lack of selective action of antineoplastic agents) still remain. The recent progress in tumor molecular biology has revealed that leukemias are likely to arise from disruption of differentiation of early hematopoietic progenitors that fail to give birth to cell lineage restricted phenotypes. Evidence supporting such mechanisms has been derived from studying bone marrow leukemiogenesis and analyzing differentiation of leukemic cell lines in culture that serve as models of erythroleukemic (murine erythroleukemia [MEL] and human leukemia [K562] cells) and myeloid (human promyelocytic leukemia [HL-60] cells) cell maturation. This paper reviews the current concepts of differentiation, the chemical/pharmacological inducing agents developed thus far, and the mechanisms involved in initiation of leukemic cell differentiation. Emphasis was given on commitment and the cell lineage transcriptional factors as key regulators of terminal differentiation as well as on membrane-mediated events and signaling pathways involved in hematopoietic cell differentiation. The developmental program of MEL cells was presented in considerable depth. It is quite remarkable that the erythrocytic maturation of these cells is orchestrated into specific subprograms and gene expression patterns, suggesting that leukemic cell differentiation represents a highly coordinated set of events that lead to irreversible growth arrest and expression of cell lineage restricted phenotypes. In MEL and other leukemic cells, differentiation appears to be accompanied by differentiation-dependent apoptosis (DDA), an event that can be exploited chemotherapeutically. The mechanisms by which the chemical inducers promote differentiation of leukemic cells have been discussed. [Copyright &y& Elsevier]

The expression of Triticum aestivum PR4 genes is regulated in response to infection with Fusarium culmorum, a widespread soil-borne pathogen that causes severe damages in crops through foot rot. The induction of PR4 transcripts in wheat coleoptils and roots is correlated with the expression of the corresponding proteins that are expressed only in the infected tissues. Wheat PR4 genes and proteins are also inducible upon treatments with systemic acquired resistance (SAR) chemical inducers such as salicylic acid (SA), benzo (1,2,3) thiodiazole-7-carbothioic acid S-methyl ester (BTH) and methyl jasmonate (MeJA) indicating that activation of PR4 genes follows both SA- and JA-dependent defence response pathways. Moreover, wheat PR4 genes are induced in response to wounding in young shoots and roots as well as in mature leaves suggesting that they can be considered useful markers of plant defence response, although SAR has not been conclusively demonstrated in wheat. Wheat PR1 and PR5 genes used for comparison did not respond to either SAR activators or pathogen attack. [Copyright &y& Elsevier]

Foliar sprays and soil drenches with DL-β-amino- n-butyric acid (BABA) reduced the number of Heterodera avenae and H. latipons cysts on wheat and barley. Foliar sprays of wheat with 8000 mg l−1 BABA reduced the number of H. avenae cysts by 90%, whereas 2000 mg l−1 BABA was enough to reduce the number of H. latipons cysts by 79%. Multiple spray treatments with 2000 mg l−1 BABA at 10-day intervals reduced the number of H. avenae cysts on wheat and barley. A soil drench of wheat with 125 mg l−1 BABA reduced the number of H. latipons cysts by 93% and H. avenae cysts by 43%. Second-stage juveniles of these nematodes penetrated and formed syncytia in wheat roots soil-drenched with BABA. More adult males of H. avenae were produced in BABA (<250 mg 1−1)-treated wheat roots (~76%) than in untreated roots (27%). Soil drenches with higher concentrations of BABA inhibited development of adult males and females. Several chemical elicitors of induced resistance were tested for their ability to reduce the number of H. avenae cysts on wheat. Only BABA was found to be an effective resistance inducer. The number of egg masses of an unidentified Meloidogyne sp. root-knot nematode, which infects only monocots, was also reduced by 95% by a soil drench of wheat with 500 mg l−1 BABA. Development of this nematode inside the BABA-treated roots was also inhibited. [ABSTRACT FROM AUTHOR]

A potential alternative to the use of chemical products with oomyceticidal action for the control of Phytophthora capsici in vegetables is the use of antimicrobial metabolites, biosynthesized in Bacillus species. The objective of this study was to induce the biosynthesis of lipopeptides in Bacillus amyloliquefaciens KX953161.1 by using glutamic acid, iron, cellulose, chitin, or inactive Colletotrichum spp. cells. The in vitro oomyceticidal effect of the bacterial lipopeptides on zoospores of Phytophthora capsici was evaluated. The lipopeptides identified and quantified in the crude extracts by high performance thin layer chromatography (HPTLC) were fengycin and surfactin. The bacterial culture with inactive fungal cells yielded the greatest biosynthesis of lipopeptides, at 1847.02± 11.8 and 2563.45± 18.4 μg/ml of fengycin and surfactin, respectively and the treatments that obtained lower production of these lipopeptides, were those to which iron and cellulose were added with 608.05 ± 22.6 and 903.74± 22.1; 563.31± 11.9 and 936.96± 41.1 μg/ml for fengicin and surfactin, respectively. The lipopeptide extracted showed 100% germination inhibition on zoospores of P. capsici, revealing encystment, malformations in the germ tube and cellular degradation. Lipopeptides have the potential to control P. capsici; however, the biosynthesis of these lipopeptides requires further study to determine their biological mode of action and optimize lipopeptide performance and profile., (Copyright © 2022 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

• SA and Pseudomonas fluorescens CHA0 improved the plant growth indices. • SA and Pseudomonas fluorescens CHA0 reduced the infection of Meloidogyne javanica in tomato. • PR1 gene expression changed after SA and Pseudomonas fluorescens CHA0 treatments. Root-knot nematodes (Meloidogyne spp.) are among the most dangerous herbal parasites which destroy 8.8 to 14.6 percent of agricultural products annually. This study examined inducing resistance to tomato against Meloidogyne javanica , as well as time-dependent changes in the expression of PR1 gene, after applying salicylic acid (SA) and Pseudomonas fluorescens CHA0 (Pf) in the leaf tissue of healthy and infected tomatoes. Combined application of SA and Pf improved the plant growth and reduced root-galling, the number of eggs and egg-masses and reproduction factor. The results of the experiment of gene expression revealed that in all of the treatments, the expression of PR1 gene changed at different time points. The expression of PR1 gene in infected plants, 24 h after inoculation with nematode, was 98% higher than that of the control plants and 48 h after nematode inoculation, was about 58% less than that of control plants. The maximum expression of PR1 gene in nematode infected plants treated with Pf + SA was observed eight days after soil drench application of Pf that was 48 h after treatment with SA and 24 h after nematode inoculation and nine days after application of Pf , downregulation of the PR1 gene occurred. This study revealed that SA and Pf improved the plant growth indices and reduced the infection of Meloidogyne javanica in tomato plants and also it was observed that the expression of PR1 gene was significantly reduced in treatments with Pf and SA, as compared to their combination. [ABSTRACT FROM AUTHOR]