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Among the many biotic factors with adverse effects on Solanum lycopersicum (tomato), diseases caused by fungi, viruses and nematodes are notable. Since the genome of S. lycopersicum became available, efforts have continued to identify the genes and proteins associated with the plant defence activity. One such gene family belongs to TIR-NBS-LRR (TNL), a subfamily of larger NBS-LRR genes. In total, 27 full-length TNLs were identified via genome wide analysis. Four pairs of segmental duplication events were observed involving different pairs of chromosomes, except the pairing of Solyc02g082050-Solyc02g032650, which were both present on chromosome 2. More than twenty nine percent (29.63%) of the genes were localised on chromosome 1 alone. Hormone-mediated biotic stress-responsive cis-regulatory elements were detected for methyl-jasmonate, salicylic acid (TCA motif) and ethylene (ERE motif). Differential gene expression was observed for many genes under different plant tissues and biotic stresses. The upregulation of many genes including SlBS4 was observed against Alternaria solani attacks in the disease tolerant varieties. Altogether, the results suggested that TNLs play a significant role in plant defence under biotic stress.

Among the many biotic factors with adverse effects on Solanum lycopersicum (tomato), diseases caused by fungi, viruses and nematodes are notable. Since the genome of S. lycopersicum became available, efforts have continued to identify the genes and proteins associated with the plant defence activity. One such gene family belongs to TIR-NBS- -LRR (TNL), a subfamily of larger NBS-LRR genes. In total, 27 full-length TNLs were identified via genome wide analysis. Four pairs of segmental duplication events were observed involving different pairs of chromosomes, except the pairing of Solyc02g082050-Solyc02g032650, which were both present on chromosome 2. More than twenty nine percent (29.63%) of the genes were localised on chromosome 1 alone. Hormone-mediated biotic stress-responsive cis-regulatory elements were detected for methyl-jasmonate, salicylic acid (TCA motif) and ethylene (ERE motif). Differential gene expression was observed for many genes under different plant tissues and biotic stresses. The upregulation of many genes including SlBS4 was observed against Alternaria solani attacks in the disease tolerant varieties. Altogether, the results suggested that TNLs play a significant role in plant defence under biotic stress. [ABSTRACT FROM AUTHOR]

Abstract Early blight (EB), caused by Alternaria solani, is a serious problem in tomato production. Plant growth-promoting rhizobacteria promote plant growth and inhibit plant disease. The present study explored the bio-efficacy of synergistic effect of rhizobacterial isolates and ginger powder extract (GPE) against tomato EB disease, singly and in combination. Six fungal isolates from symptomatic tomato plants were identified as A. solani on the basis of morphological features i.e., horizontal septation (6.96 to 7.93 µm), vertical septation (1.50 to 2.22 µm), conidia length (174.2 to 187.6 µm), conidial width (14.09 to 16.52 µm), beak length (93.06 to 102.26 µm), and sporulation. Five of the twenty-three bacterial isolates recovered from tomato rhizosphere soil were nonpathogenic to tomato seedlings and were compatible with each other and with GPE. Out of five isolates tested individually, three isolates (St-149D, Hyd-13Z, and Gb-T23) showed maximum inhibition (56.3%, 48.3%, and 42.0% respectively) against mycelial growth of A. solani. Among combinations, St-149D + GPE had the highest mycelial growth inhibition (76.9%) over the untreated control. Bacterial strains molecularly characterized as Pseudomonas putida, Bacillus subtilis, and Bacillus cereus and were further tested in pot trials through seed bacterization for disease control. Seeds treated with bacterial consortia + GPE had the highest disease suppression percentage (78.1%), followed by St-149D + GPE (72.2%) and Hyd-13Z + GPE (67.5%). Maximum seed germination was obtained in the bacterial consortia + GPE (95.0 ± 2.04) followed by St-149D + GPE (92.5 ± 1.44) and Hyd-13Z + GPE (90.0 ± 2.04) over control (73.8 ± 2.39) and chemical control as standard treatment (90.0 ± 2). Ginger powder extracts also induce the activation of defence-related enzymes (TPC, PO, PPO, PAL, and CAT) activity in tomato plants. These were highly significant in the testing bacterial inoculants against A. solani infection in tomato crops.

Agriculture includes the production of crops, animals, aquaculture, fisheries, and forests for both food and non-food use. The primary factor in the rise of sedentary civilization among humans was agriculture, which allowed people to live in cities by producing surpluses of food from the farming of domesticated species. Uncertainties in the Agricultural Sector directly imply a steep decline in every other aspect of any society. The Agronomical Products, be they raw vegetables, or produced fruits, are all prone to Parasites and Microorganisms. In this research, we will focus on Solanum Tuberosum, and its disease Early Blight, of which, Alternaria Solani is a Causal Vector. For the detection of Early Blight in Potato Leaves, we will make use of the Image Segmentation Technique, based on Spectral Clustering, with Normalized Laplacian Cuts. The model works by segmenting, or rather segregating the affected part of the Potato leaf from the unaffected part, resulting in the formation of a few clusters, based on which the affected leaves can be classified from the healthy leaves. Though the model is a parametrized model, the results have been explored for different values of the parameters, σ i , and σ x that correspond to the varying configuration of the Gaussian Kernel. The efficiency of the Proposed Model have been compared with existing Image Clustering Models, like, Fuzzy C-means Clustering, Agglomerate Clustering, etc. [ABSTRACT FROM AUTHOR]

Phytohormones are the key regulators of various developmental and physiological processes in plants. In the present study, we have examined the efficacy of Methyl Jasmonate Methyl Ester (MJME) as a potent elicitor on inducing resistance factors against early blight disease of tomato. Both PKM1 (susceptible) and Arka Rakshak (resistant) cultivars of tomato were sprayed with different concentrations of MJME (1, 5, 10 and 25 μM) and/or infected with A. solani. MJME pre‐treatment followed by A. solani infected leaves showed a higher accumulation of superoxide anion radicals and hydrogen peroxide at the early stages and then decreased gradually in both resistant and susceptible cultivars. A significant increase in antioxidant enzyme activity such as superoxide dismutase, guaiacol peroxidase and catalase was evident in MJME pre‐treatment followed by A. solani infected leaves in susceptible cultivar of tomato compared with control. Manifestation of disease symptoms was reduced to 60% in tomato leaves pre‐treated with higher concentrations of MJME and infected with A. solani in susceptible cultivar on par with resistant cultivar. Quantitative real‐time polymerase chain reaction (qRT‐PCR) analysis revealed an induction of expression of defence‐related genes such as ACO1, EDS1, LoxD, NP24, NPR1 and Sl10EAH30 in tomato leaves pre‐treated with MJME followed by A. solani infection. Interestingly, a two‐fold increase in the expression of EDS1 gene was evident in both susceptible and resistant cultivars after MJME treatment compared with control. The present study showed that MJME could be a potential elicitor of resistance factors against the early blight disease of tomato. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have gained considerable interest in recent decades due to their antimicrobial activity and are used in water disinfection, wound healing, food packaging, and plant protection. This study tested the potential of silver nanoparticles synthesized using the neem (Azadirachta indica) leaf extract against Alternaria solani causes early blight disease in tomato plants. The pathogen was isolated from infected tomato plants and identified using morphological and molecular features. The results showed significant variation among isolates. Isolates, Shk-1 and Ksr-1 were highly pathogenic, causing up to 80% disease incidence. The potential of silver nanoparticles against each isolate was determined using different concentrations of silver nanoparticles. During in vitro and in vivo experiments, the growth inhibition rate of the pathogen was 70–100% at 50 ppm. Lower concentrations of silver nanoparticles (5 and 10 ppm) increased phenolics, PO, PPO, and PAL production by more than 50% as compared to the untreated control. These defensive mechanisms clearly demonstrate the fungicidal potential of AgNPs and recommend their utilization in different crop protection programs. [ABSTRACT FROM AUTHOR]

In this study, efficiency of the endophytic fungal isolate Msh5 was evaluated on promoting tomato plant growth and controlling Alternaria alternata, the causal agent of early blight in tomatoes. Morphological and molecular (ITS and tub2 sequences) analyses revealed that the fungal isolate, Msh5, was Acrophialophora jodhpurensis (Chaetomium jodhpurense Lodha). This beneficial fungus was capable of producing indole-3-acetic acid (IAA), urease, siderophore, extracellular enzymes, and solubilized phosphate. Under laboratory conditions, the Msh5 isolate of A. jodhpurensis inhibited A. alternata growth in dual culture, volatile and non-volatile metabolites assays. The supernatant of this endophytic fungus was capable of reducing spore germination and altering the hyphal structure of A. alternata and the spores produced germ tubes showed vacuolization and abnormal structure compared to the control. Also, the effect of A. jodhpurensis on plant growth parameters (such as shoot and root weight and length) and suppressing A. alternata was investigated in vivo via seed inoculation with spores of A. jodhpurensis using 1% sugar, 0.5% carboxymethyl cellulose (CMC) or 0.5% molasses solution as stickers. Colonization of tomato roots by the endophytic fungus resulted in significant increasing plant growth parameters and reduction in the progress of the diseases caused by A. alternata compared to the controls. Among the different coating materials used as stickers, sugar was found to be the most effective for enhancing plant growth parameters and decreasing the disease progress. Therefore, A. jodhpurensis isolate Msh5 can be suggested as a potential biofertilizer and biocontrol agent for protecting tomato plants against A. alternata. [ABSTRACT FROM AUTHOR]

Early blight (EB) disease, caused mainly by Alternaria solani, is an economic threat to potato and tomato production worldwide. Thus, accurate and sensitive detection of the fungal pathogen of this disease in plants at the early infection stage is important for forecasting EB epidemics. In this study, we developed an RNA-based method that enables highly accurate and sensitive A. solani detection in a whole potato leaf at a single spore level based on quantitative real-time polymerase chain reaction (qPCR). We discovered jg1677, a highly expressed gene whose full-length coding sequence is very specific for A. solani, by analyzing A. solani transcripts isolated from enhanced high throughput transcriptome of infected potato leaves by A. solani and using the National Center for Biotechnology Information’s basic local alignment search tool. The specificity of the primers derived from jg1677 was determined using 22 isolates of common potato pathogens, including seven Alternaria isolates. Detecting jg1677 transcripts with qPCR is 1,295 times more sensitive than detecting genomic DNA. In addition, the expression pattern of jg1677 at different infection stages was determined by qPCR. What is more, jg1677 was expressed relatively stable between 15 and 35°C in infected leaves, and its expression was virtually unaffected in isolated leaves left at room temperature for 24 h. Our work provides a much more sensitive and accurate method compared to conditional DNA-based ones, permitting a very early diagnosis of EB and lowering the risk of EB epidemics. [ABSTRACT FROM AUTHOR]

In this study, efficiency of the endophytic fungal isolate Msh5 was evaluated on promoting tomato plant growth and controlling Alternaria alternata, the causal agent of early blight in tomatoes. Morphological and molecular (ITS and tub2 sequences) analyses revealed that the fungal isolate, Msh5, was Acrophialophora jodhpurensis (Chaetomium jodhpurense Lodha). This beneficial fungus was capable of producing indole-3-acetic acid (IAA), urease, siderophore, extracellular enzymes, and solubilized phosphate. Under laboratory conditions, the Msh5 isolate of A. jodhpurensis inhibited A. alternata growth in dual culture, volatile and non-volatile metabolites assays. The supernatant of this endophytic fungus was capable of reducing spore germination and altering the hyphal structure of A. alternata and the spores produced germ tubes showed vacuolization and abnormal structure compared to the control. Also, the effect of A. jodhpurensis on plant growth parameters (such as shoot and root weight and length) and suppressing A. alternata was investigated in vivo via seed inoculation with spores of A. jodhpurensis using 1% sugar, 0.5% carboxymethyl cellulose (CMC) or 0.5% molasses solution as stickers. Colonization of tomato roots by the endophytic fungus resulted in significant increasing plant growth parameters and reduction in the progress of the diseases caused by A. alternata compared to the controls. Among the different coating materials used as stickers, sugar was found to be the most effective for enhancing plant growth parameters and decreasing the disease progress. Therefore, A. jodhpurensis isolate Msh5 can be suggested as a potential biofertilizer and biocontrol agent for protecting tomato plants against A. alternata.

Resistance gene analogs (RGAs) comprising NBS-LRR gene family members are considered prominent candidates in the development of disease-resistant genotypes. NBS-LRR gene family comprised a very large number of genes; therefore, members of one subfamily TIR-NBS-LRR (TNL) are identified in the present study from Solanum tuberosum genome, followed by their bioinformatics characterization. The study identified a total of 44 genes encoding 60 TNL transcripts with two prominent clusters at chromosome 1 and chromosome 11. Expression analysis of 14 TNL genes after Alternaria solani infection at 1, 2, 3, 5, and 7 days post inoculation in two disease-tolerant varieties, Kufri Jyoti and Kufri Pukhraj, and one relatively susceptible variety, Kufri Chandramukhi, showed differential expression of many genes including a high expression (>15-fold) of StTNLC6G2T1 and StTNLC11G9T1. Functional characterization of one such gene, StTNLC7G2 , reveals involvement in the generation of reactive oxygen species under A. solani attack, implicating its putative role in plant defense via hypersensitive response. [ABSTRACT FROM AUTHOR]

Resistance gene analogs (RGAs) comprising NBS-LRR gene family members are considered prominent candidates in the development of disease-resistant genotypes. NBS-LRR gene family comprised a very large number of genes; therefore, members of one subfamily TIR-NBS-LRR (TNL) are identified in the present study from Solanum tuberosum genome, followed by their bioinformatics characterization. The study identified a total of 44 genes encoding 60 TNL transcripts with two prominent clusters at chromosome 1 and chromosome 11. Expression analysis of 14 TNL genes after Alternaria solani infection at 1, 2, 3, 5, and 7 days post inoculation in two disease-tolerant varieties, Kufri Jyoti and Kufri Pukhraj, and one relatively susceptible variety, Kufri Chandramukhi, showed differential expression of many genes including a high expression (>15-fold) of StTNLC6G2T1 and StTNLC11G9T1. Functional characterization of one such gene, StTNLC7G2, reveals involvement in the generation of reactive oxygen species under A. solani attack, implicating its putative role in plant defense via hypersensitive response.

Silver nanoparticles have gained considerable interest in recent decades due to their antimicrobial activity and are used in water disinfection, wound healing, food packaging, and plant protection. This study tested the potential of silver nanoparticles synthesized using the neem (Azadirachta indica) leaf extract against Alternaria solani causes early blight disease in tomato plants. The pathogen was isolated from infected tomato plants and identified using morphological and molecular features. The results showed significant variation among isolates. Isolates, Shk-1 and Ksr-1 were highly pathogenic, causing up to 80% disease incidence. The potential of silver nanoparticles against each isolate was determined using different concentrations of silver nanoparticles. During in vitro and in vivo experiments, the growth inhibition rate of the pathogen was 70–100% at 50 ppm. Lower concentrations of silver nanoparticles (5 and 10 ppm) increased phenolics, PO, PPO, and PAL production by more than 50% as compared to the untreated control. These defensive mechanisms clearly demonstrate the fungicidal potential of AgNPs and recommend their utilization in different crop protection programs.

Early blight commonly attacks the tomato leaf. The drone and image processing technologies offer a tool to detect the symptom of the tomato disease. One of the stages in the early blight detection is the segmentation of the tomato leaf. The K-means algorithm is a known image segmentation method which works simply and quickly. However, randomized initialization of centroids causes the K-means algorithm to easily get stuck in the local optimum and, as a result, gives imprecise segmentation. The swarm intelligence-based algorithm can avoid this problem. For this reason, we propose the early blight disease segmentation method on tomato leaves uses K-means algorithm with swarm intelligence-based algorithm. This research uses the Particle Swarm Optimization (PSO) because PSO is one of the swarm intelligence-based algorithms which has a balance in exploration and exploitation. The Hue of the HSV color space is used as input. From the experimental results, we can conclude that the performance of the early blight disease segmentation method using the K-means algorithm with swarm intelligence-based algorithm is much better. [ABSTRACT FROM AUTHOR]

Early blight disease of tomato, triggered by Alternaria species, is one of the destructive diseases of tomato in Pakistan and around the globe. In this study, a survey was conducted during 2016-17 to estimate the early blight disease incidence and severity, and the identification of fungal species associated with the disease from the eight districts in Punjab Province of Pakistan: Gujranwala, Lahore, Multan, Bahawalpur, Sahiwal, Muzaffargarh, Rajanpur and Faisalabad. The disease incidence and severity from the eight districts were further associated with the different environmental variables. Eight Alternaria isolates, representing eight districts, were characterized on morphological basis and the four most pathogenic isolates on molecular (ITS rDNA) basis. The pathogenicity of the most pathogenic isolate was first evaluated by detached leaf assay and then compared with attached leaf assay. Bahawalpur district was found to be the most infected with maximum 75 % disease incidence and Rajanpur was the least affected region with 9% disease incidence while maximum disease severity index was recorded from Multan with 24% and lowest from Rajanpur with 1%. The disease incidence showed positive correlation with relative humidity and negative correlation with temperature while the rainfall and UV showed no influence. Out of four molecularly identified isolates of Alternaria, only one isolate was identified as being A. solani and the remaining three belonged to A. alternata species. A. solani showed the highest (score 3.33) level of pathogenicity over all the A. alternata isolates (0.66-2.66). This study concluded that the early blight disease is of high importance with great prevalence in Pakistan due to highly favorable environment especially relative humidity (55-61 %) and temperature (14-36 °C). Here, two Alternaria species are the main cause of early blight disease and out of them A. alternata is the most common while A. solani is the most pathogenic fungus. [ABSTRACT FROM AUTHOR]

Early blight disease causes a significant loss in tomato production. This study focuses on the effective suppression of Alternaria solani , which causes huge losses in tomato yield. This research was conducted at the Egyptian Atomic Energy Authority Nuclear Research Centre. Infected plants were treated with silver nanoparticles (AgNPs). Two chemical materials, sodium borohydride and trisodium phosphate, were used for the synthesized silver nanoparticles. 1% polyvinylpyridine (PVP) was used as a stabilizer agent. AgNPs were exposed to several doses of gamma irradiation (0, 1.5, 3, 6, 12, and 24) kilo Gray (kGy) in order to enhance and maximize the effect of AgNPs on Alternaria solani. UV–Vis spectroscopy (UV), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) were used to characterize AgNPs; sodium borohydride and trisodium citrate were used for the chemical reduction. AgNPs and AgNPs + gamma irradiation led to increases in shoot fresh weight and shoot dry weight; they also elevated the antioxidant enzymes, as well as peroxides and catalase, when compared with control (untreated) plants. AgNPs and AgNPs + gamma irradiation decreased the disease severity compared with the control untreated. Our study not only corroborates established trends in nano-agriculture but also introduces novel insights into the specific effects of gamma irradiation on AgNP that led to a decrease in this size in the quantum dot range (3–10) nm, as shown in Tem. By drawing parallels with the work of esteemed researchers in the field. • " Chemical Synthesis of AgNPs:Using Chemical Reduction of Synthesis AgNPs. • " Innovative Synthesis : Quantum Dote : Transforming AgNPs to quantum dot dimensions with the power of gamma irradiation." • " Thorough Characterization : Delving deep into the unique properties of irradiated AgNPs." • " Crop Guardian : Managing Early Blight Disease in tomatoes through the application of irradiated AgNPs." • " Plant Defense Boost : Irradiated AgNPs sparks heightened peroxidase and catalase activity, enhancing plant resilience." [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.), an important food crop in the world, is susceptible to many fungal pathogens including Alternaria solani and Fusarium oxysporum causing Fusarium wilt and early blight diseases. Mycoparasitic fungi like Trichoderma encode chitinases, cell wall degrading enzymes, with high antifungal activity against a wide range of phytopathogenic fungi. In this study, a binary vector harboring endochitinase gene of ~1,000 bp was constructed and used to transform potato nodes through Agrobacterium-mediated transformation. Out of several primary transformants, two transgenic potato lines were verified for transgene insertion and integration by Southern blot. In a pot experiment for Fusarium resistance, the transgenic potato lines didn’t show any symptoms of disease, instead they remained healthy post infection. The transgenic potato lines exhibited 1.5 fold higher mRNA expression of endochitinase at 7 days as compared to 0 day post fungus inoculation. It was evident that the mRNA expression decreased over days of inoculation but was still higher than at 0 day and remained stable upto 30 days post inoculation. Similarly, for A. solani infection assay, the mRNA expression of the endochitinase gene was 3 fold higher 7 days post inoculation compared to expression at 0 day. Although the expression decreased by1.2 fold during subsequent days post infection, it remained stable for 30 days, suggesting that protection in transgenic potato plants against fungal pathogens was achieved through an increase in endochitinase transcript.

Early blight caused by Alternaria solani (Ell. and Mart.) is one of the most important economic diseases, which caused considerable loss in their yield and quality under Egyptian conditions. Aim the research was to study the relationship between climate change and disease severity for prediction in future seasons. Disease severity was recorded for three growing periods i.e. summer (May. to Aug), autumn (Jul. to Oct) and winter (Nov. to Mar.), at three governorates (Behira, Ismailia, and Assuit) during growing seasons 2016/2017-2017/2018. Severity of early blight disease on tomato has been predicted by regression estimated accumulative disease severity values during 2007/2008 to 2015/2016 season and average max and min temperature and humidity through these seasons. Prediction of disease has been formed as Y= b0+b1x1+b2x2+.......... bqxq. Three models were created to describe the severity disease by multiple regressions (MINITAB® program). The highest value of early blight disease was recorded through season 2017/2018, while the lowest value was recorded during season 2016/2017. Also, highly disease severity was estimated during summer period compared with autumn and winter growing periods, but through winter growing period was the least severity and moderately severity estimated in the autumn growing period. Influence of environmental conditions on the severity of early blight disease during seasons from 2007/2008 to 2015/2016, in Behira governorate, the highest disease severity was showed in season 2010-2011, and the lowest disease was in season 2012-2013, but in Ismailia governorate, highest disease severity was estimated in season 2010-2011and lowest disease was recorded in season 2013-2014 and in Assuit governorate, the highest value of disease was in season 2010-2011, and the lowest value was in season 2013-2014. For Forecasting, significantly differences noticed between disease severity through 2020/2030, 2030/2040 and 2040/ 2050s seasons compared with 2008/2018s seasons and thier relation with climate change in tested governorates, where severity of tomato early blight disease was icreased from 11.8% during 2008/2018s seasons to 2040/ 2050s seasons 15.4% during at Behira governorate, from 18.8% during 2008/2018s seasons to 2040/ 2050s seasons 36.3% during at Ismailia governorate and from 18.8% during 2008/2018s seasons to 2040/ 2050s seasons 40.4% during at Assuit governorate with slight change in maximum or minimum temperatures and percentage of relative humidity.

Tomato (Solanum lycopersicum L.), is an important horticulture crop supporting rural economy of Sirmaur district of Himachal Pradesh. Tomato crops in this geographical region are highly susceptible to plant pathogens resulting in significant loss of productivity and yield. In this study, we have determined the prevalence and causative pathogens of early blight disease affecting tomato crops in 18 geographical sites of district Sirmaur. On the basis of colony characteristics, microscopic features and ITS region sequence-based phylogenetic analysis, blight disease-associated isolates exhibited close resemblance to Alternaria alternata and other related species. These findings necessitates an integrated management strategy for effective pathogen control towards minimising the crop losses. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.), an important food crop in the world, is susceptible to many fungal pathogens including Alternaria solani and Fusarium oxysporum causing Fusarium wilt and early blight diseases. Mycoparasitic fungi like Trichoderma encode chitinases, cell wall degrading enzymes, with high antifungal activity against a wide range of phytopathogenic fungi. In this study, a binary vector harboring endochitinase gene of ~1,000 bp was constructed and used to transform potato nodes through Agrobacterium-mediated transformation. Out of several primary transformants, two transgenic potato lines were verified for transgene insertion and integration by Southern blot. In a pot experiment for Fusarium resistance, the transgenic potato lines didn't show any symptoms of disease, instead they remained healthy post infection. The transgenic potato lines exhibited 1.5 fold higher mRNA expression of endochitinase at 7 days as compared to 0 day post fungus inoculation. It was evident that the mRNA expression decreased over days of inoculation but was still higher than at 0 day and remained stable upto 30 days post inoculation. Similarly, for A. solani infection assay, the mRNA expression of the endochitinase gene was 3 fold higher 7 days post inoculation compared to expression at 0 day. Although the expression decreased by1.2 fold during subsequent days post infection, it remained stable for 30 days, suggesting that protection in transgenic potato plants against fungal pathogens was achieved through an increase in endochitinase transcript. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) is among the most important vegetable crops worldwide. Early blight disease, caused by Alternaria solani, is a destructive foliar disease of tomato and other Solanaceae species. Herein, we investigated the in vitro antifungal properties of gallic acid and two of its derivatives (syringic and pyrogallic acids) against A. solani during 2019 and 2020 seasons. The physiological and biochemical effects of these compounds on infected tomato plants were also investigated using the whole plant bioassay. The in vitro investigation showed that all tested compounds showed fungistatic action and inhibited the mycelial radial growth of A. solani in a dose-dependent manner. In two separate pot-experiments, those compounds efficiently suppressed the development of the disease symptoms and area under disease progress curve (AUDPC), without any phytotoxic effects on the treated tomato plants. Additionally, all tested compounds positively enhanced the biochemical traits of treated plants including the chlorophyll content, the total soluble phenolics, the total soluble flavonoids, and the enzymatic activities of catalase, peroxidase, and polyphenol oxidase during 2019 and 2020 seasons. Moreover, the treatment with gallic acid and its derivatives significantly increased all yield components of A. solani-infected tomato plants such as the total number of flowers and fruits, and the fruit yield for each tomato plant in both experiments. Considering the fungitoxicity of phenolic acids against A. solani with no phytotoxicity on treated tomato plants, we believe that gallic acid and its derivatives might be a sustainable eco-friendly control strategy to reduce the usage of chemical fungicides partially or entirely against A. solani particularly, and fungal diseases in general.

Three different fungitoxicants, i.e., Trichoderma harzianum, Bacillus subtilis and Roxil Plus WP50 fungicide, were investigated against tomato early blight disease caused by Alternaria solani fungus in vitro and in vivo. By using dual culture technique, the highest reduction percentage of A. solani growth was recorded with B. subtilis followed by Roxil treatments, while Roxil followed by T. harzianum treatments recorded highest reduction percentage of sporulation. Meanwhile, by using poisoned food technique the highest reduction percentage of A. solani growth was recorded with Roxil followed by B. subtilis treatments, while B. subtilis recorded highest reduction percentage of sporulation. Three fungitoxicants were investigated as foliar spray for their abilities for controlling early blight disease on naturally infected tomato plants under open field conditions. Roxil fungicide followed by B. subtilis treatments caused the highest significant reduction in disease incidence and disease severity percentage during the two successive growing seasons 2013/14 and 2014/15. Concerning to yield parameters, Roxil and T. harzianum treatments were significantly increased total yield weight and average weight of tomato fruit. Moreover, all tested treatments increased clearly total phenol content, peroxidase, polyphenoloxidase and chitinase activities, as well as, vitamince C contents as compared to control treatment. [ABSTRACT FROM AUTHOR]

This study investigated both spectrum and texture features for detecting early blight disease on eggplant leaves. Hyperspectral images for healthy and diseased samples were acquired covering the wavelengths from 380 to 1023 nm. Four gray images were identified according to the effective wavelengths (408, 535, 624 and 703 nm). Hyperspectral images were then converted into RGB, HSV and HLS images. Finally, eight texture features (mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment and correlation) based on gray level co-occurrence matrix (GLCM) were extracted from gray images, RGB, HSV and HLS images, respectively. The dependent variables for healthy and diseased samples were set as 0 and 1. K-Nearest Neighbor (KNN) and AdaBoost classification models were established for detecting healthy and infected samples. All models obtained good results with the classification rates (CRs) over 88.46% in the testing sets. The results demonstrated that spectrum and texture features were effective for early blight disease detection on eggplant leaves. [ABSTRACT FROM AUTHOR]

Early blight (EB) disease, caused mainly by Alternaria solani , is an economic threat to potato and tomato production worldwide. Thus, accurate and sensitive detection of the fungal pathogen of this disease in plants at the early infection stage is important for forecasting EB epidemics. In this study, we developed an RNA-based method that enables highly accurate and sensitive A. solani detection in a whole potato leaf at a single spore level based on quantitative real-time polymerase chain reaction (qPCR). We discovered jg1677, a highly expressed gene whose full-length coding sequence is very specific for A. solani , by analyzing A. solani transcripts isolated from enhanced high throughput transcriptome of infected potato leaves by A. solani and using the National Center for Biotechnology Information's basic local alignment search tool. The specificity of the primers derived from jg1677 was determined using 22 isolates of common potato pathogens, including seven Alternaria isolates. Detecting jg1677 transcripts with qPCR is 1,295 times more sensitive than detecting genomic DNA. In addition, the expression pattern of jg1677 at different infection stages was determined by qPCR. What is more, jg1677 was expressed relatively stable between 15 and 35°C in infected leaves, and its expression was virtually unaffected in isolated leaves left at room temperature for 24 h. Our work provides a much more sensitive and accurate method compared to conditional DNA-based ones, permitting a very early diagnosis of EB and lowering the risk of EB epidemics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Niu, Zheng, Yang, Wang, Tian, Pan, Zhao, Yang and Zhu.)

[Display omitted] • Pathogen of early blight of potato was isolated and identified as A. alternata. • Endophyte Bacillus velezensis SEB1 showed antagonistic activity against the pathogen. • SEB1 produced thermostable antifungal metabolites and cell wall degrading enzymes. • EA fraction of SEB1 inhibited conidial germination and radial growth of the pathogen. • SEB1 reduced early blight disease severity during challenge experiment. Early blight is a well known disease causing severe loss in potato production which is used as staple food in many parts of the world. For overcoming the drawbacks of chemical fungicides used for controlling the disease, searching of suitable biocontrol agents are essential. In the present endeavour, the fungal pathogen was isolated and identified from the infected leaves of potato grown in the lateritic belt of Santiniketan, West Bengal, India. Based on morphological characteristics and sequencing of ITS region, the isolated pathogen EBP3 was identified as Alternaria alternata instead of Alternaria. solani. The pathogen was further confirmed by pathogenecity test following pot based experiment. One endophytic bacterial strain Bacillus velezensis SEB1 isolated from Vigna mungo (L.) Hepper was checked for its biocontrol efficacy against the isolated pathogen. SEB1 was found effective for inhibiting the pathogenic growth on dual culture overlay plates. In addition to fungal cell wall degrading enzymes ß-glucanase and protease, SEB1 can secrete thermostable antifungal metabolites to the extracellular broth which are insensitive to proteinase K. The crude EA fraction of the CFS of SEB1 inhibited the conidial germination and germ tube elongation of EBP3. 82.34 ± 4.56% inhibition in fungal radial growth was also observed in the presence of EA fraction at 1000 µg/ml. In vivo challenge experiments suggested decrease of disease severity form 52.47 ± 3.8% to 9.59 ± 2.1% due to application of the biocontrol agent SEB1. Based on overall observation the endophytic bacterial isolate SEB1 can be considered as a suitable biocontrol agent for controlling the early blight of potato caused by A. alternata. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) is among the most important vegetable crops worldwide. Early blight disease, caused by Alternaria solani, is a destructive foliar disease of tomato and other Solanaceae species. Herein, we investigated the in vitro antifungal properties of gallic acid and two of its derivatives (syringic and pyrogallic acids) against A. solani during 2019 and 2020 seasons. The physiological and biochemical effects of these compounds on infected tomato plants were also investigated using the whole plant bioassay. The in vitro investigation showed that all tested compounds showed fungistatic action and inhibited the mycelial radial growth of A. solani in a dose-dependent manner. In two separate pot-experiments, those compounds efficiently suppressed the development of the disease symptoms and area under disease progress curve (AUDPC), without any phytotoxic effects on the treated tomato plants. Additionally, all tested compounds positively enhanced the biochemical traits of treated plants including the chlorophyll content, the total soluble phenolics, the total soluble flavonoids, and the enzymatic activities of catalase, peroxidase, and polyphenol oxidase during 2019 and 2020 seasons. Moreover, the treatment with gallic acid and its derivatives significantly increased all yield components of A. solani-infected tomato plants such as the total number of flowers and fruits, and the fruit yield for each tomato plant in both experiments. Considering the fungitoxicity of phenolic acids against A. solani with no phytotoxicity on treated tomato plants, we believe that gallic acid and its derivatives might be a sustainable eco-friendly control strategy to reduce the usage of chemical fungicides partially or entirely against A. solani particularly, and fungal diseases in general. [ABSTRACT FROM AUTHOR]

• Peppermint based nanoemulsion has been synthesized by high energy sonication method. • 1% dose of PNE was able to inhibit the growth of A. solani. • 1% PNE reduce the disease severity caused by A. solani in tomato up to 87.5%. • PNE modulates plant physiology at biochemical, morphological, gene expression level. Early blight, caused by Alternaria solani is one of the most devastating disease affecting to the Solanum lycopersicum (tomato), reducing its productivity by 80%. The present study illustrates the synthesis of nanoemulsion using peppermint oil for potent antimicrobial activity against A. solani. A peppermint oil based nanoemulsion (PNE) was synthesized which was further characterized by Dynamic Light Scattering and Transmission Electron Microscopy. The nano-droplets present in nanoemulsion were spherical in shape with average size <100 nm. In-vitro antimicrobial activity of PNE was examined against A. solani with the carbendazim as positive control. A green-house study was performed to evaluate the antimicrobial efficacy and plant immunity developed by nanoemulsion as well as compared with carbendazim, chemical fungicide. PNE was much competent to reduce the disease severity up to 68.7% at 14th day and 87.5% at 21st day respectively. Physiological modulation was showed in tomato plants against A. solani, they were confirmed by measured the physical parameters, plant physiology, changes in leaf morphology and stress responses. A significant changes were found in proline and lipid peroxidation content in infected plants whereas nanoemulsion treated infected plants was able to cope-up from stress condition. Physical parameters and Scanning Electron Microscopy (SEM) analysis also revealed the similar observations. A reduced photosynthesis rate and transpiration rate were found in diseased plants as compared to other treatments, although stomatal conductance was not much affected. Defence responsive gene expression also up-regulated in PNE treated diseased plants than pathogen alone. Thus, the current study demonstrated the peppermint oil based nanoemulsion was more efficacious than chemical fungicide to early blight disease management in Solanum lycopersicum. [ABSTRACT FROM AUTHOR]

This study investigated both spectrum and texture features for detecting early blight disease on eggplant leaves. Hyperspectral images for healthy and diseased samples were acquired covering the wavelengths from 380 to 1023 nm. Four gray images were identified according to the effective wavelengths (408, 535, 624 and 703 nm). Hyperspectral images were then converted into RGB, HSV and HLS images. Finally, eight texture features (mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment and correlation) based on gray level co-occurrence matrix (GLCM) were extracted from gray images, RGB, HSV and HLS images, respectively. The dependent variables for healthy and diseased samples were set as 0 and 1. K-Nearest Neighbor (KNN) and AdaBoost classification models were established for detecting healthy and infected samples. All models obtained good results with the classification rates (CRs) over 88.46% in the testing sets. The results demonstrated that spectrum and texture features were effective for early blight disease detection on eggplant leaves.