Biogenic synthesis, characterization, and evaluation of synthesized nanoparticles against the pathogenic fungus Alternaria solani

In the present study, Trichoderma harzianum culture filtrate (CF) was used as a reducing and capping agent to synthesize silver nanoparticles (Ag NPs) in a quick, simple, cost-effective, and eco-friendly manner. The effects of different ratios (silver nitrate (AgNO3): CF), pH, and incubation time on the synthesis of Ag NPs were also examined. Ultraviolet–visible (UV–Vis) spectra of the synthesized Ag NPs showed a distinct surface plasmon resonance (SPR) peak at 420 nm. Spherical and monodisperse NPs were observed using scanning electron microscopy (SEM). Elemental silver (Ag) was identified in the Ag area peak indicated by energy dispersive x-ray (EDX) spectroscopy. The crystallinity of Ag NPs was confirmed by x-ray diffraction (XRD), and Fourier transform infrared (FTIR) was used to examine the functional groups present in the CF. Dynamic light scattering (DLS) revealed an average size (43.68 nm), which was reported to be stable for 4 months. Atomic force microscopy (AFM) was used to confirm surface morphology. We also investigated the in vitro antifungal efficacy of biosynthesized Ag NPs against Alternaria solani, which demonstrated a significant inhibitory effect on mycelial growth and spore germination. Additionally, microscopic investigation revealed that Ag NP-treated mycelia exhibited defects and collapsed. Apart from this investigation, Ag NPs were also tested in an epiphytic environment against A. solani. Ag NPs were found to be capable of managing early blight disease based on field trial findings. The maximum percentage of early blight disease inhibition by NPs was observed at 40 parts per million (ppm) (60.27%), followed by 20 ppm (58.68%), whereas in the case of the fungicide mancozeb (1,000 ppm), the inhibition was recorded at 61.54%

Unraveling Microbial Volatile Elicitors Using a Transparent Methodology for Induction of Systemic Resistance and Regulation of Antioxidant Genes at Expression Levels in Chili against Bacterial Wilt Disease

Microbial volatiles benefit the agricultural ecological system by promoting plant growth and systemic resistance against diseases without harming the environment. To explore the plant growth-promoting efficiency of VOCs produced by Pseudomonas fluorescens PDS1 and Bacillus subtilis KA9 in terms of chili plant growth and its biocontrol efficiency against Ralstonia solanacearum, experiments were conducted both in vitro and in vivo. A closure assembly was designed using a half-inverted plastic bottle to demonstrate plant–microbial interactions via volatile compounds. The most common volatile organic compounds were identified and reported; they promoted plant development and induced systemic resistance (ISR) against wilt pathogen R. solanacearum. The PDS1 and KA9 VOCs significantly increased defensive enzyme activity and overexpressed the antioxidant genes PAL, POD, SOD, WRKYa, PAL1, DEF-1, CAT-2, WRKY40, HSFC1, LOX2, and NPR1 related to plant defense. The overall gene expression was greater in root tissue as compared to leaf tissue in chili plant. Our findings shed light on the relationship among rhizobacteria, pathogen, and host plants, resulting in plant growth promotion, disease suppression, systemic resistance-inducing potential, and antioxidant response with related gene expression in the leaf and root tissue of chili

Screening and Biocontrol Potential of Rhizobacteria Native to Gangetic Plains and Hilly Regions to Induce Systemic Resistance and Promote Plant Growth in Chilli against Bacterial Wilt Disease

Plant growth-promoting rhizobacteria (PGPR) is a microbial population found in the rhizosphere of plants that can stimulate plant development and restrict the growth of plant diseases directly or indirectly. In this study, 90 rhizospheric soil samples from five agro climatic zones of chilli (Capsicum annuum L.) were collected and rhizobacteria were isolated, screened and characterized at morphological, biochemical and molecular levels. In total, 38% of rhizobacteria exhibited the antagonistic capacity to suppress Ralstonia solanacearum growth and showed PGPR activities such as indole acetic acid production by 67.64% from total screened rhizobacteria isolates, phosphorus solubilization by 79.41%, ammonia by 67.75%, HCN by 58.82% and siderophore by 55.88%. We performed a principal component analysis depicting correlation and significance among plant growth-promoting activities, growth parameters of chilli and rhizobacterial strains. Plant inoculation studies indicated a significant increase in growth parameters and PDS1 strain showed maximum 71.11% biocontrol efficiency against wilt disease. The best five rhizobacterial isolates demonstrating both plant growth-promotion traits and biocontrol potential were characterized and identified as PDS1—Pseudomonas fluorescens (MN368159), BDS1—Bacillus subtilis (MN395039), UK4—Bacillus cereus (MT491099), UK2—Bacillus amyloliquefaciens (MT491100) and KA9—Bacillus subtilis (MT491101). These rhizobacteria have the potential natural elicitors to be used as biopesticides and biofertilizers to improve crop health while warding off soil-borne pathogens. The chilli cv. Pusa Jwala treated with Bacillus subtilis KA9 and Pseudomonas fluorescens PDS1 showed enhancement in the defensive enzymes PO, PPO, SOD and PAL activities in chilli leaf and root tissues, which collectively contributed to induced resistance in chilli plants against Ralstonia solanacearum. The induction of these defense enzymes was found higher in leave tissues (PO—4.87-fold, PP0—9.30-fold, SOD—9.49-fold and PAL—1.04-fold, respectively) in comparison to roots tissue at 48 h after pathogen inoculation. The findings support the view that plant growth-promoting rhizobacteria boost defense-related enzymes and limit pathogen growth in chilli plants, respectively, hence managing the chilli bacterial wilt

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Not AvailableCucurbitaceae crop are important vegetable and ranked among the top 10 vegetable crops in the world. Cucurbits as gourd vegetable share about 5.6% of the total vegetable production of India. Members of the family Cucurbitaceae contains Cucurbita (pumpkins, squashes, gourds, mallows, courgettes), Mamordica charantia (bitter gourd), Cucumis (melons, cucumbers), Colocynthis (watermelon), Cucurmeropsis (egusi), Lagenaria siceraria (Morina), Luffa cylindrical etc. Crop losses due to the biotic factors like pests and disease h major constrain and affects the productivity of cucurbits. Wilt and rot are the major soil borne fungal diseases caused by Fusarium spp. and damping off caused by Phytophthora spp., Acremonium spp., and Pythium spp. are responsible for 70% yield losses. Biointensive management proved to be best alternative for chemical pesticides which concerns about environmental quality and food safety. With this objective the presen chapter aim provide a concise rewiew on biointensive IPM stratergy for soilborne diseases of cucurbitaceous crops.Not Availabl

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Not AvailableQuality seed is a basic input for crop production in agriculture, and there is always high demand of quality seed in national and international seed trade. The seed health and thereby its quality is affected by various seed-borne pathogens including fungi, bacteria, viruses, nematodes, etc. and also by abiotic factors. The science of seed pathology is an integral part of seed science and technology, which deals with the study of seed-borne diseases, overall seed health status, and management of seed-borne diseases. This science has traveled a long journey of more than a century. Many important institutions have come into existence, and a number of technologies related to seed health testing, detection, and diagnosis of seed-borne microflora and management of the seed-borne pathogens have been developed. To investigate seed health, many tests were standardized by individual researchers and organizations. Paul Neergaard made great contribution in the development of seed pathology, and hence he is considered as the father of seed pathology. Three primary organizations publish standardized seed health testing methods, and these are the International Seed Testing Association (ISTA), the International Seed Health Initiative (ISHI), and the USDA’s National Seed Health System (NSHS). Among them, ISTA is key institution which provides internationally agreed set of rules for seed sampling and testing, gives authority to seed testing laboratories, and provides international seed analysis certificates to facilitate seed trading nationally and internationally. Keeping in the view above facts, the major contributions of different individuals and various organizations are being discussed in this chapter.Not Availabl

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Not AvailableFifty years ago, the green revolution increased agricultural production worldwide, saving millions of people from starvation and undernourishment. To enhance plant growth and nutrition, plant growth-promoting rhizobacteria (PGPR) plays a significant role in the intensively managed agricultural systems. The rising demand for crop production with a significant reduction in synthetic chemical fertilizers and pesticide use is a challenge. Plant growth-promoting rhizobacteria (PGPR) are those microorganisms that live within a rhizospheric zone of plant host in a symbiosis relationship. PGPRis beneficial microorganism to plant that can protect it from deleterious effects of environmental stresses such as drought, salinity, flooding, and phytopathogens. The mechanisms of PGPR include curbing hormonal and nutritional harmony, inducing systemic resistance against phytopathogens, and solubilizing nutrients for easy uptake by crops. Molecular tools showed great potential in the identification and tracking of the phylogeny of soil microbes. Today is the era of omics which including genomics, transcriptomics, proteomics and metabolomics, these omics helps us to the better understanding of the PGPRs function and their interaction with the host. Proteomics enhances the knowledge of the gene (s) and pathways induced during the host-PGPR interaction. The 2D-PAGE strategy has been widely used in understanding stress responses as well as in understanding constitutive differences between developmental stages or genotypes.it provides a broad overview of proteins produced by both the partners.Not Availabl

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Not AvailablePlant Growth Promoting Rhizobacteria (PGPR) is a community of bacteria located in the rhizosphere of plant which are can suppress directly or indirectly plant diseases caused by different plant pathogens and also promote plant growth. Twenty three rhizospheric soil samples of chilli plants from Southern Plateau and Hills region agro-climatic zones of Karnataka and Andhra Pradesh states of India were collected and isolated on four different types of media viz. TSA (Tryptone soya agar), NA (Nutrient Agar), CPG (Casamino peptone glucose) and Kings’ B media in the present study. A total of thirty one bacterial isolates were isolated and screened their antagonistic against Ralastonia solanacearum UTT- 25 and plant growth promoting activities in vitro condition. Out of 31 isolates of rhizobacteria, 35.4 % rhizobacteria showed antagonistic ability to inhibit growth of R. solanacearum. In vitro screening of PGP activities rhizobacteria showed phosphate solubilization (64.2%), production of IAA (78.5%), production of ammonia (78.5%), production of HCN (35.7%), and siderophore production (50%). The rhizobacterial isolates showing plant growth promoting activities along with having biocontrol potentials were characterized using morphological, biochemical and physiological. These rhizobacteria are good potential to use as biopesticide and biofertilizers for improving crop health and growth.Not Availabl

Development of Diagnostic Markers and Applied for Genetic Diversity Study and Population Structure of Bipolaris sorokiniana Associated with Leaf Blight Complex of Wheat

Bipolaris sorokiniana, a key pathogenic fungus in the wheat leaf blight complex, was the subject of research that resulted in the development of fifty-five polymorphic microsatellite markers. These markers were then used to examine genetic diversity and population structure in Indian geographical regions. The simple sequence repeat (SSR) like trinucleotides, dinucleotides, and tetranucleotides accounted for 43.37% (1256), 23.86% (691), and 16.54% (479) of the 2896 microsatellite repeats, respectively. There were 109 alleles produced by these loci overall, averaging 2.36 alleles per microsatellite marker. The average polymorphism information content value was 0.3451, with values ranging from 0.1319 to 0.5932. The loci’s Shannon diversity varied from 0.2712 to 1.2415. These 36 isolates were divided into two main groups using population structure analysis and unweighted neighbour joining. The groupings were not based on where the isolates came from geographically. Only 7% of the overall variation was found to be between populations, according to an analysis of molecular variance. The high amount of gene flow estimate (NM = 3.261 per generation) among populations demonstrated low genetic differentiation in the entire populations (FST = 0.071). The findings indicate that genetic diversity is often minimal. In order to examine the genetic diversity and population structure of the B. sorokiniana populations, the recently produced microsatellite markers will be helpful. This study’s findings may serve as a foundation for developing improved management plans for the leaf blight complex and spot blotch of wheat diseases in India

Trichoderma: Advent of Versatile Biocontrol Agent, Its Secrets and Insights into Mechanism of Biocontrol Potential

Trichoderma is an important biocontrol agent for managing plant diseases. Trichoderma species are members of the fungal genus hyphomycetes, which is widely distributed in soil. It can function as a biocontrol agent as well as a growth promoter. Trichoderma species are now frequently used as biological control agents (BCAs) to combat a wide range of plant diseases. Major plant diseases have been successfully managed due to their application. Trichoderma spp. is being extensively researched in order to enhance its effectiveness as a top biocontrol agent. The activation of numerous regulatory mechanisms is the major factor in Trichoderma ability to manage plant diseases. Trichoderma-based biocontrol methods include nutrient competition, mycoparasitism, the synthesis of antibiotic and hydrolytic enzymes, and induced plant resistance. Trichoderma species may synthesize a variety of secondary metabolites that can successfully inhibit the activity of numerous plant diseases. GPCRs (G protein-coupled receptors) are membrane-bound receptors that sense and transmit environmental inputs that affect fungal secondary metabolism. Related intracellular signalling pathways also play a role in this process. Secondary metabolites produced by Trichoderma can activate disease-fighting mechanisms within plants and protect against pathogens. β- Glucuronidase (GUS), green fluorescent protein (gfp), hygromycin B phosphotransferase (hygB), and producing genes are examples of exogenous markers that could be used to identify and track specific Trichoderma isolates in agro-ecosystems. More than sixty percent of the biofungicides now on the market are derived from Trichoderma species. These fungi protect plants from harmful plant diseases by developing resistance. Additionally, they can solubilize plant nutrients to boost plant growth and bioremediate environmental contaminants through mechanisms, including mycoparasitism and antibiosis. Enzymes produced by the genus Trichoderma are frequently used in industry. This review article intends to provide an overview update (from 1975 to 2022) of the Trichoderma biocontrol fungi, as well as information on key secondary metabolites, genes, and interactions with plant diseases

<i>Trichoderma</i>: Advent of Versatile Biocontrol Agent, Its Secrets and Insights into Mechanism of Biocontrol Potential

Trichoderma is an important biocontrol agent for managing plant diseases. Trichoderma species are members of the fungal genus hyphomycetes, which is widely distributed in soil. It can function as a biocontrol agent as well as a growth promoter. Trichoderma species are now frequently used as biological control agents (BCAs) to combat a wide range of plant diseases. Major plant diseases have been successfully managed due to their application. Trichoderma spp. is being extensively researched in order to enhance its effectiveness as a top biocontrol agent. The activation of numerous regulatory mechanisms is the major factor in Trichoderma ability to manage plant diseases. Trichoderma-based biocontrol methods include nutrient competition, mycoparasitism, the synthesis of antibiotic and hydrolytic enzymes, and induced plant resistance. Trichoderma species may synthesize a variety of secondary metabolites that can successfully inhibit the activity of numerous plant diseases. GPCRs (G protein-coupled receptors) are membrane-bound receptors that sense and transmit environmental inputs that affect fungal secondary metabolism. Related intracellular signalling pathways also play a role in this process. Secondary metabolites produced by Trichoderma can activate disease-fighting mechanisms within plants and protect against pathogens. β- Glucuronidase (GUS), green fluorescent protein (gfp), hygromycin B phosphotransferase (hygB), and producing genes are examples of exogenous markers that could be used to identify and track specific Trichoderma isolates in agro-ecosystems. More than sixty percent of the biofungicides now on the market are derived from Trichoderma species. These fungi protect plants from harmful plant diseases by developing resistance. Additionally, they can solubilize plant nutrients to boost plant growth and bioremediate environmental contaminants through mechanisms, including mycoparasitism and antibiosis. Enzymes produced by the genus Trichoderma are frequently used in industry. This review article intends to provide an overview update (from 1975 to 2022) of the Trichoderma biocontrol fungi, as well as information on key secondary metabolites, genes, and interactions with plant diseases