Abstract Traditional agricultural practices are getting severely hampered by multiple problems su... more Abstract Traditional agricultural practices are getting severely hampered by multiple problems such as disease, pest, drought, salinity, decreased soil fertility because of the use of hazardous chemical pesticides and pollution. As a result, need of an hour is selection for some eco-friendly biocontrol agent that is a multitasker in terms of resolving the above mentioned problems. Trichoderma is one such genus that is ubiquitously present in the environment which has naturally sustained the agricultural yields and supported the human population over million years. They are known to produce different kinds of enzymes and elicit defense responses in plants which have a significant role in biotic and abiotic stress tolerance, hyphal growth as well as plant growth promotion. Trichoderma's mechanisms of antagonism and role in plant growth promotion have been well documented but fast paced current research utilizing all the “omics” in this field would actually unravel the hidden features of this fungus.
International Journal of Agriculture, Environment and Biotechnology, 2016
Seed biopriming is an advance technique of seed treatment that involves application of beneficial... more Seed biopriming is an advance technique of seed treatment that involves application of beneficial microorganism on seed surface followed by seed hydration. Seed bioprimig is a ecological to control the many seed and soil-borne pathogens which provide an alternative to chemical treatment. Seed biopriming enhance the initial step of plant development by increased seed germination and provide protection before seedling emergence. Trichoderma spp. is widely used for biocontrol agent that enhance plant growth as well as inhibits phytopathogen. In the present study, effectiveness of biopriming with T. asperellum BHUT8 evaluated for plant growth promotion effect in pea. The results showed enhancement in plant growth in the treated plants as compared to control. There was increase in shoot length, root length, number of leaves, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight by 35.29, 96.49, 28.13, 36.10, 146.26, 30.17 and 77.20%, respectively, as compared to the control.
Background Trichoderma asperellum and T. harzianum were assessed in this study as a potential bio... more Background Trichoderma asperellum and T. harzianum were assessed in this study as a potential biological control against Colletotrichum truncatum. C. truncatum is a hemibiotrophic fungus that causes anthracnose disease in chilli thereby affecting plant growth and fruit yield. Scanning electron microscope (SEM) technique showed the beneficial interaction between chilli root-Trichoderma spp. inducing the plant growth promotion, mechanical barrier, and defense network under C. truncatum challenged conditions. Methods Seeds bio-primed with T. asperellum, T. harzianum, and T. asperellum + T. harzianum promoted the plant growth parameters and strengthening of physical barrier via lignification on the wall of vascular tissues. Seed primed with bioagents were used for exploring the molecular mechanism of defense response in pepper against anthracnose to assess the temporal expression of six defense genes in the Surajmukhi variety of Capsicum annuum. QRT-PCR demonstrated induction of defense responsive genes in chilli pepper bioprimed with Trichoderma spp. such as plant defensin 1.2 (CaPDF1.2), superoxide dismutase (SOD), ascorbate peroxidase (APx), guaiacol peroxidase (GPx), pathogenesis related proteins PR-2 and PR-5. Results The results showed that bioprimed seeds were assessed for T. asperellum, T. harzianum, and T. asperellum + T. harzianum-chilli root colonization interaction under in vivo conditions. The results of the scanning electron microscope revealed that T. asperellum, T. harzianum and T. asperellum + T. harzianum interact with chilli roots directly via the development of plant-Trichoderma interaction system. Seeds bio-primed with bioagents promoted the plant growth parameters, fresh and dry weight of shoot and root, plant height, leaf area index, number of leaves, stem diameter and strengthening of physical barrier via lignification on the wall of vascular tissues and expression of six defense related genes in pepper against anthracnose. Conclusions Application of T. asperellum and T. harzianum and in combination of treatments enhanced the plant growth. Further, as seeds bioprimed with T. asperellum, T. harzianum and in combination with treatment of T. asperellum + T. harzianum induced the strengthening of the cell wall by lignification and expression of six defense related genes CaPDF1.2, SOD, APx, GPx, PR-2 and PR-5 in pepper against C. truncatum. Our study contributed for better disease
International journal of engineering research and technology, Dec 3, 2013
Recognition of a diverse range of pathogens, followed by an appropriate defense response, is cruc... more Recognition of a diverse range of pathogens, followed by an appropriate defense response, is crucial for the survival of plants. It is conditioned by initial recognition events between host plant and pathogen, which lead to activation of various host defense responses, including a specialized type of programmed cell death known as a Hypersensitive Response (HR). HR may play in plants the same role as certain programmed cell deaths in animals with respect to restricting pathogen growth. In addition, the HR could regulate the defense responses of the plant in both local and distant tissues. HR is commonly regulated by direct or indirect interactions between avirulence gene products from pathogen and resistance gene products from plant and it can be the result of multiple signalling pathways. Ion fluxes and the generation of reactive oxygen species (ROS) commonly precede cell death, but a direct involvement of the latter seems to vary with the plant-pathogen combination. ROS and ion fluxes are proximal response probably required for the HR and finally the potential elements of the signal transduction pathways leading to the activation of various mechanisms of ROS production followed by cell death. It seems likely that cell death within the HR acts more as a signal to the rest of the plant rather than as a direct defense mechanism. Exciting advances have been made in the identification of cellular protective components and cell death suppressors that might operate in HR. In this review, the physiological, biochemical and molecular machineries of the HR will be discussed.
International Journal of Agriculture, Environment and Biotechnology, 2016
A simple and efficient protocol is developed for isolation of high quality RNA from roots and lea... more A simple and efficient protocol is developed for isolation of high quality RNA from roots and leaves of chickpea and pea. The procedure is based on use of SDS, sodium acetate and EDTA in an extraction buffer in order to eliminate polysaccharides and prevent oxidation of phenolic compounds. The current method is modification of a method described for RNA isolation from pea leaves only, and yields excess amount of high-quality RNA suitable for cDNA based gene expression analysis. The protocol requires only three disposable micro centrifuge tubes during extraction, single phenol extraction step and a single precipitation step to yield high-quality RNA. RNA extracted with this method was free from protein and phenolic contaminants as evident from gel electrophoresis analysis. This method is applicable not only for leaves but also for roots and shoots and equally applicable to both chickpea and pea. cDNA is prepared and PCR amplification have been done with universal ubiqutin primer to check the integrity of RNA and absence of inhibitory compounds in RNA samples, which proves the suitability of samples towards qRTPCR.
Plant growth and development are greatly affected by various biotic and abiotic stresses. Various... more Plant growth and development are greatly affected by various biotic and abiotic stresses. Various strategies are utilized to minimize stresses in plants. Seed priming with beneficial microorganisms is one of the most beneficial methods to improve plant growth and development and induce systemic tolerance in plants towards biotic as well as abiotic stresses. Seed priming is a method of conditioning the seeds by plant growth-promoting microbes which provide better abilities to the plant to withstand various environmental challenges beginning from seed germination. Seed priming with beneficial microorganism is also known as bio-priming that enhances seed germination, protects germinating seed from different phytopathogens, and provides suitable conditions for establishment of the plant. Bio-priming has several mechanisms to stimulate morphogenesis and plant immunity, viz., production of phytohormones, induced expression of plant growth-promoting genes, increased nutrient status into the plant, mycoparasitism, antibiosis, induced phenolic production, activation of antioxidant production, and systemic defense activation. Some important microorganisms that synthesize phytohormones include Azotobacter spp., Pantoea agglomerans, Rhodospirillum rubrum, Rhizobium spp., Bacillus subtilis, Pseudomonas fluorescens, Paenibacillus polymyxa, Trichoderma spp., Pseudomonas putida, Rhizobium phaseoli, Bacillus cereus, and Acinetobacter calcoaceticus. The main objective of this chapter is to enlighten the importance of seed priming with microorganisms and the role of different phytohormones produced by them in modulating growth, development, and defense activation in the host plant.
In the present study, Paenibacillus dendritiformis, Trichoderma harzianum, and Trichoderma aspere... more In the present study, Paenibacillus dendritiformis, Trichoderma harzianum, and Trichoderma asperellum were appraised as potential biocontrol agents that induce resistance in chilli (Capsicum annuum) against the devastating pathogen Colletotrichum truncatum, which causes anthracnose. Bright-field and scanning electron micrographs showed the hyphal degradation, lysis, and abnormal swelling in C. truncatum against P. dendritiformis in a dual plate assay. Under greenhouse conditions, chilli seeds pretreated with P. dendritiformis, T. asperellum, T. harzianum, and T. asperellum + T. harzianum by soil soak method inflicted an induced systemic resistance (ISR) in chilli against a C. truncatum-challenged condition. In chilli, the disease index percentage was significantly reduced in the T. asperellum + T. harzianum-treated seeds, followed by the T. harzianum-, T. asperellum-, and P. dendritiformis-treated seeds as compared to the untreated and challenged, respectively. Chilli seeds were pri...
Background: In response to various environmental stresses, many plant species synthesize L-prolin... more Background: In response to various environmental stresses, many plant species synthesize L-proline in the cytosol and accumulates in the chloroplasts. L-Proline accumulation in plants is a well-recognized physiological reaction to osmotic stress prompted by salinity, drought and other abiotic stresses. L-Proline plays several protective functions such as osmoprotectant, stabilizing cellular structures, enzymes, and scavenging reactive oxygen species (ROS), and keeps up redox balance in adverse situations. In addition, ample-studied osmoprotective capacity, Lproline has been also ensnared in the regulation of plant improvement, including flowering, pollen, embryo, and leaf enlargement. Scope and conclusions: Albeit, ample is now well-known about L-proline metabolism, but certain characteristics of its biological roles are still indistinct. In the present review, we discuss the L-proline accumulation, metabolism, signaling, transport and regulation in the plants. We also discuss the effects of exogenous L-proline during different environmental conditions. L-Proline biosynthesis and catabolism are controlled by several cellular mechanisms, of which we identify only very fewer mechanisms. So, in the future, there is a requirement to identify such types of cellular mechanisms.
Archives of Phytopathology and Plant Protection, 2019
Trichodrema is considered to be the most beneficial fungal genus for protecting crops in organic ... more Trichodrema is considered to be the most beneficial fungal genus for protecting crops in organic systems. The present study focuses on isolation, screening and identification of salinity tolerant Trichoderma isolates from eastern Uttar Pradesh, India. Among all the Trichoderma isolates, BHUT6 and BHUT8 were highly salt tolerant under in vitro condition and showed good growth up to 1400 mM NaCl concentration. The highest salinity tolerant Trichoderma BHUT8 isolate was selected for further study. This isolate was identified as Trichoderma asperellum (accession number KU533735). T. asperellum BHUT8 also possessed temperature tolerance showing good growth up to 38 C. The BHUT8 isolate also showed biocontrol potential against major soilborne phytopathogens namely Scletotium rolfsii, Fusarium oxysporum, Colletotrichum capsici, Rhizoctonia bataticola, and Sclerotinia sclerotiorum in dual culture assay. Amylolytic, proteolytic and chitinolytic activities of BHUT8 were also high, and produced IAA, HCN, siderophore and solubilised phosphate.
Out of the various mycotoxigenic food and feed contaminant, the fungal species belonging to gener... more Out of the various mycotoxigenic food and feed contaminant, the fungal species belonging to genera, particularly is of great economic importance, and well known for its crucial role in the manufacturing of Roquefort and Gorgonzola cheese. The mycotoxicosis effect of this mold is due to secretion of several metabolites, of which PR toxin is of considerable importance, with regard to food quality and safety challenges issues. The food products and silages enriched with PR toxin could lead into damage to vital internal organs, gastrointestinal perturbations, carcinogenicity, immunotoxicity, necrosis, and enzyme inhibition. Moreover, it also has the significant mutagenic potential to disrupt/alter the crucial processes like DNA replication, transcription, and translation at the molecular level. The high genetic diversities in between the various strains of persuaded their nominations with Protected Geographical Indication (PGI), accordingly to the cheese type, they have been employed. R...
Plant defense against their pathogens can be induced by a complex network of different inducers. ... more 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 enzy...
Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for u... more Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.
The WRKY transcription factors (TFs), play crucial role in plant defense response against various... more The WRKY transcription factors (TFs), play crucial role in plant defense response against various abiotic and biotic stresses. The role of WRKY3 and WRKY4 genes in plant defense response against necrotrophic pathogens is well-reported. However, their functional annotation in tomato is largely unknown. In the present work, we have characterized the structural and functional attributes of the two identified tomato WRKY transcription factors, WRKY3 (SlWRKY3), and WRKY4 (SlWRKY4) using computational approaches. Arabidopsis WRKY3 (AtWRKY3: NP_178433) and WRKY4 (AtWRKY4: NP_172849) protein sequences were retrieved from TAIR database and protein BLAST was done for finding their sequential homologs in tomato. Sequence alignment, phylogenetic classification, and motif composition analysis revealed the remarkable sequential variation between, these two WRKYs. The tomato WRKY3 and WRKY4 clusters with Solanum pennellii showing the monophyletic origin and evolution from their wild homolog. The f...
Numerous plants and fungi produce mannitol, which may serve as an osmolyte or metabolic store; fu... more Numerous plants and fungi produce mannitol, which may serve as an osmolyte or metabolic store; furthermore, mannitol also acts as a powerful quencher of reactive oxygen species (ROS). Some phytopathogenic fungi use mannitol to stifle ROSmediated plant resistance. Mannitol is essential in pathogenesis to balance cell reinforcements produced by both plants and animals. Mannitol likewise serves as a source of reducing power, managing coenzymes, and controlling cytoplasmic pH by going about as a sink or hotspot for protons. The metabolic pathways for mannitol biosynthesis and catabolism have been characterized in filamentous fungi by direct diminishment of fructose-6-phosphate into mannitol-1-phosphate including a mannitol-1-phosphate phosphatase catalyst. In plants mannitol is integrated from mannose-6phosphate to mannitol-1-phosphate, which then dephosphorylates to mannitol. The enzyme mannitol dehydrogenase plays a key role in host-pathogen interactions and must be co-localized with pathogen-secreted mannitol to resist the infection.
Background: Fusaric acid (FA) has been shown to stimulate the rapid development of disease sympto... more Background: Fusaric acid (FA) has been shown to stimulate the rapid development of disease symptoms, such as necrosis and foliar desiccation. In this study, we have evaluated the phytotoxicity of FA on tomato plants (Solanum lycopersicum L.). FA induced necrotic lesions in detached leaves, which are reminiscent of hypersensitive response (HR) lesions induced by plant-pathogen interactions and other abiotic stress factors. Results: FA-treated tomato leaves exhibited visible necrotic lesion as a result of cell death which was evident by Evans blue staining, enhanced reactive oxygen species (ROS) levels and DNA degradation. Changes in the generation of O 2 .and H 2 O 2 as well as the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were examined in FA-treated tomato leaves. It was observed that FA exposure stimulated oxidative burst in the leaves, resulting in a lasting activation of O 2 .and H 2 O 2 production. After first day of FA application, the H 2 O 2 scavenging enzymes CAT and APX showed a strong activity decrease followed by gradual recovery to the control level after 2 and 3 days. Conclusion: A concomitant increase in ROS production, the down regulation of antioxidative enzymes activities and upregulation of lipid peroxidation were crucial for the onset of cell death. These results suggested that FA-induced damage might result from ROS pathways. Thus, our experiments provide a useful model plant system for research on FA-induced plant cell death.
Microbial populations have functional roles within communities where interactions among distinct ... more Microbial populations have functional roles within communities where interactions among distinct microorganisms will permit their survival. Therefore, it is suggested to device mixed inoculants that may interact synergistically, with different or complementary mode of action, so that increased disease resistance is provided and under certain stresses we can assume that atleast one is functional. The mechanisms responsible for this biocontrol activity include competition for nutrients, niche exclusion, induced systemic resistance (ISR), and the production of anti-microbial metabolites. Therefore, seeing the success stories of mixed inoculants (combination of microorganisms that interact synergistically) over single bioinoculant, consortiums are being currently devised for crop management. The extreme complexity of interactions occurring is highlighted, and some potential areas and shortcomings required to overcome for future researches in this area are discussed briefly.
Please cite this article in press as: Singh A, et al. Rhizosphere competent microbial consortium ... more Please cite this article in press as: Singh A, et al. Rhizosphere competent microbial consortium mediates rapid changes in phenolic profiles in chickpea during Sclerotium rolfsii infection. Microbiol Res (2013),
Plant signaling mechanisms are not completely understood in plant-fungal biotrophic pathogen inte... more Plant signaling mechanisms are not completely understood in plant-fungal biotrophic pathogen interactions. Further how such interactions are influenced by compatible rhizosphere microbes are also not well-studied. Therefore, we explored the pea-Erysiphe pisi (obligate biotroph) system to understand the interaction and applied compatible rhizospheric bio-agents Trichoderma asperellum (T42) and Pseudomonas fluorescens (OKC) singly or in combination to assess their influence on the host while under the pathogen challenge. Transcript accumulation pattern of some vital genes in the lignin biosynthetic pathway in pea under E. pisi challenge indicated enhanced activation of the pathway. Interestingly, transcript accumulations were even higher in the bio-agent treated plants compared to untreated plants after pathogen inoculation particularly in co-inoculated treatments. Further, down regulation of the lignifications-associated ABC transporter gene in the pathogen challenged plants possibly...
In the present study we bioprimed seeds of six vegetable crops (tomato, brinjal, chilli, okra, ri... more In the present study we bioprimed seeds of six vegetable crops (tomato, brinjal, chilli, okra, ridge gourd and guar) with different spore doses of Trichoderma asperellum BHUT8 ranging from 10 2 to 10 8 spores ml-1 and the effect of biopriming was seen on seed germination and development. The most effective spore dose for enhancement in seed germination and radicle length was found to be 10 3 spores ml-1 in tomato and ridge gourd, 10 4 spores ml-1 in brinjal and okra while 10 6 spores ml-1 in chilli and guar. At the most effective spore dose, the
Abstract Traditional agricultural practices are getting severely hampered by multiple problems su... more Abstract Traditional agricultural practices are getting severely hampered by multiple problems such as disease, pest, drought, salinity, decreased soil fertility because of the use of hazardous chemical pesticides and pollution. As a result, need of an hour is selection for some eco-friendly biocontrol agent that is a multitasker in terms of resolving the above mentioned problems. Trichoderma is one such genus that is ubiquitously present in the environment which has naturally sustained the agricultural yields and supported the human population over million years. They are known to produce different kinds of enzymes and elicit defense responses in plants which have a significant role in biotic and abiotic stress tolerance, hyphal growth as well as plant growth promotion. Trichoderma's mechanisms of antagonism and role in plant growth promotion have been well documented but fast paced current research utilizing all the “omics” in this field would actually unravel the hidden features of this fungus.
International Journal of Agriculture, Environment and Biotechnology, 2016
Seed biopriming is an advance technique of seed treatment that involves application of beneficial... more Seed biopriming is an advance technique of seed treatment that involves application of beneficial microorganism on seed surface followed by seed hydration. Seed bioprimig is a ecological to control the many seed and soil-borne pathogens which provide an alternative to chemical treatment. Seed biopriming enhance the initial step of plant development by increased seed germination and provide protection before seedling emergence. Trichoderma spp. is widely used for biocontrol agent that enhance plant growth as well as inhibits phytopathogen. In the present study, effectiveness of biopriming with T. asperellum BHUT8 evaluated for plant growth promotion effect in pea. The results showed enhancement in plant growth in the treated plants as compared to control. There was increase in shoot length, root length, number of leaves, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight by 35.29, 96.49, 28.13, 36.10, 146.26, 30.17 and 77.20%, respectively, as compared to the control.
Background Trichoderma asperellum and T. harzianum were assessed in this study as a potential bio... more Background Trichoderma asperellum and T. harzianum were assessed in this study as a potential biological control against Colletotrichum truncatum. C. truncatum is a hemibiotrophic fungus that causes anthracnose disease in chilli thereby affecting plant growth and fruit yield. Scanning electron microscope (SEM) technique showed the beneficial interaction between chilli root-Trichoderma spp. inducing the plant growth promotion, mechanical barrier, and defense network under C. truncatum challenged conditions. Methods Seeds bio-primed with T. asperellum, T. harzianum, and T. asperellum + T. harzianum promoted the plant growth parameters and strengthening of physical barrier via lignification on the wall of vascular tissues. Seed primed with bioagents were used for exploring the molecular mechanism of defense response in pepper against anthracnose to assess the temporal expression of six defense genes in the Surajmukhi variety of Capsicum annuum. QRT-PCR demonstrated induction of defense responsive genes in chilli pepper bioprimed with Trichoderma spp. such as plant defensin 1.2 (CaPDF1.2), superoxide dismutase (SOD), ascorbate peroxidase (APx), guaiacol peroxidase (GPx), pathogenesis related proteins PR-2 and PR-5. Results The results showed that bioprimed seeds were assessed for T. asperellum, T. harzianum, and T. asperellum + T. harzianum-chilli root colonization interaction under in vivo conditions. The results of the scanning electron microscope revealed that T. asperellum, T. harzianum and T. asperellum + T. harzianum interact with chilli roots directly via the development of plant-Trichoderma interaction system. Seeds bio-primed with bioagents promoted the plant growth parameters, fresh and dry weight of shoot and root, plant height, leaf area index, number of leaves, stem diameter and strengthening of physical barrier via lignification on the wall of vascular tissues and expression of six defense related genes in pepper against anthracnose. Conclusions Application of T. asperellum and T. harzianum and in combination of treatments enhanced the plant growth. Further, as seeds bioprimed with T. asperellum, T. harzianum and in combination with treatment of T. asperellum + T. harzianum induced the strengthening of the cell wall by lignification and expression of six defense related genes CaPDF1.2, SOD, APx, GPx, PR-2 and PR-5 in pepper against C. truncatum. Our study contributed for better disease
International journal of engineering research and technology, Dec 3, 2013
Recognition of a diverse range of pathogens, followed by an appropriate defense response, is cruc... more Recognition of a diverse range of pathogens, followed by an appropriate defense response, is crucial for the survival of plants. It is conditioned by initial recognition events between host plant and pathogen, which lead to activation of various host defense responses, including a specialized type of programmed cell death known as a Hypersensitive Response (HR). HR may play in plants the same role as certain programmed cell deaths in animals with respect to restricting pathogen growth. In addition, the HR could regulate the defense responses of the plant in both local and distant tissues. HR is commonly regulated by direct or indirect interactions between avirulence gene products from pathogen and resistance gene products from plant and it can be the result of multiple signalling pathways. Ion fluxes and the generation of reactive oxygen species (ROS) commonly precede cell death, but a direct involvement of the latter seems to vary with the plant-pathogen combination. ROS and ion fluxes are proximal response probably required for the HR and finally the potential elements of the signal transduction pathways leading to the activation of various mechanisms of ROS production followed by cell death. It seems likely that cell death within the HR acts more as a signal to the rest of the plant rather than as a direct defense mechanism. Exciting advances have been made in the identification of cellular protective components and cell death suppressors that might operate in HR. In this review, the physiological, biochemical and molecular machineries of the HR will be discussed.
International Journal of Agriculture, Environment and Biotechnology, 2016
A simple and efficient protocol is developed for isolation of high quality RNA from roots and lea... more A simple and efficient protocol is developed for isolation of high quality RNA from roots and leaves of chickpea and pea. The procedure is based on use of SDS, sodium acetate and EDTA in an extraction buffer in order to eliminate polysaccharides and prevent oxidation of phenolic compounds. The current method is modification of a method described for RNA isolation from pea leaves only, and yields excess amount of high-quality RNA suitable for cDNA based gene expression analysis. The protocol requires only three disposable micro centrifuge tubes during extraction, single phenol extraction step and a single precipitation step to yield high-quality RNA. RNA extracted with this method was free from protein and phenolic contaminants as evident from gel electrophoresis analysis. This method is applicable not only for leaves but also for roots and shoots and equally applicable to both chickpea and pea. cDNA is prepared and PCR amplification have been done with universal ubiqutin primer to check the integrity of RNA and absence of inhibitory compounds in RNA samples, which proves the suitability of samples towards qRTPCR.
Plant growth and development are greatly affected by various biotic and abiotic stresses. Various... more Plant growth and development are greatly affected by various biotic and abiotic stresses. Various strategies are utilized to minimize stresses in plants. Seed priming with beneficial microorganisms is one of the most beneficial methods to improve plant growth and development and induce systemic tolerance in plants towards biotic as well as abiotic stresses. Seed priming is a method of conditioning the seeds by plant growth-promoting microbes which provide better abilities to the plant to withstand various environmental challenges beginning from seed germination. Seed priming with beneficial microorganism is also known as bio-priming that enhances seed germination, protects germinating seed from different phytopathogens, and provides suitable conditions for establishment of the plant. Bio-priming has several mechanisms to stimulate morphogenesis and plant immunity, viz., production of phytohormones, induced expression of plant growth-promoting genes, increased nutrient status into the plant, mycoparasitism, antibiosis, induced phenolic production, activation of antioxidant production, and systemic defense activation. Some important microorganisms that synthesize phytohormones include Azotobacter spp., Pantoea agglomerans, Rhodospirillum rubrum, Rhizobium spp., Bacillus subtilis, Pseudomonas fluorescens, Paenibacillus polymyxa, Trichoderma spp., Pseudomonas putida, Rhizobium phaseoli, Bacillus cereus, and Acinetobacter calcoaceticus. The main objective of this chapter is to enlighten the importance of seed priming with microorganisms and the role of different phytohormones produced by them in modulating growth, development, and defense activation in the host plant.
In the present study, Paenibacillus dendritiformis, Trichoderma harzianum, and Trichoderma aspere... more In the present study, Paenibacillus dendritiformis, Trichoderma harzianum, and Trichoderma asperellum were appraised as potential biocontrol agents that induce resistance in chilli (Capsicum annuum) against the devastating pathogen Colletotrichum truncatum, which causes anthracnose. Bright-field and scanning electron micrographs showed the hyphal degradation, lysis, and abnormal swelling in C. truncatum against P. dendritiformis in a dual plate assay. Under greenhouse conditions, chilli seeds pretreated with P. dendritiformis, T. asperellum, T. harzianum, and T. asperellum + T. harzianum by soil soak method inflicted an induced systemic resistance (ISR) in chilli against a C. truncatum-challenged condition. In chilli, the disease index percentage was significantly reduced in the T. asperellum + T. harzianum-treated seeds, followed by the T. harzianum-, T. asperellum-, and P. dendritiformis-treated seeds as compared to the untreated and challenged, respectively. Chilli seeds were pri...
Background: In response to various environmental stresses, many plant species synthesize L-prolin... more Background: In response to various environmental stresses, many plant species synthesize L-proline in the cytosol and accumulates in the chloroplasts. L-Proline accumulation in plants is a well-recognized physiological reaction to osmotic stress prompted by salinity, drought and other abiotic stresses. L-Proline plays several protective functions such as osmoprotectant, stabilizing cellular structures, enzymes, and scavenging reactive oxygen species (ROS), and keeps up redox balance in adverse situations. In addition, ample-studied osmoprotective capacity, Lproline has been also ensnared in the regulation of plant improvement, including flowering, pollen, embryo, and leaf enlargement. Scope and conclusions: Albeit, ample is now well-known about L-proline metabolism, but certain characteristics of its biological roles are still indistinct. In the present review, we discuss the L-proline accumulation, metabolism, signaling, transport and regulation in the plants. We also discuss the effects of exogenous L-proline during different environmental conditions. L-Proline biosynthesis and catabolism are controlled by several cellular mechanisms, of which we identify only very fewer mechanisms. So, in the future, there is a requirement to identify such types of cellular mechanisms.
Archives of Phytopathology and Plant Protection, 2019
Trichodrema is considered to be the most beneficial fungal genus for protecting crops in organic ... more Trichodrema is considered to be the most beneficial fungal genus for protecting crops in organic systems. The present study focuses on isolation, screening and identification of salinity tolerant Trichoderma isolates from eastern Uttar Pradesh, India. Among all the Trichoderma isolates, BHUT6 and BHUT8 were highly salt tolerant under in vitro condition and showed good growth up to 1400 mM NaCl concentration. The highest salinity tolerant Trichoderma BHUT8 isolate was selected for further study. This isolate was identified as Trichoderma asperellum (accession number KU533735). T. asperellum BHUT8 also possessed temperature tolerance showing good growth up to 38 C. The BHUT8 isolate also showed biocontrol potential against major soilborne phytopathogens namely Scletotium rolfsii, Fusarium oxysporum, Colletotrichum capsici, Rhizoctonia bataticola, and Sclerotinia sclerotiorum in dual culture assay. Amylolytic, proteolytic and chitinolytic activities of BHUT8 were also high, and produced IAA, HCN, siderophore and solubilised phosphate.
Out of the various mycotoxigenic food and feed contaminant, the fungal species belonging to gener... more Out of the various mycotoxigenic food and feed contaminant, the fungal species belonging to genera, particularly is of great economic importance, and well known for its crucial role in the manufacturing of Roquefort and Gorgonzola cheese. The mycotoxicosis effect of this mold is due to secretion of several metabolites, of which PR toxin is of considerable importance, with regard to food quality and safety challenges issues. The food products and silages enriched with PR toxin could lead into damage to vital internal organs, gastrointestinal perturbations, carcinogenicity, immunotoxicity, necrosis, and enzyme inhibition. Moreover, it also has the significant mutagenic potential to disrupt/alter the crucial processes like DNA replication, transcription, and translation at the molecular level. The high genetic diversities in between the various strains of persuaded their nominations with Protected Geographical Indication (PGI), accordingly to the cheese type, they have been employed. R...
Plant defense against their pathogens can be induced by a complex network of different inducers. ... more 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 enzy...
Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for u... more Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.
The WRKY transcription factors (TFs), play crucial role in plant defense response against various... more The WRKY transcription factors (TFs), play crucial role in plant defense response against various abiotic and biotic stresses. The role of WRKY3 and WRKY4 genes in plant defense response against necrotrophic pathogens is well-reported. However, their functional annotation in tomato is largely unknown. In the present work, we have characterized the structural and functional attributes of the two identified tomato WRKY transcription factors, WRKY3 (SlWRKY3), and WRKY4 (SlWRKY4) using computational approaches. Arabidopsis WRKY3 (AtWRKY3: NP_178433) and WRKY4 (AtWRKY4: NP_172849) protein sequences were retrieved from TAIR database and protein BLAST was done for finding their sequential homologs in tomato. Sequence alignment, phylogenetic classification, and motif composition analysis revealed the remarkable sequential variation between, these two WRKYs. The tomato WRKY3 and WRKY4 clusters with Solanum pennellii showing the monophyletic origin and evolution from their wild homolog. The f...
Numerous plants and fungi produce mannitol, which may serve as an osmolyte or metabolic store; fu... more Numerous plants and fungi produce mannitol, which may serve as an osmolyte or metabolic store; furthermore, mannitol also acts as a powerful quencher of reactive oxygen species (ROS). Some phytopathogenic fungi use mannitol to stifle ROSmediated plant resistance. Mannitol is essential in pathogenesis to balance cell reinforcements produced by both plants and animals. Mannitol likewise serves as a source of reducing power, managing coenzymes, and controlling cytoplasmic pH by going about as a sink or hotspot for protons. The metabolic pathways for mannitol biosynthesis and catabolism have been characterized in filamentous fungi by direct diminishment of fructose-6-phosphate into mannitol-1-phosphate including a mannitol-1-phosphate phosphatase catalyst. In plants mannitol is integrated from mannose-6phosphate to mannitol-1-phosphate, which then dephosphorylates to mannitol. The enzyme mannitol dehydrogenase plays a key role in host-pathogen interactions and must be co-localized with pathogen-secreted mannitol to resist the infection.
Background: Fusaric acid (FA) has been shown to stimulate the rapid development of disease sympto... more Background: Fusaric acid (FA) has been shown to stimulate the rapid development of disease symptoms, such as necrosis and foliar desiccation. In this study, we have evaluated the phytotoxicity of FA on tomato plants (Solanum lycopersicum L.). FA induced necrotic lesions in detached leaves, which are reminiscent of hypersensitive response (HR) lesions induced by plant-pathogen interactions and other abiotic stress factors. Results: FA-treated tomato leaves exhibited visible necrotic lesion as a result of cell death which was evident by Evans blue staining, enhanced reactive oxygen species (ROS) levels and DNA degradation. Changes in the generation of O 2 .and H 2 O 2 as well as the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were examined in FA-treated tomato leaves. It was observed that FA exposure stimulated oxidative burst in the leaves, resulting in a lasting activation of O 2 .and H 2 O 2 production. After first day of FA application, the H 2 O 2 scavenging enzymes CAT and APX showed a strong activity decrease followed by gradual recovery to the control level after 2 and 3 days. Conclusion: A concomitant increase in ROS production, the down regulation of antioxidative enzymes activities and upregulation of lipid peroxidation were crucial for the onset of cell death. These results suggested that FA-induced damage might result from ROS pathways. Thus, our experiments provide a useful model plant system for research on FA-induced plant cell death.
Microbial populations have functional roles within communities where interactions among distinct ... more Microbial populations have functional roles within communities where interactions among distinct microorganisms will permit their survival. Therefore, it is suggested to device mixed inoculants that may interact synergistically, with different or complementary mode of action, so that increased disease resistance is provided and under certain stresses we can assume that atleast one is functional. The mechanisms responsible for this biocontrol activity include competition for nutrients, niche exclusion, induced systemic resistance (ISR), and the production of anti-microbial metabolites. Therefore, seeing the success stories of mixed inoculants (combination of microorganisms that interact synergistically) over single bioinoculant, consortiums are being currently devised for crop management. The extreme complexity of interactions occurring is highlighted, and some potential areas and shortcomings required to overcome for future researches in this area are discussed briefly.
Please cite this article in press as: Singh A, et al. Rhizosphere competent microbial consortium ... more Please cite this article in press as: Singh A, et al. Rhizosphere competent microbial consortium mediates rapid changes in phenolic profiles in chickpea during Sclerotium rolfsii infection. Microbiol Res (2013),
Plant signaling mechanisms are not completely understood in plant-fungal biotrophic pathogen inte... more Plant signaling mechanisms are not completely understood in plant-fungal biotrophic pathogen interactions. Further how such interactions are influenced by compatible rhizosphere microbes are also not well-studied. Therefore, we explored the pea-Erysiphe pisi (obligate biotroph) system to understand the interaction and applied compatible rhizospheric bio-agents Trichoderma asperellum (T42) and Pseudomonas fluorescens (OKC) singly or in combination to assess their influence on the host while under the pathogen challenge. Transcript accumulation pattern of some vital genes in the lignin biosynthetic pathway in pea under E. pisi challenge indicated enhanced activation of the pathway. Interestingly, transcript accumulations were even higher in the bio-agent treated plants compared to untreated plants after pathogen inoculation particularly in co-inoculated treatments. Further, down regulation of the lignifications-associated ABC transporter gene in the pathogen challenged plants possibly...
In the present study we bioprimed seeds of six vegetable crops (tomato, brinjal, chilli, okra, ri... more In the present study we bioprimed seeds of six vegetable crops (tomato, brinjal, chilli, okra, ridge gourd and guar) with different spore doses of Trichoderma asperellum BHUT8 ranging from 10 2 to 10 8 spores ml-1 and the effect of biopriming was seen on seed germination and development. The most effective spore dose for enhancement in seed germination and radicle length was found to be 10 3 spores ml-1 in tomato and ridge gourd, 10 4 spores ml-1 in brinjal and okra while 10 6 spores ml-1 in chilli and guar. At the most effective spore dose, the
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