scholarly journals Synergistic Effect of Plant Defense Elicitors and Biocontrol Agents on Induction of Defense Enzymes in Pea against Downy Mildew

2021 ◽  
Author(s):  
Puja Pandey ◽  
K.P.S. Kushwaha ◽  
Vinod Upadhyay ◽  
Jyotika Purohit
Keyword(s):  
Enzyme Activity ◽  
Synergistic Effect ◽  
Oxalic Acid ◽  
Plant Defense ◽  
Pseudomonas Fluorescens ◽  
Trichoderma Harzianum ◽  
Isonicotinic Acid ◽  
Defense Responses ◽  
Fresh Weight ◽  
Challenge Inoculation

Background: Plant defense against the pathogens can be induced by using different defense inducers. Plants can be treated with elicitors for fast and more intense mobilization of defense responses which can enhance the resistance against biotic or abiotic stresses. Methods: The present study has been undertaken to evaluate the synergistic effect of different plant defense inducing chemical (Salicylic acid, Isonicotinic acid, Oxalic acid and Chitosan) and biological (Trichoderma harzianum and Pseudomonas fluorescens) elicitors. Enzyme activity was expressed as the increase in absorbance using spectrophotometer. Result: Among all the treatments the maximum PAL activity (35.58 mg/g of fresh weight) was found in case of oxalic acid but after 48 hrs its activity reduced drastically. Next to oxalic acid Pseudomonas fluorescens (31.38 mg/g of fresh weight), chitosan + Trichoderma harzianum (29.38 mg/g of fresh weight) and chitosan + Pseudomonas fluorescens (27.89 mg/g of fresh weight) showed the maximum enzyme activity. The PPO activity reached the highest at 96 hr after challenge inoculation in case of chitosan + Trichoderma harzianum (9.74 µmol/min/mg/protein) treated plants followed by Trichoderma harzianum (3.53 µmol/min/mg/protein) alone. the maximum PO activity (49.12 µmol/min/mg/protein) was found in case of chitosan + Pseudomonas fluorescens treated plants followed by chitosan (42.48 µmol/min/mg/protein) after 72 hrs. the maximum phenolics (27.53 mg/gm of fresh weight) was found in case of chitosan + Pseudomonas fluorescens after 48 hrs of treatment.

scholarly journals Trichoderma harzianum Strain T22 Modulates Direct Defense of Tomato Plants in Response to Nezara viridula Feeding Activity

2021 ◽  
Author(s):  
Tuğcan Alınç ◽  
Antonino Cusumano ◽  
Ezio Peri ◽  
Livio Torta ◽  
Stefano Colazza
Keyword(s):  
Growth Rate ◽  
Plant Defense ◽  
Trichoderma Harzianum ◽  
Defense Responses ◽  
Nezara Viridula ◽  
Marker Genes ◽  
Stink Bug ◽  
Tomato Plants ◽  
Southern Green Stink Bug ◽  
The Impact

AbstractPlant growth-promoting fungi belonging to genus Trichoderma are known to help plants when dealing with biotic stressors by enhancing plant defenses. While beneficial effects of Trichoderma spp. against plant pathogens have long been documented, fewer studies have investigated their effect on insect pests. Here, we studied the impact of Trichoderma root colonization on the plant defense responses against stink bug feeding attack. For this purpose, a model system consisting of tomato plant, Solanum lycopersicum cv Dwarf San Marzano, Trichoderma harzianum strain T22 and the southern green stink bug, Nezara viridula, was used. We firstly determined stink bug performance in terms of relative growth rate and survival on tomato plants inoculated by T. harzianum T22. Then, we evaluated relative expression of plant defense-related genes on inoculated plants induced by stink bug feeding. We found evidence that T. harzianum T22 affects tomato defense responses against N. viridula nymphs leading to reduction of growth rate. Our results also showed that T. harzianum T22 enhances plant direct defenses by an early increase of transcript levels of jasmonic acid marker genes. Yet this effect was time-dependent and only detected 8 h after herbivore induction. Taken together, our findings provide better understanding on the mechanisms underlying tomato induced resistance against herbivorous stink bugs.

Synergistic effect of anion and cation in oxalic acid for graphene surface engineering and its enhanced pseudocapacitance performance

2021 ◽  
Vol 868 ◽  
pp. 159128
Author(s):  
Yang Yang ◽  
Minghua Wang ◽  
Zhengyue Shi ◽  
Rubo Xiao ◽  
Xiangcheng Sun ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Oxalic Acid ◽  
Surface Engineering ◽  
Graphene Surface

scholarly journals An efficient direct screening system for microorganisms that activate plant immune responses based on plant–microbe interactions using cultured plant cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mari Kurokawa ◽  
Masataka Nakano ◽  
Nobutaka Kitahata ◽  
Kazuyuki Kuchitsu ◽  
Toshiki Furuya
Keyword(s):  
Immune Responses ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Large Scale ◽  
Plant Cells ◽  
Defense Responses ◽  
Root Tip ◽  
General Strategy ◽  
Plant Defense Responses ◽  
Microbe Interactions

AbstractMicroorganisms that activate plant immune responses have attracted considerable attention as potential biocontrol agents in agriculture because they could reduce agrochemical use. However, conventional methods to screen for such microorganisms using whole plants and pathogens are generally laborious and time consuming. Here, we describe a general strategy using cultured plant cells to identify microorganisms that activate plant defense responses based on plant–microbe interactions. Microbial cells were incubated with tobacco BY-2 cells, followed by treatment with cryptogein, a proteinaceous elicitor of tobacco immune responses secreted by an oomycete. Cryptogein-induced production of reactive oxygen species (ROS) in BY-2 cells served as a marker to evaluate the potential of microorganisms to activate plant defense responses. Twenty-nine bacterial strains isolated from the interior of Brassica rapa var. perviridis plants were screened, and 8 strains that enhanced cryptogein-induced ROS production in BY-2 cells were selected. Following application of these strains to the root tip of Arabidopsis seedlings, two strains, Delftia sp. BR1R-2 and Arthrobacter sp. BR2S-6, were found to induce whole-plant resistance to bacterial pathogens (Pseudomonas syringae pv. tomato DC3000 and Pectobacterium carotovora subsp. carotovora NBRC 14082). Pathogen-induced expression of plant defense-related genes (PR-1, PR-5, and PDF1.2) was enhanced by the pretreatment with strain BR1R-2. This cell–cell interaction-based platform is readily applicable to large-scale screening for microorganisms that enhance plant defense responses under various environmental conditions.

scholarly journals Method for the Production and Purification of Plant Immuno-Active Xylanase from Trichoderma

2021 ◽  
Vol 22 (8) ◽  
pp. 4214
Author(s):  
Gautam Anand ◽  
Meirav Leibman-Markus ◽  
Dorin Elkabetz ◽  
Maya Bar
Keyword(s):  
Immune System ◽  
Plant Defense ◽  
Plant Immunity ◽  
Xylanase Activity ◽  
Hydrolytic Enzymes ◽  
Adaptive Immune System ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Xylanase Production ◽  
Ideal System

Plants lack a circulating adaptive immune system to protect themselves against pathogens. Therefore, they have evolved an innate immune system based upon complicated and efficient defense mechanisms, either constitutive or inducible. Plant defense responses are triggered by elicitors such as microbe-associated molecular patterns (MAMPs). These components are recognized by pattern recognition receptors (PRRs) which include plant cell surface receptors. Upon recognition, PRRs trigger pattern-triggered immunity (PTI). Ethylene Inducing Xylanase (EIX) is a fungal MAMP protein from the plant-growth-promoting fungi (PGPF)–Trichoderma. It elicits plant defense responses in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum), making it an excellent tool in the studies of plant immunity. Xylanases such as EIX are hydrolytic enzymes that act on xylan in hemicellulose. There are two types of xylanases: the endo-1, 4-β-xylanases that hydrolyze within the xylan structure, and the β-d-xylosidases that hydrolyze the ends of the xylan chain. Xylanases are mainly synthesized by fungi and bacteria. Filamentous fungi produce xylanases in high amounts and secrete them in liquid cultures, making them an ideal system for xylanase purification. Here, we describe a method for cost- and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate. Xylanase produced by this method possessed xylanase activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis, and ROS burst.

scholarly journals Using maize wastes, fermented by co-cultures of Trichoderma harzianum and Pseudomonas fluorescens, as grain dressing against m maize diseases under field conditions

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Sherien M. M. Atalla ◽  
Mokhtar M. Abdel-Kader ◽  
Nadia G. El-Gamal ◽  
Nehal S. El-Mougy
Keyword(s):  
Pseudomonas Fluorescens ◽  
Trichoderma Harzianum ◽  
Raw Materials ◽  
Chitosan Nanoparticles ◽  
Field Conditions ◽  
Optimum Ratio ◽  
Transmission Electron ◽  
Environmentally Safe ◽  
The Mean ◽  
Uv Visible

Abstract Maize (Zea mays L.) is one of the most economic crops in Egypt. Production of amylase from the waste of maize is the most economic and cheap renewable and most abundant raw materials present in environment. Biosynthesis of Cu-chitosan nanoparticles for amylase production by co-culturing between Trichoderma harzianum and Pseudomonas fluorescens at different ratios compared to free conditions was the main purpose of this study. The optimum ratio 8:2, recorded between P. fluorescens: T. harzianum, was the most promising for production of amylase produce 22.47 and 28.60 U/ml for free and nano, respectively. The UV visible spectral analysis Cu-chitosan NPs was 220 nm, while the mean diameter, using transmission electron microscopy was 0.5 μm. Application of fermented maize wastes by co-cultivation of P. fluorescence and T. harzianum, as a grain dressing before sowing declared the reduction in both root and foliar diseases during the maize growing season, starting from germination up to 70 days of its vegetative growth under field conditions. A promising approach is the creation and use of environmentally safe products, whose protective effect is based on the induction of hydrolase inhibitors in plants.

scholarly journals Deletion of the SACPD-C Locus Alters the Symbiotic Relationship Between Bradyrhizobium japonicum USDA110 and Soybean, Resulting in Elicitation of Plant Defense Response and Nodulation Defects

2016 ◽  
Vol 29 (11) ◽  
pp. 862-877 ◽  
Author(s):  
Hari B. Krishnan ◽  
Alaa A. Alaswad ◽  
Nathan W. Oehrle ◽  
Jason D. Gillman
Keyword(s):  
Plant Defense ◽  
Defense Response ◽  
Acyl Carrier Protein ◽  
Defense Responses ◽  
Nodule Development ◽  
Plant Defense Response ◽  
Wild Type ◽  
Two Dimensional Gel Electrophoresis ◽  
Symbiotic Associations ◽  
Soybean Nodule

Legumes form symbiotic associations with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia-encoded nitrogenase facilitates the conversion of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of stearoyl-acyl carrier protein desaturase isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen-fixing nodules. In-depth cytological investigation of nodule development in sacpd-c mutant lines M25 and MM106 revealed gross anatomical alteration in the sacpd-c mutants. Transmission electron microscopy observations revealed ultrastructural alterations in the sacpd-c mutants that are typically associated with plant defense response to pathogens. In nodules of two sacpd-c mutants, the combined jasmonic acid (JA) species (JA and the isoleucine conjugate of JA) were found to be reduced and 12-oxophytodienoic acid (OPDA) levels were significantly higher relative to wild-type lines. Salicylic acid levels were not significantly different between genotypes, which is divergent from previous studies of sacpd mutant studies on vegetative tissues. Soybean nodule phytohormone profiles were very divergent from those of roots, and root profiles were found to be almost identical between mutant and wild-type genotypes. The activities of antioxidant enzymes, ascorbate peroxidase, and superoxide dismutase were also found to be higher in nodules of sacpd-c mutants. PR-1 gene expression was extremely elevated in M25 and MM106, while the expression of nitrogenase was significantly reduced in these sacpd-c mutants, compared with the parent ‘Bay’. Two-dimensional gel electrophoresis and matrix-assisted laser desorption-ionization time of flight mass spectrometry analyses confirmed sacpd-c mutants also accumulated higher amounts of pathogenesis-related proteins in the nodules. Our study establishes a major role for SACPD-C activity as essential for proper maintenance of soybean nodule morphology and physiology and indicates that OPDA signaling is likely to be involved in attenuation of nodule biotic defense responses.

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