Role of L-phenylalanine ammonia Lyase in the induced resistance and susceptibility of sotato plants

Герасимова, Н. Г.; Придворова, С. М.; Ozeretskovskaya, O. L.

doi:10.1007/s10438-005-0019-3

Cited by 22 publications

(17 citation statements)

References 11 publications

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“…This enzyme acts in the conversion of L-phenylalanine to trans-cinnamic acid, resulting in several phenolic compounds, such as phytoalexins, flavonoids, and lignin, which confers resistance to the cell wall and act as a signal to the plant defense responses against biotic and abiotic stresses (Gerasimova et al, 2005;Latha et al, 2009).…”

Section: Characmentioning

confidence: 99%

Lactobacillus plantarum Exopolysaccharides Induce Resistance against Tomato Bacterial Spot

Blainski¹,

Neto²,

Luiz³

et al. 2017

JAS

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Lactic acid bacteria produce several exopolysaccharides (EPS) that may have antimicrobial action and/or induce defense responses in plants. This work aims to evaluate the potential of EPS produced by Lactobacillus plantarum in the protection of tomato plants against bacterial spot caused by Xanthomonas gardneri, as well as to predict the possible mechanisms of action. The EPS were characterized through FTIR and applied at 0; 0.5; 1.5 and 3.0 mg mL -1 in tomato plants with five expanded leaves, followed by the pathogen inoculation after 3 or 7 days. Antimicrobial activity of the biopolymer (1.5 or 10.0 mg mL -1 ) was evaluated in bioassay when EPS was incorporated into culture medium or embedded in antibiogram disk. The defense mechanisms i.e., total phenolic compounds and flavonoids content, phenylalanine ammonia-lyase (PAL), glutathione reductase (GR) and lipoxygenase (LOX) activities, were measured in tomato plants treated with EPS (1.5 mg mL -1 ), inoculated or not with X. gardneri. EPS reduced bacterial spot symptoms by up to 72.0% compared to the control. There were no direct effects of EPS on the in vitro growth of X. gardneri. The spectrophotometric profile, ascorbic and ellagic acid concentrations were change in tomato plants after EPS application, in plants challenged with the pathogen. Increases in PAL, GR and LOX activities were observed in plants treated with EPS. Thus, the application of L. plantarum exopolysaccharides can be considered as an effective alternative for controlling bacterial spot in tomato plants. This paper also discusses how these exopolysaccharides reduced the severity of the disease.

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Section: Characmentioning

confidence: 99%

Lactobacillus plantarum Exopolysaccharides Induce Resistance against Tomato Bacterial Spot

Blainski¹,

Neto²,

Luiz³

et al. 2017

JAS

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“…This process naturally produces secondary lighter nuclei, mixing thus with the primary composition. As was first predicted by Gerasimova and Rozental [9] in 1961, i.e. before the discovery of CMB, nuclei photo-disintegration on EBL results in a suppression of the UHECR energy spectrum (GR steepening).…”

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confidence: 69%

Towards Solving the Mass-Composition Problem in Ultra High Energy Cosmic Rays

Aloisio

Berezinsky

2019

J. Exp. Theor. Phys.

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Using the Auger mass-composition analysis of ultra high energy cosmic rays, based on the shape-fitting of Xmax distributions [1], we demonstrate that mass composition and energy spectra measured by Auger, Telescope Array and HiRes can be brought into good agreement. The shape-fitting analysis of Xmax distributions shows that the measured sum of proton and Helium fractions, for some hadronic-interaction models, can saturate the total flux. Such p+He model, with small admixture of other light nuclei, naturally follows from cosmology with recombination and reheating phases. The most radical assumption of the presented model is the assumed unreliability of the experimental separation of Helium and protons, which allows to consider He/p ratio as a free parameter. The results presented here show that the models with dominant p+He composition explain well the energy spectrum of the dip in the latest (2015 -2017) data of Auger and Telescope Array, but have some tension at the highest energies with the expected Greisen-Zatsepin-Kuzmin cutoff. The Auger-Prime upgrade experiment has a great potential to reject or confirm this model. ЖЭТФprocess on the Extragalactic Background Light (EBL) and on CMB. This process naturally produces secondary lighter nuclei, mixing thus with the primary composition. As was first predicted by Gerasimova and Rozental [9] in 1961, i.e. before the discovery of CMB, nuclei photo-disintegration on EBL results in a suppression of the UHECR energy spectrum (GR steepening). In fact, as was realised later, see e.g. [10], a more sharp cutoff occurs at higher energies where the nucleus photo-disintegration time on CMB becomes equal to that on EBL. This cutoff arises at Lorenz-factor Γ ∼ (3 − 5) × 10 9 for all nuclei. The energy of the cutoff E cut ∝ AΓ is different for primary nuclei with different A. This fact together with the unavoidable mixed composition, due to the production of secondary nuclei makes unclear any composition signature in the observed spectrum.At present the best method to measure the mass composition is given by the observation of fluorescent light produced by the e-m component of EAS in the atmosphere. All three aforementioned detectors use this method. However, for better accuracy the fluorescent-light method needs additional information, which in the case of HiRes is given by the stereo observation of fluorescent light, and in the case of Auger (and recently of TA) this additional information is obtained from the data of on-ground detectors (water-Cherenkov detectors in Auger and scintillation detectors in TA).The basic observable parameter related to mass composition is X max (E), the atmospheric depth where the number N (E) of particles in the cascade, with total energy E, reaches its maximum X max , is sensitive to the number of nucleons in the primary nucleus. Heavy nuclei interact higher in the atmosphere and have smaller fluctuations. In practice the actual quantity which allows to find the mass composition is the distribution N (X max ) of the showers with total energy E.I...

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“…PAL is the primary enzyme in the phenylpropanoid pathway, which leads to the conversion of L-phenylalanine to transcinnamic acid with the elimination of ammonia. It is the key enzyme in the synthesis of several defense-related secondary compounds such as phenols and lignin (Gerasimova et al, 2005). PPO is a nuclear encoded enzyme that catalyzes the oxygendependent oxidation of phenols to quinones.…”

Section: Discussionmentioning

confidence: 99%

Potentiality of Inducer Resistance Chemicals and Bioagents in Managing Lettuce Downy Mildew

Abada¹,

Attia²

2017

AJBIO

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Abstract:The tested inducer resistance chemicals (IRCs) bion (BTH), chitosan and salicylic acid as well as the bacterial bioagents Bacillus pumilus B. subtilis, B. thuringiensis and Pseudomonas fluorescens and the fungal bioagents Trichoderma album, T. harzianum and T. viride resulted in significant reduction to the germinated sporangia (conidia) of the fungus like Bremia lactucae Regel, the causal of lettuce downy mildew. This reduction was gradually increased by increasing the used concentration. The role of the tested IRCs and bioagents on management of the disease under greenhouse was evaluated. Under greenhouse conditions, spraying of lettuce plants artificially inoculted with the causal fungus like resulted in significant reduction to the severity of the disease compared with control treatment. Moreover, the IRC bion as well as P. fluorescens and T. harzianum were the most efficient treatments in this regard. Two field experiments were carried out during 2016/ 2017 growing season under natural infection by the disease to evaluate the efficacy of spraying of lettuce plants with any of the IRC bion and the bioagents P. fluorescens and T. harzianum on plants previously soaked or not in bion just before transplanting on the severity of the disease and weight of the grown plants. Data revealed that there was significant reduction to the severity of the disease with considerable increase to the average weight of each plant compared with control treatment due to sprying of these treatments. However, the fungicide Ridomil Gold MZ was the superior treatment in reducing the disease and increasing the weight of the foliage growth of lettuce plants. In addition, spraying of the IRC bion on plants soaked in bion just before transplanting ranked the second in this regarad followed by spraying of any of the two bioagents. Considerable increase in the activity of the oxidative reductive enzymes, i.e phenylalanine ammonia lyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO), due to spraying of lettuce plants with bion, the bioagents P. fluorescens and T. harzianum as well as the fungicide Ridomil Gold MZ compared with unsprayed plants (control).

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Role of L-phenylalanine ammonia Lyase in the induced resistance and susceptibility of sotato plants

Cited by 22 publications

References 11 publications

Lactobacillus plantarum Exopolysaccharides Induce Resistance against Tomato Bacterial Spot

Lactobacillus plantarum Exopolysaccharides Induce Resistance against Tomato Bacterial Spot

Towards Solving the Mass-Composition Problem in Ultra High Energy Cosmic Rays

Potentiality of Inducer Resistance Chemicals and Bioagents in Managing Lettuce Downy Mildew

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