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The most important viral pathogens of the cultivated potato are Potato virus X (PVX) and Potato virus Y (PVY), which can reduce potato production up to 80%. Thus resistance breeding is one of the major goals of plant breeders. Wild potato species are good sources of resistance (R) genes. The resistant plants respond to viral infection with hypersensitive reaction (HR) or extreme resistance (ER). HR is accompanied by programmed cell death, while ER localizes the virus at the primary infection site and limits virus replication without visible symptoms. While HR is generally strain-specific, ER can act against a broad spectrum of viral pathogens. This review aims to describe the molecular mechanisms of resistance against PVX and PVY in potato.

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The recent review summarizes the major achievements in discovery of role of phytoglobins in mediation of nitric oxide generated cellular functions in higher plants. Genes encoding non-symbiotic hemoglobins have been cloned from several plant species. The expression pattern of these genes show tissue-specificity that is also under the control of stress factors like hypoxia. The nitric oxide has pivotal role in signalling pathway specifically in hypersensitive reactions and programmed cell death. Production of transgenic tobacco plants overexpressing the alfalfa hemoglobin showed altered necrotic symptoms after treatment with nitric oxide generating compounds or infection by necrotic pathogens. The present review helps to outline the similar relation between hemoglobin and nitric oxide in plants as it was found in animal cells.

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Plant resistance breeding has, so far, been based on specific resistance genes which regulate hypersensitive reaction, resulting in fast tissue destruction. Hungarian researchers have, however, discovered the existence of the general defense system ( gds ), which regulates a completely different plant defense reaction. This manifests itself in tissue thickening through cell enlargement. We have studied the biochemical background of these different plant defense processes by OPLC, a forced-flow version of planar chromatography. We also exploited some basic well-known advantages of planar chromatography which made its application suitable and favorable in our experiments. As a result of analysis of time-dependent changes in carbohydrate compounds, we confirmed pathological and symptomatological observations that plants have both general and specific defense systems. These two systems have different roles and strategies in excluding pathogens, but together constitute the complete disease resistance of plants.

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Cereal Research Communications
Authors:
Erika Szabó
,
Éva Klement
,
Katalin Medzihradszky
,
Gabriella Varga
,
Eszter Besenyei
, and
Péter Ott

Rudolph, K., 1999, Symptomless resistant response instead of the hypersensitive reaction in tobacco after infiltration of heterologous pathovars of Pseudomonas syringae . J. Phytopathol. 12:479–489 Rudolph K

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Elm trees (Ulmus spp.) are one of the most widespread landscape plants, widely used as ornamental trees to embellish parks and streets of different countries including Iran. Elm trees cultivation is seriously limited by biotic factors such as bacterial pathogens. Recently, bacterial wetwood has been identified as a common disease on elm trees in Northwest Iran. In present study, in order to identify bacterial pathogens associated with elm trees, wetwood infected samples were collected from elm trees showing wetwood symptom across Tabriz city and immediately transferred to the lab. After isolation and purification of isolates, hypersensitive reaction (HR), pathogenicity, biochemical and molecular tests were used to characterize the isolates. In total of 92 isolates obtained, 32 and 10 isolates were able to induce HR and wetwood symptoms on tobacco leaves and young branches of elm, respectively. Based on biochemical and molecular tests, the identity of the isolates studied were determined as Brevundimonas bullata, Paracoccus alcaliphilus, P. marcusii and Luteimonas aestuarii. To the best of our knowledge, this study shows that these four bacterial species here reported are responsible for the causal agent-complex of wetwood disease on elm trees for the first time in the world.

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Cereal Research Communications
Authors:
László Zsiros
,
Ágnes Szatmári
,
László Palkovics
,
Zoltán Klement
, and
Zoltán Bozsó

— Rudolph K.: 1999. Symptomless resistant response instead of the hypersensitive reaction in tobacco leaves after infiltration of heterologous pathovars of Pseudomonas syringae . Journal of Phytophathology 147: 467

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Naisbitt, D. J.: Drug hypersensitivity reactions in skin: understanding mechnisms and the development of diagnostic and predicive tests. Toxicology, 2004, 194 , 181–196. Naisbitt D. J

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, Quazi F, et al. Clinical features of oxaliplatin induced hypersensitivity reactions and therapeutic approaches. Asian Pac J Cancer Prev. 2016; 17: 1637–1641. 4 Lenz HJ

Open access
Orvosi Hetilap
Authors:
Gabriella Nagy
,
Katalin Lukács
,
Ágnes Sziray
,
Katalin Fazekas
,
Ágnes Florián
,
László Tamási
, and
Zsuzsánna Károlyi

Az elmúlt másfél évtizedben a biológiai válaszmódosító szerek, különösképpen a TNF-α-gátlók jelentős áttörést hoztak számos immunmediált reumatológiai, gasztroenterológiai és bőrgyógyászati betegség kezelésében. Egyre szélesebb körű alkalmazásuk során mellékhatásaikat is mind jobban megismerjük. Cél: Jelen munkánk célja az volt, hogy biológiai terápiában részesülő reumatológiai és bőrgyógyászati betegeink kezelése során, 3 éves nyomon követési periódus tapasztalatait összefoglalva elemezzük az előforduló mellékhatásokat, különös tekintettel a bőrgyógyászati szövődményekre. Módszer: A vizsgált 3 éves időszak alatt 324 beteget kezeltünk biológiai válaszmódosítókkal (adalimumab: 92, etanercept: 107, infliximab: 125 beteg). A kezelés alapjául szolgáló diagnózis rheumatoid arthritis volt 174 esetben, spondylarthritis ankylopoetica 60 betegnél, míg arthritis psoriatica 11 és psoriasis vulgaris 79 esetben. Eredmények: Hiperszenzitivitást 11 betegnél tapasztaltunk (3,4%), közülük 5 volt súlyos, a kezelés elhagyását igénylő eset. A mellékhatások legnagyobb részét az infekciók tették ki, közülük 10 (3,1%) érintette a bőrt, míg 9 (2,8%) a légzőtraktusra lokalizálódott. A fertőzések többsége enyhe vagy középsúlyos lefolyású volt. Malignus bőrtumor kialakulását csupán 1 esetben (0,3%) észleltük. Ritka mellékhatásként néhány betegnél gyógyszer indukálta gyulladásos reakciót figyeltünk meg: egy betegnél psoriasis jelentkezett a kezelés alatt, háromnál a már meglévő pikkelysömör jelent meg új, palmoplantaris lokalizációban. Egy esetben lichenoid exanthema kialakulását észleltük (n = 5; 1,5%). Megállapítások: A TNF-α-blokkolók alkalmazása során relatíve gyakoriak a bőrgyógyászati jellegű mellékhatások. Tapasztalataink alapján a túlérzékenységi reakciók mellett ezek döntő többsége bőrinfekció vagy gyulladásos dermatosis, mint például gyógyszer indukálta psoriasis. Jelen anyagunkban csak elenyészően kis számban tapasztaltuk malignus bőrtumor keletkezését. Orv. Hetil., 2011, 152, 212–220.

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changes in peroxidase activity accompany hydrogen peroxide generation during the development of a nonhost hypersensitive reaction in lettuce . Plant Physiol . 118 : 1067 – 1078

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