Search results for "Acquired resistance"

Purification, crystallization and preliminary X-ray studies of sylvaticin, an elicitin-like protein from Pythium sylvaticum.

2003

Sylvaticin belongs to the elicitin family. These 10 kDa oomycetous proteins induce a hypersensitive response in plants, including necrosis and cell death, but subsequently leading to a non-specific systemic acquired resistance (SAR) against other pathogens. Sylvaticin has been crystallized using PEG 2000 MME as a precipitant agent in the presence of nickel chloride. The crystals belong to space group C2, with unit-cell parameters a = 99.29, b = 25.67, c = 67.45 A, beta = 99.66 degrees. Diffraction data were recorded to 2.1 A resolution at a synchrotron-radiation source.

Free Radicals Mediate Systemic Acquired Resistance

2014

Summary: Systemic acquired resistance (SAR) is a form of resistance that protects plants against a broad spectrum of secondary infections. However, exploiting SAR for the protection of agriculturally important plants warrants a thorough investigation of the mutual interrelationships among the various signals that mediate SAR. Here, we show that nitric oxide (NO) and reactive oxygen species (ROS) serve as inducers of SAR in a concentration-dependent manner. Thus, genetic mutations that either inhibit NO/ROS production or increase NO accumulation (e.g., a mutation in S-nitrosoglutathione reductase [GSNOR]) abrogate SAR. Different ROS function additively to generate the fatty-acid-derived azel…

NUTRITION AND CANCER

1969

The last decades have seen the identification of a number of drugs targeting oncogene pathways, therefore contributing to moving the cancer therapy field toward precision medicine. However, existing and acquired resistance to targeted therapies represent major obstacles against their long-term effectiveness. In fact, the initial efficacy of targeted therapies is often limited to a portion of the patient population and is frequently followed by the acquisition of drug-resistant disease.

Physiological and Molecular Characteristics of Elicitin-Induced Systemic Acquired Resistance in Tobacco

1996

Elicitins are low molecular weight proteins secreted by all Phytophthora species analyzed so far. Application of the purified proteins to tobacco Nicotiana tabacum leads to the induction of resistance to subsequent inoculations with the black shank-causing agent, Phytophthora parasitica var nicotianae. In this paper, we describe the systemic characteristics of elicitin-induced acquired resistance in tobacco. Elicitin application is followed by the rapid translocation of the protein in the plant. The basic elicitin, cryptogein, induces necrosis formation in the leaves, which results from accumulation of the protein in these organs. Necrosis does not seem to be essential for the establishment…

Proteinaceous and oligosaccharidic elicitors induce different calcium signatures in the nucleus of tobacco cells.

2005

We previously reported elevated cytosolic calcium levels in tobacco cells in response to elicitors [D. Lecourieux, C. Mazars, N. Pauly, R. Ranjeva, A. Pugin, Analysis and effects of cytosolic free calcium elevations in response to elicitors in Nicotiana plumbaginifolia cells, Plant Cell 14 (2002) 2627-2641]. These data suggested that in response to elicitors, Ca2+, as a second messenger, was involved in both systemic acquired resistance (RSA) and/or hypersensitive response (HR) depending on calcium signature. Here, we used transformed tobacco cells with apoaequorin expressed in the nucleus to monitor changes in free nuclear calcium concentrations ([Ca2+](nuc)) in response to elicitors. Two …

Immunization of trout (Salmo trutta) against freshwater pearl mussel (Margaritifera margaritifera) by duck mussel (Anodonta anatina) glochidia

2013

Freshwater pearl mussel Margaritifera margaritifera is endangered throughout its range of distribution in Europe. In some rivers M. margaritifera may co-occur with the duck mussel Anodonta anatina. Brown trout Salmo trutta serves as suitable fish host for both mussel species. Thus it is possible that exposure of brown trout to A. anatina glochidia might increase resistance of fish against M. margaritifera glochidia. The aim was to test this ‘cross immunity hypothesis’. Brown trout were immunized by duck mussel (Anodonta anatina) glochidia in late May. Then brown trout were challenged by pearl mussel (Margaritifera margaritifera) glochidia in late August after the A. anatina glochidia were d…

Acquired resistance triggered by elicitins in tobacco and other plants

1996

Elicitins are a family of proteins excreted byPhytophthora spp. They exhibit high sequence homology but large net charge differences. They induce necrosis in tobacco plants which then become resistant to the tobacco pathogenPhytophthora parasitica var.nicotianae. In stem-treated plants, resistance was not restricted to the site of elicitin application, but could be demonstrated by petiole inoculation at all levels on the stem. Resistance was already maximum after two days and lasted for at least two weeks. It was effective not only towardsP. p. var.nicotianae infection, but also against the unrelated pathogenSclerotinia sclerotiorum. In contrast to dichloroisonicotinic acid, an artificial i…

Prevalence of acquired resistance mutations in a large cohort of perinatally infected HIV-1 patients

2019

Recent Insights into the Development of Preclinical Trastuzumab- Resistant HER2+ Breast Cancer Models.

2018

Background: Overexpression and amplification of the human epidermal growth factor receptor 2 (HER2) occur in 20% of total breast carcinomas. HER2-overexpression is implicated in disease initiation and progression and associated with poor prognosis. Trastuzumab, a humanized monoclonal antibody, is the standard HER2-targeted therapy for early and metastatic HER2-amplified breast cancer patients. Trastuzumab has significantly increased clinical benefit in HER2+ metastatic and adjuvant settings; however, it is not effective for many patients due to primary or acquired resistance to the drug. During the last decade, many studies have revealed a number of novel molecular traits of HER2+ breast c…

The priming fingerprint on the plant transcriptome investigated through meta-analysis of RNA-Seq data

2020

Plants may enter into a state of alert that allows them to deploy defensive measures in a more effective way upon stress occurrence. This phenomenon is termed defense priming, and it is started in plants with a still enigmatic priming phase in which complex molecular and physiological changes occur. During the priming phase the plant transcriptome is deeply affected, but it remains largely unclear the extent of the transcriptional changes that contribute to prime the plant. In this study, we performed a meta-analysis of publicly available RNA-Seq data obtained during different priming conditions and in different plant species in order to investigate the existence of a transcriptional "primi…