Uwe Conrath | RWTH Aachen University (original) (raw)
Papers by Uwe Conrath
Plant Biotechnology Journal, 2015
Fungal pathogens pose a major challenge to global crop production. Crop varieties that resist dis... more Fungal pathogens pose a major challenge to global crop production. Crop varieties that resist disease present the best defence and offer an alternative to chemical fungicides. Exploiting durable nonhost resistance (NHR) for crop protection often requires identification and transfer of NHR-linked genes to the target crop. Here, we identify genes associated with NHR of Arabidopsis thaliana to Phakopsora pachyrhizi, the causative agent of the devastating fungal disease called Asian soybean rust. We transfer selected Arabidopsis NHR-linked genes to the soybean host and discover enhanced resistance to rust disease in some transgenic soybean lines in the greenhouse. Interspecies NHR gene transfer thus presents a promising strategy for genetically engineered control of crop diseases.
Annual review of phytopathology, Jan 11, 2015
When plants recognize potential opponents, invading pathogens, wound signals, or abiotic stress, ... more When plants recognize potential opponents, invading pathogens, wound signals, or abiotic stress, they often switch to a primed state of enhanced defense. However, defense priming can also be induced by some natural or synthetic chemicals. In the primed state, plants respond to biotic and abiotic stress with faster and stronger activation of defense, and this is often linked to immunity and abiotic stress tolerance. This review covers recent advances in disclosing molecular mechanisms of priming. These include elevated levels of pattern-recognition receptors and dormant signaling enzymes, transcription factor HsfB1 activity, and alterations in chromatin state. They also comprise the identification of aspartyl-tRNA synthetase as a receptor of the priming activator β-aminobutyric acid. The article also illustrates the inheritance of priming, exemplifies the role of recently identified priming activators azelaic and pipecolic acid, elaborates on the similarity to defense priming in mamm...
Methods in molecular biology (Clifton, N.J.), 2014
In eukaryotic cells many diverse cellular functions are regulated by reversible protein phosphory... more In eukaryotic cells many diverse cellular functions are regulated by reversible protein phosphorylation. In recent years, phosphoproteomics has become a powerful tool to study protein phosphorylation because it allows unbiased localization, and site-specific quantification, of in vivo phosphorylation of hundreds of proteins in a single experiment. A common strategy to identify phosphoproteins and their phosphorylation sites from complex biological samples is the enrichment of phosphopeptides from digested cellular lysates followed by mass spectrometry. However, despite the high sensitivity of modern mass spectrometers the large dynamic range of protein abundance and the transient nature of protein phosphorylation remained major pitfalls in MS-based phosphoproteomics. Tandem metal-oxide affinity chromatography (MOAC) represents a robust and highly selective approach for the identification and site-specific quantification of low abundant phosphoproteins that is based on the successive...
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Induced disease resistance of plants is often associated with an enhanced capacity to activate ce... more Induced disease resistance of plants is often associated with an enhanced capacity to activate cellular defense responses to pathogen attack, named the ''primed'' state of the plant. Exopolysaccharides of Pantoea agglomerans have recently been reported as the first priming active component of bacterial origin in wheat cells. We now show that Pantoea exopolysaccharides also prime rice cells for better elicitation of a rapid oxidative burst. In contrast, in tobacco and parsley cell cultures Pantoea exopolysaccharides activate the oxidative burst response directly. Our results point to a different recognition and/or mode of action of Pantoea exopolysaccharides in monocot and dicot plants.
Transgenic tobacco plants expressing an inhibitor of ubiquitin-dependent protein degradation, ubi... more Transgenic tobacco plants expressing an inhibitor of ubiquitin-dependent protein degradation, ubiquitin variant ubR48, spontaneously formed necrotic lesions and displayed altered responsiveness to tobacco mosaic virus attack. These plants were analyzed for the accumulation of defense-related compounds and the expression of pathogenesis-related proteins, which serve as convenient markers for systemic acquired resistance. Callose was detected in the cells of vascular bundles and in the leaf blade. In addition, ubR48 transgenic plants constitutively accumulated enhanced levels of salicylic acid (SA) and/or its glucoside. Accumulation of SA glucoside coincided with high levels of pathogenesis-related protein 1, underscoring the similarity of certain changes in ubR48-expressing plants to an authentic defense reaction.
Journal of Visualized Experiments, 2011
Chromatin structure is important for the regulation of gene expression in eukaryotes. In this pro... more Chromatin structure is important for the regulation of gene expression in eukaryotes. In this process, chromatin remodeling, DNA methylation, and covalent modifications on the amino-terminal tails of histones H3 and H4 play essential roles 1-2 . H3 and H4 histone modifications include methylation of lysine and arginine, acetylation of lysine, and phosphorylation of serine residues 1-2 . These modifications are associated either with gene activation, repression, or a primed state of gene that supports more rapid and robust activation of expression after perception of appropriate signals (microbe-associated molecular patterns, light, hormones, etc.) 3-7 .
Current Plant Science and Biotechnology in Agriculture, 1994
A major objective of our research is to understand how plants perceive and then respond to pathog... more A major objective of our research is to understand how plants perceive and then respond to pathogenic attack at the molecular and cellular levels. As a model system for our studies we have chosen the interaction of tobacco mosaic virus (TMV; one of the best characterized RNA viruses) with its host Nicotiana tabacum. Infection of tobacco plants with TMV results
Proceedings of The National Academy of Sciences, 1995
2,6-Dichloroisonicotinic acid (INA) and salicylic acid (SA) are potent inducers of plant defense ... more 2,6-Dichloroisonicotinic acid (INA) and salicylic acid (SA) are potent inducers of plant defense responses including the synthesis of pathogenesis-related (PR) proteins and the development of enhanced disease resistance. A soluble SA-binding protein has been purified from tobacco with an affinity and specificity of binding that suggest it is a SA receptor. Recently, this protein has been shown to be a
Proceedings of The National Academy of Sciences, 1995
Studies in our laboratory as well as others strongly suggest that salicylic acid (SA) plays an im... more Studies in our laboratory as well as others strongly suggest that salicylic acid (SA) plays an important signaling role in plant defense against pathogens. We have found that increases in endogenous SA levels correlates with both resistance of tobacco to infection with tobacco mosaic virus and induction of defense-related genes such as that encoding pathogenesis-related protein 1 (PR-1). Some of
Molecular plant-microbe interactions : MPMI, 2010
When grown under short-day conditions at low light, leaves of an Arabidopsis thaliana (accession ... more When grown under short-day conditions at low light, leaves of an Arabidopsis thaliana (accession Col-0) mutant with defects in the two genes encoding plastid ATP/ADP antiporters (so-called ntt1-2 null mutants) display a variety of physiological changes. These include the formation of necrotic lesions and the accumulation of hydrogen peroxide in the leaves. Here, we show that, under short-day conditions, leaves of the ntt1-2 mutant display enhanced resistance to Hyaloperonospora arabidopsidis, Botrytis cinerea, and Pseudomonas syringae pv. tomato DC3000. Resistance to these pathogens was associated with constitutively elevated levels of the plant hormone salicylic acid and, eventually, jasmonic acid, and constitutive or primed activation after pathogen attack of various defense genes that are dependent on these hormones. In addition, the antagonistic crosstalk between the salicylic acid and jasmonic acid signaling pathways seems to be affected in ntt1-2. Because the enhanced resistan...
Trends in Plant Science, 2002
Trends in Plant Science, 2006
4 Vaquerizas, J.M. et al. (2005) GEPAS, an experiment-oriented pipeline for the analysis of micro... more 4 Vaquerizas, J.M. et al. (2005) GEPAS, an experiment-oriented pipeline for the analysis of microarray gene expression data. Nucleic Acids Res. 33, W616-W620 5 Ramonell, K. et al. (2005) Loss-of-function mutations in chitin responsive genes show increased susceptibility to the powdery mildew pathogen Erysiphe cichoracearum. Plant Physiol. 138, 1027-1036 6 Gachon, C.M. et al. (2005) Transcriptional co-regulation of secondary metabolism enzymes in Arabidopsis: functional and evolutionary implications. Plant Mol. Biol. 58, 229-245 7 Brown, D.M. et al. (2005) Identification of novel genes in Arabidopsis involved in secondary cell wall formation using expression profiling and reverse genetics. Plant Cell 17, 2281-2295 8 Persson, S. et al. (2005) Identification of genes required for cellulose synthesis by regression analysis of public microarray data sets.
THE PLANT CELL ONLINE, 2009
In plants and animals, induced resistance (IR) to biotic and abiotic stress is associated with pr... more In plants and animals, induced resistance (IR) to biotic and abiotic stress is associated with priming of cells for faster and stronger activation of defense responses. It has been hypothesized that cell priming involves accumulation of latent signaling components that are not used until challenge exposure to stress. However, the identity of such signaling components has remained elusive. Here, we show that during development of chemically induced resistance in Arabidopsis thaliana, priming is associated with accumulation of mRNA and inactive proteins of mitogen-activated protein kinases (MPKs), MPK3 and MPK6. Upon challenge exposure to biotic or abiotic stress, these two enzymes were more strongly activated in primed plants than in nonprimed plants. This elevated activation was linked to enhanced defense gene expression and development of IR. Strong elicitation of stress-induced MPK3 and MPK6 activity is also seen in the constitutive priming mutant edr1, while activity was attenuated in the priming-deficient npr1 mutant. Moreover, priming of defense gene expression and IR were lost or reduced in mpk3 or mpk6 mutants. Our findings argue that prestress deposition of the signaling components MPK3 and MPK6 is a critical step in priming plants for full induction of defense responses during IR.
Plant Biotechnology Journal, 2015
Fungal pathogens pose a major challenge to global crop production. Crop varieties that resist dis... more Fungal pathogens pose a major challenge to global crop production. Crop varieties that resist disease present the best defence and offer an alternative to chemical fungicides. Exploiting durable nonhost resistance (NHR) for crop protection often requires identification and transfer of NHR-linked genes to the target crop. Here, we identify genes associated with NHR of Arabidopsis thaliana to Phakopsora pachyrhizi, the causative agent of the devastating fungal disease called Asian soybean rust. We transfer selected Arabidopsis NHR-linked genes to the soybean host and discover enhanced resistance to rust disease in some transgenic soybean lines in the greenhouse. Interspecies NHR gene transfer thus presents a promising strategy for genetically engineered control of crop diseases.
Annual review of phytopathology, Jan 11, 2015
When plants recognize potential opponents, invading pathogens, wound signals, or abiotic stress, ... more When plants recognize potential opponents, invading pathogens, wound signals, or abiotic stress, they often switch to a primed state of enhanced defense. However, defense priming can also be induced by some natural or synthetic chemicals. In the primed state, plants respond to biotic and abiotic stress with faster and stronger activation of defense, and this is often linked to immunity and abiotic stress tolerance. This review covers recent advances in disclosing molecular mechanisms of priming. These include elevated levels of pattern-recognition receptors and dormant signaling enzymes, transcription factor HsfB1 activity, and alterations in chromatin state. They also comprise the identification of aspartyl-tRNA synthetase as a receptor of the priming activator β-aminobutyric acid. The article also illustrates the inheritance of priming, exemplifies the role of recently identified priming activators azelaic and pipecolic acid, elaborates on the similarity to defense priming in mamm...
Methods in molecular biology (Clifton, N.J.), 2014
In eukaryotic cells many diverse cellular functions are regulated by reversible protein phosphory... more In eukaryotic cells many diverse cellular functions are regulated by reversible protein phosphorylation. In recent years, phosphoproteomics has become a powerful tool to study protein phosphorylation because it allows unbiased localization, and site-specific quantification, of in vivo phosphorylation of hundreds of proteins in a single experiment. A common strategy to identify phosphoproteins and their phosphorylation sites from complex biological samples is the enrichment of phosphopeptides from digested cellular lysates followed by mass spectrometry. However, despite the high sensitivity of modern mass spectrometers the large dynamic range of protein abundance and the transient nature of protein phosphorylation remained major pitfalls in MS-based phosphoproteomics. Tandem metal-oxide affinity chromatography (MOAC) represents a robust and highly selective approach for the identification and site-specific quantification of low abundant phosphoproteins that is based on the successive...
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Induced disease resistance of plants is often associated with an enhanced capacity to activate ce... more Induced disease resistance of plants is often associated with an enhanced capacity to activate cellular defense responses to pathogen attack, named the ''primed'' state of the plant. Exopolysaccharides of Pantoea agglomerans have recently been reported as the first priming active component of bacterial origin in wheat cells. We now show that Pantoea exopolysaccharides also prime rice cells for better elicitation of a rapid oxidative burst. In contrast, in tobacco and parsley cell cultures Pantoea exopolysaccharides activate the oxidative burst response directly. Our results point to a different recognition and/or mode of action of Pantoea exopolysaccharides in monocot and dicot plants.
Transgenic tobacco plants expressing an inhibitor of ubiquitin-dependent protein degradation, ubi... more Transgenic tobacco plants expressing an inhibitor of ubiquitin-dependent protein degradation, ubiquitin variant ubR48, spontaneously formed necrotic lesions and displayed altered responsiveness to tobacco mosaic virus attack. These plants were analyzed for the accumulation of defense-related compounds and the expression of pathogenesis-related proteins, which serve as convenient markers for systemic acquired resistance. Callose was detected in the cells of vascular bundles and in the leaf blade. In addition, ubR48 transgenic plants constitutively accumulated enhanced levels of salicylic acid (SA) and/or its glucoside. Accumulation of SA glucoside coincided with high levels of pathogenesis-related protein 1, underscoring the similarity of certain changes in ubR48-expressing plants to an authentic defense reaction.
Journal of Visualized Experiments, 2011
Chromatin structure is important for the regulation of gene expression in eukaryotes. In this pro... more Chromatin structure is important for the regulation of gene expression in eukaryotes. In this process, chromatin remodeling, DNA methylation, and covalent modifications on the amino-terminal tails of histones H3 and H4 play essential roles 1-2 . H3 and H4 histone modifications include methylation of lysine and arginine, acetylation of lysine, and phosphorylation of serine residues 1-2 . These modifications are associated either with gene activation, repression, or a primed state of gene that supports more rapid and robust activation of expression after perception of appropriate signals (microbe-associated molecular patterns, light, hormones, etc.) 3-7 .
Current Plant Science and Biotechnology in Agriculture, 1994
A major objective of our research is to understand how plants perceive and then respond to pathog... more A major objective of our research is to understand how plants perceive and then respond to pathogenic attack at the molecular and cellular levels. As a model system for our studies we have chosen the interaction of tobacco mosaic virus (TMV; one of the best characterized RNA viruses) with its host Nicotiana tabacum. Infection of tobacco plants with TMV results
Proceedings of The National Academy of Sciences, 1995
2,6-Dichloroisonicotinic acid (INA) and salicylic acid (SA) are potent inducers of plant defense ... more 2,6-Dichloroisonicotinic acid (INA) and salicylic acid (SA) are potent inducers of plant defense responses including the synthesis of pathogenesis-related (PR) proteins and the development of enhanced disease resistance. A soluble SA-binding protein has been purified from tobacco with an affinity and specificity of binding that suggest it is a SA receptor. Recently, this protein has been shown to be a
Proceedings of The National Academy of Sciences, 1995
Studies in our laboratory as well as others strongly suggest that salicylic acid (SA) plays an im... more Studies in our laboratory as well as others strongly suggest that salicylic acid (SA) plays an important signaling role in plant defense against pathogens. We have found that increases in endogenous SA levels correlates with both resistance of tobacco to infection with tobacco mosaic virus and induction of defense-related genes such as that encoding pathogenesis-related protein 1 (PR-1). Some of
Molecular plant-microbe interactions : MPMI, 2010
When grown under short-day conditions at low light, leaves of an Arabidopsis thaliana (accession ... more When grown under short-day conditions at low light, leaves of an Arabidopsis thaliana (accession Col-0) mutant with defects in the two genes encoding plastid ATP/ADP antiporters (so-called ntt1-2 null mutants) display a variety of physiological changes. These include the formation of necrotic lesions and the accumulation of hydrogen peroxide in the leaves. Here, we show that, under short-day conditions, leaves of the ntt1-2 mutant display enhanced resistance to Hyaloperonospora arabidopsidis, Botrytis cinerea, and Pseudomonas syringae pv. tomato DC3000. Resistance to these pathogens was associated with constitutively elevated levels of the plant hormone salicylic acid and, eventually, jasmonic acid, and constitutive or primed activation after pathogen attack of various defense genes that are dependent on these hormones. In addition, the antagonistic crosstalk between the salicylic acid and jasmonic acid signaling pathways seems to be affected in ntt1-2. Because the enhanced resistan...
Trends in Plant Science, 2002
Trends in Plant Science, 2006
4 Vaquerizas, J.M. et al. (2005) GEPAS, an experiment-oriented pipeline for the analysis of micro... more 4 Vaquerizas, J.M. et al. (2005) GEPAS, an experiment-oriented pipeline for the analysis of microarray gene expression data. Nucleic Acids Res. 33, W616-W620 5 Ramonell, K. et al. (2005) Loss-of-function mutations in chitin responsive genes show increased susceptibility to the powdery mildew pathogen Erysiphe cichoracearum. Plant Physiol. 138, 1027-1036 6 Gachon, C.M. et al. (2005) Transcriptional co-regulation of secondary metabolism enzymes in Arabidopsis: functional and evolutionary implications. Plant Mol. Biol. 58, 229-245 7 Brown, D.M. et al. (2005) Identification of novel genes in Arabidopsis involved in secondary cell wall formation using expression profiling and reverse genetics. Plant Cell 17, 2281-2295 8 Persson, S. et al. (2005) Identification of genes required for cellulose synthesis by regression analysis of public microarray data sets.
THE PLANT CELL ONLINE, 2009
In plants and animals, induced resistance (IR) to biotic and abiotic stress is associated with pr... more In plants and animals, induced resistance (IR) to biotic and abiotic stress is associated with priming of cells for faster and stronger activation of defense responses. It has been hypothesized that cell priming involves accumulation of latent signaling components that are not used until challenge exposure to stress. However, the identity of such signaling components has remained elusive. Here, we show that during development of chemically induced resistance in Arabidopsis thaliana, priming is associated with accumulation of mRNA and inactive proteins of mitogen-activated protein kinases (MPKs), MPK3 and MPK6. Upon challenge exposure to biotic or abiotic stress, these two enzymes were more strongly activated in primed plants than in nonprimed plants. This elevated activation was linked to enhanced defense gene expression and development of IR. Strong elicitation of stress-induced MPK3 and MPK6 activity is also seen in the constitutive priming mutant edr1, while activity was attenuated in the priming-deficient npr1 mutant. Moreover, priming of defense gene expression and IR were lost or reduced in mpk3 or mpk6 mutants. Our findings argue that prestress deposition of the signaling components MPK3 and MPK6 is a critical step in priming plants for full induction of defense responses during IR.