9 results on '"Roitsch, Thomas"'
Search Results
2. PHYSIOLOGICAL CHANGES AS EARLY RESPONSE IN INFECTED WINTER WHEAT (TRITICUM AESTIVUM L.) SEEDLINGS WITH LEAF RUST
- Author
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Španić, Valentina, Vuković, Ana, Cseplo, Monika, Vuković, Rosemary, Puskas, Katalin, Roitsch, Thomas, Mihály-Langó, Bernadett, Bona, Lajos, Tóth, Beáta, and Börner, Andreas
- Subjects
leaf rust ,physiology ,wheat seedlings - Abstract
Leaf rust, also known as brown rust, is caused by the fungus Puccinia triticina Eriks., that can result in a significant threat to the grain yield and quality of wheat. Elevated disease severity, known as increased biotic stress pressure, correlates with increased accumulation of reactive oxygen species (ROS), where plants activate defence mechanisms against oxidative damage to regulate toxic levels of ROS. To improve our understanding of the physiological mechanism of wheat resistance to leaf rust, we set up the experiment with wheat seedlings of six genotypes differing in leaf rust resistance to elucidate interactions of this pathogen with carbohydrate and antioxidant metabolism of wheat genotypes. Obtained results showed that genotype with the highest severity of leaf rust symptoms decreased cytoplasmic invertase (cytInv) very early, 8 hours after inoculation (hai) with leaf rust. The downregulation of cytInv in susceptible plants may facilitate the maintenance of elevated apoplastic sucrose availability serving as nutrients for pathogen growth thus allowing spreading of symptoms more rapidly. The significant role in wheat seedling resistance to leaf rust can be attributed to vacuolar invertase (vacInv) that was supported by the fact that moderately resistant genotypes to leaf rust significantly increased vacInv when symptoms were fully developed. Also, vacInv were previously reported to assist in pathogen defence and scavenging of ROS. Simultaneously, glucose-6-phosphate dehydrogenase (G6PDH) and UDP-glucose pyrophosphorylase (UGPase) in moderately resistant genotypes decreased and further might restrict normal growth and development of pathogen due to reduced sugar content. The main contributors of leaf rust resistance in antioxidative metabolism were ascorbate peroxidase (APX) and catalase (CAT) activity resulting in less oxidative damage in the early stage of leaf rust development and thus maintaining a higher antioxidant capacity resulting in lower oxidative damage. Thereby, carbohydrate and antioxidant mechanisms acted mutually in defence of wheat seedlings during leaf rust stress. In addition to well-known antioxidative defence systems, carbohydrate metabolism can now be recognized as a crucial mechanism in coordinating plant developmental responses under leaf rust occurrence in wheat.
- Published
- 2023
3. Plant phenomics and the need for physiological phenotyping across scales to narrow the genotype-to-phenotype knowledge gap
- Author
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Großkinsky, Dominik K., Svensgaard, Jesper, Christensen, Svend, and Roitsch, Thomas
- Published
- 2015
4. Elevated CO2 modulates the effect of heat stress responses in Triticum aestivum by differential expression of an isoflavone reductase-like gene.
- Author
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Shokat, Sajid, Novák, Ondřej, Široká, Jitka, Singh, Sukhwinder, Gill, Kulvinder Singh, Roitsch, Thomas, Großkinsky, Dominik K, and Liu, Fulai
- Subjects
WHEAT ,PHYSIOLOGY ,SUPEROXIDE dismutase ,CARBON dioxide ,GENETIC markers ,PHYSIOLOGICAL effects of heat ,WHEAT breeding - Abstract
Two wheat genotypes forming high and low biomass, exhibiting differential expression of an isoflavone reductase -like (IRL) gene, and resulting in contrasting grain yield under heat stress field conditions were analyzed in detail for their responses under controlled heat and elevated CO
2 conditions. Significant differences in IRL expression between the two lines were hypothesized to be the basis of their differential performance under the tested conditions and their stress tolerance potential. By a holistic approach integrating advanced cell physiological phenotyping of the antioxidative and phytohormone system in spikes and leaves with measurements of ecophysiological and agronomic traits, the genetic differences of the genotypes in IRL expression were assessed. In response to heat and elevated CO2 , the two genotypes showed opposite regulation of IRL expression, which was associated with cytokinin concentration, total flavonoid contents, activity of superoxide dismutase, antioxidant capacity and photosynthetic rate in leaves, and cytokinin concentration and ascorbate peroxidase activity in spikes. Our study showed that IRL expression is associated with wheat yield performance under heat stress at anthesis, mediated by diverse physiological mechanisms. Hence, based on our results, the IRL gene is a promising candidate for developing genetic markers for breeding heat-tolerant wheat. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
5. Plant phenomics and the need for physiological phenotyping across scales to narrow the genotype-to-phenotype knowledge gap.
- Author
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Groβkinsky, Dominik K., Svensgaard, Jesper, Christensen, Svend, and Roitsch, Thomas
- Subjects
PLANT genetics ,PHENOTYPES ,GENOTYPE-environment interaction ,FUNCTIONAL genomics ,PLANT breeding ,GENETICS - Abstract
Plants are affected by complex genome×environment×management interactions which determine phenotypic plasticity as a result of the variability of genetic components. Whereas great advances have been made in the cost-efficient and high-throughput analyses of genetic information and non-invasive phenotyping, the large-scale analyses of the underlying physiological mechanisms lag behind. The external phenotype is determined by the sum of the complex interactions of metabolic pathways and intracellular regulatory networks that is reflected in an internal, physiological, and biochemical phenotype. These various scales of dynamic physiological responses need to be considered, and genotyping and external phenotyping should be linked to the physiology at the cellular and tissue level. A highdimensional physiological phenotyping across scales is needed that integrates the precise characterization of the internal phenotype into high-throughput phenotyping of whole plants and canopies. By this means, complex traits can be broken down into individual components of physiological traits. Since the higher resolution of physiological phenotyping by 'wet chemistry' is inherently limited in throughput, high-throughput non-invasive phenotyping needs to be validated and verified across scales to be used as proxy for the underlying processes. Armed with this interdisciplinary and multidimensional phenomics approach, plant physiology, non-invasive phenotyping, and functional genomics will complement each other, ultimately enabling the in silico assessment of responses under defined environments with advanced crop models. This will allow generation of robust physiological predictors also for complex traits to bridge the knowledge gap between genotype and phenotype for applications in breeding, precision farming, and basic research. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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- View/download PDF
6. Differences between winter oilseed rape (Brassica napus L.) cultivars in nitrogen starvation-induced leaf senescence are governed by leaf-inherent rather than root-derived signals.
- Author
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Koeslin-Findeklee, Fabian, Becker, Martin A., van der Graaff, Eric, Roitsch, Thomas, and Horst, Walter J.
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RUTABAGA ,BRASSICA varieties ,LEAF aging ,BRASSICA yields ,BRASSICA ,PHYSIOLOGY ,REPRODUCTION - Abstract
Nitrogen (N) efficiency of winter oilseed rape (Brassica napus L.) line-cultivars (cvs.), defined as high grain yield under N limitation, has been primarily attributed to maintained N uptake during reproductive growth (N uptake efficiency) in combination with delayed senescence of the older leaves accompanied with maintained photosynthetic capacity (functional stay-green). However, it is not clear whether genotypic variation in N starvation-induced leaf senescence is due to leaf-inherent factors and/or governed by root-mediated signals. Therefore, the N-efficient and stay-green cvs. NPZ-1 and Apex were reciprocally grafted with the N-inefficient and early-senescing cvs. NPZ-2 and Capitol, respectively and grown in hydroponics. The senescence status of older leaves after 12 days of N starvation assessed by SPAD, photosynthesis and the expression of the senescence-specific cysteine protease gene SAG12-1 revealed that the stay-green phenotype of the cvs. NPZ-1 and Apex under N starvation was primarily under the control of leaf-inherent factors. The same four cultivars were submitted to N starvation for up to 12 days in a time-course experiment. The specific leaf contents of biologically active and inactive cytokinins (CKs) and the expression of genes involved in CKS homeostasis revealed that under N starvation leaves of early-senescing cultivars were characterized by inactivation of biologically active CKs, whereas in stay-green cultivars synthesis, activation, binding of and response to biologically active CKs were favoured. These results suggest that the homeostasis of biologically active CKs was the predominant leaf-inherent factor for cultivar differences in N starvation-induced leaf senescence and thus N efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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7. A Rapid Phytohormone and Phytoalexin Screening Method for Physiological Phenotyping.
- Author
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Großkinsky, Dominik K., Albacete, Alfonso, Jammer, Alexandra, Krbez, Peter, van der Graaff, Eric, Pfeifhofer, Hartwig, and Roitsch, Thomas
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PLANT hormones ,PHYTOALEXINS ,PHENOTYPES ,PLANT species ,ABSCISIC acid ,ARABIDOPSIS thaliana ,PLANT physiology research ,PLANT protection research ,PHYSIOLOGY - Abstract
A letter is presented that proposes a rapid screening method for the parallel determination of various phytohormones such as abscisic acid (ABA) and indole-3-acetic acid (IAA), and phytoalexins like camalexin and scopoleptin in various plant species, notably "Arabidopsis thaliana" and "Nicotiana tabacum." It claims that this method can increase the process of physiological phenotyping in plants, thus helping researchers to develop effective strategies for the protection of agricultural crops.
- Published
- 2014
8. Tomato mitogen activated protein kinases regulate the expression of extracellular invertase Lin6in response to stress related stimuli.
- Author
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Hyun, Tae Kyung, Hoffmann, Anja, Sinha, Alok K., and Roitsch, Thomas
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MITOGEN-activated protein kinases ,TOMATOES ,GENETIC regulation in plants ,PLANT enzymes ,PLANT cellular signal transduction ,EFFECT of stress on crops ,REGULATION of plant metabolism ,PHYSIOLOGY - Abstract
Activation of mitogen-activated protein kinases (MAPKs) is a common reaction of plant cells in defence-related signal transduction pathways. Since the downstream events after the activation of MAPKs are largely unknown in plants, the role of MAPKs in the coordinate regulation of defence reactions and primary carbon metabolism by stress related stimuli has been analysed in tomato (Lycopersicon peruvianumMill.). Thus, the relationship between MAPK, LpMPK2 and LpMPK3 and extracellular invertase Lin6, as the key enzyme of an apoplasmic phloem unloading pathway, has been analysed. It was observed that the mRNAs of LpMPK3and Lin6are sequentially induced by the same set of stress related stimuli, wounding, a fungal elicitor derived from Fusarium oxysporum lycopersici, the endogenous plant derived elicitor PGA and salt stress, while LpMPK2transcripts are constitutively expressed. In a gain of function approach, a His-tagged version of LpMPK2and a HA-tagged version of LpMPK3were transiently and functionally expressed in leaves of transgenic tobacco (Nicotiana tabacumL.) plants expressing the β-glucuronidase reporter gene under control of the Lin6promoter via agro-infection. The induction of the Lin6promoter, as revealed by an increase in β-glucuronidase activity after 24h, was dependent both on the expression and activation of both LpMPK2 and LpMPK3. These data suggest that the induction of extracellular invertase Lin6 by stress-related stimuli requires LpMPK2 and LpMPK3, and thus demonstrate that MAPK signalling might be involved in the regulation of primary carbon metabolism in general and sink metabolism in particular. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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9. Phenotyping in the fields: dissecting the genetics of quantitative traits and digital farming.
- Author
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Großkinsky, Dominik K., Pieruschka, Roland, Svensgaard, Jesper, Rascher, Uwe, Christensen, Svend, Schurr, Ulrich, and Roitsch, Thomas
- Subjects
PHENOTYPES ,AGRICULTURE ,CONFERENCES & conventions ,BREEDING ,GENOMICS ,QUANTITATIVE research - Abstract
The article offers information on the European Field Phenotyping Workshop held at Copenhagen, Denmark on September 2014. Topics discussed include the development of field phenotyping toolbox, agriculture and genomic breeding as future challenges, and field phenotyping methods result use as a basis to improve and develop techniques in phenotyping platforms.
- Published
- 2015
- Full Text
- View/download PDF
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