| 1. |
- Abreha, Kibrom Berhe, et al.
(author)
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Inoculation of Transgenic Resistant Potato by Phytophthora infestans Affects Host Plant Choice of a Generalist Moth
- 2015
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10
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Journal article (peer-reviewed)abstract
- Pathogen attack and the plant's response to this attack affect herbivore oviposition preference and larval performance. Introduction of major resistance genes against Phytophthora infestans (Rpi-genes), the cause of the devastating late blight disease, from wild Solanum species into potato changes the plant-pathogen interaction dynamics completely, but little is known about the effects on non-target organisms. Thus, we examined the effect of P. infestans itself and introduction of an Rpi-gene into the crop on host plant preference of the generalist insect herbivore, Spodoptera littoralis (Lepidoptera: Noctuidae). In two choice bio-assays, S. littoralis preferred to oviposit on P. infestans-inoculated plants of both the susceptible potato (cv. Desiree) and an isogenic resistant clone (A01-22: cv. Desiree transformed with Rpi-blb1), when compared to uninoculated plants of the same genotype. Both cv. Desiree and clone A01-22 were equally preferred for oviposition by S. littoralis when uninoculated plants were used, while cv. Desiree received more eggs compared to the resistant clone when both were inoculated with the pathogen. No significant difference in larval and pupal weight was found between S. littoralis larvae reared on leaves of the susceptible potato plants inoculated or uninoculated with P. infestans. Thus, the herbivore's host plant preference in this system was not directly associated with larval performance. The results indicate that the Rpi-blb1 based resistance in itself does not influence insect behavior, but that herbivore oviposition preference is affected by a change in the plant-microbe interaction.
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| 2. |
- Abreha, Kibrom Berhe, et al.
(author)
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Phosphite protects against potato and tomato late blight in tropical climates and has varying toxicity depending on the Phytophthora infestans isolate
- 2019
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In: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 121, s. 139-146
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Journal article (peer-reviewed)abstract
- Late blight caused by the oomycete Phytophthora infestans is one of the most severe diseases of potato (Solarium tuberosum L.) and tomato (Solarium lycopersicum L.). In this study, field trials were conducted in a cool tropical highland of Ethiopia for three consecutive years to investigate the efficacy of phosphite alone and in combination with conventional fungicide against late blight in two potato cultivars and one tomato cultivar. Phosphite alone and in combination with reduced dosages of the fungicide Ridomil (mancozeb 64% and metalaxyl-M 4% (w/w)) led to effective suppression of late blight in research plots and in farmers' fields under light-to-normal late blight pressure. However, phosphite was not as effective as the fungicide under high disease pressure. Notably, phosphite was more effective against tomato late blight than against potato late blight, and gave the same protection as the fungicide in tomato. In vitro assays showed small differences in sensitivity to phosphite among five European and two Ethiopian isolates of P. infestans in terms of radial growth, sporangium production and sporangium germination, which could affect the population structure. Since phosphite can be provided at a lower price than conventional fungicides, it can reduce expenses for Ethiopian farmers with preserved late blight control.
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| 3. |
- Alexandersson, Erik, et al.
(author)
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Field-omics-understanding large-scale molecular data from field crops
- 2014
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In: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 5
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Journal article (peer-reviewed)abstract
- The recent advances in gene expression analysis as well as protein and metabolite quantification enable genome-scale capturing of complex biological processes at the molecular level in crop field trials. This opens up new possibilities for understanding the molecular and environmental complexity of field-based systems and thus shedding light on the black box between genotype and environment, which in agriculture always is influenced by a multi-stress environment and includes management interventions. Nevertheless, combining different types of data obtained from the field and making biological sense out of large datasets remain challenging. Here we highlight the need to create a cross-disciplinary platform for innovative experimental design, sampling and subsequent analysis of large-scale molecular data obtained in field trials. For these reasons we put forward the term field-omics: "Field-omics strives to couple information from genomes, transcriptomes, proteomes, metabolomes and metagenomes to the long-established practice in crop science of conducting field trials as well as to adapt current strategies for recording and analysing field data to facilitate integration with '-omics' data."
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| 4. |
- Alexandersson, Erik, et al.
(author)
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Plant Resistance Inducers against Pathogens in Solanaceae Species-From Molecular Mechanisms to Field Application
- 2016
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In: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 17
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Research review (peer-reviewed)abstract
- This review provides a current summary of plant resistance inducers (PRIs) that have been successfully used in the Solanaceae plant family to protect against pathogens by activating the plant's own defence. Solanaceous species include many important crops such as potato and tomato. We also present findings regarding the molecular processes after application of PRIs, even if the number of such studies still remains limited in this plant family. In general, there is a lack of patterns regarding the efficiency of induced resistance (IR) both between and within solanaceous species. In many cases, a hypersensitivity-like reaction needs to form in order for the PRI to be efficient. "-Omics" studies have already given insight in the complexity of responses, and can explain some of the differences seen in efficacy of PRIs between and within species as well as towards different pathogens. Finally, examples of field applications of PRIs for solanaceous crops are presented and discussed. We predict that PRIs will play a role in future plant protection strategies in Solanaceae crops if they are combined with other means of disease control in different spatial and temporal combinations.
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| 5. |
- Alexandersson, Erik, et al.
(author)
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Plant secretome proteomics
- 2013
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In: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 4
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Research review (peer-reviewed)abstract
- The plant secretome refers to the set of proteins secreted out of the plant cell into the surrounding extracellular space commonly referred to as the apoplast. Secreted proteins maintain cell structure and acts in signaling and are crucial for stress responses where they can interact with pathogen effectors and control the extracellular environment. Typically, secreted proteins contain an N-terminal signal peptide and are directed through the endoplasmic reticulum/Golgi pathway. However, in plants many proteins found in the secretome lack such a signature and might follow alternative ways of secretion. This review covers techniques to isolate plant secretomes and how to identify and quantify their constituent proteins. Furthermore, bioinformatical tools to predict secretion signals and define the putative secretome are presented. Findings from proteomic studies and important protein families of plant secretomes, such as proteases and hydrolases, are highlighted.
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| 6. |
- Ali, Ashfaq, et al.
(author)
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Quantitative proteomics and transcriptomics of potato in response to Phytophthora infestans in compatible and incompatible interactions
- 2014
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In: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 15
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Journal article (peer-reviewed)abstract
- Background: In order to get global molecular understanding of one of the most important crop diseases worldwide, we investigated compatible and incompatible interactions between Phytophthora infestans and potato (Solanum tuberosum). We used the two most field-resistant potato clones under Swedish growing conditions, which have the greatest known local diversity of P. infestans populations, and a reference compatible cultivar. Results: Quantitative label-free proteomics of 51 apoplastic secretome samples (PXD000435) in combination with genome-wide transcript analysis by 42 microarrays (E-MTAB-1515) were used to capture changes in protein abundance and gene expression at 6, 24 and 72 hours after inoculation with P. infestans. To aid mass spectrometry analysis we generated cultivar-specific RNA-seq data (E-MTAB-1712), which increased peptide identifications by 17%. Components induced only during incompatible interactions, which are candidates for hypersensitive response initiation, include a Kunitz-like protease inhibitor, transcription factors and an RCR3-like protein. More secreted proteins had lower abundance in the compatible interaction compared to the incompatible interactions. Based on this observation and because the well-characterized effector-target C14 protease follows this pattern, we suggest 40 putative effector targets. Conclusions: In summary, over 17000 transcripts and 1000 secreted proteins changed in abundance in at least one time point, illustrating the dynamics of plant responses to a hemibiotroph. Half of the differentially abundant proteins showed a corresponding change at the transcript level. Many putative hypersensitive and effector-target proteins were single representatives of large gene families.
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| 7. |
- Andreasson, Erik, et al.
(author)
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Phosphite alters the behavioral response of potato tuber moth (Phthorimaea operculella) to field-grown potato
- 2019
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In: Pest Management Science. - : Wiley. - 1526-498X .- 1526-4998. ; 75, s. 616-621
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Journal article (peer-reviewed)abstract
- BACKGROUND The potato tuber moth (PTM) (Phthorimaea operculella) is a pest of solanaceous species that causes serious damage to potato tubers and tomato fruits. Control is mainly dependent on the use of synthetic chemicals, which pose a risk to the environment and health of farmers, especially in developing countries where application safety rules are often neglected. In this study we aimed at investigating the effects of a plant resistance inducer (PRI) potassium phosphite on PTM larval population density and PTM parasitoid levels, which can be used as biocontrol agents. We also tested whether intercropping with tomato, which is less attractive to PTM, provided a spatial border to further reduce PTM numbers. RESULTS In two different locations over two seasons, we showed that foliar application of phosphite more than halved the PTM larval populations on potato, and that PTM parasitoid numbers were unaffected. No consistent reduction in PTM was achieved by intercropping potato with tomato. CONCLUSIONS Phosphite reduced PTM numbers in the field without interfering with autochthonous parasitoids, indicating its suitability as part of an Integrated Pest Management strategy. Ex situ choice tests showed that phosphite-treated potato deterred PTM, which could be a reason for the control of PTM in the field. (c) 2018 Society of Chemical Industry
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| 8. |
- Bengtsson, Therese, et al.
(author)
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Proteomics and transcriptomics of the BABA-induced resistance response in potato using a novel functional annotation approach
- 2014
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In: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 15
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Journal article (peer-reviewed)abstract
- Background: Induced resistance (IR) can be part of a sustainable plant protection strategy against important plant diseases. beta-aminobutyric acid (BABA) can induce resistance in a wide range of plants against several types of pathogens, including potato infected with Phytophthora infestans. However, the molecular mechanisms behind this are unclear and seem to be dependent on the system studied. To elucidate the defence responses activated by BABA in potato, a genome-wide transcript microarray analysis in combination with label-free quantitative proteomics analysis of the apoplast secretome were performed two days after treatment of the leaf canopy with BABA at two concentrations, 1 and 10 mM. Results: Over 5000 transcripts were differentially expressed and over 90 secretome proteins changed in abundance indicating a massive activation of defence mechanisms with 10 mM BABA, the concentration effective against late blight disease. To aid analysis, we present a more comprehensive functional annotation of the microarray probes and gene models by retrieving information from orthologous gene families across 26 sequenced plant genomes. The new annotation provided GO terms to 8616 previously un-annotated probes. Conclusions: BABA at 10 mM affected several processes related to plant hormones and amino acid metabolism. A major accumulation of PR proteins was also evident, and in the mevalonate pathway, genes involved in sterol biosynthesis were down-regulated, whereas several enzymes involved in the sesquiterpene phytoalexin biosynthesis were up-regulated. Interestingly, abscisic acid (ABA) responsive genes were not as clearly regulated by BABA in potato as previously reported in Arabidopsis. Together these findings provide candidates and markers for improved resistance in potato, one of the most important crops in the world.
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| 9. |
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| 10. |
- Burra, Dharani, et al.
(author)
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Phosphite-induced changes of the transcriptome and secretome in Solanum tuberosum leading to resistance against Phytophthora infestans
- 2014
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In: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 14
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Journal article (peer-reviewed)abstract
- Background: Potato late blight caused by the oomycete pathogen Phytophthora infestans can lead to immense yield loss. We investigated the transcriptome of Solanum tubersoum (cv. Desiree) and characterized the secretome by quantitative proteomics after foliar application of the protective agent phosphite. We also studied the distribution of phosphite in planta after application and tested transgenic potato lines with impaired in salicylic and jasmonic acid signaling. Results: Phosphite had a rapid and transient effect on the transcriptome, with a clear response 3 h after treatment. Strikingly this effect lasted less than 24 h, whereas protection was observed throughout all time points tested. In contrast, 67 secretome proteins predominantly associated with cell-wall processes and defense changed in abundance at 48 h after treatment. Transcripts associated with defense, wounding, and oxidative stress constituted the core of the phosphite response. We also observed changes in primary metabolism and cell wall-related processes. These changes were shown not to be due to phosphate depletion or acidification caused by phosphite treatment. Of the phosphite-regulated transcripts 40% also changed with beta-aminobutyric acid (BABA) as an elicitor, while the defence gene PR1 was only up-regulated by BABA. Although phosphite was shown to be distributed in planta to parts not directly exposed to phosphite, no protection in leaves without direct foliar application was observed. Furthermore, the analysis of transgenic potato lines indicated that the phosphite-mediated resistance was independent of the plant hormones salicylic and jasmonic acid. Conclusions: Our study suggests that a rapid phosphite-triggered response is important to confer long-lasting resistance against P. infestans and gives molecular understanding of its successful field applications.
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