| 1. |
- Abreha, Kibrom Berhe, et al.
(författare)
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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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Ingår i: Crop Protection. - : Elsevier BV. - 0261-2194 .- 1873-6904. ; 121, s. 139-146
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Alexandersson, Erik, et al.
(författare)
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Plant Resistance Inducers against Pathogens in Solanaceae Species-From Molecular Mechanisms to Field Application
- 2016
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 17
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Forskningsöversikt (refereegranskat)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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| 3. |
- Ali, Ashfaq, et al.
(författare)
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Paranoid potato : phytophthora-resistant genotype shows constitutively activated defense
- 2012
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Ingår i: Plant Signaling and Behavior. - : Informa UK Limited. - 1559-2316 .- 1559-2324. ; 7:3, s. 400-408
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Tidskriftsartikel (refereegranskat)abstract
- Phytophthora is the most devastating pathogen of dicot plants. There is a need for resistance sources with different modes of action to counteract the fast evolution of this pathogen. In order to better understand mechanisms of defense against P. infestans, we analyzed several clones of potato. Two of the genotypes tested, Sarpo Mira and SW93-1015, exhibited strong resistance against P. infestans in field trials, whole plant assays and detached leaf assays. The resistant genotypes developed different sizes of hypersensitive response (HR)-related lesions. HR lesions in SW93-1015 were restricted to very small areas, whereas those in Sarpo Mira were similar to those in Solanum demissum, the main source of classical resistance genes. SW93-1015 can be characterized as a cpr (constitutive expressor of PR genes) genotype without spontaneous microscopic or macroscopic HR lesions. This is indicated by constitutive hydrogen peroxide (H₂O₂) production and PR1 (pathogenesis-related protein 1) secretion. SW93-1015 is one of the first plants identified as having classical protein-based induced defense expressed constitutively without any obvious metabolic costs or spontaneous cell death lesions.
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| 4. |
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| 5. |
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| 6. |
- Araujo Sandroni, Murilo, et al.
(författare)
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Plant resistance inducers (PRIs): perspectives for future disease management in the field
- 2020
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Ingår i: Cab Reviews: Perspectives In Agriculture, Veterinary Science, Nutrition And Natural Resources. - 1749-8848. ; 15, s. 10-
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Forskningsöversikt (refereegranskat)abstract
- Plants are confronted with numerous biotic stresses that may affect productivity. Besides their constitutive defence, plants can activate specific metabolic processes to enhance resistance upon stress detection. These defence mechanisms can also be activated through the recognition of plant resistance inducers (PRIs). This review highlights some of the current challenges that prevent the adoption of PRIs in agriculture, and explore research topics and knowledge gaps to be addressed for bringing PRIs closer to practice. First, we present studies on the variance of induced defence responses and examine the possibility of employing inducibility in breeding strategies as well as the possible role of epigenetics. We also discuss the efficiency of PRIs in future climate and knowledge gaps on this subject. Remote sensing, high-throughput phenotyping and modelling in combination with PRIs as part of decision support systems and integrated pest management are further possibilities to advance the use of PRIs. Finally, we discuss the challenges which need to be addressed to make PRIs available for small-scale farmers in low-income countries. Although PRIs have successfully presented significant rates of disease prevention under controlled conditions, converting these findings into field application still depends on more studies, e.g. on how they can be integrated into disease management programmes. Better mechanistic understanding of IR together with the coupling of PRIs to new disease monitoring and protection strategies can give PRIs a stronger role in future agricultural practice.
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| 7. |
- Bengtsson, Therese, et al.
(författare)
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Activation of defence responses to Phytophthora infestans in potato by BABA
- 2014
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Ingår i: Plant Pathology. - : Wiley. - 0032-0862 .- 1365-3059. ; 63, s. 193-202
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Tidskriftsartikel (refereegranskat)abstract
- Late blight caused by Phytophthora infestans is one of the most devastating diseases of the potato crop. Resistance breeding and current fungicides are unable to control the rapidly evolving P. infestans and new control strategies are urgently needed. This study examined mechanisms of dl-β-aminobutyric acid (BABA)-induced resistance (IR) in the potato-P. infestans system. Leaves from two cultivars that differ in their degree of resistance, Bintje and Ovatio, were analysed after foliar treatment with BABA. Rapid activation of various defence responses and a significant reduction in P. infestans growth were observed in leaves treated with BABA. In the more resistant cultivar, Ovatio, the activation was both faster and stronger than in Bintje. Microscopic analysis of leaves treated with BABA revealed induction of small hypersensitive response (HR)-like lesions surrounded by callose, as well as production of hydrogen peroxide (H2O2). Molecular and chemical analyses revealed soluble phenols such as arbutin and chlorogenic acid and activation of PR-1. These results show a direct activation of defence responses in potato, rather than priming as reported for other plant species. They also show that the efficiency of BABA-IR differs between cultivars, which highlights the importance of taking all aspects into consideration when establishing new methods for disease management.
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| 8. |
- Bengtsson, Therese, et al.
(författare)
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Biosurfactants Have the Potential to Induce Defence Against Phytophthora infestans in Potato
- 2015
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 58, s. 83-90
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Tidskriftsartikel (refereegranskat)abstract
- Potato late blight caused by Phytophthora infestans is one of the most destructive plant diseases worldwide. Currently, its management mainly relies on the frequent use of synthetic chemicals, and there is a need to develop more sustainable strategies. Biosurfactants produced by fluorescent pseudomonads have been shown to rapidly, within 1 min, cause zoospore lyses. This study investigated if the biosurfactant-producing strain Pseudomonas koreensis 2.74 and its biosurfactants have the potential to induce resistance in potato to late blight. The experiments were performed with treatments of whole plants of the susceptible potato cultivar Bintje and the partially resistant cultivar Ovatio. A significant disease reduction and an induced secretion of proteins such as pathogenesis-related (PR) protein 1, within the leaf apoplast, were observed in the potato cultivar Ovatio after treatment with the biosurfactant at a concentration of 1 mg ml(-1). No significant effects on disease development were observed after treatment with the bacterial suspension of Pseudomonas koreensis 2.74.
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| 9. |
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| 10. |
- Bengtsson, Therese, et al.
(författare)
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Kan inducerad resistens och biotensider minska behovet av kemisk bekämpning i potatis?
- 2011
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Ingår i: Växtskyddsnotiser. - 2000-8465. ; 66, s. 15-18
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Annan publikation (populärvet., debatt m.m.)abstract
- Det krävs stora insatser och nya strategier för att ta ledningen i den ständigt pågående evolutionära kapplöpningen mellan P. infestans och dess värd. Framför allt behövs metoder som leder till minskad användning av fungicider och som är bättre både ur ett miljö- och hälsoperspektiv. Dagens konsumenter är medvetna om miljöfrågor och efterfrågar i högre grad obesprutade varor. Flera fungicider har redan förbjudits inom EU och fler är på väg att förbjudas, vilket kan få stora konsekvenser utifall ingen alternativ strategi mot bladmögel tas fram. För bekämpning av bladmögel har vi undersökt möjligheten att kombinera sortval med både så kallad inducerad resistens och biologisk bekämpning.
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