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81.
Aleš Lebeda Barbora Mieslerová Marek Petřivalský Lenka Luhová Martina Špundová Michaela Sedlářová Vladimíra Nožková-Hlaváčková David A. C. Pink 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(3):569-596
Tomato powdery mildew (Oidium neolycopersici) is one of the most devastating diseases of cultivated tomatoes worldwide. Although the first epidemics were recorded more than 25 years ago many aspects of this host-pathogen interaction are still not well understood. Detailed morphological and molecular studies of the anamorphs confirmed that O. neolycopersici is phylogeneticaly close to Erysiphe aquilegiae var. ranunculi. Host range is rather broad, apart from Solanaceae hosts were found in the families Apocynaceae, Campanulaceae, Crassulaceae, Cistaceae, Cucurbitaceae, Linaceae, Malvaceae, Papaveraceae, Pedialiaceae, Scrophulariaceae, Valerianaceae a Violaceae. Non-host resistance within these families is not based on inhibition of formation of primary haustorium, however, on post-haustorial hypersensitive reponse and another type of non-hypersensitive resistance. Screening of wild Solanum species (previous Lycopersicon spp.) germplasm revealed valuable sources of resistance (S. habrochaites, S. pennellii, S. cheesmaniae, S. chilense, S. peruvianum). The main resistance mechanism was found to be a hypersensitive response (HR), in some cases followed by limited development of the pathogen. However, there is a broad variation in resistance response on the histological and cytological level. Interaction between many wild Solanum spp. and O. neolycopersici is race-specific, at least three races were differentiated. In some interspecific crosses (S. lycopersicum × S. habrochaites) adult plant resistance was observed. Biochemical studies focusing on production of reactive oxygen species (ROS) and peroxidase activity during infection of O. neolycopersici showed that production of ROS and activity of corresponding enzymes is related to activation of defence responses in genotypes of wild Solanum sect. Lycopersicon. The significance of nitric oxide (NO) in O. neolycopersici pathogenesis was supported by experiments with NO donors and scavengers. In moderately resistant genotype S. chmielewskii, treatment by heat stress caused slight deceleration of pathogen development, increased production of jasmonic acid (JA) and abscisic acid (ABA) and increased peroxidase activity in infected plants. The different degree of tomato resistance/susceptibility did not markedly change the rate and extent of photosynthetic response to O. neolycopersici; only minimal impairment of photosynthesis was found in both susceptible and moderately resistant genotypes during the first 9 days after inoculation. The accumulated evidence confirm a crucial role of localised increased production of ROS and reactive nitrogen species (RNS) in response to pathogen penetration into plant tissue and its involvement in the plant resistance responses including the initiation and progression of plant cell death in host wild Solanum species. Crucial points of further research are discussed. 相似文献
82.
Saša Likić Ivana Šola Jutta Ludwig-Müller Gordana Rusak 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(2):257-271
The roles of several phenolic compounds in plant defence response have been extensively studied, yet little is known about the role of flavonoids in plant-virus interaction. Quantitative and qualitative changes of selected phenolics in Arabidopsis thaliana induced by Cucumber mosaic virus containing satellite RNA (CMVsat) infection were analysed accompanied by plant hormone, chalcone synthase and pathogenesis-related gene expression analysis. Lower leaves of infected plants had a lower concentration of total phenolics compared to control plants. The concentration of kaempferol in upper leaves of all infected plants was significantly lower compared to control plants, while the expression of the chalcone synthase gene in those leaves was in most cases upregulated. All infected plants had a higher concentration of indole-3-acetic acid in lower leaves, which was accompanied with a lower concentration of kaempferol in upper leaves. Our research demonstrates a correlation between kaempferol and indole-3-acetic acid in response to CMVsat infection in Arabidopsis. We demonstrated two different metabolic patterns in infected plants suggesting the activation of two different defence responses. We also propose kaempferol to be an important part of the auxin-dependent defence response which limits systemic movement of CMVsat and that this defence response is activated prior to the well-known salicylic acid dependent defence response. Further research on kaempferol and its role in Arabidopsis-CMVsat interaction will improve our understanding on the role of flavonoids in plant defence. 相似文献
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85.
Andreas Schober Nenad Šimunović Andras Darabant Tobias Stern 《Journal of Sustainable Forestry》2018,37(6):537-554
Although it is obvious that research regarding Sustainable Forest Management (SFM) is context specific and developed over time, not many research papers yet intended to investigate these changes. As a matter of fact, the number of scientific publications addressing SFM is relatively high. Hence, such a wide field cannot be sufficiently covered by traditional literature review approaches. With this paper, we aim at identifying the most convergent narratives within the SFM-research landscape by applying a text mining methodology to recent scientific literature. By doing so, we generated results that indicate that there may have been three phases in the evolution of SFM-research: the early phase covers in particular issues regarding land use in tropical and developing countries. Furthermore, papers in this phase tend to focus on general concepts or policy issues. In contrast, the second phase is characterized by a larger share of publications in forestry focused journals. This process is seemingly connected with issues like forest management, certification, forest stand management and the development of sustainability indicators. A third phase can be observed by the relative downturn of publications in forest-focused journals between 2005 and 2010. A new focus in this period is climate change. 相似文献
86.
Monika Drážovská Katarína Šiviková Ján Dianovský Miroslav Horňák 《Animal Science Journal》2017,88(1):27-32
In this study, chromosomal imbalances in tumor tissues (lymphomas) and nucleotide changes in tumor suppressor TP53 were studied in a Bernese Mountain dog bitch and a cross breed bitch. Using comparative genomic hybridization, numerous chromosomal rearrangements were detected, which indicated the heterogeneity in tumor growth: in the cross breed bitch, a deletion on the chromosome 9, and duplications on chromosomes 5, 8 and 17 have been found. In the Bernese Mountain Dog bitch, losses on chromosomes 1, 5, 8, 12, 18, 22, 27, 29 and gains on chromosomes 1, 2, 9, 11, 15, 16, 18, 20, 23, 24, 25, 28, 29, 30, 34, 36, 37 and 38 were identified. With the sequencing of the TP53 gene, one silent mutation, transition A/G at position 138 in exon 5 was detected, without changing the amino acid. 相似文献
87.
Hana Bilošová Bořivoj Šarapatka Marie Štýbnarová Pavlína Mičová Marie Svozilová 《Archives of Agronomy and Soil Science》2017,63(11):1535-1545
This study shows the effect of organic fertilizers at different stocking rates, on nitrogen (N) leaching, measured using zero-tension lysimeters under undisturbed grassland soil. The experiment included two organic fertilizer types – cow dung with dung water (D) and slurry (S), both at a range of stocking rates: 0.9 LU (livestock unit) ha?1, 1.4 LU ha?1, 2.0 LU ha?1 (corresponding to 54, 84 and 120 kg N ha?1, respectively) and a control (C) treatment. In percolated water, the contents of ammonia nitrogen (NH4+–N) and nitrate nitrogen (NO3?–N) were studied. The average concentration of NH4+–N ranged from 0.91 to 1.44 mg l?1 on fertilized plots compared to 0.55 mg l?1 on the control plot. The average concentration of NO3?–N ranged from 5.2 to 9.5 mg l?1 on fertilized plots compared to 3.2 mg l?1 on the control plot. The results of this study showed that the use of organic fertilizers at chosen stocking rates influenced N leaching, but the concentration of N did not exceed the limits for drinking water permitted by Czech legislation. Stocking rates at 2.0 LU ha?1 and below do not result in elevated N concentrations in percolated water that pose environmental threat. 相似文献
88.
Lucia Kořenková Martin Šebesta Martin Urík Marek Kolenčík Gabriela Kratošová Marek Bujdoš 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(4):285-291
Since the fate of nanoparticles after their release in the environment and their possible transfer in plants and subsequent impacts is still largely unknown, this paper evaluates the potential phytotoxic effects of up to 20% w/w TiO2 nanoparticles (nTiO2) on barley cultivated in hydroponics and agar media. The X-ray diffraction analysis confirmed that nTiO2 powder corresponds to anatase phase. On agar medium only high concentrations of nTiO2 (10% and 20% w/w) induced significant inhibition of shoot growth. However, hydroponics treatment with nTiO2 up to 1000?mg?L?1 did not show any adverse effect on the shoot growth. In both experiments, (i) root growth inhibition effects became visible with increasing concentration of nTiO2, (ii) plants treated with nTiO2 showed no change in chlorophyll a and b content, even though the plants absorbed nTiO2, (iii) weight of biomass treated with nTiO2 was not significantly different compared to control. Therefore, we assume that transport of nTiO2 into the aerial parts is limited due to the presence of effective mechanical or physiological barriers in roots. Overall, it appears that early root growth is a relevant indicator of potential effects of nTiO2 exposure. Our results also indicate that synthesized nTiO2 are not significantly toxic to the barley when applied at the concentrations used in this work, even though plants absorb titanium. 相似文献
89.
Branimir Urlić Maja Jukić Špika Christine Becker Hans-Peter Kläring Angelika Krumbein Smiljana Goreta Ban 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(8):748-757
The effect of suboptimal supply of nitrogen (N) and of replacing nitrate in the nutrient solution with ammonia on growth, yield, and nitrate concentration in green and red leaf lettuce was evaluated over two seasons (autumn and spring) using multiple regression analysis. The plants were grown in a greenhouse on a Nutrient Film Technique (NFT) system. Nitrogen concentrations in the nutrient solution were either 3?mM or 12?mM, and the form of N was varied as follows: 100% NO3, 50% NO3?+?50% NH4, and 100% NH4. In both seasons, the biomass (fresh weight) of lettuce heads increased with increasing NO3 concentrations and in autumn, NO3 even at 1.5?mM was sufficient for high yield. However, head dry weight was affected neither by the season nor by changes in the composition of the nutrient solution. The concentration of NO3 had no effect on root dry weight, but it decreased at higher concentrations of NH4. The number of leaves increased as the ratio of NO3 to NH4 in the nutrient solution increased and was higher in autumn because of the longer growth period. Increasing the concentration of NO3 in nutrient solution increased both total N and nitrate concentration in lettuce heads (dry weight) but decreased the concentration of total C. Also, leaf nitrate concentration was lower in spring than in autumn and decreased with increasing NH4 concentration. Nitrogen utilization efficiency was maximum when NH4 levels in the nutrient solution were either 0% or 50% irrespective of the season. Our results thus show that suboptimal N supply in autumn will not affect lettuce yield, and that nitrate concentration in leaves is lower when NH4 concentrations in nutrient solution are higher and also much lower in red lettuce than in green lettuce. 相似文献
90.