Does fungal infection increase the palatability of oilseed rape to insects?

BACKGROUND: Multiple and simultaneous attacks by pathogens and insect pests frequently occur in nature. Plants respond to biotic stresses by activating distinct defense mechanisms, but little is known about how plants cope with multiple stresses. The focus of this study was the combined interaction of fungal infection caused by Leptosphaeria maculans (synonym Plenodomus lingam) and arthropod infestation by the diamondback moth (Plutella xylostella) in oilseed rape (Brassica napus). We hypothesized that infection by the fungal pathogen L. maculans could alter oilseed rape palatability to P. xylostella-chewing caterpillars. Feeding preference tests were complemented with analyses of defense gene transcription, and levels of glucosinolates (GLSs) and volatile organic compounds (VOCs) in L. maculans-inoculated and non-inoculated (control) leaves to determine possible causes of larval choice. RESULTS: Caterpillars preferred true leaves to cotyledons, hence true leaves were used for further experiments. True leaves inoculated with L. maculans were more palatable to caterpillars over control leaves during the early stage of infection at 3 days post inoculation (dpi), but this preference disappeared in the later stages of infection at 7 dpi. In parallel, genes involved in the salicylic acid and ethylene pathways were up-regulated in L. maculans-inoculated leaves at 3 and 7 dpi; L. maculans increased the level of total aliphatic GLSs, specifically glucobrassicanapin, and decreased the level of glucoiberin at 3 dpi and altered the content of specific VOCs. A group of 55 VOCs with the highest variability between treatments was identified. CONCLUSION: We suggest that the P. xylostella preference for L. maculans-inoculated leaves in the early stage of disease development could be caused by the underlying mechanisms leading to changes in metabolic composition. Further research should pinpoint the compounds responsible for driving larval preference and evaluate whether the behavior of the adult moths, i.e. the stage that makes the first choice regarding host plant selection in field conditions, correlates with our results on larval host acceptance. © 2024 Society of Chemical Industry.

Mid-term functional and radiological outcomes after total hip replacement performed for complications of acetabular fractures.

OBJECTIVE: Acetabular fractures can lead to serious complications such as avascular necrosis of the femoral head (AVN), osteoarthritis, non-union. Total hip replacement (THR) is a treatment option for these complications. The purpose of this study was to assess the functional and radiological outcomes of THR at least 5 years after the primary implantation. METHODS: This retrospective study analysed clinical data from 77 patients (59 males, 18 females) who were treated from 2001 to 2022. Data was collected on the incidence of AVN of the femoral head, complications, interval from fracture to THR, reimplantation. The modified Harris Hip Score (MHHS) was used to evaluate outcome. RESULTS: The mean age at the time of fracture was 48 years. Avascular necrosis developed in 56 patients (73%), with 3 cases of non-union. Osteoarthritis without AVN developed in 20 patients (26%), non-union without AVN in one patient (1%). The mean time from fracture to THR was 24 months for AVN with non-union, 23 months for AVN alone, 22 months for AVN with arthritis, 49 months for hip osteoarthritis without AVN. The time interval was significantly shorter for cases of AVN than for cases of osteoarthritis without AVN (p = 0.0074). Type C1 acetabular fracture was found to be a risk factor for femoral head AVN (p = 0.0053). Common complications of acetabular fractures included post-traumatic sciatic nerve paresis (17%), deep venous thrombosis (4%), infections (4%). Hip dislocation was the most common complication of THR (17%). There were no cases of thrombosis following THR. According to Kaplan-Meier analysis, the proportion of patients without revision surgery within 10-year period was 87.4% (95% CI 86.7-88.1). The results of the MHHS after THR: 59.3% of patients had excellent results, 7.4% good, 9.3% satisfactory results, and 24.0% had poor results. The mean MHHS was 84 points (95% CI 78.5-89.5). Paraarticular ossifications were observed in 69.4% of patients in the radiological evaluation. CONCLUSION: Total hip replacement is an effective treatment for serious complications of acetabular fracture treatment. Its results are comparable to THR peformed for other indications, although it is associated with a higher number of paraarticular ossifications. Type C1 acetabular fracture was found to be a significant risk factor for early femoral head AVN.

Cytokinins act synergistically with heat acclimation to enhance rice thermotolerance affecting hormonal dynamics, gene expression and volatile emission.

Heat stress is a frequent environmental constraint. Phytohormones can significantly affect plant thermotolerance. This study compares the effects of exogenous cytokinin meta-topolin-9-(tetrahydropyran-2-yl)purine (mT9THP) on rice (Oryza sativa) under control conditions, after acclimation by moderate temperature (A; 37 °C, 2h), heat stress (HS; 45 °C, 6h) and their combination (AHS). mT9THP is a stable cytokinin derivative that releases active meta-topolin gradually, preventing the rapid deactivation reported after exogenous cytokinin application. Under control conditions, mT9THP negatively affected jasmonic acid in leaves and abscisic and salicylic acids in crowns (meristematic tissue crucial for tillering). Exogenous cytokinin stimulated the emission of volatile organic compounds (VOC), especially 2,3-butanediol. Acclimation upregulated trans-zeatin, expression of stress- and hormone-related genes, and VOC emission. The combination of acclimation and mT9THP promoted the expression of stress markers and antioxidant enzymes and moderately increased VOC emission, including 2-ethylhexyl salicylate or furanones. AHS and HS responses shared some common features, namely, increase of ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), cis-zeatin and cytokinin methylthio derivatives, as well as the expression of heat shock proteins, alternative oxidases, and superoxide dismutases. AHS specifically induced jasmonic acid and auxin indole-3-acetic acid levels, diacylglycerolipids with fewer double bonds, and VOC emissions [e.g., acetamide, lipoxygenase (LOX)-derived volatiles]. Under direct HS, exogenous cytokinin mimicked some positive acclimation effects. The combination of mT9THP and AHS had the strongest thermo-protective effect, including a strong stimulation of VOC emissions (including LOX-derived ones). These results demonstrate for the first time the crucial contribution of volatiles to the beneficial effects of cytokinin and AHS on rice thermotolerance.

Suicide attempts as a cause of pelvic injuries during the COVID-19 pandemic.

OBJECTIVES: We decided to compare the incidence and spectrum of pelvic fractures in 2020 affected by the anti-pandemic measures due to COVID-19 with previous years 2018 and 2019. METHODS: This retrospective study included 391 patients treated at the author's clinic for pelvic fractures. From the medical records we recorded gender, age, mechanism of injury, trauma energy, fracture type based on the AO classification and severity of injury. RESULTS: As expected, we observed no difference in the number of fractures caused by simple falls. However, we failed to prove a reduction in the number of high-energy injuries. In contrary, we observed an increase in the number of high-energy injuries in the period between lockdowns (p=0.0375). A surprising result was a dramatic increase in suicide attempts as a cause of pelvic fractures, with 6 (2.2 %) in 2018 and 2019 compared to 13 (10 %) in 2020 alone (p=0.0017). CONCLUSION: We observed the increased number of suicidal attempts only on a limited number of specific patients with pelvic fractures; therefore, we cannot formulate any general conclusions regarding the incidence of suicide during the COVID-19 pandemic. Nevertheless, we consider this to be a warning signal highlighting the worsened population mental health due to COVID-19 pandemic (Tab. 2, Fig. 1, Ref. 34).

Nutritional and Antioxidant Potential of Fiddleheads from European Ferns.

Ferns are part of the diet and traditional medicine in East Asia, North America, and Oceania, however, their importance has been forgotten in Europe. Here, the nutritional and antioxidant potential of young fern fronds (fiddleheads) of eight families were studied. Most of the tested fern species excelled in high antioxidant capacity when compared to the reference leafy vegetables spinach and rocket. On average, the total phenol content reached 220 mg·g-1 of extract dry weight for all fiddleheads, and 15 out of 24 tested species exceeded 1 g Trolox equivalent per gram of extract dry weight in Oxygen Radical Absorbance Capacity (ORAC) assay. On the other hand, fiddleheads contained a comparable amount of carotenoids and ascorbic acid with the reference vegetables. In the case of fatty acid composition, fiddleheads contained especially high amounts of essential omega-3 (n3) and omega-6 (n6) polyunsaturated fatty acids with a beneficial n6/n3 ratio. The n6/n3 ratio in all tested species was between 2 and 6.4, whereas the ratio in the reference vegetables was below 0.4. All in all, fiddleheads from European ferns are a rich source of valuable antioxidants and essential fatty acids with a desirable n-6/n-3 ratio and may thus form an alternative source of these compounds, especially for those people not consuming fish and fish products.

Preliminary study of phytoremediation of brownfield soil contaminated by PAHs.

Our project was aimed at improving a brownfield in the city of Kladno, where an old steel producing facility used to be in operation. Ecological risk is mainly caused by the processing of co-products during coal production (tars, oils). Knowledge of toxicology and environmental aspects can help us protect human health and the environment. Primarily, we focused on soil sampling and identification of pollutants. Results showed that organic contamination on the site is very high. Average concentration of total petroleum carbon in the soil was about 13g/kg DW, which is much more than the maximum allowed concentration. For selection of suitable plant species for phytoremediation at the site, experiments were conducted in a greenhouse. Biomass growth, root morphology, and pigment content in the leaves of Brassica napus var. Opus-C1 and Sorghum×drummondii var. Honey Graze BMR plants were studied. Plant analysis confirmed that polyaromatic hydrocarbons (PAHs) accumulated in the shoots of both plant species. B. napus plants grown on Poldi soil in a greenhouse were able to survive the toxicity of PAHs in soil, and their ability to accumulate PAHs from soil was evident. However, more studies are needed to decide if the plants are usable for phytoremediation of this brownfield.

Non-steroidal anti-inflammatory drugs in the watercourses of Elbe basin in Czech Republic.

Non-steroidal anti-inflammatory drugs (NSAIDs) belong to most used pharmaceuticals in the human and veterinary medicine. The widespread consumption of NSAIDs has led to their ubiquitous occurrence in water environment including large river systems. In the present study, concentrations of the five most frequently used NSAIDs (ibuprofen, diclofenac, naproxen, ketoprofen and indomethacin) were determined in the watercourses of the river Elbe basin in Czech Republic. The presence of the pharmaceuticals was measured at 29 sampling sites including urban and rural areas, small creeks and main tributaries of the Elbe monthly from April to December of 2011. For the NSAIDs quantitation, the comprehensive analytical method combing pentafluorobenzyl bromide (PFBBr) derivatization with highly sensitive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) was developed. Although the content of all NSAIDs varied at the particular sampling points significantly, total amount of particular compounds was relatively stable during all monitored periods with only non-significant increase in the spring and autumnal months. Ibuprofen was found to be the most abundant drug with maximum concentration of 3210 ng/L, followed by naproxen, diclofenac and ketoprofen (1423.8 ng/L, 1080 ng/L and 929.8 ng/L, respectively). Indomethacin was found only at several sampling sites (maximum concentration of 69.3 ng/L). Concentrations of all compounds except ibuprofen were significantly higher at sampling sites with low flow rates (creeks), followed by the biggest watercourses.

Trade-off among different anti-herbivore defence strategies along an altitudinal gradient.

The type and intensity of plant-herbivore interactions are likely to be altered under climate change as a consequence of differential dispersal rates of plants and their herbivores. Here, we studied variation in herbivore damage on Salvia nubicola in the field and compared its growth and defence strategies against herbivores in controlled conditions using seeds from populations along a broad altitudinal gradient. Our work is one of the first studies to simultaneously measure complex intraspecific variation in plant growth, direct and indirect defences as well as plant tolerance (ability to regrow) as a consequence of herbivore attack simulated by clipping. In the field, we found that plants experienced higher herbivore pressure in lower altitudes. In the greenhouse, plants grown from seeds collected in lower-altitude populations grew better and produced a higher content of phenolic compounds (direct defence) and volatile organic compounds (indirect defence) in response to simulated herbivory. However, there were no differences in tolerance and effect of S. nubicola extracts on the model generalist herbivore Spodoptera littoralis (direct defence) along the altitudinal gradient. Although we found that S. nubicola developed a range of defence strategies, the strategies do not seem to be used simultaneously in all populations even though most of them are correlated with altitudinal gradient. Our finding is in agreement with the current knowledge that co-expression of multiple defences might be costly for a plant, since investment in defensive traits is assumed to reduce the resource availability for growth and reproduction. Our study thus shows the importance of simultaneous study of different defence strategies since understanding these trade-offs could be necessary for detecting the mechanisms by which plants are able to cope with future climate change.

Metabolites of 2,2'-dichlorobiphenyl and 2,6-dichlorobiphenyl in hairy root culture of black nightshade Solanum nigrum SNC-9O.

The hairy root culture of black nightshade (Solanum nigrum) SNC-9O was exposed to 2,2'-dichlorobiphenyl (PCB 4) and 2,6-dichlorobiphenyl (PCB 10) to follow the metabolites produced. The analytical standards of 4-hydroxy-2,2'-dichlorobiphenyl, 5'-hydroxy-2,2'-dichlorobiphenyl, 4-hydroxy-2,6-dichlorobiphenyl, 2-hydroxy-2',6'-dichlorobiphenyl, 3-hydroxy-2',6'-dichlorobiphenyl and 4-hydroxy-2',6'-dichlorobiphenyl have been synthesized. Hydroxy-metabolites of both PCB 4 and PCB 10 were present in the biomass. These appeared mainly as conjugates rather than as free hydroxy-PCBs, both maintained in plant cells. The concentrations of non-conjugated hydroxy-PCBs ranged between 0.9 and 35.2 µg kg(-1) of biomass fresh weight and the concentration of the conjugated ones ranged between 2.0 and 113.0 µg kg(-1) depending on the position of hydroxyl. The para- position of biphenyl (4 or 4') seems to be preferred for hydroxylation. Methoxy-PCBs and hydroxy-methoxy-PCBs have also been identified in plant cells. Hydroxyl in the meta-position (3, 3', 5 or 5') appears to be preferred for methylation in hydroxy-PCBs. Hydroxy-methoxy-PCBs have occurred in the conjugated form as well.

Phyto/rhizoremediation studies using long-term PCB-contaminated soil.

PURPOSE: Polychlorinated biphenyls (PCBs) represent a large group of recalcitrant environmental pollutants, differing in the number of chlorine atoms bound to biphenyl ring. Due to their excellent technological properties, PCBs were used as heat-transfer media, for filling transformers and condensers, as paint additives, etc. With increasing knowledge of their toxicity, transfer to food chains and accumulation in living organisms, their production ended in most countries in the 1970s and in 1984 in the former Czechoslovakia. But even a quarter of century after the PCB production ceased, from contaminated areas, the volatile PCBs evaporate and contaminate much larger areas even at very distant parts of the world. For this reason, PCBs still represent a global problem. The main method of PCB removal from contaminated environment is at present the expensive incineration at high temperatures. With the aim of finding effective alternative approaches, we are studying biological methods for PCB removal from the environment. In this paper, we summarise 10 years of studies using long-term PCB-contaminated soil from a dumpsite in South Bohemia, targeted for the use of plants (phytoremediation) and their cooperation with microorganisms in the root zone (rhizoremediation). MATERIALS AND METHODS: Long-term contaminated soil from Lhenice dumpsite, more than hundred kilograms of homogenised material, was used in microcosms (pots and buckets), and field plots were established at the site. Tested plants include among others tobacco, black nightshade, horseradish, alfalfa and willow. Aseptic plant cell and tissue cultures were from the collection of the IOCB. Microorganisms were our own isolates. The paper summarises experiments done between 1998 and 2008 with real contaminated soil, both vegetated and non-vegetated. PCB analysis was performed by GC-ECD, metabolic products identified mostly using 2D-GC/MS-MS and synthetic standards, whereas molecular methods included quantitative PCR and sequencing. RESULTS: The soil was used both for preparation of field plots at the site and for greenhouse and laboratory tests in microcosms. The results include analyses of changes in PCB content in untreated and vegetated soil, PCB uptake and distribution in different parts of various plant species, analysis of products formed, identification and characterisation of cultivable and non-cultivable bacteria both in rhizosphere and in bulk soil. Different treatments and amendments were also tested. Experiments in real contaminated soil were accompanied by in vitro experiments using aseptic cultures of plant biomass, genetically modified (GM) plants and bacteria, to allow identification of players responsible for PCB metabolisation in soil. The time-span of the experiments allows extrapolating some of the results and drawing conclusions concerning the effectivity of exploitation of various plant species and treatments to remove PCBs from soils. DISCUSSION: The approach using plants proved to represent a viable alternative to costly incineration of PCB-contaminated soils. The recent studies using molecular methods show that plants are responsible for the composition of consortia of microorganisms present in their root zone, including those with ability to degrade the chlorinated aromatic compounds. CONCLUSIONS: In addition to uptake, accumulation and partial metabolisation of PCBs by plants, compounds produced by plants allow survival of microorganisms even in poor soils, serve as carbon and energy source, and can even induce the degradation pathways of different xenobiotics. Thus, the choice of proper plant species is crucial for effective cleaning of different polluted sites. Our study shows how the efficiency of PCB removal is dependent on the plant used. RECOMMENDATIONS AND PERSPECTIVES: The use of plants in biological remediation of different organic xenobiotics proved to be a useful approach. Further improvement can be expected by application of specifically tailored GM plants and use of selective conditions ensuring high remediation potential based on optimal composition of the soil microbial consortia designed for the needs of given site.

Hydroxy-PCBs, methoxy-PCBs and hydroxy-methoxy-PCBs: metabolites of polychlorinated biphenyls formed in vitro by tobacco cells.

While the metabolism of polychlorinated biphenyls (PCBs) in plant cells is a rarely studied field, hydroxy-PCBs have been detected in several studies involving the use of various plant species. The ability of the tobacco (Nicotiana tabacum) callus culture WSC-38 to metabolize six dichlorobiphenyls under aseptic conditions was studied, and the resulting PCB metabolites were analyzed. WSC-38 cultures were cultivated with individual dichlorinated PCB congeners. The metabolites were identified based on mass spectra characteristics after gas chromatography separation. In addition, metabolites of PCB 9 (2,5-dichlorobiphenyl) were identified by comparing their retention characteristics with the available standards. In most cases at least two hydroxy-PCBs were produced from each parent PCB. Methoxy-PCBs and hydroxy-methoxy-PCBs were other groups of metabolites produced. To the best of our knowledge, ours is the first report to determine the presence of methoxy- and hydroxy-methoxy-metabolites of PCBs in plants. The role of the O-methyltransferases (OMTs) in the methylation of hydroxy-PCBs is discussed. As methoxy-metabolites of acetophenone were found among our samples, we posit that the OMTs responsible for the methylation of these compounds are also involved in the metabolism of PCBs in cultures of WSC-38.

The effect of ryegrass (Lolium perenne) on decrease of PAH content in long term contaminated soil.

The biodegradation of polycyclic aromatic hydrocarbons in microecosystems containing long-term contaminated soil was investigated. Soil was contaminated by different chemicals, including PAHs since World War II. Aging of the soil was expected to act as a principal factor limiting biodegradation. Half of the microecosystems contained ryegrass (Lolium perenne) and long-term selected natural soil microflora originally present in contaminated soil. The others contained contaminated soil with natural microflora only. Half of the microecosystems in each parallel experiment was fertilised with N-P-K fertiliser. Cultivation was carried out at 12 and 18 months in a greenhouse with a natural photoperiod and the ability to degrade 15 chosen PAH was investigated. For analysis, the soil from each pot was divided into three horizontal layers for mutual comparison among layers and each layer was further divided into four equal samples. Soil extracts were analysed using HPLC. After a one-year-cultivation period the content of the monitored PAHs declined to 50%. Mostly, there were no significant differences between the microecosystems. Best degraded were fluoranthene and pyrene, which were the major contaminants present in original soil. Also, other compounds were successfully degraded, even benzo[a]pyrene and benzo[ghi]perylene. Dibenz[a,h]anthracene and indeno[1,2,3-cd]pyrene were the only PAHs, examined that showed no significant degradation. Although some differences between the soil layers were detected, no conclusive trends could be found. However, significantly lower concentrations of PAHs were determined mostly in the bottom layer of the analysed profiles. In vegetated microecosystems the decline of PAHs concentrations was more remarkable after 18 months cultivation.

Plant metabolites of polychlorinated biphenyls in hairy root culture of black nightshade Solanum nigrum SNC-9O.

The present study is intended to determine metabolites of 12 dichlorinated, seven trichlorinated, five tetrachlorinated and one pentachlorinated PCB congener transformed by black nightshade (Solanum nigrum) hairy root culture SNC-9O. Free hydroxylated PCB metabolites were identified based on the mass spectra characteristics after gas chromatography separation. The number of metabolites decreases with an increasing number of chlorine atoms per molecule of PCB. Dichlorinated PCBs lead always to at least two metabolites. In the case of PCB 9 some metabolites could be identified by comparing their RF values due to available standards. The 2',5'-dichloro-2-biphenylol, 2',5'-dichloro-3-biphenylol and 2',5'-dichloro-4-biphenylol, present as the main metabolite, were found in biomass of SNC-9O hairy root culture. Two monochlorinated biphenylols were found in biomass of SNC-9O degrading PCB 9 congener. It was the only case when metabolites with decreased number of chlorine atoms compared to parent PCB were found. Trichlorinated PCBs mostly lead to a lower number of metabolites but tetrachlorinated and pentachlorinated PCBs mostly did not give any metabolites. In the media, only traces of metabolites were found in sporadic cases, so exudation of unbound biphenylols from the cells is not expected.

Phytoremediation: biological cleaning of a polluted environment.

Phytoremediation is the direct use of living green plants to degrade, contain, or render harmless various environmental contaminants, including recalcitrant organic compounds or heavy metals. The methods involved include phytoextraction, direct phytodegradation, rhizofiltration, phytovolatilization or formation of artificial wetlands, and lagoon systems. More research background and the development of plants tailored for remediation purposes, using genetic engineering and deeper understanding of plant cooperation with microorganisms is needed. This approach is illustrated by our studies of heavy metal uptake improvement or studies of the PCB conversion, which include in-vitro screening of plant species, analysis of the products, evaluation of their toxicity and field plots, and also studies of enzymes and cloning of foreign genes into plants.