scholarly journals Intraspecific aluminium response in Suillus luteus (L.) s.f. gray., an ectomycorrhizal symbiont of scots pine

2014 ◽  
Vol 64 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Tomasz Leski ◽  
Maria Rudawska ◽  
Barbara Kieliszewska-Rokicka

Ten isolates of the ectomycorrhizal fungus <i>Suillus luteus</i> have been cultured on an aluminium containing growth medium in order to determine their <i>in vitro</i> aluminium tolerance. Five isolates originated from a site heavily polluted by acid rain with a high availability of aluminium in the soil. Five others were collected from a site free from direct pollution. Aluminium content in the sporocarps of <i>S. luteus</i> differed according to the site of origin and did not reveal symptoms of bioconcentration, although such phenomena were found when mycelium isolated from the sporocarps was submited to 100 mg/L Al in liquid culture. A clear relationship between Al accumulation <i>in vitro</i> and the site of origin of the isolate was not observed, although the highest amount of Al was found in the mycelium derived from the polluted soil. In a second experiment all isolates were grown in agar media containing 10, 100, 500 and 1000 mg/L<sup>-1</sup> Al and the colony diameter during culture and the final colony dry weight determined.<i> S. luteus</i> appeared to be very tolerant to the presence of Al in the medium. Each of the parameters used to measure the metal tolerance of the fungus ranked the isolates in a slightly different order, but those originating from the polluted area showed some superiority over the others. In polluted soils this species seems to have been submitted to a selection for higher aluminium tolerance. The results are discussed with reference to the possibilities of transformating in vitro studies to situation in the forest ecosystem.

2014 ◽  
Vol 67 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Maria Rudawska ◽  
Tomasz Leski

The caps of the sporocarps of <em>P. involutus</em> originating from the polluted site (Luboń) and from the control site in Kórnik and Puszcza Nadnotecka accumulated high amounts of aluminium and revealed symptoms of bioconcentration. However in caps of the sporocarps from the control sites a lower amount of Al was accumulated than in caps from the polluted site (Luboń). A significantly lower concentration of Al was found in stems of sporocarps originating from the special control site in Puszcza Nadnotecka. Mycelia of 11 strains isolated from sporocarps collected at the polluted and control sites were cultivated on a liquid medium containing 100 mg L<sup>-1</sup> Al. All strains showed high bioconcentration of Al despite of the place of origin. In a subsequent experiment 10 strains of <em>P. involutus</em> originating from polluted soil and 8 strains derived from the control sites were grown in agar media containing 10, 100, 500 and 1000 mg/L<sup>-1</sup> of Al. The radial growth rates during culture, the final colony dry weight and the metal tolerance indices calculated on the basis of measured parameters were determined. <em>P. involutus</em> strains appeared to be very tolerant to the presence of Al in the medium and were able to grow even at the highest Al concentration. Increasing aluminium level in the medium to different extent influenced growth of tested strains, however the site of the origin did not influence the response of <em>P. involutus</em> to aluminium: among 18 strains tested, the most tolerant were selected both from the polluted and from the unpolluted sites. The results are discussed with reference to the high intraspecific variability of different physiological features of the ectomycorrhizal fungus <em>P. involutus</em>.


2005 ◽  
Vol 71 (11) ◽  
pp. 7279-7284 ◽  
Author(s):  
K. Adriaensen ◽  
T. Vrålstad ◽  
J.-P. Noben ◽  
J. Vangronsveld ◽  
J. V. Colpaert

ABSTRACT Natural populations thriving in heavy-metal-contaminated ecosystems are often subjected to selective pressures for increased resistance to toxic metals. In the present study we describe a population of the ectomycorrhizal fungus Suillus luteus that colonized a toxic Cu mine spoil in Norway. We hypothesized that this population had developed adaptive Cu tolerance and was able to protect pine trees against Cu toxicity. We also tested for the existence of cotolerance to Cu and Zn in S. luteus. Isolates from Cu-polluted, Zn-polluted, and nonpolluted sites were grown in vitro on Cu- or Zn-supplemented medium. The Cu mine isolates exhibited high Cu tolerance, whereas the Zn-tolerant isolates were shown to be Cu sensitive, and vice versa. This indicates the evolution of metal-specific tolerance mechanisms is strongly triggered by the pollution in the local environment. Cotolerance does not occur in the S. luteus isolates studied. In a dose-response experiment, the Cu sensitivity of nonmycorrhizal Pinus sylvestris seedlings was compared to the sensitivity of mycorrhizal seedlings colonized either by a Cu-sensitive or Cu-tolerant S. luteus isolate. In nonmycorrhizal plants and plants colonized by the Cu-sensitive isolate, root growth and nutrient uptake were strongly inhibited under Cu stress conditions. In contrast, plants colonized by the Cu-tolerant isolate were hardly affected. The Cu-adapted S. luteus isolate provided excellent insurance against Cu toxicity in pine seedlings exposed to elevated Cu levels. Such a metal-adapted Suillus-Pinus combination might be suitable for large-scale land reclamation at phytotoxic metalliferous and industrial sites.


2020 ◽  
Vol 13 (2) ◽  
pp. 54-65 ◽  
Author(s):  
M.E.A. Bendaha ◽  
H.A. Belaouni

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.


2021 ◽  
Vol 14 (7) ◽  
pp. 624
Author(s):  
Valentina Corvaglia ◽  
Imène Ait Mohamed Amar ◽  
Véronique Garambois ◽  
Stéphanie Letast ◽  
Aurélie Garcin ◽  
...  

Inhibition of protein–DNA interactions represents an attractive strategy to modulate essential cellular functions. We reported the synthesis of unique oligoamide-based foldamers that adopt single helical conformations and mimic the negatively charged phosphate moieties of B-DNA. These mimics alter the activity of DNA interacting enzymes used as targets for cancer treatment, such as DNA topoisomerase I, and they are cytotoxic only in the presence of a transfection agent. The aim of our study was to improve internalization and selective delivery of these highly charged molecules to cancer cells. For this purpose, we synthesized an antibody-drug conjugate (ADC) using a DNA mimic as a payload to specifically target cancer cells overexpressing HER2. We report the bioconjugation of a 16-mer DNA mimic with trastuzumab and its functional validation in breast and ovarian cancer cells expressing various levels of HER2. Binding of the ADC to HER2 increased with the expression of the receptor. The ADC was internalized into cells and was more efficient than trastuzumab at inhibiting their growth in vitro. These results provide proof of concept that it is possible to site-specifically graft high molecular weight payloads such as DNA mimics onto monoclonal antibodies to improve their selective internalization and delivery in cancer cells.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 332
Author(s):  
Min Li ◽  
Haoyun Wang ◽  
Xizhou Zhao ◽  
Zhongke Lu ◽  
Xueguang Sun ◽  
...  

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 312
Author(s):  
Nolwenn Hymery ◽  
Xavier Dauvergne ◽  
Halima Boussaden ◽  
Stéphane Cérantola ◽  
Dorothée Faugère ◽  
...  

Twelve halophyte species belonging to different families, widely represented along French Atlantic shoreline and commonly used in traditional medicine, were screened for protective activities against mycotoxins, in order to set out new promising sources of natural ingredients for feed applications. Selected halophytic species from diverse natural habitats were examined for their in vitro anti-mycotoxin activities, through viability evaluation of Madin-Darby Bovine Kidney (MDBK) and intestinal porcine enterocyte (IPEC-J2) cell lines. Besides, the in vitro antioxidant activities of plant extracts were assessed (total antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-scavenging bioassays). Of the 12 species, Galium arenarium, Convolvulus soldanella and Eryngium campestre exhibited the most protective action on MDBK and IPEC-J2 cells against zearalenone (ZEN) or T2 toxin contamination (restoring about 75% of cell viability at 10 μg·mL−1) without inflammation response. They also had strong antioxidant capacities (Inhibitory concentration of 50% (IC50) < 100 μg·mL−1 for DPPH radical and total antioxidant capacity (TAC) of 100 to 200 mg Ascorbic Acid Equivalent (AAE)·g−1 Dry Weight), suggesting that cell protection against intoxication involves antioxidant action. A bio-guided study showed that fractions of G. arenarium extract protect MDBK cells against T2 or ZEN toxicity and several major compounds like chlorogenic acid and asperuloside could be involved in this protective effect. Overall, our results show that the halophytes G. arenarium, C. soldanella and E. campestre should be considered further as new sources of ingredients for livestock feed with protective action against mycotoxin intoxication.


Mycologia ◽  
2021 ◽  
pp. 1-10
Author(s):  
María Belén Pildain ◽  
Paula Marchelli ◽  
María Marta Azpilicueta ◽  
Cristian Starik ◽  
Carolina Barroetaveña

Separations ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 57
Author(s):  
Rokayya Sami ◽  
Abeer Elhakem ◽  
Mona Alharbi ◽  
Manal Almatrafi ◽  
Nada Benajiba ◽  
...  

Onions contain high antioxidants compounds that fight inflammation against many diseases. The purpose was to investigate some selected bioactive activities of onion varieties (Yellow, Red, Green, Leek, and Baby). Antioxidant assays and anti-inflammatory activities such as NO production with the addition of some bioactive components were determined and analyzed by using a spectrophotometer. Gas chromatography and mass spectrometry (GC–MS) was used for the volatile compounds, while an Atomic absorption spectrometer was used for mineral determinations. Red variety achieved the highest antioxidant activities. The total flavonoids were between (12.56 and 353.53 mg Quercetin/gin dry weight) (dw) and the total phenol was (8.75–25.73 mg/g dw). Leek, Yellow and Green extracts achieved highly anti-inflammatory values (3.71–4.01 μg/mL) followed by Red and Baby extracts, respectively. The highest contents of sodium, potassium, zinc, and calcium were established for Red onions. Furfuraldehyde, 5-Methyl-2-furfuraldehyde, 2-Methyl-2-pentenal, and 1-Propanethiol were the most predominant, followed by a minor abundance of the other compounds such as Dimethyl sulfide, Methyl allyl disulfide, Methyl-trans-propenyl-disulfide, and Methyl propyl disulfide. The results recommend that these varieties could act as sources of essential antioxidants and anti-inflammatories to decrease inflammation and oxidative stresses, especially red onions that recorded high activities.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2579
Author(s):  
Carmen-Alina Bolea ◽  
Mihaela Cotârleț ◽  
Elena Enachi ◽  
Vasilica Barbu ◽  
Nicoleta Stănciuc

Two multi-functional powders, in terms of anthocyanins from black rice (Oryza sativa L.) and lactic acid bacteria (Lactobacillus paracasei, L. casei 431®) were obtained through co-microencapsulation into a biopolymer matrix composed of milk proteins and inulin. Two extracts were obtained using black rice flour as a raw material and hot water and ethanol as solvents. Both powders (called P1 for aqueous extract and P2 for ethanolic extract) proved to be rich sources of valuable bioactives, with microencapsulation efficiency up to 80%, both for anthocyanins and lactic acid bacteria. A higher content of anthocyanins was found in P1, of 102.91 ± 1.83 mg cyanindin-3-O-glucoside (C3G)/g dry weight (DW) when compared with only 27.60 ± 17.36 mg C3G/g DW in P2. The morphological analysis revealed the presence of large, thin, and fragile structures, with different sizes. A different pattern of gastric digestion was observed, with a highly protective effect of the matrix in P1 and a maximum decrease in anthocyanins of approximatively 44% in P2. In intestinal juice, the anthocyanins decreased significantly in P2, reaching a maximum of 97% at the end of digestion; whereas in P1, more than 45% from the initial anthocyanins content remained in the microparticles. Overall, the short-term storage stability test revealed a release of bioactive from P2 and a decrease in P1. The viable cells of lactic acid bacteria after 21 days of storage reached 7 log colony forming units (CFU)/g DW.


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