scholarly journals Aluminium tolerance of different Paxillus involutus Fr. strains originating from polluted and nonpolluted sites

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>.

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.


1984 ◽  
Vol 62 (12) ◽  
pp. 2827-2834 ◽  
Author(s):  
R. J. Staniforth ◽  
S. S. Sidhu

Reproductive and vegetative characteristics of raspberry and blueberry plants were monitored at six sites downwind from a phosphorus plant which emitted gaseous and particulate fluorides. Atmospheric fluoridation rates ranged from an average of 347.4 μg F∙dm−2∙week−1 (or 11.38 μg F∙m−1) at 1.4 km to 2.5 μg F∙dm−2∙week−1 (or 0.08 μg F∙m−3) at 18.7 km from the source. The highest fluoridation levels were in July, the month in which flowering in the two species reached its peak. At the most polluted site, flower mortality was 89% for blueberry and 78% for raspberry; this accounted for most of the loss in reproductive potential. Comparative values of the control site (18.7 km from source) were 27 and 26%, respectively. There were 21- and 10-fold decreases in seed production per plant in blueberry and raspberry, respectively, as well as significant decreases in the size, number, and dry weight of fruit. Fluoride damage to blueberry plants did not result in any effects being passed on to seedlings, except for a slightly accelerated germination rate. Fluoride accumulations in the foliage of plants 1.4 km from the source were 403 ppm for raspberry and 216 ppm for blueberry but only 8 and 9 ppm, respectively, at the control site. Fluoride-affected raspberry plants also showed foliar injury, enhanced vegetative spread, and delayed leaf fall in the autumn.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1625
Author(s):  
Antonio De Agostini ◽  
Pierluigi Cortis ◽  
Annalena Cogoni ◽  
Roberta Gargiulo ◽  
Giuseppe Fenu

Analysis of the seed morphology is a widely used approach in ecological and taxonomic studies. In this context, intraspecific variability with respect to seed morphology (size, weight, and density) was assessed in two close Epipactis tremolsii Pau. populations sharing the same ecological conditions, except for the soil pollution distinguishing one of them. Larger and heavier seeds were found in plants growing on the heavy metal polluted site, while no differences in seed density were detected between seeds produced by plants growing on the contaminated and the control site. Moreover, seed coats and embryos varying together in their dimensions were described in the control population, while coats varying in their size independently from embryos were described in plants growing on the polluted site. Seeds from the two studied populations significantly differed in several parameters suggesting that intraspecific seed variability occurred in the case study.


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.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 889
Author(s):  
Aviad Perry ◽  
Noemi Tel-Zur ◽  
Arnon Dag

Jojoba (Simmondsia chinensis) is a wax crop cultivated mainly in arid and semi-arid regions. This crop has been described as an alternate-bearing plant, meaning that it has a high-yield year (“on-year”) followed by a low-yield year (“off-year”). We investigated the effect of fruit load on jojoba’s vegetative and reproductive development. For two consecutive years, we experimented with two high-yielding cultivars—Benzioni and Hazerim—which had opposite fruit loads, i.e., one was under an on-year load, while the other was under an off-year load simultaneously. We found that removing the developing fruit from the shoot during an off-year promotes further vegetative growth in the same year, whereas in an on-year, this action has no effect. Moreover, after fruit removal in an on-year, there was a delay in vegetative growth renewal in the consecutive year, suggesting that the beginning of the growing period is dependent on the previous year’s yield load. We found that seed development in the 2018 season started a month earlier than in the 2017 season in both cultivars, regardless of fruit load. This early development was associated with higher wax content in the seeds. Hence, the wax accumulation rate, as a percentage of dry weight, was affected by year and not by fruit load. However, on-year seeds stopped growing earlier than off-year seeds, resulting in smaller seeds and an overall lower amount of wax per seed.


2004 ◽  
Vol 70 (12) ◽  
pp. 7413-7417 ◽  
Author(s):  
Mikael Courbot ◽  
Laurent Diez ◽  
Roberta Ruotolo ◽  
Michel Chalot ◽  
Pierre Leroy

ABSTRACT Molecular and cellular mechanisms underlying the sustained metal tolerance of ectomycorrhizal fungi are largely unknown. Some of the main mechanisms involved in metal detoxification appear to involve the chelation of metal ions in the cytosol with thiol-containing compounds, such as glutathione, phytochelatins, or metallothioneins. We used an improved high-performance liquid chromatography method for the simultaneous measurement of thiol-containing compounds from cysteine and its derivatives (γ-glutamylcysteine, glutathione) to higher-molecular-mass compounds (phytochelatins). We found that glutathione and γ-glutamylcysteine contents increased when the ectomycorrhizal fungus Paxillus involutus was exposed to cadmium. An additional compound with a 3-kDa molecular mass, most probably related to a metallothionein, increased drastically in mycelia exposed to cadmium. The relative lack of phytochelatins and the presence of a putative metallothionein suggest that ectomycorrhizal fungi may use a different means to tolerate heavy metals, such as Cd, than do their plant hosts.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4478 ◽  
Author(s):  
Vinicius H. De Oliveira ◽  
Mark Tibbett

BackgroundMetal contamination in soils affects both above- and belowground communities, including soil microorganisms. Ectomycorrhizal (ECM) fungi are an important component in belowground community and tolerant strains have great potential in enhancing plant-based remediation techniques. We assessed cadmium and zinc toxicity in five ECM species in liquid media (Hebeloma subsaponaceum;H. cylindrosporum;H. crustuliniforme;Sclerodermasp.;Austroboletus occidentalis) and investigated the potential of Zn to alleviate Cd toxicity. Due to highly divergent results reported in the literature, liquid and solid media were compared experimentally for the first time in terms of differential toxicity thresholds in Cd and Zn interactions.MethodsA wide range of Cd and Zn concentrations were applied to ectomycorrhizal fungi in axenic cultures (in mg L−1): 0; 1; 3; 9; 27; 81; 243 for the Cd treatments, and 0; 1; 30; 90; 270; 810; 2,430 for Zn. Combined Zn and Cd treatments were also applied toH. subsaponaceumandSclerodermasp. Dry weight was recorded after 30 days, and in case of solid medium treatments, radial growth was also measured.Results and DiscussionAll species were adversely affected by high levels of Cd and Zn, andA. occidentaliswas the most sensitive, with considerable biomass decrease at 1 mg L−1Cd, whileSclerodermasp. andH. subsaponaceumwere the most tolerant, which are species commonly found in highly contaminated sites. Cd was generally 10 times more toxic than Zn, which may explain why Zn had little impact in alleviating Cd effects. In some cases, Cd and Zn interactions led to a synergistic toxicity, depending on the concentrations applied and type of media used. Increased tolerance patterns were detected in fungi grown in solid medium and may be the cause of divergent toxicity thresholds found in the literature. Furthermore, solid medium allows measuring radial growth/mycelial density as endpoints which are informative and in this case appeared be related to the high tolerance indices found inH. subsaponaceum.


Author(s):  
Fei Huang ◽  
Xiao-Hui Wen ◽  
Yi-Xia Cai ◽  
Kun-Zheng Cai

Silicon (Si) plays important roles in alleviating heavy metal stress in rice plants. Here we investigated the physiological response of rice at different growth stages under the silicon-induced mitigation of cadmium (Cd) and zinc (Zn) toxicity. Si treatment increased the dry weight of shoots and roots and reduced the Cd and Zn concentrations in roots, stems, leaves and grains. Under the stress of exposure to Cd and Zn, photosynthetic parameters including the chlorophyll content and chlorophyll fluorescence decreased, while the membrane permeability and malondialdehyde (MDA) increased. Catalase (CAT) and peroxidase (POD) activities increased under heavy metals stress, but superoxide dismutase (SOD) activities decreased. The magnitude of these Cd- and Zn-induced changes was mitigated by Si-addition at different growth stages. The available Cd concentration increased in the soil but significantly decreased in the shoots, which suggested that Si treatment prevents Cd accumulation through internal mechanisms by limiting Cd2+ uptake by the roots. Overall, the phenomena of Si-mediated alleviation of Cd and excess Zn toxicity in two rice cultivars could be due to the limitation of metal uptake and transport, resulting in an improvement in cell membrane integrity, photosynthetic performance and anti-oxidative enzyme activities after Si treatment.


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