138 research outputs found

    Characterization of normal and "albino" phenotypes in Erythrina crista-galli

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    We present here a characterization of Erythrina crista-galli L. (syn: Erythrina lamifolia Jacq.) seedlings, obtained from a plant from the Botanical Garden of Pisa University. This plant produces seeds that, during germination, have shown two different seedling phenotypes: normal (NT, 75%) and "albino" types (AT, 25%). Albino seedlings survive only 8–9 weeks and their growth is dramatically reduced when compared with wild type seedlings. Biochemical investigations have shown that albino seedlings completely lack chlorophyll and carotenoids and also soluble sugar levels are lower than in the normal type. We have also conducted sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) experiments and silver staining analysis on different protein extracts from shoots and leaves of both phenotypes, and demonstrated strong differences in protein patterns. The almost total absence of putative small and large RuBisCo bands in albino seedlings should be emphasized. We have also microspectrophotometrica..

    Thermophilous fungi isolated from the air at Pavia

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    Se presentan los resultados de un año de investigación sobre hongos termófilos en el aire de la ciudad de Pavia (Italia).Se detectan ocho especies, las más frecuentes son: Aspergillus fumigatus Fres., Thermomyces lanuginosus, Tsiklinsky, y Rhizomucor pusillus (Lindt) Schipper

    Cover crop introduction in a Mediterranean maize cropping system. Effects on soil variables and yield

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    Cover crops (CCs) are able to affect subsequent crop behaviour by acting on many soil variables and affecting the dynamics of different ecological processes. This study aimed to investigate the effects of introducing CC in continuous-maize cropping systems within Mediterranean areas. The experimental site was located in Central Italy, on a sandy loam and the research activity was carried out over two years (2019–2020). The two cropping systems in comparison differed from each other in terms of the CC cultivation: TR (treated, with CC) and CO (control, without CC). In both years, we observed a significant reduction (p < 0.05) of soil nitrate and water content for the TR system. In the shallowest layer (0–30 cm), nitrate content was reduced by up 80% and 65% (July 2019 and 2020), whereas soil moisture showed decreases ranging from 13% (July 2019) to 34% (May 2019). In 2019, the TR-maize (Zea mays L.) yield was statistically lower than CO (443 g dm m2), whereas in 2020 the yields of the two systems resulted statistically equivalent. This different behaviour can be explained with the serious delay in the CC sowing occurred in 2019 (12 December). Conversely, an increase in the apparent remaining N in the soil (+140 and +133 kg N ha1 for 2019 and 2020, respectively) and in the C (carbon) inputs (+4.78 and +7.39 t dm ha1 of biomass) were pointed out for the TR system. The large use of inputs in Mediterranean maize cropping systems limited some of the benefits from CCs, but their suitability has to be evaluated by considering all the involved effects, some of which need a long time to become appreciable

    SEASONAL BEHAVIOUR OF KERATINOPHILIC FUNGI ISOLATED FROM PARKS SOIL IN MILAN

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    Soil samples collected from 10 parks in Milan were examined for the presence of keratinophilic fungi by the Orr’s hair baiting technique. The organisms isolated and their frequency were as follows: Arthroderma uncinatum and its anamorph Keratinomyces ajelloi were dominantand recovered from 22.5% - 43.7% and 40% - 50% of the soil samples collected in summer and winter respectively. Myceliophthora vellerea was isolated in 31.2% of the samples, particularly in winter, Microsporum gypseum in winter (20%) and Trichophyton terrestre (10%) in summer.Chrysosporium keratinophilum (16.2% in summer and 18.7% in winter) C. indicum (15% s- 23.7% w), C. pannicola (5% s - 37% w). Aphanoascus fulvescens was isolated in summer (23.7%). Among the cycloheximide-resistant keratinophilic fungi Alternaria alternata (27.5% s – 33.7% w), Paecilomyces lilacinus (26.2% s - 18.7% w) and Acremonium strictum (8.7% s - 20% w) also were observed. The distribution of the different species is discussed.

    Behind the loss of salinity resistance during domestication: alternative eco-physiological strategies are revealed in tomato clade.

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    Salinity stress impairs growth and physiological performance in tomato, which is one of the most economically important vegetables and is widely cultivated in arid and semi-arid areas of the world. Plant landraces, which are heterogeneous, local adaptations of domesticated species, offer a unique opportunity to valorize available germplasm, underpinning the productivity, resilience, and adaptive capacity of staple crops in vulnerable environments. Here, we investigated the response of fully mature tomato plants from a commercial variety, an ancestral wild relative, and a landrace under short-term salinity exposure, as well as their ability to recover upon cessation of stress. The heterogeneous panel evaluated in this study revealed different adaptative strategies to cope the stress. Our data highlighted the ability of the tomato clade to handle low and intermediate salinity stress for short-term exposure time, as well as its capacity to recover after the cessation of stress, although inter- and intraspecific variations in morphological and physiological responses to salinity were observed. Overall, the landrace and the wild type performed similarly to control conditions under low salinity, demonstrating an improved ability to maintain ionic balance. In contrast, the commercial genotype showed susceptibility and severe symptoms even under low salinity, with pronounced reductions in K+/Na+ ratio, PSII photochemical efficiency, and photosynthetic pigments. This research confirmed that improved salt tolerant genotypes can lead to substantial, positive impacts on horticultural production. While the salt tolerance mechanism of domesticated tomato was efficient under mild stress conditions, it failed at higher salinity levels

    seasonal behaviour of keratinophilic fungi isolated from parks soil in milan

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    Soil samples collected from 10 parks in Milan were examined for the presence of keratinophilic fungi by the Orr's hair baiting technique. The organisms isolated and their frequency were as follows: Arthroderma uncinatum and its anamorph Keratinomyces ajelloi were dominant and recovered from 22.5% - 43.7% and 40% - 50% of the soil samples collected in summer and winter respectively. Myceliophthora vellerea was isolated in 31.2% of the samples, particularly in winter, Microsporum gypseum in winter (20%) and Trichophyton terrestre (10%) in summer. Chrysosporium keratinophilum (16.2% in summer and 18.7% in winter) C. indicum (15% s- 23.7% w), C. pannicola (5% s - 37% w). Aphanoascus fulvescens was isolated in summer (23.7%). Among the cycloheximide-resistant keratinophilic fungi Alternaria alternata (27.5% s – 33.7% w), Paecilomyces lilacinus (26.2% s - 18.7% w) and Acremonium strictum (8.7% s - 20% w) also were observed. The distribution of the different species is discussed

    Production of serine chymotrypsin - like elastase by aspergillus fumigatus strains

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    Thirty-four Aspergillus fumigatus strains isolated from air, horse-hair; agricultural soil and human samples were screened to evaluate the production of elastase. Aspergillus fumigatus strains were grown in elastin solid medium, showing a widespread elastin solubilization. However, isolates from human and agricultural soil samples were found to be the highest elastase producers. Then, eight out of 34 strains were grown in four different liquid media, on wich we investigated total and specific proteolytic activity. Results from this experiments suggest that the elastase production is induced by the presence of elastin as a substrate and that the elastase is a chymotrypsin like enzyme. Inhibitory profile showed that the A.fumigatus elastase is a serine proteinase

    Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice

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    Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions

    Effect of honey and syrup diets enriched with 1,3-1,6 β-glucans on honeybee survival rate and phenoloxidase activity (Apis mellifera l. 1758)

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    β-glucans can activate the animal innate immune system by acting as immune-modulators and inducing various stimulatory effects. The aim of this study was to investigate the effect of 1,3-1,6 β-glucans administered orally for 96 h on Apis mellifera workers (newly emerged and nurse bees). β-glucans were included in honey and syrup. Survival rate and phenoloxidase activity were measured. In both newly emerged and nurse bees, β-glucans supplementation did not affect survival rate (p > 0.05). Conversely, phenoloxidase activity was higher in both newly emerged bees (p = 0.048) and nurse bees (p = 0.014) fed with a honey diet enriched with β-glucans compared to those fed with only honey. In both the newly emerged and nurse bees, no statistical differences in phenoloxidase activity were recorded between the group fed with a syrup-based diet enriched with β-glucans and the control group (p > 0.05). The absence of significant variation in survival suggests that the potential negative effect of β-glucans in healthy bees could be mitigated by their metabolism. Conversely, the inclusion of β-glucans in a honey-based diet determined an increase of phenoloxidase activity, suggesting that the effect of β-glucan inclusion in the diet of healthy bees on phenoloxidase activity could be linked to the type of base-diet. Further investigations on β-glucans metabolism in bees, on molecular mechanism of phenoloxidase activation by 1,3-1,6 β-glucans, and relative thresholds are desirable. Moreover, investigation on the combined action of honey and β-glucans on phenoloxidase activity are needed

    Interference with oxidative phosphorylation enhances anoxic expression of rice α-amylase genes through abolishing sugar regulation

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    Rice has the unique ability to express α-amylase under anoxic conditions, a feature that is critical for successful anaerobic germination and growth. Previously, anaerobic conditions were shown to up-regulate the expression of Amy3 subfamily genes (Amy3B/C, 3D, and 3E) in rice embryos. These genes are known to be feedback regulated by the hydrolytic products of starchy endosperm such as the simple sugar glucose. It was found that oxygen deficiency interferes with the repression of Amy3D gene expression imposed by low concentrations of glucose but not with that imposed by higher amounts. This differential anoxic de-repression depending on sugar concentration suggests the presence of two distinct pathways for sugar regulation of Amy3D gene expression. Anoxic de-repression can be mimicked by treating rice embryos with inhibitors of ATP synthesis during respiration. Other sugar-regulated rice α-amylase genes, Amy3B/C and 3E, behave similarly to Amy3D. Treatment with a respiratory inhibitor or anoxia also relieved the sugar repression of the rice CIPK15 gene, a main upstream positive regulator of SnRK1A that is critical for Amy3D expression in response to sugar starvation. SnRK1A accumulation was previously shown to be required for MYBS1 expression, which transactivates Amy3D by binding to a cis-acting element found in the proximal region of all Amy3 subfamily gene promoters (the TA box). Taken together, these results suggest that prevention of oxidative phosphorylation by oxygen deficiency interferes with the sugar repression of Amy3 subfamily gene expression, leading to their enhanced expression in rice embryos during anaerobic germination
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