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The role of beneficial microorganisms, such as mycorrhizas, in improving the resistance to environmental stress of colonized plants is well-known. Plants of Brassicaceae family are of large economic importance, especially for the synthesis of anticarcinogenic compounds such as glucosinolates and their derivatives isothiocyanates. The endophyte fungus Piriformospora indica is able to colonize them and improves their growth and response to environmental stress. However, no information are available on the impact of colonization on glucosinolate metabolism. In this work, colonization of black cabbage (Brassica oleracea cv. Acephala sabellica) is reported as well as the effects on plant growth and on the expression of myrosinase encoding genes, the isothyocianate producing enzymes. Results indicate that P. indica successfully colonized black cabbage as validated by the expression of the marker gene Ptef1. Colonized plants showed increase of biomass weights and shoot length respect to the uncolonized plants and a decrease of myrosinase gene expression. This last finding indicates that P. indica might affect the resistance against biotic stress of black cabbage. [ABSTRACT FROM AUTHOR]

Knowledge of the natural emissions of mercury in the Mediterranean basin, which has large cinnabar anomalies, has particular weight as these deposits could be an important source of atmospheric mercury. Data on the degassing rate of mercury from soils sampled both in mineralized areas (Mt. Amiata, Italy and Almaden, Spain) and rural areas arereported. Measurements were carried out 'in situ' using a transparent flux chamber and collecting the gaseous mercury on gold collectors.The highest values were observed in Almaden over the roasted cinnabar banks (up to 100 mu g/m{sup}2{end} h) from past and present mining activity. In Italian rural areas the values of the volatilization rate of mercury are on the order of few ng/m{sup}2{end} h. The degassingrate was observed to be strongly dependent on the ambient temperature and not only seasonal but also daily variations were measured in all the studied areas. [ABSTRACT FROM AUTHOR]

Arundo donax L. is an invasive species that has been recently employed for biomass production due to its well-known ability to colonize harsh environment. Based on previous observations, the present study investigated the potential role of phenylpropanoids and class III peroxidases to confer adaptation through biochemical and transcriptomic analysis in A. donax after Na + and P excess supply, both in single stress and in combination, and after growth at low P level. The levels of hydrogen peroxide, flavonoids (i.e., quercetin, apigenin and kaempferol derivatives) and the activity of class III peroxidases, as well as the expression of several genes encoding for their enzymes involved in their biosynthesis, increased when Na + was supplied in combination with P. These results suggest that those biomolecules are involved in the response of A. donax, to the presence of +Na and P in the soil. Moreover, even though at the sampling time no significant accumulation of lignin has been determined, the trend of accumulation of such metabolite and most of all the increase of several transcripts involved in its synthesis was found. This work for the first time indicates the need for further investigation devoted to elucidating whether the strengthening of cell walls via lignin synthesis is one of the mechanisms used by A. donax to adapt to harsh environments., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

The expression of two genes, namely Mir1 and Mir3 and the abundance of their encoded proteins, the putative miraculin-like proteins, MLP1 and MLP3, showing similarity to the Kunitz family of protease inhibitors, were monitored in the leaves of the citrus variety, 'Clementine' after Tetranychus urticae infestation and elicitor treatments, or in the leaves of three other diploid citrus: 'Willow leaf', 'Cleopatra' mandarins and 'Trifoliate' orange, as well as their respective doubled diploids and the allotetraploid somatic hybrid 'FLHORAG1' under salt stress. RT-PCR and 2-DE indicated that Mir1 and Mir3 and their products were present at low-basal expression in all citrus genotypes. Both genes and products were induced in the 'Clementine' leaves infested by T. urticae, but a contrasting profile was observed under elicitor treatments. Under salt stress, the two genes showed an expression pattern contrasting each other and depending on the genotypes. 'Cleopatra' mandarin, 'Trifoliate' orange and 'FLHORAG1' presented overexpression of Mir3 and MLP3 and decreased levels of Mir1 and MPL1. The opposite behaviour was found in 'Willow leaf' mandarin. The positive correlation of the expression profile of the two genes with that of a gene encoding a putative apoplastic cysteine protease (CysP) might suggest a possible interaction of the respective encoded proteins during the response to biotic stress. Under salt stress, CysP and Mir 1 showed a similar expression pattern but only at transcript level. The possible occurrence of post-translational CysP regulation is discussed., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Citrus plants are currently facing biotic and abiotic stresses. Therefore, the characterization of molecular traits involved in the response mechanisms to stress could facilitate selection of resistant varieties. Although large cDNA microarray profiling has been generated in citrus tissues, the available protein expression data are scarce. In this study, to identify differentially expressed proteins in Citrus clementina leaves after infestation by the two-spotted spider mite Tetranychus urticae, a proteome comparison was undertaken using two-dimensional gel electrophoresis. The citrus leaf proteome profile was also compared with that of leaves treated over 0-72h with methyl jasmonate, a compound playing a key role in the defense mechanisms of plants to insect/arthropod attack. Significant variations were observed for 110 protein spots after spider mite infestation and 67 protein spots after MeJA treatments. Of these, 50 proteins were successfully identified by liquid chromatography-mass spectrometry-tandem mass spectrometry. The majority constituted photosynthesis- and metabolism-related proteins. Five were oxidative stress associated enzymes, including phospholipid glutathione peroxidase, a salt stressed associated protein, ascorbate peroxidase and Mn-superoxide dismutase. Seven were defense-related proteins, such as the pathogenesis-related acidic chitinase, the protease inhibitor miraculin-like protein, and a lectin-like protein. This is the first report of differentially regulated proteins after T. urticae attack and exogenous MeJA application in citrus leaves., (Copyright © 2010 Elsevier GmbH. All rights reserved.)

With the aim of studying differentially expressed proteins as a function of abiotic and biotic stress in citrus plants, we optimized a protocol for the extraction of total leaf proteins and their 2-DE separation using commercially available immobilized pH gradient strips (IPGs) in the first dimension. Critical factors for good reproducibility of citrus leaf protein separation were identified: trichloroacetic acid (TCA)/acetone precipitation after extraction in lysis buffer, sample fractionation on narrow range overlapping IPGs and sample-cup loading at the anodic or cathodic end of the strip. The use of thiourea and a strong detergent (C7BzO) in the solubilization/rehydration buffer, coupled with the increase to 10% of SDS in the equilibration buffer before the second dimension seemed to affect positively the resolution of basic proteins. Using our protocol we resolved about 30 basic proteins on 6.3-8.3 pH range strips. Further, our protocol was successfully applied reproducibly on the analysis of control and salt exposed leaf samples of Citrus reshni Hort. Ex Tan.

The accumulation of cadmium or mercury and the effect of these elements on the levels of non-protein thiols in the blades of the marine macrophyte Posidonia oceanica were investigated. A significant accumulation of cadmium or mercury, dependent on metal concentration supplied, was observed in metal-treated blades. In the blades treated either with cadmium or mercury, a significant increase in the levels of non-protein thiols (other than glutathione) and a marked depletion of the reduced glutathione content as a function of the metal, exposure time and metal concentration supplied were found. This investigation provides first experimental report on the relationship between non-protein thiol pools and accumulated cadmium or mercury in P. oceanica.

Mercury levels in total suspended matter (TSM) and in plankton of sea water from some Mediterranean areas have been determined. The mercury concentration in TSM collected with a filter of 0.45 micron pore size ranges from 0.1 to 2.4 ng l-1 and from 0.1 to 4.7 ng mg-1, dry wt. These levels are 3-10 times higher than those observed in plankton (0.08-0.29 ng mg-1 dry wt.) collected with a 200 microns net mesh size. The larger amounts of mercury in TSM than in the matter collected by the plankton nets are probably due to the high abundance of smaller sized particles selected by the filter.