The influence of polycyclic aromatic hydrocarbons in protein profile of Medicago sativa L.

Medicago sativa L. (alfalfa) are studied as potential phytoremediation agents of priority pollutants like polycyclic aromatic hydrocarbons (PAH). However, elucidation of the biochemical mechanisms involved in phytoremediation is a topic to be explored with knowledge gaps. This study aims to identify and classify proteins expressed in the aerial parts of laboratory-cultivated alfalfa in the presence and absence of pyrene, anthracene, and phenanthrene. Soil samples were amended with 100 mg.kg-1 of each PAH (total concentration of 300 ppm) and cultivated with alfalfa plants for 20 days. After this, aerial parts of cultivated plants from each condition were collected for qualitative proteomic analysis (ESI-Q/TOF). The results showed a significant increase (Student's t-test p < 0.05) of 41.7% in the concentration of proteins from plants grown in PAH-amended substrates, changes in the protein profile, with intense protein bands observed at 40-55, 34, 28, and 15 kDa when compared to the control. A total of 504 proteins were identified and classified into 12 functional categories, highlighting the identification of 11 phytoremediation-related proteins candidates in plants grown in the presence of PAH, with biological functions related to diverse metabolisms involved in the xenobiotics biodegradation (included PAH), glutathione and response to stress.

Phytoremediation of polycyclic aromatic hydrocarbons (PAH) by cv. Crioula: A Brazilian alfalfa cultivar.

This work aimed to evaluate the phytoremediation capacity of the alfalfa cultivar Crioula in soils contaminated with polycyclic aromatic hydrocarbons (PAHs), primary pollutants with mutagenic and carcinogenic potential. Alfalfa was grown from seed for 40 days on soil amended with anthracene, pyrene, and phenanthrene. Soil and plant tissue was collected for biometric assay, dry mass analysis, and PAH analysis by liquid chromatography. Increased total PAH concentration was associated with decreases in plant biomass, height, and internode length. The Crioula cultivar had a satisfactory phytoremediation effect, reducing total PAH concentration (300 ppm) in the experimental soil by 85% in 20 days, and by more than 95% in 40 days. The PAH showed a tendency to be removed in the temporal order: phenanthrene before pyrene before anthracene, and the removal ratio was influenced by the initial soil concentration of each PAH.

Detection of polycyclic aromatic hydrocarbons (PAHs) in Medicago sativa L. by fluorescence microscopy.

Green technologies, such as phytoremediation, are effective for removing organic pollutants derived from oil and oil products, including polycyclic aromatic hydrocarbons (PAHs). Given the increasing popularity of these sustainable remediation techniques, methods based on fluorescence microscopy and multiphoton microscopy for the environmental monitoring of such pollutants have emerged in recent decades as effective tools for phytoremediation studies aimed at understanding the fate of these contaminants in plants. However, little is known about the cellular and molecular mechanisms involved in PAH uptake, responses and degradation by plants. Thus, the present study aimed to detect the location of pyrene, anthracene and phenanthrene using fluorescence microscopy techniques in shoots and roots of Medicago sativa L. (alfalfa) plants grown in artificially contaminated soil (150ppm PAHs) for 40days. Leaflet and root samples were then collected and observed under a fluorescence microscope to detect the presence of PAHs in various tissues. One important finding of the present study was intense fluorescence in the glandular secreting trichomes (GSTs) of plants grown in contaminated soil. These trichomes, with a previously unknown function, may be sites of PAH conjugation and degradation.