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It is well known that in the rhizosphere soluble Fe sources available for plants are mainly a mixture of complexes between the micronutrient and organic ligands such as organic acids and phytosiderophores (PS) released by roots, microbial siderophores as well as fractions of humified organic matter. In the present work, mechanisms of Fe acquisition operating at the leaf level of plants fed with different Fe-complexes were investigated at the micro-analytical, physiological and molecular levels. Fe-deficient tomato plants (Solanum Lycopersicum L., cv. 'Marmande') were fed for 24 h with a solution (pH 7.5) containing 1 A mu M Fe as Fe-PS, Fe-citrate or Fe-WEHS. Thereafter, leaf tissue was used for the visualization of Fe distribution, measurements of Fe content, reduction and uptake, and evaluation of expression of Fe-chelate reductase (LeFRO1), Fe-transporter (LeIRT1) and Ferritin (Ferritin2) genes. Leaf discs isolated from Fe-deficient plants treated for 24 h with Fe-WEHS developed higher rates of translocation, Fe-chelate reduction and Fe-59 uptake as compared to plants supplied with Fe-citrate or Fe-PS. Leaves of plants treated with Fe-WEHS also showed higher transcript levels of LeFRO1, LeIRT1 and Ferritin2 genes with respect to plants fed with the other Fe-sources. Data obtained support the idea that the efficient use of Fe complexed to WEHS-like humic fractions involves, at least in part, also the activation of Fe-acquisition mechanisms operating at the leaf level

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In the present investigation, essential oil (EO) and methanolic extract of Tunisian Mentha spicata leaves were tested for their chemical composition and biological activities. Results showed that EO was characterized by the predominance of oxygenated monoterpenes (92.18%), followed by monoterpene hydrocarbons and sesquiterpenes whose respective amounts were 2.74 and 3.1% of the whole EO. The main volatile compound of M. spicata EO was L‐menthone, accounting for 32.74% of the total volatiles, followed by pulegone (26.67%). The phenolic composition of methanolic extracts was determined by reversed‐phase high‐performance liquid chromatography. The major flavonoid component was apigenin with a mean concentration of 38.4 mg/100 g dry weight. M. spicata leave extract tested for their antioxidant and antibacterial activities showed a significant antiradical and superoxide anion scavenging capacity in addition to the great potential for antimicrobial activities against the bacteria tested. PRACTICAL APPLICATIONS Spearmint (Mentha spicata L.) is an aromatic plant belonging to the Lamiaceae family. M. spicata L. is commercially cultivated in many regions of the world. Spearmint oil has economical importance and is used in perfumery, confectionary and pharmaceutical preparations. Tunisia is blessed with a rich source of aromatic plants, many of which have not been previously investigated for their chemical constituents and biological potentials. Among these plants, we can mention M. spicata L. (Lamiaceae), which is largely distributed from the humid to the upper arid regions. This work was carried out as a first step for a chemical and biological activity of Tunisian M. spicata through phenolic and essential oil composition. A further isolation and purification of M. spicata phenolics and volatiles will be associated with an application in food industry as antioxidants, additives for food preservation and for enhancing their nutritional value and organoleptic quality. Furthermore, a pharmacological study could be established through in vivo assays in order to discover new anticarcenogenic, anti‐inflammatory, antimutagenic and other activities of M. spicata. Such results could be used in pharmaceutical formulations, leading to new human drugs from this medicinal plant.