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This study was conducted to evaluate the variability of salt tolerance potentials among nine wheat genotypes representing wild and cultivated species namely Triticum turgidum subsp. durum, Triticum aestivum and Aegilops geniculata. Ionomic and photosynthetic traits were used for the screening of the studied samples when faced with four salinity levels of NaCl (0, 50, 100 and 150 mM) under green house conditions at the seedling stage. The investigated genotypes exhibited different levels of salt stress tolerance. Ionomic and photosynthetic traits underline the distinctiveness of the common wheat varieties which highlighted particular performances under salt stress conditions and showed higher tolerance potentials among the studied genotypes. Interestingly, the Vaga variety showed more ability to maintain higher K+/Na+ ratios and Pq coefficients compared with the control conditions and stable Fv/F0 and Fv/Fm ratios. Stable behaviour was exhibited by wild Aegilops accessions while durum wheat varieties have been shown to be more sensitive to salt stress. Further investigations were required for the common wheat variety Vaga, which could be useful for successful breeding and biotechnological improvement strategies concerning wheat species.

Background: The Mentha rotundifolia L. (Lamiaceae family), is a medicinal herb used since the ancient times as an antiseptic, analgesic and anti-inflammatory agent. In the present work, metabolomic profiling of two Mentha rotundifolia L. ecotypes leaf tissues spontaneously growing in the North of Tunisia was achieved. Methods: Phenolic contents (TPC, TFC and TTC) were assessed using colorimetric methods. Metabolomic profiling of leaf tissues extracts was assessed based on Gas Chromatography-Mass Spectrometry (GC/MS) analysis. The antioxidant ability of M. rotundifolia extracts was achieved based on two test systems namely DPPH and FRAP assays. Antimicrobial activity against a set of Gram negative and Gram positive bacteria was estimated by measuring ID, MIC and MBC values. Results: Fifty metabolites were identified as belonging mainly to phenolics, fatty acids, terpenes, steroids and aldehydes classes with qualitative and quantitative variability. Most of the identified compounds are reputed bioactive with potent antioxidant, antimicrobial and anti-inflammatory among others effects. To confirm these findings common in vitro biological activities were achieved. The investigated extracts showed significant antioxidant abilities based on both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Ferric reducing antioxidant potential (FRAP) assays. Furthermore, the extracts revealed promising antimicrobial ability against tested Gram+ and Gram- bacterial strains (ID: 12.5–14.5 mm, MIC: 3.125–25 (µg/mL), MBC: 6.25–100 (µg/mL)). Conclusions: Based on our findings Mentha rotundifolia L. leaves extracts present a potential source of natural antioxidants and diverse bioactive compounds which could be used in green pharmacy, food preservation, alternative medicine and natural therapies. [ABSTRACT FROM AUTHOR]

Sl-ERF.B.3 (Solanum lycopersicum ethylene response factor B.3) gene encodes for a tomato transcription factor of the ERF (ethylene responsive factor) family. Our results of real-time RT-PCR showed that Sl-ERF.B.3 is an abiotic stress responsive gene, which is induced by cold, heat, and flooding, but downregulated by salinity and drought. To get more insight into the role of Sl-ERF.B.3 in plant response to separate salinity and cold, a comparative study between wild type and two Sl-ERF.B.3 antisense transgenic tomato lines was achieved. Compared with wild type, Sl-ERF.B.3 antisense transgenic plants exhibited a salt stress dependent growth inhibition. This inhibition was significantly enhanced in shoots but reduced in roots, leading to an increased root to shoot ratio. Furthermore, the cold stress essay clearly revealed that introducing antisense Sl-ERF.B.3 in transgenic tomato plants reduces their cell injury and enhances their tolerance against 14?d of cold stress. All these results suggest that Sl-ERF.B.3 gene is involved in plant response to abiotic stresses and may play a role in the layout of stress symptoms under cold stress and in growth regulation under salinity. [ABSTRACT FROM AUTHOR]

Sl-ERF.B.3 (Solanum lycopersicum ethylene response factor B.3) gene encodes for a tomato transcription factor of the ERF (ethylene responsive factor) family. Our results of real-time RT-PCR showed that Sl-ERF.B.3 is an abiotic stress responsive gene, which is induced by cold, heat, and flooding, but downregulated by salinity and drought. To get more insight into the role of Sl-ERF.B.3 in plant response to separate salinity and cold, a comparative study between wild type and two Sl-ERF.B.3 antisense transgenic tomato lines was achieved. Compared with wild type, Sl-ERF.B.3 antisense transgenic plants exhibited a salt stress dependent growth inhibition. This inhibition was significantly enhanced in shoots but reduced in roots, leading to an increased root to shoot ratio. Furthermore, the cold stress essay clearly revealed that introducing antisense Sl-ERF.B.3 in transgenic tomato plants reduces their cell injury and enhances their tolerance against 14 d of cold stress. All these results suggest that Sl-ERF.B.3 gene is involved in plant response to abiotic stresses and may play a role in the layout of stress symptoms under cold stress and in growth regulation under salinity.