Pathogen-related proteins (PRs) are diversified proteins with a low molecular weight implicated in plant response to biotic and abiotic stress as well in regulating different functions in plant maturation. Interestingly, no systematical study has been conducted in durum wheat (Triticum turgidum subsp. durum). In the present study, 12 PR-1 genes encoding a CAP superfamily domain were identified in the genome of Triticum turgidum subsp. durum, which is an important cereal, using in silico approaches. Additionally, phylogenetic analysis showed that the PR-1 genes were classified into three groups based on their isoelectric point and the conserved motif domain. Moreover, our analysis showed that most of the TdPR-1 proteins presented an N-terminal signal peptide. Expression patterns analysis showed that the PR-1 gene family presented temporal and spatial specificity and was induced by different abiotic stresses. This is the first report describing the genome-scale analysis of the durum wheat PR-1 gene family, and these data will help further study the roles of PR-1 genes during stress responses, leading to crop improvement.

New lupeol long-chain alkanoic ester 1 and lupeol β-hydroxy fatty acid esters 2c,d (laevigatins I and II) in a mixture with the previously isolated procrims a and b (2a,b) were isolated together with lupeol 3 and lupeol acetate 4 from the latex of Periploca laevigata collected in Tunisia. Their structures were elucidated by extensive spectroscopic methods including 1D (1H, 13C and DEPT 135), 2D-NMR experiments, (1H–1H COSY and NOESY), EI–MS, MALDI-TOF and GC analysis. Anti-acetylcholinesterase activity of most isolated compounds was evaluated and showed that lupeol (3) was the best inhibitor of AChE

Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all aerobic organisms. In fact, the CAT enzyme modulates the hydrogen peroxide (H₂O₂) contents in cells by translating this toxic compound into water (H₂O) and O₂⁻ to reduce reactive oxygen species (ROS) contents in cells. ROS are produced as a result of biotic and abiotic environmental stressors. To avoid ROS toxicity, plants are armed with different enzymatic and non-enzymatic systems to decompose ROS. Among the enzymatic system, CAT proteins are well studied. CAT not only controls growth and development in plants but is also involved in plant defense against different stresses. So far, the CAT gene family has not been reported in durum wheat (Triticum turgidum ssp. durum L.). Therefore, a genome-wide comprehensive analysis was conducted to classify the CAT genes in the durum wheat genome. Here, six TdCAT genes were identified. Based on phylogenetics, the TdCAT genes belong to three groups (Groups I–III) which is explainable by their comparable structural characteristics. Using bio-informatic analysis, we found that the secondary and tertiary structures were conserved among plants and present similar structures among durum wheat CATs. Two conserved domains (pfam00199 and pfam06628) are also present in all identified proteins, which have different subcellular localizations: peroxisome and mitochondrion. By analyzing their promoters, different cis-elements were identified, such as hormone-correlated response and stress-related responsive elements. Finally, we studied the expression pattern of two catalase genes belonging to two different sub-classes under different abiotic stresses. Expression profiling revealed that TdCAT2 and TdCAT3 presented a constitutive expression pattern. Moreover, both genes are induced in response to salt, mannitol, cold, heat and ABA. Thus, we speculate that those genes are activated by different stresses, such as oxygen deficiency, light, cold, abscisic acid and methyl jasmonate. Further, this study will help in understanding the behavior of CAT genes during environmental stress in durum wheat and in Triticeae species in general.

Catalase is a crucial enzyme in the antioxidant defense system protecting organisms from oxidative stress. Proteins of this kind play important roles in controlling plant response to biotic and abiotic stresses by catalyzing the decomposition of H₂O₂. The durum wheat catalase 1, TdCAT1, has been previously isolated and characterized. Here, using bio-informatic analysis, we showed that durum wheat catalase 1 TdCAT1 harbors different novel conserved domains. In addition, TdCAT1 contains various phosphorylation residues and S-Nitrosylation residues located at different positions along the protein sequence. TdCAT1 activity decreased after treatment with λ−phosphatase. On the other hand, we showed that durum wheat catalase 1 (TdCAT1) exhibits a low CAT activity in vitro, whereas a deleted form of TdCAT1 has better activity compared to the full-length protein (TdCAT460), suggesting that TdCAT1 could present a putative autoinhibitory domain in its C-terminal portion. Moreover, we showed that TdCAT1 positively regulates E. coli cells in response to salt, ionic and osmotic stresses as well as heavy metal stress in solid and liquid mediums. Such effects had not been reported and lead us to suggest that the durum wheat catalase 1 TdCAT1 protein could play a positive role in response to a wide array of abiotic stress conditions.

The chemical composition, cytotoxic and antibacterial activities of the hydrodistilled essential oil of the aerial parts of Ononis angustissima from south Tunisia has been evaluated. The oil yield was 0.04% (w/w). The chemical composition, determined by GC and GC-MS is reported for the first time. Forty-five components, accounting for 93.7% of the total oil have been identified. The oil was characterized by a high proportion of oxygenated sesquiterpenes (33.2%), followed by sesquiterpene hydrocarbons (6.3%) and apocarotenoids (10.3%). The main components of the oil were α-eudesmol (22.4%), 2-tridecanone (9.3%) and acetophenone (7.4%). The essential oil was tested for its possible cytotoxic activity towards the human cervical cell line HeLa using the MTT assay and the antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and the clinical strain Acinetobacter sp. This oil exerted a cytotoxic activity with an IC50 of 0.53 ± 0.02 mg/mL and a significant antibacterial effect against P. aeruginosa and E. faecalis.