Molecular cloning and in silico analysis of three somatic embryogenesis receptor kinase mRNA from date palm

We report here the isolation and characterizations of three somatic embryogenesis receptor kinase (PhSERK) genes from palm date by a rapid amplification of cDNA ends (RACE) approach. PhSERKs belong to a small family of receptor kinase genes, share a conserved structure and extensive sequence homology with previously reported plant SERK genes. Sequence analysis of these genes revealed the sequence size of 11051 pb (PhSERK1), 7981 pb (PhSERK2) and 10510 pb (PhSERK3). The open reading frames of PhSERK1, PhSERK2 and PhSERK3 are 1914 pb, 1797 pb and 1719 pb respectively. PhSERKs belongs to the LRR-type cell surface RLKs, which possess a number of characteristic domains. These include an extracellular domain (EX) containing a variable number of LRR units, signal pepetide (SP) immediately followed by a single transmembrane domain (TM) and an intracellular kinase domain. The phylogenetic tree shows that the protein PhSERK1, PhSERK2 and PhSERK3 clustered within monocots SERKs proteins groups. We also predicted the secondary and tertiary with ligand binding sites structure of the protein PhSERKs

Staminodes evolution and in vitro development innovation in date palm (Phoenix dactylifera L.)

The in vitro cultivation of date palm staminodes (vestigial stamens) at different stages of female floral ontogenesis confirms the persistence at an immature state of such organs at all the floral differentiation stages. This is evidenced even in fully mature female flowers. Our study revealed the advanced developmental patterns of these rudimentary structures, which bear diverse morphogenetic potentialities. In vitro cultivation of staminodes provides new opportunities for in vitro regeneration of date palm. Such developmental processes were found to be modulated by the stage of floral differentiation, which closely reflected the level of staminode maturity. Development was also impacted by the composition and concentration in plant growth regulators (NAA, BAP and 2,4-D) of the culture media. The large morphogenetic plasticity of the staminodes disposed them to evolutionary variations of the date palm reproduction system. The practical benefits (micropropagation) and the fundamental interests (evolutionary process) of our investigation are discussed.The authors would like to express their sincere gratitude to Mr. Anouar Smaoui and Mrs. Hanen Ben Salem from the English Language Unit at the Sfax Faculty of Science for their appreciated translation and language polishing services. They also thank Dr. Riadh Drira for his valued contribution to language revision. This work was supported by the Tunisian Ministry of Higher Education, Scientific Research .Scopu

Ceratonia siliqua honeys from Morocco: Physicochemical properties, mineral contents, and antioxidant activities

Physicochemical properties, main mineral content, and antioxidant activity were determined for eight floral carob honeys collected from different geographical regions of Morocco. Moroccan honeys showed good chemical and nutritional qualities, fulfilling the criteria described in the standard codex for honey. The percentages obtained for ashes were (0.13–0.69%), electrical conductivity (0.36–1.35 mS/cm), water content (17.30–22.80%), pH (4.17–5.05), free acidity (11.0–42.50 meq/kg), lactone acidity (4.0–16.50 meq/kg), and for total acidity (16.50–59.50 meq/kg). In addition, minerals such as K, Na, Mg, Cu, Zn, and Ca of honey samples were determined and potassium was the major mineral in all samples. The antioxidant activities based on the free radical scavenging, reducing power, and total antioxidant activity were investigated, and the antioxidant capacity of the honey samples was correlated with their biochemical constituents such as total phenol and flavonoids content, and the best antioxidant capacity was confirmed by the honey from Taounate

Citrus limon from Tunisia: Phytochemical and Physicochemical Properties and Biological Activities

Natural plant extracts contain a variety of phenolic compounds which are assigned various biological activities. Our work aims to make a quantitative and qualitative characterization of the Zest (ZL) and the Flesh (FL) of lemon (Citrus limon), to valorize the pharmacological uses of lemon, by evaluating in vitro activities (DPPH, free radical scavenging and reducing power). The antibacterial, antifungal, and antiproliferative activities were sought in the ability of Citrus limon extracts to protect DNA and protein. We found that the ZL contains high amounts of phenolics responsible for the important antioxidant properties of the extract. However, the FL is richer in flavonoids than the ZL. The FL extract was also found to be more effective than the ZL in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals. We also concluded that the FL extract exhibited potent antibacterial activity unlike ZL. Analysis by LC/MS-MS identified 6 compounds (Caffeoyl N-Tryptophan, Hydroxycinnamoyl-Oglucoside acid, Vicenin 2, Eriocitrin, Kaempferol-3-O- rutinoside, and Quercetin-3-rutinoside). These preliminary results showed that Citrus limon has antibacterial and antioxidant activity in vitro. It would be interesting to conduct further studies to evaluate the in vivo potential in an animal model

In-Site and Ex-Site Date Palm Exposure to Heavy Metals Involved Infra-Individual Biomarkers Upregulation

As a tree of considerable importance in arid regions—date palm, Phoenix dactylifera L. survival in contaminated areas of Sfax city has drawn our attention. Leaf samples of the plants grown in the study area showed high levels of cadmium (Cd), copper (Cu), and chromium (Cr). On the basis of this finding, the cellular mechanisms that explain these metal accumulations were investigated in controlled conditions. After four months of exposure to Cd, Cr, or Cu, high bioconcentration and translocation factor (TF > 1) have been shown for date palm plantlets exposed to Cd and low TF values were obtained for plantlets treated with Cr and Cu. Moreover, accumulation of oxidants and antioxidant enzyme activities occurred in exposed roots to Cu and Cd. Secondary metabolites, such as polyphenols and flavonoids, were enhanced in plants exposed at low metal concentrations and declined thereafter. Accumulation of flavonoids in cells may be correlated with the expression of the gene encoding Pdmate5, responsible for the transport of secondary metabolites, especially flavonoids. Other transporter genes responded positively to metal incorporation, especially Pdhma2, but also Pdabcc and Pdnramp6. The latter would be a new candidate gene sensitive to metallic stress in plants. Expressions of gene coding metal chelators were also investigated. Pdpcs1 and Pdmt3 exhibited a strong induction in plants exposed to Cr. These modifications of the expression of some biochemical and molecular based-markers in date palm helped to better understand the ability of the plant to tolerate metals. They could be useful in assessing heavy metal contaminations in polluted soils and may improve accumulation capacity of other plants

Numerical Investigation of the Electro-Thermo Convection in an Inclined Cavity Filled with a Dielectric Fluid

The present work is a numerical analysis of electro-thermo convection, occurring in a square differentially heated cavity filled with a dielectric fluid. The cavity experiences the combined effects of viscous, electrical, and thermal forces. The equations modelling the physical problem are solved via the finite volume approach. The study focuses on the effect of cavity tilt on the fluid flow structure and thermal performance inside the enclosure under the action of an electric field. A parametric study was performed, where the tilt angle is getting varied between 0° and 90°, as well as the Rayleigh number (5000 ≤ Ra ≤ 250,000) and the electric field (0 ≤ T ≤ 800). Furthermore, the electric charge injection level C, the mobility M and the Prandtl Pr numbers were all adjusted to a value of 10. The obtained results demonstrate that the hydrodynamic and thermal fields are significantly impacted by the cavity inclination. In addition, regardless of the thermal Rayleigh’s number, high electric field values could govern fluid movement through electric forces. Electro-convection typically demonstrates an oscillating flow due to the tilting of the cavity which gives rise to a bicellular regime occupying the entire cavity. A correlation has been established to estimate heat transfer by considering various system parameters such as cavity inclination, electrical Rayleigh number, and thermal Rayleigh number