Abstract MicroRNAs (miRNAs) naturally occur in plants and all living organisms. They play an important role in gene regulation through binding toa specific region in open reading frames (ORFs) and/or untranslated regions (UTRs) to block... more
Abstract MicroRNAs (miRNAs) naturally occur in plants and all living organisms. They play an important role in gene regulation through binding toa specific region in open reading frames (ORFs) and/or untranslated regions (UTRs) to block the translation processes through either degrading or blocking mRNA resulting in knocking down or suppression of targeted genes. Plants and many organisms protect themselves from viruses through the production of miRNAs, which are complementary to 3UTR of viruses resulting in degrading the viral mRNA or block the translation on ribosomes. As pandemic, COVID-19, and its consequences on the global economy, we hypothesized a new approach for the treatment of COVID-19 paints. This approach includes designing a mix of miRNAs targeting several regions on COVID-19 open reading frame (ORF) and 3 UTR and suitable delivery system targeting respiratory system tissues. These synthesized miRNAs may be delivered to humansinnon-viral delivery systems such as liposomes like exosome (extracellular vesicle), polymer-based carriers, or inorganic nanoparticles, which are considered to be more suitable for human use.
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Previous studies have shown that the beneficial effect of suppression of the Arabidopsis phytoglobin 2 gene, PGB2, on somatic embryogenesis occurs through the accumulation of nitric oxide (NO) within the embryogenic cells originating from... more
Previous studies have shown that the beneficial effect of suppression of the Arabidopsis phytoglobin 2 gene, PGB2, on somatic embryogenesis occurs through the accumulation of nitric oxide (NO) within the embryogenic cells originating from the cultured explant. NO activates the expression of Allene oxide synthase (AOS) and Lipoxygenase 2 (LOX2), genes encoding two key enzymes of the jasmonic acid (JA) biosynthetic pathway, elevating JA content within the embryogenic tissue. The number of embryos in the single aos1-1 mutant and pgb2-aos1-1 double mutant declined, and was not rescued by increasing levels of NO stimulating embryogenesis in wild-type tissue. NO also influenced JA responses by up-regulating PLANT DEFENSIN 1 (PDF1) and JASMONATE-ZIM-PROTEIN (JAZ1), as well as down-regulating MYC2. The NO and JA modulation of MYC2 and JAZ1 controlled embryogenesis. Ectopic expression of JAZ1 or suppression of MYC2 promoted the formation of somatic embryos, while repression of JAZ1 and up-re...
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Somatic embryogenesis in plants is a process by which embryos can be produced from somatic cells cultured under specific conditions. A key initial step is represented by the ability of some cells within the explants to dedifferentiate,... more
Somatic embryogenesis in plants is a process by which embryos can be produced from somatic cells cultured under specific conditions. A key initial step is represented by the ability of some cells within the explants to dedifferentiate, i.e., reacquire a “young” or immature state, and then redirect their fate into an embryogenic pathway, demarked by precise changes in gene expression. While the initial morphological patterns of somatic embryo formation can be quite different and difficult to categorize, developing somatic embryos can be assigned similar stages ascribed to zygotic embryos. These similarities allow the utilization of somatic embryogenesis as a model system to investigate physiological and molecular events governing zygotic embryogenesis. The aim of this chapter is to provide a general overview of somatic embryogenesis, by describing and analyzing several in vitro embryogenic systems, and to decipher the molecular network responsible for the generation of somatic embryos.
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Over the last decades protocols have been developed for the propagation of several ornamental coniferous species, including spruce which is one of the most responsive to culture conditions. Somatic embryogenesis in spruce consists of... more
Over the last decades protocols have been developed for the propagation of several ornamental coniferous species, including spruce which is one of the most responsive to culture conditions. Somatic embryogenesis in spruce consists of distinct steps including induction, proliferation, development and maturation. Embryogenic tissue is induced from juvenile explants and proliferated in the presence of auxins and cytokinins. Applications of abscisic acid are commonly used to stimulate the formation of somatic embryos which become fully developed after a few weeks in culture. In order to germinate at high frequency, these embryos must undergo a maturation process needed to terminate the developmental program and initiate germination. Maturation is encouraged by lowering the water status of the embryos by supplementing the medium with osmoticum agents and/or by desiccating the embryos with different drying treatments. The aim of this review is to examine the major steps for inducing somat...
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Embryogenesis is a crucial phase of the plant life cycle, initiated with the fertilization of the zygote and culminated with the formation of a fully developed embryo. The process is executed with defined patterns of cell divisions... more
Embryogenesis is a crucial phase of the plant life cycle, initiated with the fertilization of the zygote and culminated with the formation of a fully developed embryo. The process is executed with defined patterns of cell divisions resulting in the proper formation of the body plan, which is delineated by an apical–basal axis (from cotyledons, to shoot meristem, to hypocotyl, and to root meristem) and a radial axis (epidermis, cortical/ground tissue, and vascular tissue). A well-described and critical event during embryogenesis is the formation of a functional shoot meristem that will generate leaves, stems, and floral structures during postembryonic growth. Genetic studies in Arabidopsis , used as a model system in embryogenesis, have revealed that the establishment of the body plan is governed by an elaborate gene network that ensures the proper execution of the morphogenic events. Experimental perturbations of factors within this network have remarkable implications for the proper formation and functionality of the embryo.
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Research Interests: Plant Biology, Biology, Medicine, NO, Histidine kinase, and 15 morePlant growth, Detoxification, Plant Roots, Arabidopsis, Plant Physiology and Biochemistry, Embryonic Development, Auxin, Acetic Acid, Callus induction, Cell Proliferation, Culture Media, Knock out, DNA binding proteins, Hemoglobins, and Cytokinins
Changes in the endogenous ascorbate redox status through genetic manipulation of cellular ascorbate levels were shown to accelerate cell proliferation during the induction phase and improve maturation of somatic embryos in Arabidopsis.... more
Changes in the endogenous ascorbate redox status through genetic manipulation of cellular ascorbate levels were shown to accelerate cell proliferation during the induction phase and improve maturation of somatic embryos in Arabidopsis. Mutants defective in ascorbate biosynthesis such as vtc2-5 contained ~70 % less cellular ascorbate compared with their wild-type (WT; Columbia-0) counterparts. Depletion of cellular ascorbate accelerated cell division processes and cellular reorganization and improved the number and quality of mature somatic embryos grown in culture by 6-fold compared with WT tissues. To gain insight into the molecular mechanisms underlying somatic embryogenesis (SE), we profiled dynamic changes in the transcriptome and analysed dominant patterns of gene activity in the WT and vtc2-5 lines across the somatic embryo culturing process. Our results provide insight into the gene regulatory networks controlling SE in Arabidopsis based on the association of transcription fa...
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Seeds of five cowpea varieties, Kaha 1, Dokki 331, Azmerly, Cream 7 and Giza 6, were exposed to different doses of gamma radiation at50, 100, 200 and 300Gy. Some growth parameters and yield components were measured in 22 M2 genotypes.... more
Seeds of five cowpea varieties, Kaha 1, Dokki 331, Azmerly, Cream 7 and Giza 6, were exposed to different doses of gamma radiation at50, 100, 200 and 300Gy. Some growth parameters and yield components were measured in 22 M2 genotypes. Variation in seed protein electrophoretic pattern, RAPD and ISSR fingerprinting was scored to assess genetic variation among the M2 genotypes. T he gamma dose of 50 Gy resulted in an increase of growth parameters and enhanced yield components in the three varieties Dokki 331, Azmerly and Cream 7; while the dose of 100 Gy resulted in higher growth rate and yield in var. Kaha 1 and var. Giza 6. Analysis of seed protein profile indicated specific bands for each variety; two bands appeared only in control plants and two other bands appeared inM2 plants of exposed seeds. Seven RAPD primers produced 30 polymorphic and 30 monomorphic bands. Meanwhile, 54 markers including 45 polymorphic bands were produced by the nine ISSR primers. Gamma radiation induced mor...
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Research Interests: Plant Biology, Biology, Medicine, Antioxidants, Reactive Oxygen Species, and 15 moreMicroarray, Plant Growth Regulators, Arabidopsis, Soil sciences, Plant Physiology and Biochemistry, Brassica Napus, ASC, Gr, Plant Development, Transgenic, Embryogenesis, PLANT PROTEINS, Gene Expression Regulation, Cytokinins, and APX
Cellular brassinolide (BL) levels regulate the development of Brassica napus microspore-derived embryos (MDEs). Synthesis and degradation of nucleotides were measured on developing MDEs treated with BL or brassinazole (BrZ), a... more
Cellular brassinolide (BL) levels regulate the development of Brassica napus microspore-derived embryos (MDEs). Synthesis and degradation of nucleotides were measured on developing MDEs treated with BL or brassinazole (BrZ), a biosynthetic ...
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A member of the homeodomain-leucine zipper (HD-Zip) family was isolated from white spruce (Picea glauca) and designated as PgHZ1 (Gene Bank Accession No. DQ201170). The gene has an open reading frame of 1268bp and encodes a protein of 309... more
A member of the homeodomain-leucine zipper (HD-Zip) family was isolated from white spruce (Picea glauca) and designated as PgHZ1 (Gene Bank Accession No. DQ201170). The gene has an open reading frame of 1268bp and encodes a protein of 309 amino acid residues. PgHZ1 has all the features of a HD-ZIP protein: a homeodomain composed by three α-helices involved in DNA
Research Interests: Plant Biology, Arabidopsis thaliana, Phylogeny, Plant Physiology, Identification, and 15 morePolymerase Chain Reaction, Arabidopsis, Abscisic Acid, Plant Physiology and Biochemistry, Molecular cloning, Embryonic Development, Picea, DNA binding, Amino Acid Profile, Amino Acid Sequence, Base Sequence, Open Reading Frame, Embryos, Homeobox genes, and Molecular Sequence Data
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Applications of buthionine sulfoximine (BSO), an inhibitor of GSH (reduced glutathione), which switches the cellular glutathione pool towards the oxidized form GSSG, positively inXuences embryo quality by improving the structure of the... more
Applications of buthionine sulfoximine (BSO), an inhibitor of GSH (reduced glutathione), which switches the cellular glutathione pool towards the oxidized form GSSG, positively inXuences embryo quality by improving the structure of the shoot apical meristem and ...
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Somatic embryogenesis (SE) is an in vitro biological process in which bipolar structures (somatic embryos) can be induced to form from somatic cells and regenerate into whole plants. Acquisition of the embryogenic potential in culture is... more
Somatic embryogenesis (SE) is an in vitro biological process in which bipolar structures (somatic embryos) can be induced to form from somatic cells and regenerate into whole plants. Acquisition of the embryogenic potential in culture is initiated when some competent cells within the explants respond to inductive signals (mostly plant growth regulators, PRGs), and de-differentiate into embryogenic cells. Such cells, “canalized” into the embryogenic developmental pathway, are able to generate embryos comparable in structure and physiology to their in vivo counterparts. Genomic and transcriptomic studies have identified several pathways governing the initial stages of the embryogenic process. In this review, the authors emphasize the importance of the developmental signals required for the progression of embryo development, starting with the de-differentiation of somatic cells and culminating with tissue patterning during the formation of the embryo body. The action and interaction of...
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Somatic embryogenesis in Arabidopsis is achieved by culturing bending-cotyledon embryos on a 2, 4-D-containing induction medium for 14 d followed by a transfer on to a hormone-free development medium. Several genes orthologous to... more
Somatic embryogenesis in Arabidopsis is achieved by culturing bending-cotyledon embryos on a 2, 4-D-containing induction medium for 14 d followed by a transfer on to a hormone-free development medium. Several genes orthologous to Arabidopsis ...