scholarly journals Confirmation of “pre-plasmolysis mediated ex-osmosis hypothesis” to obtain shoot bud morphogenesis in Catharanthus roseus

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Vyoma Mistry ◽  
Abhishek Sharma ◽  
Ajay Kumar Mathur
Keyword(s):  
Genetic Engineering ◽  
Catharanthus Roseus ◽  
Cultured Cells ◽  
De Novo ◽  
Leaf Explants ◽  
Direct Regeneration ◽  
Engineering Process ◽  
Shoot Bud ◽  
Regeneration Response

AbstractThe antineoplastic herb, Catharanthus roseus is a classified high-value low-volume medicinal herb which is in global attention of scientific research for modulation of its monoterpenoid indole alkaloids (MIA) pathway through genetic engineering. These secondary metabolites are generally stored in specific types of structures/compartments due to their cytotoxic nature and designated roles in plant defense response. However, their presence can hinder the genetic engineering process used to develop transgenic plants through de novo morphogenesis and regeneration of plants from cultured cells/tissues and hence, it always remained a critical impediment in transgenic research in C. roseus. The pre-plasmolysis treatment of leaf explants can help to tackle the recalcitrant nature of leaf explant and can support the direct regeneration response by ex-osmosis that minimizes the concentration of alkaloids. Therefore, this study was performed to chase the effect of osmotic conditions on recalcitrant leaves of C. roseus engaged in vitro plant regeneration and hypothesis of alkaloids ex-osmosis is confirmed by HPLC analysis.

THE CONSTRUCTION OF TUMOR-SELECTIVE ADENOVIRAL VECTORS WITH MODIFIED TROPISM AND INCREASED ONCOLYTIC ACTIVITIES USING ADVANCED GENETIC ENGINEERING

2020 ◽  
pp. 18-19
Author(s):  
A. Sosnovtseva ◽  
V. Chekhonin
Keyword(s):  
Genetic Engineering ◽  
De Novo ◽  
Adenoviral Vectors ◽  
Intratumoral Heterogeneity ◽  
Chemotherapeutic Resistance ◽  
Tumor Selectivity ◽  
Adenovirus 5 ◽  
Tumor Selective

A panel of replication competent adenoviral vectors based on the adenovirus 5 genome with high tumor selectivity, modified tropism and increased oncolytic activities to overcome the intratumoral heterogeneity and chemotherapeutic resistance are de novo constructed and characterized in vitro.

scholarly journals Centrosomal protein centrin is not detectable during early pre-implantation development but reappears during late blastocyst stage in porcine embryos

Reproduction ◽  
2006 ◽  
Vol 132 (3) ◽  
pp. 423-434 ◽  
Author(s):  
G Manandhar ◽  
D Feng ◽  
Y-J Yi ◽  
L Lai ◽  
J Letko ◽  
...  
Keyword(s):  
Western Blotting ◽  
Immunofluorescence Microscopy ◽  
Cultured Cells ◽  
De Novo ◽  
Germinal Vesicle ◽  
Donor Cell ◽  
Blastocyst Stage ◽  
Embryonic Cells ◽  
Perinuclear Area

Centrin is an evolutionarily conserved 20 kDa, Ca+2-binding, calmodulin-related protein associated with centrioles and basal bodies of phylogenetically diverse eukaryotic cells. Earlier studies have shown that residual centrosomes of non-rodent mammalian spermatozoa retain centrin and, in theory, could contribute this protein for the reconstruction of the zygotic centrosome after fertilization. The present work shows that CEN2 and CEN3 mRNA were detected in germinal vesicle-stage (GV) oocytes, MII oocytes, and pre-implantation embryos from the two-cell through the blastocyst stage, but not in spermatozoa. Boar ejaculated spermatozoa possess centrin as revealed by immunofluorescence microscopy and western blotting. Immature, GV oocytes possess speckles of centrin particles in the perinuclear area, visualized by immunofluorescence microscopy and exhibit a 19 kDa band revealed by western blotting. Mature MII stage oocytes lacked centrin that could be detected by immunofluorescence or western blotting. The sperm centrin was lost in zygotes afterin vitrofertilization. It was not detectable in embryos by immunofluorescence microscopy until the late blastocyst stage. Embryonic centrin first appeared as fine speckles in the perinuclear area of some interphase blastocyst cells and as putative centrosomes of the spindle poles of dividing cells. The cells of the hatched blastocysts developed centrin spots comparable with those of the cultured cells. Some blastomeres displayed undefined curved plate-like centrin-labeled structures. Anti-centrin antibody labeled interphase centrosomes of cultured pig embryonic fibroblast cells as distinct spots in the juxtanuclear area. Enucleated pig oocytes reconstructed by electrofusion with pig fibroblasts displayed centrin of the donor cell during the early stages of nuclear decondensation but became undetectable in the late pronuclear or cleavage stages. These observations suggest that porcine zygotes and pre-blastocyst embryonic cells lack centrin and do not retain exogenously incorporated centrin. The early embryonic centrosomes function without centrin. Centrin in the blastocyst stage embryos is likely a result ofde novosynthesis at the onset of differentiation of the pluripotent blastomeres.

scholarly journals In vitro Propagation of Vanda testacea (Lindl.) Reichb.f. – A Rare Orchid of High Medicinal Value

2010 ◽  
Vol 19 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Saranjeet Kaur ◽  
K.K. Bhutani
Keyword(s):  
Leaf Explants ◽  
Subsequent Development ◽  
Individual Treatment ◽  
Chemical Stimulus ◽  
Medicinal Value ◽  
Best Response ◽  
High Regeneration ◽  
Regeneration Response ◽  
High Regeneration Frequency

Foliar explants of Vanda testacea (Lindl.) Reichb. f. were cultured on Mitra (M) medium with 1.0 mg/l BAP, Kn  each and 1.0 mg/l NAA individually and in combination for initiation of regeneration response, proliferation of regenerants and subsequent development of plantlets. Juvenility of the tissues and chemical stimulus were important factors in initiating the regeneration response in the explants. The relatively older leaf explants (>1cm in length) remained recalcitrant to regeneration the representing younger ones (<1cm in length) responded to certain chemical regimes. BAP, Kn individually in the medium should direct PLB regeneration whereas when used with NAA, the explants showed callus proliferation and further differentiated into PLBs. An individual treatment with NAA (1.0 mg/l) impaired the response frequency and delayed further morphogenetic processes leading to plantlet development. The best response in the explants (in terms of high regeneration frequency, early initiation, PLB proliferations, and plantlet development) was observed in 1.0 mg/l BAP alone/with 1.0 mg/l NAA + activated charcoal. Plantlets were transferred to pots containing epiphytic compost (1 charcoal : 1 brick pices : 1 bats). Nearly 75% of plantlets survival was recorded.  Key words: In vitro, Orchid, Vanda testacea, Micropropagation, Protocorm-like bodies, callus D.O.I. 10.3329/ptcb.v19i1.4077 Plant Tissue Cult. & Biotech. 19(1): 1-7, 2009 (June) 

REGENERATION OF TREMA ORIENTALIS (BLUME) LINN.: EFFECT OF GROWTH REGULATORS, CULTURE CONDITIONS, AND AGE AND SOURCE OF EXPLANTS

1995 ◽  
Vol 43 (4) ◽  
pp. 391-395 ◽  
Author(s):  
G.R. Rout ◽  
S. Samantaray ◽  
P. Das
Keyword(s):  
Growth Regulators ◽  
Leaf Explants ◽  
Naphthaleneacetic Acid ◽  
Mature Trees ◽  
Regeneration Rate ◽  
Bud Regeneration ◽  
Shoot Bud ◽  
Shoot Bud Regeneration ◽  
Trema Orientalis

Optimal conditions for high frequency shoot bud regeneration from leaf callus of Trema orientalis (Blume) Linn. were studied. The regeneration rate was controlled by the growth regulators, the age and the source of the explants, and the illumination conditions. Irrespective of illumination conditions, shoot bud regeneration was achieved only in media containing benzyladenine (BA) + α-naphthaleneacetic acid (NAA) combinations, with the best results being obtained in the presence of 2.5 mg/1 BA and 0.25–0.5 mg/1 NAA. The morphogenic response was less frequent in the calluses derived from leaf explants of the mature trees compared to those of the in vitro-grown seedlings. The rate of shoot bud regeneration was more pronounced in the cultures maintained for 4 weeks in the light (16-h photoperiod) than the cultures incubated in the dark. Regenerated shoots were rooted on the medium containing 1/2 strength basal Murashige and Skoog (MS) salts supplemented with 0.01 mg/1 NAA or indole-3-butyric acid (IBA). The rooted plantlets were established in the greenhouse.

scholarly journals Nutrient optimization for improved in vitro plant regeneration in Eclipta alba (L.) Hassk. and assessment of genetic fidelity using RAPD analysis

2015 ◽  
Vol 24 (2) ◽  
pp. 223-234
Author(s):  
Shruti Bardar ◽  
Varsha Khurana Kaul ◽  
Sumita Kachhwaha ◽  
SL Kothari
Keyword(s):  
Basal Medium ◽  
Genetic Fidelity ◽  
Ex Situ ◽  
Nutrient Level ◽  
Induction Medium ◽  
Eclipta Alba ◽  
Shoot Bud ◽  
Bud Induction ◽  
Regeneration Response

This study highlights the effect of different inorganic micronutrients like copper, cobalt, molybdenum, zinc, boron, iodine, iron and manganese in accelerating and amplifying in vitro shoot bud induction and proliferation of a medicinally important plant, Eclipta alba (L.) Hassk. Direct shoot bud induction was observed on MS fortified with Kn (2 mg/l). However, maximum number of shoots was achieved when GA3, 0.5 mg/l was added to induction medium along with 1?M copper sulphate (ten times the normal MS level). Optimization of nutrient level in the basal medium promoted maximum regeneration response from both shoot tips and nodal explants. Elongated shoots were rooted in MS supplemented with IBA, 1.0 mg/l. Healthy, green plantlets with well developed roots, flowered normally in the field. Genetic stability of micropropagated plantlets was evaluated using RAPD markers. The amplification products were monomorphic in micropropagated plantlets and similar to those of mother plant revealing the genetic uniformity of plantlets. The regeneration protocol is highly efficient and reproducible so would be useful for mass multiplication, ex situ conservation and genetic transformation of E. alba (L.) Hassk.Plant Tissue Cult. & Biotech. 24(2): 223-234, 2014 (December)

scholarly journals Inhibiting Pyridoxal Kinase of Entamoeba histolytica Is Lethal for This Pathogen

2021 ◽  
Vol 11 ◽  
Author(s):  
Suneeta Devi ◽  
Priya Tomar ◽  
Khaja Faisal Tarique ◽  
Samudrala Gourinath
Keyword(s):  
Entamoeba Histolytica ◽  
Drug Targets ◽  
Cultured Cells ◽  
De Novo ◽  
Active Form ◽  
Protozoan Parasite ◽  
Vitamin B ◽  
Pyridoxal Kinase ◽  
Small Molecule Libraries

Pyridoxal 5’-phosphate (PLP) functions as a cofactor for hundreds of different enzymes that are crucial to the survival of microorganisms. PLP-dependent enzymes have been extensively characterized and proposed as drug targets in Entamoeba histolytica. This pathogen is unable to synthesize vitamin B6via de-novo pathway and relies on the uptake of vitamin B6 vitamers from the host which are then phosphorylated by the enzyme pyridoxal kinase to produce PLP, the active form of vitamin B6. Previous studies from our lab shows that EhPLK is essential for the survival and growth of this protozoan parasite and its active site differs significantly with respect to its human homologue making it a potential drug target. In-silico screening of EhPLK against small molecule libraries were performed and top five ranked molecules were shortlisted on the basis of docking scores. These compounds dock into the PLP binding site of the enzyme such that binding of these compounds hinders the binding of substrate. Of these five compounds, two compounds showed inhibitory activity with IC50 values between 100-250 μM when tested in-vitro. The effect of these compounds proved to be extremely lethal for Entamoeba trophozoites in cultured cells as the growth was hampered by 91.5% and 89.5% when grown in the presence of these compounds over the period of 72 hours.

scholarly journals Bauhinia forficata link shoot regeneration: histological analysis of organogenesis pathway

2000 ◽  
Vol 43 (4) ◽  
pp. 431-431 ◽  
Author(s):  
Marcia O. Mello ◽  
Murilo Melo ◽  
Beatriz Appezzato-da-Glória
Keyword(s):  
Plant Regeneration ◽  
Culture Medium ◽  
De Novo ◽  
Shoot Elongation ◽  
Small Cells ◽  
Indirect Organogenesis ◽  
Shoot Bud ◽  
Half Strength ◽  
Bauhinia Forficata

Plant regeneration was achieved from cells of callus induced from hypocotyl segments of Bauhinia forficata on half strength Murashige and Skoog culture medium supplemented with several concentrations of BAP. Within 40 days of culture shoot buds formation was observed on callus surface. Calli were then transferred to a same composition culture medium without plant growth regulator in order to induce shoot elongation. Histological studies indicated that in vitro plant regeneration in B. forficata occurred through indirect organogenesis. Meristemoids consisting of small cells with dense cytoplasm and prominent nuclei were randomly distributed throughout the callus surface indicating early stages of shoot bud differentiation. Shoots developed de novo from superficial layers of cells and the pattern of shoot origin and development were very similar to those previously described for other leguminous species.

scholarly journals In vitro Direct Regeneration from Node and Leaf Explants of Phalaenopsis cv. ‘Surabaya’

2016 ◽  
Vol 25 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Khosro Balilashaki ◽  
Maryam Vahedi ◽  
Roghayeh Karimi
Keyword(s):  
Shoot Regeneration ◽  
Leaf Explants ◽  
Nodal Explants ◽  
Direct Regeneration ◽  
Flower Stalk ◽  
Breeding Programs ◽  
Half Strength ◽  
Direct Embryogenesis ◽  
Regenerated Plantlets

An efficient and reproducible procedure for the direct regeneration of phalaenopsis cv. ‘Surabaya’ using of nodal explants and leaf segments derived from in vitro flower stalk was conducted. Three experiments were carried out for shoot development and subsequent plant regeneration: Direct shoot regeneration from nodal explants of Phalaenopsis cv. ‘Surabaya’ flower stalks on MS added with different combination of NAA and BAP, direct regeneration of protocormlike bodies (PLBs) from leaf explants in a MS with different concentrations of the TDZ, acclimatization of regenerated plantlets in different mixture of components and nutrients. The results showed that 5 mg/l BAP and 2 mg/l NAA were most effective concentration for shoot regeneration, regenerated shoots were cultured on half strength of MS containing activated charcoal, IAA and NAA at various concentrations, highest number of root (6.7) was obtained in higher concentration of NAA (2 mg/l). TDZ induced a higher frequency of embryogenesis from leaf explants than BAP, the highest number of embryos per explant was 22.45 at 3 mg/l TDZ. Altogether, BAP at higher concentration (10 mg/l) with 1 mg/l NAA had the highest enhancement on the amount of direct embryogenesis. In our investigation 87.20% plantlets via nodal explants survived acclimatization process in medium containing cocopeat and coal (1 : 1). The survival rate of regenerated plantlets via nodal explants (82.07%) was more than of regenerated plantlets via leaf explants (70.47). This protocol provides the basis for further investigation on micropropagation and breeding programs in Phalaenopsis cv. ‘Surabaya’.Plant Tissue Cult. & Biotech. 25(2): 193-205, 2015 (December)

scholarly journals Morphogenic processes in callus tissue cultures and de novo regeneration of plants in Actinidia chinensis Planch

2014 ◽  
Vol 67 (3-4) ◽  
pp. 217-222 ◽  
Author(s):  
Adela Ludvová ◽  
Mária G. Ostrolucká
Keyword(s):  
De Novo ◽  
Leaf Explants ◽  
Structural Heterogeneity ◽  
Callus Cultures ◽  
Culture Conditions ◽  
Actinidia Chinensis ◽  
Indirect Organogenesis ◽  
Vascular Elements ◽  
Callus Tissues

Our experiments have confirmed the considerable disposition of leaf explants of <em>Actinidia chinensis</em> Planch. for induction and intensive proliferation of callus cultures, as well as, a possibility to regulate morhogenesis in in vitro conditions. Under specific culture conditions the morphogenic potential of callus cells of <em>Actinidia chinensis</em> was manifested both in organogenesis and somatic embryogenesis. Organogenesis was represented by induction of adventitious buds and regeneration shoots on the modified MS culture medium (Murashige and Skoog 1962) with BAP in combination with GA<sub>3</sub> (each 1.0 mg. l<sup>-1</sup>). Rooting of shoots was successful on modified MS medium containing IBA (0.5-1.0 mg. l<sup>-1</sup>). Histological studies of callus tissues revealed their structural heterogeneity. Morphogenic processes in the callus were characterized by the appearance of meristematic zones and vascular elements. The formation of apical meristem, leaf primordia and finally shoot development proved de novo regeneration in callus culture. The obtained results demonstrate a possibility of plant regeneration through indirect organogenesis, which can be used for propagation of<em> Actinidia chinensis</em> Planch.

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