Flow cytometry and start codon targeted (SCoT) genetic fidelity assessment of regenerated plantlets in Tylophora indica (Burm.f.) Merrill

Tylophora indica (Burm.f.) Merrill. is a pharmacologically important plant, popular for alkaloidal and non-alkaloidal richness. Large scale propagation of T. indica is difficult in the wild as the seeds are small and the frequency of germination is very poor. In the present study, the genome size estimation of in vitro regenerated (indirect, direct and somatic embryo mediated) T. indica was made by flow cytometric method. Clonal fidelity of the regenerants was assessed using a start codon targeted (SCoT) molecular marker. Initially, the explants were inoculated on Murashige and Skoog basal medium supplemented with various concentrations of plant growth regulators like 2,4-dichlorophenoxy acetic acid (2,4-D), Kinetin, 6-benzyl amino purine (BAP) and 1-naphthalene acetic acid either singly or in combinations. The highest callus induction frequency (87.75%) was obtained in 6.7 µM 2,4-D added MS medium which metamorphosed into progressive stages (globular, heart, torpedo, and cotyledonary) of embryos. Mature and healthy somatic embryos efficiently germinated into plantlets on 8.8 µM BAP?+?1.4 µM GA₃ enriched MS medium. Histological and scanning electron microscopic study confirmed the above developing stages. The regenerated shoots were rooted best in 2.45 µM Indole-3-butyric acid supplemented solid MS medium. The plants were hardened and acclimatized with 90% survivability. The flow cytometric 2C DNA content of indirect, direct and somatic embryo derived plants was 1.896 pg, 1.940 pg and 1.926 pg respectively, very similar to the mother plant (1.928 pg). SCoT marker generated a high percentage of monomorphic bands (94%) revealing similarity with the mother plant, thus ensuring genetic fidelity. To the best of our knowledge, this is perhaps the first ever report of 2C DNA content estimation and SCoT marker based genetic homogeneity study in T. indica.

     

Computer aided screening of natural compounds targeting the E6 protein of HPV using molecular docking

The cancer profile in the Indian state of Uttarakhand reveals that the breast cancer is the most prevalent type of cancers in females followed by cervical and ovarian type. Literature survey shows that the E6 protein of Human Papilloma Virus-16 (HPV-16) is responsible for causing several forms of cancer in human. Therefore, it is of interest to screen HPV-16 E6 target protein with known natural compounds using computer aided molecular modeling and docking tools. The complete structure of E6 is unknown. Hence, the E6 structure model was constructed using different online servers followed by molecular docking of Colchine, Curcumin, Daphnoretin, Ellipticine and Epigallocatechin-3-gallate; five known natural compounds with best E6 protein model predicted by Phyre2 server. The screening exercise shows that Daphnoretin (with binding free energy of -8.3 kcal/mol), a natural compound derived from Wikstroemia indica has the top binding properties. Thus, it is of interest to consider the compound for further validation.     

Comprehensive in vitro regeneration study with SCoT marker assisted clonal stability assessment and flow cytometric genome size analysis of Carthamus tinctorius L.: an important medicinal plant

An efficacious and reproducible in vitro regeneration technique for safflower was established using varying concentrations and composition of plant growth regulators (PGRs) supplemented Murashige and Skoog (MS) medium. Successful in vitro seed germination in half strength MS (H-MS) with 1.4 µM GA₃ resulted in procurement of sterile explants (cotyledons, apical meristems) for in vitro study. Callogenesis (2.2 µM BAP?+?2.7 µM NAA), indirect organogenesis of shoot buds (0.54 µM NAA?+?9.08 µM TDZ), somatic embryogenesis (2.2 µM BAP?+?5.4 µM NAA) and somatic embryo germinated plantlets (H-MS?+?1.4 µM GA₃?+?2.2 µM BAP?+?5.4 µM NAA) were successfully obtained. Histological study and scanning electron micrographs of embryogenic callus revealed pre-globular, heart-shaped and torpedo stages of dicot embryogeny. H-MS?+?8 µM NAA showed maximum rhizogenic response with a mean root and shoot length of 17.5 mm and 48.50 mm respectively in 2.2 µM BAP?+?0.54 µM NAA bearing an average of 9 capitula per plantlet with 70% post transplantation survival rate. True to type nature of the regenerates was confirmed using Start Codon Targeted (SCoT) marker, exhibiting 100% and 97.3% monomorphic bands for direct and somatic embryo regenerated plants respectively. Flow cytometry method (FCM) was employed for 2C DNA content analysis. The histogram peaks of 2C nuclear DNA content of in vitro regenerated safflower (direct and embryo derived) were similar to the peak of field grown donor plant. 2C nuclear DNA content of field grown, direct and somatic embryo regenerated C. tinctorius was 2.65?±?0.04 pg, 2.62?±?0.06 pg and 2.68?±?0.04 pg respectively, further verifying genetic homogeneity. All things considered, the above protocol is insusceptible to genetic alteration and can be used for large scale production and sustainable utilization of desired genotype.

     

Synthesis, thermal stability, antimalarial activity of symmetrically and asymmetrically substituted tetraoxanes

Symmetrically and asymmetrically substituted 1,2,4,5-tetraoxanes were synthesized by the oxidative system H(2)O(2)/TFE in presence of MeReO(3) as a catalyst. All of the synthesized compounds were characterized spectroscopically, and evaluated for cytotoxicity, and antimalarial activity. Several of these tetraoxanes exhibited in vitro antimalarial activity without showing any cytotoxicity. Thermal stability of these compounds was studied by differential scanning calorimetry.