Somatic Embryogenesis and Plant Regeneration from Tissue Cultures of Hyoscyamus muticus L.

Somatic embryogenesis and regeneration of plantlets was achieved In callus cultures derived from cotyledonary leaf pieces of Hyoscyamus muticus L on MS medium enriched with 2 mg/l 2,4–0 and 0.5 mg/l BAP. For embryogenesis and organogenesis varying concentrations of NAA with or without BAP were added In the medium. Organogenesis was also achieved when callus was transferred to the hormone free medium.     

Use of Plackett-Burman design for rapid screening of several nitrogen sources,growth/product promoters,minerals and enzyme inducers for the production of alpha-galactosidase by Aspergillus niger MRSS 234 in solid state fermentation system

Five sources of nitrogen, six minerals, six enzyme inducers and one each of growth as well as product promotors were screened by Plackett-Burman design, consisting of a total of 20 experiments for the above 19 sources/categories of medium ingredients, for their effect on the production of alpha-galactosidase by Aspergillus niger MRSS 234 in solid state fermentation system. The enzyme production was recorded from 2 to 5 days of fermentation. Data on enzyme titres was analysed by compatible analysis to obtain regression coefficients and t-ratios. Among the nitrogen sources, urea contributed positively to enzyme production and its effect increased with the fermentation time, in contrast to negative effect of all the ammonium salts used. Corn steep liquor, citric acid and legume seed flours showed significantly positive effects on enzyme production, though lactose showed negative effect upto 3 days of fermentation and then turned positive but not significantly. Calcium chloride and ferrous sulphate showed considerable negative effect, in contrast to mixed effect by other mineral salts studied. Among the legume seed flours, guar and French bean flours showed larger positive effects. The studies allowed the selection of urea, corn steep liquor, guar flour, soy bean flour and citric acid as most promising sources/categories for further optimization studies based on the effects as well as their trend with fermentation time. The use of Plackett-Burman design for rapid screening of large number of nutrients, in a very small number of experiments, for reliable short-listing of a few of most effective sources/categories for further optimization, has been scarce in submerged fermentation and never attempted earlier in solid state fermentation system.Authors are thankful to Dr. S. R. Bhowmik, Director of the institute for interest in the work. M. R. S. Srinivas thanks Council of Scientific and Industrial Research, New Delhi, for the award of junior research fellowship.     

Detection and localization of triadin in rat ventricular muscle

Summary Dyads (transverse tubule—junctional sarcoplasmic reticulum complexes) were enriched from rat ventricle microsomes by continuous sucrose gradients. The major vesicle peak at 36% sucrose contained up to 90% of those membranes which possessed dihydropyridine (DHP) binding sites (markers for transverse tubules) and all membranes which possessed ryanodine receptors and the putative junctional foot protein (markers for junctional sarcoplasmic reticulum). In addition, the 36% sucrose peak contained half of the vesicles with muscarine receptors. Vesicles derived from the nonjunctional plasma membrane as defined by a low content of dihydropyridine binding sites per muscarine receptor and from the free sarcoplasmic reticulum as defined by the M_r 102K Ca²⁺ ATPase were associated with a diffuse protein band (22–30% sucrose) in the lighter region of the gradient. These organelles were recovered in low yield. Putative dyads were not broken by French press treatment at 8,000 psi and only partially disrupted at 14,000 psi. The monoclonal antibody GE4.90 against skeletal muscle triadin, a protein which links the DHP receptor to the junctional foot protein in skeletal muscle triad junctions, cross-reacted with a protein in rat dyads of the same M_r as triadin. Western blots of muscle microsomes from preparations which had been treated with 100mm iodoacetamide throughout the isolation procedure showed that cardiac triadin consisted predominantly of a band of Mr 95 kD. Higher molecular weight polymers were detectable but low in content, in contrast with the ladder of oligomeric forms in rat psoas muscle microsomes. Cardiac triadin was not dissolved from the microsomes by hypertonic salt or Triton X-100, indicating that it, as well as skeletal muscle triadin, was an integral protein of the junctional SR. The cardiac epitope was localized to the junctional SR by comparison of its distribution with that of organelle markers in both total microsome and in French press disrupted dyad preparations. Immunofluorescence localization of triadin using mAb GE4.90 revealed that intact rat ventricular muscle tissue was stained following a well-defined pattern of bands every sarcomere. This spacing of bands was consistent with the interpretation that triadin was present in the dyadic junctional regions.     

Facilitation of Sexual Receptivity by Ventromedial Hypothalamic Implants of the Antiprogestin RU 486

RU 486 is known primarily as an antagonist to progestins and glucocorticoids. However, RU 486 has also been shown to have agonistic progestational properties in biochemical and behavioral studies. In the current study, RU 486 was implanted directly into tim ventromedial hypothalamus (VMH) to test for facilitative action on the receptive behavior of female ovariectomized Long-Evans rats primed with 5 μg of estradiol benzoate. Cannulae containing RU 486, progesterone (P), or empty cannulae were implanted 48 hr after estrogen priming. The lordosis quotient and the lordosis score were assessed 4 hr after the cannulae were lowered by a standardized test consisting of 10 mounts by a stimulus male. P and RU 486 significantly facilitated receptivity compared to blank implants in terms of lordosis quotient and lordosis score, with no significant difference between the hormone treatments. While only a single dose of each treatment was given in the current study, RU 486 facilitated lordosis when implanted to the VMH as well as progesterone in contrast to our previous results where the steroids were administered systemically.     

Cloning of higher plant omega-3 fatty acid desaturases.

Arabidopsis thaliana T-DNA transformants were screened for mutations affecting seed fatty acid composition. A mutant line was found with reduced levels of linolenic acid (18:3) due to a T-DNA insertion. Genomic DNA flanking the T-DNA insertion was used to obtain an Arabidopsis cDNA that encodes a polypeptide identified as a microsomal omega-3 fatty acid desaturase by its complementation of the mutation. Analysis of lipid content in transgenic tissues demonstrated that this enzyme is limiting for 18:3 production in Arabidopsis seeds and carrot hairy roots. This cDNA was used to isolate a related Arabidopsis cDNA, whose mRNA is accumulated to a much higher level in leaf tissue relative to root tissue. This related cDNA encodes a protein that is a homolog of the microsomal desaturase but has an N-terminal extension deduced to be a transit peptide, and its gene maps to a position consistent with that of the Arabidopsis fad D locus, which controls plastid omega-3 desaturation. These Arabidopsis cDNAs were used as hybridization probes to isolate cDNAs encoding homologous proteins from developing seeds of soybean and rapeseed. The high degree of sequence similarity between these sequences suggests that the omega-3 desaturases use a common enzyme mechanism.     

Influence of A1 cytoplasmic substitution on the downy-mildew incidence of pearl millet

Large-scale cultivation of pearl millet [Pennisetum glaucum (L.) R. Br. F₁ hybrids in India has led to increased incidence of downy-mildew (Sclerospora graminicola). There is concern that the A₁ male-sterile cytoplasm used in all the hybrids released so far is responsible for this increase. The influence of A₁ malesterile cytoplasm on downy-mildew incidence in pearl millet was studied by comparing the disease reaction of 40 pairs of F₁ hybrids, each pair carrying respectively a₁ male-sterile and normal B cytoplasm. Mean downy-mildew incidence was similar in the hybrids carrying either A₁ male-sterile or B cytoplasm. The general combining ability of lines with and without A₁ cytoplasm was found to be similar for downy-mildew incidence. These results indicated that in pearl millet A₁ cytoplasm is not associated with increased downymildew incidence. The possible danger of using only one source of cytoplasm has been briefly discussed.     

In Vitro,In Silico,ADME and Theoretical Analysis of Mn(II) and Co(II) Complexes Derived from Methyl-(Z)-N′-Carbamothioylcarbamohydrazonate Schiff Base Ligand

Mn(II) and Co(II) complexes of methyl-(Z)−N′-carbamothioylcarbamohydrazonate Schiff base ligand were synthesized. The ligand and metal salts were taken in 2 : 1 stoichiometric ratio. All the synthesized complexes were characterized using elemental analysis, molar conductance, magnetic moment and various spectroscopic techniques (FT-IR, UV/VIS, EPR) techniques. Elemental and spectroscopic results verified bidentate donor nature of the ligand and octahedral geometry of all the complexes. The non-electrolytic nature of Mn(II) and Co(II) complexes were suggested by conductivity data analysis. In vitro antibacterial (E. coli and S. aureus) and antifungal (C. albicans and C. tropicalis) screening were achieved by employing agar well diffusion method which revealed better antimicrobial activity of Co(II) complexes than Mn(II) complexes. In silico SwissADME study predicted the drug-likeness probability of ligand and complexes. The interaction of two bacterial proteins (E. coli and S. aureus) with compounds was also analyzed using molecular docking study, which corroborate the in vitro analysis.