Standardization of in vitro micropropagation procedure of Oriental Lilium Hybrid Cv. ‘Ravenna’

Micropropagation protocol of Oriental Hybrid Lilium cv. Ravenna was developed using bulb scale segments (Basal and Tip) as explants. Surface sterilization of healthy bulb scales with carbendazim 200 ppm for 30 min, then 0.1 percent mercuric chloride for 10 min, then 70% ethyl alcohol for 30 s was superior to all other treatments in recording highest culture asepsis (77.08%) and higher explant survival (86.12%). Explant survival was higher in basal segments (88.54%) compared to tip segments (85.52%). Highest culture establishment was recorded in basal scale segments (68.26%) followed by tip scale segments (55.21%). MS medium augmented with 0.50 mgl⁻¹ Naphthalene acetic acid and 2.0 mgl⁻¹. 6-Benzylamino Purine recorded maximum culture establishment (76.17%), highest bulblet number/explant (5.52) with maximum length of shoots (2.20 cm) and number of leaves (3.39). This treatment combination of growth regulators resulted in highest shoot proliferation (83.33%) along with maximum shoot number (2.41explant⁻¹), shoot length (2.35 cm) and leaf number (5.44) of micro shoots during proliferation stage. Rooting of explants was superior with Indole-3-butyric acid compared to Naphthalene acetic acid. Highest rooting of 92.71% along with maximum number of primary roots shoot⁻¹ (12.06), maximum primary root length (3.17 cm) was documented in Murashige and Skoog medium added with Indole-3-butyric acid 1.50 mgl⁻¹ with best ex vitro survival rate (98.96%) of rooted plantlets during primary hardening in perlite + vermiculite (1:1) mixture.     

Ischemic stroke and mitochondria: mechanisms and targets

Protoplasma - Stroke is one of the main causes of mortality and disability in most countries of the world. The only way of managing patients with ischemic stroke is the use of intravenous tissue...     

Multiple independent inputs are required for activation of the p70 S6 kinase.

Previous studies have shown that the noncatalytic carboxy-terminal tail of the p70 S6 kinase (amino acids 422 to 525) contains an autoinhibitory pseudosubstrate domain that is phosphorylated in situ during activation and in vitro by mitogen-activated protein kinases. The present study shows that a recombinant p70 deleted of the carboxy-terminal tail (p70 delta CT104) nevertheless exhibits a basal and serum-stimulated 40S kinase activity and susceptibility to inhibition by wortmannin very similar to those of the parent, full-length p70 kinase. Carboxy-terminal deletion reduces the extent of maximal inhibition produced by rapamycin, from > 95% in the full-length p70 to 60 to 80% in p70 delta CT104, without altering the sensitivity to rapamycin inhibition (50% inhibitory concentration of 2 nM). Serum activation of p70 delta CT104, as with the parent, full-length p70, is accompanied by an increase in 32P content (about twofold) in situ and a slowing in electrophoretic mobility; both modifications are inhibited by pretreatment with wortmannin or rapamycin. 32P-peptide maps of p70 delta CT104 show multisite phosphorylation, and wortmannin and rapamycin appear to cause preferential dephosphorylation of the same subset of sites. Thus, it is likely that activation of the kinase requires phosphorylation of p70 at sites in addition to those previously identified in the carboxy-terminal tail. Evidence that the carboxy-terminal tail actually functions as a potent intramolecular inhibitor of kinase activity in situ is uncovered by deletion of a short acidic segment (amino acids 29 to 46) from the p70 amino-terminal noncatalytic region. Deletion of amino acids 29 to 46 causes a >95% inhibition of p70 activity despite continue phosphorylation of the carboxy-terminal tail in situ; additional deletion of the carboxy-terminal tail (yielding p70 delta 29-46/ delta CT104) increases activity 10-fold, to a level approaching that of p70 delta CT104. Deletion of residues 29 to 46 also abolishes completely the sensitivity of p70 to inhibition by rapamycin but does not alter the susceptibility to activation by serum of inhibition by wortmannin. Although the mechanisms underlying the effects of the delta 29-46 deletion are not known, they are not attributable to loss of the major in situ p70 phosphorylation site at Ser-40. Thus, activation of the p70 S6 kinase involves multiple, independent inputs directed at different domains of the p70 polypeptide. Disinhibition from the carboxy-terminal tail requires, in addition to its multisite phosphorylation, an activating input dependent on the presence of amino acids 29 to 46; this p70-activating input may be the same as that inhibited by rapamycin but is distinct from that arising from the wortmannin-inhibitable phosphatidylinositol 3-kinase. In addition, as exemplified by the rapamycin-resistant but mitogen- and wortmannin-sensitive p70 delta 29-46/ delta CT104 mutant, a further activating input, which probably involves site-specific phosphorylation in the segment between amino acids 46 to 421, is necessary.     

Evaluation of Tris–citric acid,skim milk and sodium citrate extenders for liquid storage of Punjab Urial (Ovis vignei punjabiensis) spermatozoa

The Punjab Urial (Ovis vignei punjabiensis) is an endangered subspecie of ovidae, distributed as small scattered populations in the forest belt of the Himalayan foothills of Pakistan and in the areas enclosed by the Indus and the Jhelum rivers. The present study was conducted to evaluate the liquid storage of Punjab Urial spermatozoa in different extenders for use in future in situ conservation activities. Semen was collected by electro-ejaculation from three captive Punjab Urial rams. Suitable ejaculates of individual animals were pooled and divided into three aliquots for dilution with the experimental extenders (Tris–citric acid, skim milk and sodium citrate) at 37 °C. Extended semen was cooled from 37 °C to 5 °C in 2 h, and stored for three days at 5 °C. Sperm motility (%), viability (%; live/dead), acrosome integrity (%) and plasma membrane integrity (%) were assessed on days 1, 2 and 3 of storage. On day 1, sperm motility, viability as well as acrosome and plasma membrane integrity were similar (p > 0.05) in all three experimental extenders. On day 2, sperm motility, viability, acrosome and plasma membrane integrity were higher (p < 0.05) in Tris–citric acid extender compared to sodium citrate based extender. On day 3 of storage, the values of motility, viability and acrosome integrity were higher (p < 0.05) in Tris–citric acid extender than in skim milk and sodium citrate based extenders. In conclusion, Tris–citric acid extender appears to be a better option compared with skim milk and sodium citrate extenders for liquid storage of Punjab Urial semen.     

Effect of straw size and thawing time on quality of cryopreserved buffalo (Bubalus bubalis) semen

This study was designed to compare the effect of straw size (0.25 vs. 0.5 ml) and thawing time (30 vs. 60 sec) on the quality of cryopreserved buffalo bull semen. Sperm motility, plasma membrane integrity and viability were higher (p ≤ 0.05) in 0.25 ml than 0.5 ml straw, thawed at 37°C either for 30 or 60 sec. In conclusion, cryopreservation of buffalo semen in 0.25 ml straw resulted in a higher post-thaw quality.     

The effects of long-term elevation of air temperature and CO on the frost hardiness of Scots pine

The frost hardiness of 20 to 25-year-old Scots pine (Pinus sylvestris L.) saplings was followed for 2 years in an experiment that attempted to simulate the predicted climatic conditions of the future, i.e. increased atmospheric CO₂ concentration and/or elevated air temperature. Frost hardiness was determined by an electrolyte leakage method and visual damage scoring on needles. Elevated temperatures caused needles to harden later and deharden earlier than the controls. In the first year, elevated CO₂ enhanced hardening at elevated temperatures, but this effect disappeared the next year. Dehardening was hastened by elevating CO₂ in both springs. The frost hardiness was high (相似文献