Direct regeneration protocols of five Capsicum annuum L. varieties

The bud induction obtained is a simple and efficient protocol developed for in vitro propagation of five varieties of cultivars. Seeds of Capsicum annuum L. of five varieties red, yellow, green, purple and white were decontaminated and placed in a culture bottle containing a Murashige and Skoog medium, supplemented with 6-benzylaminopurine (BAP, 5 mg/l) and naphthalene acetic acid (NAA, 1 mg/l) or indole-3- acetic acid (IAA, 0.5 mg/l) and then were incubated in the dark for 10 - 12 days for germination. Leaf explants excised from 4 weeks -old aseptic seedlings were cultured on a MS medium supplemented with hormones BAP, kinetin (Kin), the combination of BAP + Kin, BAP with NAA (0.1 or 0.01 mg/l) and BAP with IAA (0.5 mg/l). The 2.0 mg/l BAP with 0.1 mg/l NAA media was observed to be more suitable for callus formation. The highest number of regenerated shoot buds was obtained when shoot explants were cultured on a MS medium supplemented with 2.0 mg/l BAP and 0.5 mg/l IAA. The mean number of shoot per explants was obtained in red (6.3), yellow (3.6), purple (3.3), and white (3.0) variety of C. annuum whereas 3.0 mg/l BAP and 0.5 mg/l IAA were observed to be more suitable for green (6.6) variety of C. annuum. Plantlets were successfully acclimatized in greenhouse.Keywords: Capsicum, auxin, cytokinin, micropropagation, organogenesis, sweet pepperAfrican Journal of Biotechnology, Vol. 13(2), pp. 307-312, 8 January, 201

A CFD Investigation into the Flow Distribution on a Car passing by a Truck

Abstract The flow distribution occurring on a car when it is passing by a truck is investigated using three dimensiona

The expanding functional roles and signaling mechanisms of adhesion G protein–coupled receptors

The adhesion class of G protein–coupled receptors (GPCRs) is the second largest family of GPCRs (33 members in humans). Adhesion GPCRs (aGPCRs) are defined by a large extracellular N‐terminal region that is linked to a C‐terminal seven transmembrane (7TM) domain via a GPCR‐autoproteolysis inducing (GAIN) domain containing a GPCR proteolytic site (GPS). Most aGPCRs undergo autoproteolysis at the GPS motif, but the cleaved fragments stay closely associated, with the N‐terminal fragment (NTF) bound to the 7TM of the C‐terminal fragment (CTF). The NTFs of most aGPCRs contain domains known to be involved in cell–cell adhesion, while the CTFs are involved in classical G protein signaling, as well as other intracellular signaling. In this workshop report, we review the most recent findings on the biology, signaling mechanisms, and physiological functions of aGPCRs

Calorimetric studies on the stability of the ribosome-inactivating protein abrin II: effects of pH and ligand binding.

The effects of pH and ligand binding on the stability of abrin II, a heterodimeric ribosome-inactivating protein, and its subunits have been studied using high-sensitivity differential scanning calorimetry. At pH7.2, the calorimetric scan consists of two transitions, which correspond to the B-subunit [transition temperature (Tm) 319.2K] and the A-subunit (Tm 324.6K) of abrin II, as also confirmed by studies on the isolated A-subunit. The calorimetric enthalpy of the isolated A-subunit of abrin II is similar to that of the higher-temperature transition. However, its Tm is 2.4K lower than that of the higher-temperature peak of intact abrin II. This indicates that there is some interaction between the two subunits. Abrin II displays increased stability as the pH is decreased to 4.5. Lactose increases the Tm values as well as the enthalpies of both transitions. This effect is more pronounced at pH7.2 than at pH4.5. This suggests that ligand binding stabilizes the native conformation of abrin II. Analysis of the B-subunit transition temperature as a function of lactose concentration suggests that two lactose molecules bind to one molecule of abrin II at pH7.2. The presence of two binding sites for lactose on the abrin II molecule is also indicated by isothermal titration calorimetry. Plotting DeltaHm (the molar transition enthalpy at Tm) against Tm yielded values for DeltaCp (change in excess heat capacity) of 27+/-2 kJ.mol-1.K-1 for the B-subunit and 20+/-1 kJ.mol-1.K-1 for the A-subunit. These values have been used to calculate the thermal stability of abrin II and to surmise the mechanism of its transmembrane translocation