Stability parameters and performance of interregional crosses in durum wheat (Triticum durum Desf.)

Summary Twelve durum wheat varieties originating from 3 ecologically diverse regions and their 48 intergroup crosses were evaluated for stability of performance with respect to grain yield and certain component traits. The linear component of the genotype-environment interaction was revealed for grain yield, 100-grain weight and plant height, non-linear for tiller number whereas for grains per spike both components were equally important. However, except for tiller number, the linear component appeared to be contributing to a large extent towards the prevalent interactions. NP 404, Bijaga Yellow and Giorgio VZ 331 depicted stable performance for grain yield. However, considering all the attributes, the parents NP 404, Bijaga Yellow, Anhinga s and Mexicali 75 and hybrids NP 401 x Mexicali 75, NP 404 x Anhinga s, NP 412 x Mexicali 75, NP 404 x Gerardo VZ 466 and Anhinga s x Capeiti appeared promising. The Mexican group as a whole exhibited a more stable performance than the other two evaluated groups. Compensating shift among the component characters was evident in the case of parents as well as hybrids and stability of performance appeared to be under genetic control. Effective utilization of these two aspects through introduction in otherwise desirable varieties has been advocated.Part of Ph.D. thesis of senior author submitted to the Punjab Agricultural University     

Expression of a 24 kDa GTP-binding protein (Gn24) is increased in lovastatin treated human erythroleukemia cells

A major 27 kDa particulate and a minor 24 kDa cytosolic GTP-binding protein was detected in HEL cells upon incubation with [-³²P]GTP of nitrocellulose blots containing polypeptides separated using SDS-PAGE. Addition of lovastatin (30 M) to HEL cells in culture inhibited protein synthesis by 35%. However, this treatment resulted in a 5-fold increase, as quantitated by [-³²P]GTP binding, in the amount of cytosolic 24 kDa GTP-binding protein. Addition of cycloheximide plus lovastatin to cells in culture abolished the observed increase in 24 kDa GTP-binding protein. Incubation of cells with lovastatin plus [R,S]-[5-³H]mevalonolactone resulted in the incorporation of radioactivity into several polypeptides in both the cytosolic and particulate fractions including a polypeptide of molecular mass of 24 kDa in the cytosol. The mobility of this 24 kDa isoprenylated protein on SDS-PAGE was identical to that of the GTP-binding protein increased in response to lovastatin. However, the 24 kDa protein remained in the cytosol after undergoing isoprenylation. The 24 kDa protein was distinct from the HEL cell, G25K/CDC42Hs GTP-binding protein and the GTP-binding protein that was a substrate for botulinum toxin C3 catalyzed ADP-ribosylation. Results demonstrate that lovastatin specifically increases the expression of a 24 kDa GTP-binding protein in HEL cells and that, isoprenylation of low molecular mass GTP-binding protein(s) may have function(s) in addition to its role in the targetting of these proteins to cell membrane.     

Organization of the Rosy Locus in DROSOPHILA MELANOGASTER: Further Evidence in Support of a CIS-Acting Control Element Adjacent to the Xanthine Dehydrogenase Structural Element

The present report summarizes our recent progress in the genetic dissection of an elementary genetic unit in a higher organism, the rosy locus (ry:3--52.0) in Drosophila melanogaster. Pursuing the hypothesis that the rosy locus includes a noncoding control region, as well as a structural element coding for the xanthine dehydrogenase (XDH) peptide, experiments are described that characterize and map a rosy locus variant associated with much lower than normal levels of XDH activity. Experiments are described that fail to relate this phenotype to alteration in the structure of the XDH peptide, but clearly associate this character with variation in number of molecules of XDH per fly. Large-scale fine-structure recombination experiments locate the genetic basis for this variation in the number of molecules of XDH per fly to a site immediately to the left of the XDH structural element within a region previously designated as the XDH control element. Moreover, experiments clearly separate this "underproducer" variant site from a previously described "overproducer" site within the control region. Examination of enzyme activity in electrophoretic gels of appropriate heterozygous genotypes demonstrates the cis-acting nature of this variation in the number of molecules of XDH. A revision of the map of the rosy locus, structural and control elements is presented in the light of the additional mapping data now available.     

Biocatalytic synthesis,structural elucidation,antioxidant capacity and tyrosinase inhibition activity of long chain fatty acid acylated derivatives of phloridzin and isoquercitrin

Our present investigation describes the regioselective enzymatic acylation of two series of acylated derivatives of phloridzin and isoquercitrin with six different long chain saturated, mono- and poly-unsaturated fatty acids. The biocatalytic synthesis was optimized to achieve 81–98% yields, using immobilized lipase B, from Candida antarctica (Novozym 435®), in acetone at 45 °C. The synthesized esters have been analyzed by ¹H NMR, ¹³C NMR spectroscopy and evaluated for their antioxidant capacity and tyrosinase inhibition, using in vitro assays. Among all the phloridzin and isoquercitrin derivatives, the greatest potential for inhibition of tyrosinase activity (p ?0.05) was exhibited by the α-linolenic acid ester of isoquercitrin.     

Calmodulin binds RalA and RalB and is required for the thrombin-induced activation of Ral in human platelets

Ral GTPases may be involved in calcium/calmodulin-mediated intracellular signaling pathways. RalA and RalB are activated by calcium, and RalA binds calmodulin in vitro. It was examined whether RalA can bind calmodulin in vivo, whether RalB can bind calmodulin, and whether calmodulin is functionally involved in Ral activation. Yeast two-hybrid analyses demonstrated both Rals interact directly but differentially with calmodulin. Coimmunoprecipitation experiments determined that calmodulin and RalB form complexes in human platelets. In vitro pull-down experiments in platelets and in vitro binding assays showed endogenous Ral and calmodulin interact in a calcium-dependent manner. Truncated Ral constructs determined in vitro and in vivo that RalA has an additional calmodulin binding domain to that previously described, that although RalB binds calmodulin, its C-terminal region is involved in partially inhibiting this interaction, and that in vitro RalA and RalB have an N-terminal calcium-independent and a C-terminal calcium-dependent calmodulin binding domain. Functionally, in vitro Ral-GTP pull-down experiments determined that calmodulin is required for the thrombin-induced activation of Ral in human platelets. We propose that differential binding of calmodulin by RalA and RalB underlies possible functional differences between the two proteins and that calmodulin is involved in the regulation of the activation of Ral-GTPases.     

Gastropathy and defense mechanisms in common bile duct ligated portal hypertensive rats

Portal hypertensive gastropathy is associated with a broad spectrum of gastric mucosal damage inspite of decreased gastric acid secretion, suggestive of compromised endogenous protective mechanisms. To determine the mechanisms of damage in portal hypertensive gastropathy we measured lipid peroxidation, glutathione, antioxidant and lysosomal enzymes in gastric mucosal homogenates from male Wistar rats with elevated intrasplenic pulp pressure, eighteen days after common bile duct ligation. Thiobarbituric acid-reactive substances and lysosomal enzymes (-glucuronidase and acid phosphatase) were increased in the common bile duct ligated group as compared to the sham-operated group. The levels of antioxidant defense enzymes, superoxide dismutase, glutathione peroxidase, catalase and glutathione were decreased as compared to the sham-operated controls. Pre-operative vitamin E administration decreased mucosal lipid peroxidation increased the levels of antioxidant defense enzymes and lowered the lysosomal enzymes. The plasma vitamin E levels in this group were lower when compared to animals receiving it post-operatively. In conclusion, free radical and lysosomal enzyme mediated damage may play a role in portal hypertensive gastropathy.