A new biochemical effect of erythropoietin

Erythropoietin stimulated lactoperoxidase (LP) or horseradishperoxidase (HRP) catalyzed iodination of tyrosine, the stimulation being more pronounced in case of LP. The diiodotyrosine (DIT) formation was stimulated more than MIT formation although the total quantity of DIT formed was less than MIT. Both sheep plasma erythropoietin and human urinary erythropoietin exhibited the above phenomenon and the stimulatory effects were directly propertional to their potencies. Preincubation of erythropoietin with neuraminidase abolished its stimulatory effect. Other glycoprotein hormones like thyrotropic hormone (TSH) and human chorionic gonadotrophin (HCG) did not stimulate the above system.     

An Improved Method for In Vitro Large Scale Propagation of Piper betle L

A protocol for large-scale propagation of Piper betle cvs Desawari and Desi Bangla was developed through axillary shoot proliferation. Due to systemic infection as well as high phenol content the crop was very difficult to establish in aseptic condition. But a mixture of 5 mg l^?1 each of chloramphenicol and oxytetracyclin and 100 mg l^?1 each of citric acid and ascorbic acid used in MS medium for 2 days helped in establishment. After 48 h, the explants were transferred to the antibiotic free medium having PVP and ascorbic acid (100 mg l^?1 each), citric acid (50 mg l^?1), and glutathione (20 mg l^?1). Regular subculturing of the explants into liquid medium, use of antioxidants and incubation of the cultures in the dark for initial 7–10 days played a crucial role for keeping them fresh and green. Maximum numbers of axillary shoots were obtained with 2 mg l^?1 BA and 0.2 mg l^?1 NAA as growth supplements. The plants were rooted in 0.25 mg l^?1 IBA and hardened in the soil. Phenolic compound analysis showed almost the same results in tissue-raised and in vivo grown plants in Desawari.     

竹红菌甲素在脂质体中的光谱性质和结合能力研究

竹红菌甲素在脂质体中的光谱性质和结合能力研究邹伟,安静仪,蒋丽金（中国科学院北京感光化学研究所,１００１０１）关键词竹红菌甲素;光谱特性;结合;脂质体竹红菌甲素（Ｒ人）是一种新型并配类光疗药物,临床上治疗一些皮肤病效果显著”’,研究表明ＨＡ对癌细胞有...     

小麦根系过氧化氢积累与耐盐性的关系

以抗盐性不同的2个小麦品系为材料,对其在盐胁迫下根细胞膜的膜渗透率,MDA含量,H2O2积累以及POD,SOD相对活性进行了分析和对比。结果表明：盐胁迫下抗性低的小麦品系93029#POD活性下降,导致活性氧积累而引起膜脂的过氧化作用;而抗盐性强的906#,在盐胁迫下。POD活性显著升高,没有明显的活性氧积累和膜脂过氧化现象,植物的抗盐性与其活性氧代谢和H2O2水平有关,抗必品系具有较高的清除活性氧的能力,使得H2O2浓度处于较低的水平,不对细胞造成伤害,外施Ca^2 和Vc可部分缓解盐害。     

Tropic failure of Phyllactinia corylea contributes to the mildew resistance of mulberry genotypes

Different mulberry genotypes show great variation in their resistance to the powdery mildew Phyllactinia corylea. Conidial germination and hyphal growth of P. corylea on the leaf surface of two susceptible mulberry genotypes, viz., Kanva 2 (K2) and Victory 1 (V1) varieties of Morus indica, and on two resistant species, viz., M. laevigata and M. serrata were studied by scanning electron microscopy. Conidial germination and growth of germ tubes were normal on all the leaves. The hyphae of P. coryleaidentify stomata on host leaves by their topographical features to produce the stomatopodia precisely over them. The holes and/or the grooves of stomata appear to provide the signals for the initiation of stomatopodia and similar structures are erratically developed over many local depressions or grooves on leaf surface. The abaxial surface of K2 leaf is smooth without prominent undulations of epidermal cell surface, and the stomata are flush with the leaf surface. Although successful penetration is also achieved on V1 leaf, its slightly undulated surface occasionally provides inaccurate tropic signals to the hyphae, inducing the development of stomatopodia away from the stomata. The leaf surfaces of M. laevigata and M. serrata are very rough with highly sculptured cuticle and abundant epidermal outgrowths. Stomata mostly remain sunken or hidden amidst the cuticular ornamentations and the hyphae fail to recognise the precise signals from them. As the surface architecture of the leaves provides many immense sources of tropic signals, stomatopodia are often produced over local depressions or grooves. In these cases the fungus fails to penetrate the leaf, does not develop beyond 24 h and penetration is rarely achieved on the leaves of the resistant plants. The study indicates that the stimulatory effect of the leaf surface topography of resistant varieties misleads the pathogen from successful penetration, thus contributing to the plant's resistance.This revised version was published online in October 2005 with corrections to the Cover Date.     

Marker-free transgenic (MFT) near-isogenic introgression lines (NIILs) of 'golden' indica rice (cv. IR64) with accumulation of provitamin A in the endosperm tissue

We have developed near-isogenic introgression lines (NIILs) of an elite indica rice cultivar (IR64) with the genes for β-carotene biosynthesis from dihaploid (DH) derivatives of golden japonica rice (cv. T309). A careful analysis of the DH lines indicated the integration of the genes of interest [phytoene synthase ( psy ) and phytoene desaturase ( crtI )] and the selectable marker gene (hygromycin phosphotransferase, hph ) in two unlinked loci. During subsequent crossing, progenies could be obtained carrying only the locus with psy and crtI , which was segregated independently from the locus containing the hph gene during meiotic segregation. The NIILs (BC₂F₂) showed maximum similarity with the recurrent parent cultivar IR64. Further, progenies of two NIILs were devoid of any fragments beyond the left or right border, including the chloramphenicol acetyltransferase ( cat ) antibiotic resistance gene of the transformation vector. Spectrophotometric readings showed the accumulation of up to 1.06 µg total carotenoids, including β-carotene, in 1 g of the endosperm. The accumulation of β-carotene was also evident from the clearly visible yellow colour of the polished seeds.     

Extracellular matrix proteome of chickpea (Cicer arietinum L.) illustrates pathway abundance, novel protein functions and evolutionary perspect

The extracellular matrix (ECM) or cell wall is a dynamic system and serves as the first line mediator in cell signaling to perceive and transmit extra- and intercellular signals in many pathways. Although ECM is a conserved compartment ubiquitously present throughout evolution, a compositional variation does exist among different organisms. ECM proteins account for 10% of the ECM mass, however, comprise several hundreds of different molecules with diverse functions. To understand the function of ECM proteins, we have developed the cell wall proteome of a crop legume, chickpea (Cicer arietinum). This comprehensive overview of the proteome would provide a basis for future comparative proteomic efforts for this important crop. Proteomic analyses revealed new ECM proteins of unknown functions vis-à-vis the presence of many known cell wall proteins. In addition, we report here evidence for the presence of unexpected proteins with known biochemical activities, which have never been associated with ECM.     

Molecular cloning and expression of cardiac-specific myosin heavy chain gene sequences in chick embryo

A recombinant DNA plasmid, pMHC8, that contains gene sequences for embryonic chick cardiac myosin heavy chain was constructed, identified and characterized. The identity of the clone was established by hybridization with labeled probes that afford screening of MHC²² with high specificity, by inhibition of MHC synthesis in the in vitro hybrid-arrested translation assay, and by tissue-specific hybridization of labeled pMHC8 DNA to MHC messenger RNA.The pMHC8 DNA probe is highly specific for chick heart muscle tissue, since it hybridized poorly to chick skeletal muscle RNA and did not detectably hybridize to adult rat heart RNA. Upon screening the embryonic chick heart cells in culture, no detectable level of MHC mRNA was observed in dividing myoblasts, but the mRNA appeared in differentiated cardiac myocytes paralleling morphogenetic changes in the embryonic cells.     

Nitrogen losses in puddled soils as affected by timing of water deficit and nitrogen fertilization

Erratic rainfall in rainfed lowlands and inadequate water supply in irrigated lowlands can results in alternate soil drying and flooding during a rice (Oryza sativa L.) cropping period. Effects of alternate soil drying and flooding on N loss by nitrification-denitrification have been inconsistent in previous field research. To determine the effects of water deficit and urea timing on soil NO₃ and NH₄, floodwater NO₃, and N loss from added ¹⁵N-labeled urea, a field experiment was conducted for 2 yr on an Andaqueptic Haplaquoll in the Philippines. Water regimes were continuously flooded, not irrigated from 15 to 35 d after transplanting (DT), or not irrigated from 41 to 63 DT. The nitrogen treatments in factorial combination with water regimes were no applied N and 80 kg urea-N ha^–1, either applied half basally and half at 37 DT or half at 11 DT and half at 65 DT. Water deficit at 15 to 35 DT and 41 to 63 DT, compared with continuous soil flooding, significantly reduced extractable NH₄ in the top 30-cm soil layer and resulted in significant but small (<1.0 kg N ha^–1) soil NO₃ accumulations. Soil NO₃, which accumulated during the water deficit, rapidly disappeared after reflooding. Water deficit at 15 to 35 DT, unlike that at 41 to 63 DT, increased the gaseous loss of added urea N as determined from unrecovered ¹⁵N in ¹⁵N balances. The results indicate that application of urea to young rice in saturated or flooded soil results in large, rapid losses of N (mean = 35% of applied N), presumably by NH₃ volatilization. Subsequent soil drying and flooding during the vegetative growth phase can result in additional N loss (mean = 14% of applied N), presumably by nitrification-denitrification. This additional N loss due to soil drying and flooding decreases with increasing crop age, apparently because of increased competition by rice with soil microorganisms for NH₄ and NO₃.     

Effect of adrenergic agonists and antagonists on alanine amino transferase,fructose-1:6-bisphosphatase and glucose production in hepatocytes

Using rat hepatocytes we confirmed our previous results that glucagon and -adrenergic agonists increased the enzyme activity of alanine aminotransferase (AAT) and propranolol abolished their effects. Only the enzyme activity was measured and other parameters like quantity of the enzyme or activation due to modification were not looked for. As in perfusion experiment phenylephrine and phenoxybenzamine (-agonist and -antagonist respectively) also increased the AAT activity in isolated rat hepatocytes and propranolol reversed these effects. The additive effect of glucagon and phenoxybenzamine on AAT was also persistant in hepatocyte system.Fructose- 1:6-bisphosphatase (Fru-P₂ase), another key enzyme in gluconeogenic pathway, was elevated by glucagon and other -adrenergic agonists both in liver perfusion and isolated hepatocyte experiments and was brought back to the normal level by propranolol. In this case also only the enzyme activity was measured and no other parameters were looked for. Unlike AAT this enzyme was not stimulated by phenylephrine or phenoxybenzamine. But AAT and Fru-P₂-ase activities were increased significantly by adenylate cyclase activators like fluoride or forskolin. Thus, it appears that the regulation of fru-P₂-ase by glucagon is purely a -receptor mediated process whereas AAT activation shows a mixed type of regulation where some well known -agonist and antagonists are behaving as -agonists.Results further indicate the presence of phosphodiesterase in hepatocyte membrane which was stimulated by glucagon and brought back to the normal level by propranolol.The different adrenergic compounds stated above, not only modified the activity of the above two enzymes but also stimulated glucose production by hepatocytes from alanine which was in turn abolished by propranolol as well as amino oxyacetate (AOA), a highly specified inhibitor of AAT. This confirm the participation of AAT in gluconeogenesis from alanine in liver. Forskolin and fluoride also increased the glucose production from alanine and showed additive effects with glucagon, phenylephrine and phenoxybenzamine.