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121.
122.
P.A. Wadegaonkar K.A. Bhagwat M.K. Rai 《Plant Cell, Tissue and Organ Culture》2006,84(2):100202-100204
Direct rooting from leaf explants of Withania somnifera was achieved on half strength Murashige and Skoog’s medium supplemented with 15 g l−1 sucrose, and different concentrations of growth regulators. Basal medium supplemented with 2.85 μM indoleacetic acid and
9.85 μM indolebutyric acid achieved maximum number of roots with 100% response. The roots were cultured on MS liquid medium
for the establishment of root-organ culture with the same plant growth regulators and incubated on an orbital shaker at 80 rpm
at 25 ± 2 °C. A root biomass of 6.15 ± 0.17 g was obtained after 5 weeks. When 1 g roots were inoculated to 2.5 l bubble column
reactor, 47 g roots were obtained after 6 weeks. The concentration of alkaloids was increased as compared to field grown roots.
The maximum concentration of withanolides (10 mg g−1 dry weight) was obtained in the bioreactor. 相似文献
123.
Zebra fish Dnmt1 and Suv39h1 regulate organ-specific terminal differentiation during development 总被引:1,自引:0,他引:1
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Rai K Nadauld LD Chidester S Manos EJ James SR Karpf AR Cairns BR Jones DA 《Molecular and cellular biology》2006,26(19):7077-7085
DNA methylation and histone methylation are two key epigenetic modifications that help govern heterochromatin dynamics. The roles for these chromatin-modifying activities in directing tissue-specific development remain largely unknown. To address this issue, we examined the roles of DNA methyltransferase 1 (Dnmt1) and the H3K9 histone methyltransferase Suv39h1 in zebra fish development. Knockdown of Dnmt1 in zebra fish embryos caused defects in terminal differentiation of the intestine, exocrine pancreas, and retina. Interestingly, not all tissues required Dnmt1, as differentiation of the liver and endocrine pancreas appeared normal. Proper differentiation depended on Dnmt1 catalytic activity, as Dnmt1 morphants could be rescued by active zebra fish or human DNMT1 but not by catalytically inactive derivatives. Dnmt1 morphants exhibited dramatic reductions of both genomic cytosine methylation and genome-wide H3K9 trimethyl levels, leading us to investigate the overlap of in vivo functions of Dnmt1 and Suv39h1. Embryos lacking Suv39h1 had organ-specific terminal differentiation defects that produced largely phenocopies of Dnmt1 morphants but retained wild-type levels of DNA methylation. Remarkably, suv39h1 overexpression rescued markers of terminal differentiation in Dnmt1 morphants. Our results suggest that Dnmt1 activity helps direct histone methylation by Suv39h1 and that, together, Dnmt1 and Suv39h1 help guide the terminal differentiation of particular tissues. 相似文献
124.
In the present study, we have investigated the effects of NaCl concentrations on the growth and phosphate metabolism of an
Anabaena doliolum strain isolated from a paddy field, in order to determine the possible effects of salinization. Growth rate, chlorophyll
content, and protein content decreased with increasing salt concentration in the growth medium, while carbohydrate concentration
increased. Phosphate content and phosphate uptake rate decreased. There was an increase in total alkaline phosphatase activity,
with an approximately 7-fold increase in extracellular activity compensating for an approximately 3-fold decrease in cell-bound
activity. NaCl effects on protein and chlorophyll concentrations were greater in P-deficient medium, while presence or absence
of P in the medium had little effect on cellular carbohydrate concentrations. It is concluded that growth in high salt likely
leads to reduced phosphate uptake in A. doliolum. 相似文献
125.
MukB is a bacterial SMC (structural maintenance of chromosome) protein required for faithful chromosome segregation in Escherichia coli. We report here that purified MukB introduces right-handed knots into DNA in the presence of type-2 topoisomerase, indicating that the protein promotes intramolecular DNA condensation. The pattern of generated knots suggests that MukB, similar to eukaryotic condensins, stabilizes large right-handed DNA loops. In contrast to eukaryotic condensins, however, the net supercoiling stabilized by MukB was negative. Furthermore, DNA reshaping by MukB did not require ATP. These data establish that bacterial condensins alter the shape of double-stranded DNA in vitro and lend support to the notions that the right-handed knotting is the most conserved biochemical property of condensins. Finally, we found that MukB can be eluted from a heparin column in two distinct forms, one of which is inert in DNA binding or reshaping. Furthermore, we find that the activity of MukB is reversibly attenuated during chromatographic separation. Thus, MukB has a unique set of topological properties, compared with other SMC proteins, and is likely to exist in two different conformations. 相似文献
126.
Shin JN Park SY Cha JH Park JY Lee BR Jung SA Lee ST Yun CW Seol DW Kim TH 《Experimental cell research》2006,312(19):3892-3898
TRAIL has been suggested to induce the cell death in various tumor cells but not in normal cells; however, several studies have provided the evidence that TRAIL can induce the cell death in some normal cells including human normal hepatocytes, suggesting that TRAIL may show hepatic toxicity in human. In this study, we designed a pro-form of TRAIL (sTRAIL:IL-18) in that soluble TRAIL (sTRAIL) is fused to IL-18, and a matrix metalloproteinases (MMPs) cleavage site is introduced at the connecting site. We showed that sTRAIL:IL-18 has significantly diminished the killing activity in HeLa cells but regains the activity by releasing the free sTRAIL through MMP-2-mediated cleavage. In addition, the killing activity of sTRAIL:IL-18 was significantly increased in HeLa cells when active MMP-2 was produced by TNF-alpha. Taken together, the data suggested that the sTRAIL:IL-18 can be reactivated at the specialized areas where MMPs are pathologically produced. 相似文献
127.
Baisakh N Rehana S Rai M Oliva N Tan J Mackill DJ Khush GS Datta K Datta SK 《Plant biotechnology journal》2006,4(4):467-475
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 (BC2 F2 ) 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. 相似文献
128.
Young WB Kolesnikov A Rai R Sprengeler PA Leahy EM Shrader WD Sangalang J Burgess-Henry J Spencer J Elrod K Cregar L 《Bioorganic & medicinal chemistry letters》2001,11(17):2253-2256
The structure-based design and progression of a screening lead to a 3nM factor VIIa/TF inhibitor with improved selectivity versus related enzymes is described. 相似文献
129.
Rungaroon Waditee-Sirisattha Meenakshi Singh Hakuto Kageyama Daungjai Sittipol Ashwani K. Rai Teruhiro Takabe 《Archives of microbiology》2012,194(11):909-914
Photosynthetic, nitrogen-fixing Anabaena strains play an important role in the carbon and nitrogen cycles in tropical paddy fields although they are salt sensitive. Improvement in salt tolerance of Anabaena cells by expressing glycine betaine–synthesizing genes is an interesting subject. Due to the absence of choline in cyanobacteria, choline-oxidizing enzyme could not be used for the synthesis of glycine betaine. Here, the genes encoding glycine-sarcosine and dimethylglycine methyltransferases (ApGSMT-DMT) from a halotolerant cyanobacterium Aphanothece halophytica were expressed in Anabaena sp. strain PCC7120. The ApGSMT-DMT-expressing Anabaena cells were capable of synthesizing glycine betaine without the addition of any substance. The accumulation level of glycine betaine in Anabaena increased with rise of salt concentration. The transformed cells exhibited an improved growth and more tolerance to salinity than the control cells. The present work provides a prospect to engineer a nitrogen-fixing cyanobacterium having enhanced tolerance to stress by manipulating de novo synthesis of glycine betaine. 相似文献
130.
Kumar D Plagov A Yadav I Torri DD Sayeneni S Sagar A Rai P Adabala M Lederman R Chandel N Ding G Malhotra A Singhal PC 《American journal of physiology. Renal physiology》2012,303(5):F711-F720
In the present study, we evaluated the effect of inhibition of renin activity (aliskiren) on the progression of renal lesions in two different mouse models (Vpr and Tg26) of human immunodeficiency virus (HIV)-associated nephropathy (HIVAN). In protocol A, Vpr mice were fed either water (C-VprA) or doxycycline [Doxy (D-VprA)] in their drinking water for 6 wk. In protocols B and C, Vpr mice received either normal saline (C-VprB/C), Doxy + normal saline (D-VprB/C), or Doxy + aliskiren (AD-VprB/C) for 6 wk (protocol B) or 12 wk (protocol C). In protocols D and E, Vpr mice were fed Doxy for 6 wk followed by kidney biopsy. Subsequently, half of the mice were administered either normal saline (D-VprD/E) or aliskiren (AD-VprD/E) for 4 wk (protocol D) or 8 (protocol E) wk. All D-VprA mice showed renal lesions in the form of focal segmental glomerular sclerosis and dilatation of tubules. In protocols B and C, aliskiren diminished both progression of renal lesions and proteinuria. In protocol C, aliskiren also diminished (P < 0.01) the rise in blood urea. In all groups, Doxy-treated mice displayed increased serum ANG I levels (the product of plasma renin activity); on the other hand, all aliskiren-treated mice displayed diminished serum ANG I levels. Renal tissues of D-VprC displayed increased ANG II content; however, aliskiren attenuated renal tissue ANG II production in AD-VprC. In protocol D, AD-VprD showed a 24.2% increase in the number of sclerosed glomeruli compared with 139.2% increase in sclerosed glomeruli in D-VprD (P < 0.01) from their baseline. The attenuating effect of aliskiren on the progression of renal lesions continued in AD-VprE. Aliskiren also diminished blood pressure, proteinuria, and progression of renal lesions in Tg26 mice. These findings indicate that inhibition of renin activity has a potential to slow down the progression of HIVAN. 相似文献