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81.
82.
Strain Kidachi of Pharbitis nil scarcely flowered in responseto poor nutrition (culture in tap water) under continuous light,although strain Violet flowered easily. In parallel to the floweringresponse, the chlorogenic acid (CGA) content in the cotyledonsdid not increase during the culture in tap water in Kidachi,although it rapidly increased in Violet. The F1 hybrids betweenthese two strains and their F2 progeny flowered in responseto poor nutrition, although F1 showed a lower and F2 a muchlower flowering response than the parent Violet. These floweringresponses were closely correlated with the accumulation of CGAin the cotyledons.
1Present address: Botany Department, Institute of Agriculture,Yezin, Burma. (Received November 20, 1987; Accepted March 13, 1988) 相似文献
83.
David C. Holt Venetia J. Lay Eric D. Clarke Andrew Dinsmore Ian Jepson Simon W. J. Bright Andrew J. Greenland 《Planta》1995,196(2):295-302
The safener-induced maize (Zea mays L.) glutathione S-transferase, GST II (EC 2.5.1.18) and another predominant isoform, GST I, were purified from extracts of maize roots treated with the safeners R-25788 (N,N-diallyl-2-dichloroacetamide) or R-29148 (3-dichloroace-tyl-2,2,5-trimethyl-1,3-oxazolidone). The isoforms GST I and GST II are respectively a homodimer of 29-kDa (GST-29) subunits and a heterodimer of 29 and 27-kDa (GST-27) subunits, while GST I is twice as active with 1-chloro-2,4-dinitrobenzene as GST II, GST II is about seven times more active against the herbicide, alachlor. Western blotting using antisera raised against GST-29 and GST-27 showed that GST-29 is present throughout the maize plant prior to safener treatment. In contrast, GST-27 is only present in roots of untreated plants but is induced in all the major aerial organs of maize after root-drenching with safener. The amino-acid sequences of proteolytic fragments of GST-27 show that it is related to GST-29 and identical to the 27-kDa subunit of GST IV.Abbreviations CDNB
1-chloro-2,4-dinitrobenzene
- DEAE
di-ethylaminoethyl
- FPLC
fast protein liquid chromatography
- GSH
reduced glutathione
- GST
glutathione S-transferase
- GST-26
26-kDa subunit of maize GST
- GST-27
27-kDa subunit of maize GST
- GST-29
29-kDa subunit of maize GST
- R-25788
safener N,N-diallyl-2-dichloroacetamide
- R-29148
safener 3-dichloroacetyl-2,2,5-trimethyl-1,3-oxazolidone
- RPLC
reverse phase liquid chromatography
We are grateful to M-M. Lay, ZENECA AG Products (formerly ICI Americas), Richmond, Calif., USA for providing [14C] R-25788. ZENECA Seeds in the UK is part of ZENECA Limited. 相似文献
84.
85.
STEFAN I. CSÖGÖR 《Nature: New biology》1972,238(87):287-288
CHOLESTEROL is found in the blood as a structural component of lipoproteins concerned with the transport of other lipids1. The high resolution nuclear magnetic resonance spectra of high density serum lipoproteins are similar to that observed when lipids are dissolved in organic solvents, or dispersed in water by bile salts or detergents, or in sonicated form. The lipid component in lipoproteins is therefore probably in an extremely fluid condition2. If human serum is mixed with paraffin oil, some of the cholesterol diffuses into the oil without affecting the ultraviolet absorption spectrum of serum proteins. This procedure avoids any protein denaturing action used for cholesterol extraction3–5. It therefore seems that serum cholesterol has two fractions, one strongly bound by lipoprotein structures and the other loosely bound and diffusible in an oil phase. In this article I designate the loosely bound fraction “diffusible”. 相似文献
86.
Effects of medium growth regulator composition and embryo size on shoot organogenesis of callus derived from globular- to torpedo-shaped zygotic embryos of five sunflower (Helianthus annuus L.) genotypes were examined. Forty growth regulator combinations composed of 0 to 5 mgl-1 naphthaleneacetic acid (NAA) and 0 to 1 mgl-1 6-benzylaminopurine (BA) were tested. The frequency of zygotic embryos forming shoot-regenerating callus was analysed according to categorical data modelling using a maximum-likelihood approach. Both NAA and BA must be present to induce the formation of morphogenic callus from zygotic embryos, but each growth regulator effect varied with the genotype. For four genotypes, NAA and BA effects were neither linear nor quadratic; whereas, they were linear for the fifth one. Most effective concentrations across genotypes were 0.1 mgl-1 NAA and 0.5 mgl-1 or 0.2 mgl-1 BA. However, the optimal growth regulator combination depended on the genotype and an interaction between the two growth regulators. The frequency of shoot-regenerating callus also varied with the size of the embryo explant. For all five genotypes, 0.4 to 1.2 mm long heart-shaped zygotic embryos formed morphogenic callus more frequently than smaller less-developed ones. 相似文献
87.
Ganapathy Sivakumar Daniel R. Vail Vipin Nair Fabricio Medina-Bolivar Jackson O. Lay Jr. 《Biotechnology journal》2009,4(12):1704-1711
Diabetes is one of the nation's most prevalent, debilitating and costly diseases. For diabetes, frequent insulin treatment is very expensive and may increase anti-insulin antibody production, which may cause unwanted side effects. Corosolic acid may also have some efficacy in the treatment of diabetes, but without induction of anti-insulin antibodies. Recently, corosolic acid from Lagerstroemia speciosa L. leaf extracts has been reported to act via an indirect mechanism (unlike insulin) in animal experiments. The insulin-complementary anti-diabetic therapeutic value observed in these Japanese preliminary clinical trials has led to renewed interest in the biosynthesis of this compound. So far, there has been no clear evidence for a corosolic acid biosynthetic pathway in plants. This article provides possible roles of corosolic acid and hypothetical information on the biosynthetic pathway in plants. 相似文献
88.
Markus Anton Michael Passreiter Dorothee Lay Thanh-Phuong Thai Karin Gorgas Wilhelm W. Just 《Cell biochemistry and biophysics》2000,32(1-3):27-36
The authors characterized on a molecular level the clofibrate-inducible 26-kDa integral peroxisomal membrane protein (Pmp26p,
Pex11-1p) of rat liver. By screening cDNA databases with the obtained Pex11-1p-cDNA, a second homologous cDNA was identified
that codes for a polypeptide with slightly larger molecular mass than Pex11-1p. The authors call this polypeptide Pex11-2p.
Studies on the topology of Pex11-1p revealed two transmembrane domains with the N- and C-terminus facing the cytoplasm. The
C-terminal tail of Pex11-1p ends in a consensus dilysine motif of the type-KXKXX-COOH, which is known to be involved in the
ADP-ribosylation factor (ARF)1-coat protein (COP) I coat (ARF)1-dependent membrane recruitment to Golgi membranes. Studies
with isolated peroxisomes incubated in the presence of cytosol, adenosine triphosphate and GTPγS, indeed, provided evidence
for specific binding of ARF and coatomer to peroxisomes. Expression of Pex11-1p in Chinese hamster ovary (CHO) wild-type cells
led to a twofold increase in the number of peroxisomes, but expression in a temperature-sensitive CHO mutant, defective in
coatomer, induced elongation and tubulation of peroxisomal structures, rather than numerical proliferation. The obtained results
for the first time offer a mechanism explaining Pex11-1p-, as well as ARF- and coatomer-mediated peroxisomal vesiculation.
Two models are presented that may explain how these observations fit in with peroxisome biogenesis. 相似文献
89.
Ca++-dependent binding of antigen-19 S antibody complexes to macrophages 总被引:28,自引:0,他引:28
90.
Ciro Coletta Katalin Módis Bartosz Szczesny Attila Brunyánszki Gábor Oláh Ester CS Rios Kazunori Yanagi Akbar Ahmad Andreas Papapetropoulos Csaba Szabo 《Molecular medicine (Cambridge, Mass.)》2015,21(1):1-14
Hydrogen sulfide (H2S), as a reducing agent and an antioxidant molecule, exerts protective effects against hyperglycemic stress in the vascular endothelium. The mitochondrial enzyme 3-mercaptopyruvate sulfurtransferase (3-MST) is an important biological source of H2S. We have recently demonstrated that 3-MST activity is inhibited by oxidative stress in vitro and speculated that this may have an adverse effect on cellular homeostasis. In the current study, given the importance of H2S as a vasorelaxant, angiogenesis stimulator and cellular bioenergetic mediator, we first determined whether the 3-MST/H2S system plays a physiological regulatory role in endothelial cells. Next, we tested whether a dysfunction of this pathway develops during the development of hyperglycemia and μmol/L to diabetes-associated vascular complications. Intraperitoneal (IP) 3-MP (1 mg/kg) raised plasma H2S levels in rats. 3-MP (10 1 mmol/L) promoted angiogenesis in vitro in bEnd3 microvascular endothelial cells and in vivo in a Matrigel assay in mice (0.3–1 mg/kg). In vitro studies with bEnd3 cell homogenates demonstrated that the 3-MP-induced increases in H2S production depended on enzymatic activity, although at higher concentrations (1–3 mmol/L) there was also evidence for an additional nonenzymatic H2S production by 3-MP. In vivo, 3-MP facilitated wound healing in rats, induced the relaxation of dermal microvessels and increased mitochondrial bioenergetic function. In vitro hyperglycemia or in vivo streptozotocin diabetes impaired angiogenesis, attenuated mitochondrial function and delayed wound healing; all of these responses were associated with an impairment of the proangiogenic and bioenergetic effects of 3-MP. The antioxidants dl-α-lipoic acid (LA) in vivo, or dihydrolipoic acid (DHLA) in vitro restored the ability of 3-MP to stimulate angiogenesis, cellular bioenergetics and wound healing in hyperglycemia and diabetes. We conclude that diabetes leads to an impairment of the 3-MST/H2S pathway, and speculate that this may contribute to the pathogenesis of hyperglycemic endothelial cell dysfunction. We also suggest that therapy with H2S donors, or treatment with the combination of 3-MP and lipoic acid may be beneficial in improving angiogenesis and bioenergetics in hyperglycemia. 相似文献