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1.
Summary IAA oxixase activity was very high in stem cuttings ofSalix tetrasperma andPopulus robusta, which rooted profusely, less in stem cuttings ofHibiscus rosa sinensis which rooted less, and insignificant in those ofEucalyptus citriodora which did not root at all. Protein(s) extracted from the stem cuttings ofE. citriodora inhibited the activity of IAA oxidase as well as root formation on hypocotyl cuttings ofPhaseolus mungo. The possibility of involvement of IAA oxidase activity in the process of adventitious root formation is discussed.The research has been financed by a grant from U.S. Department of Agriculture. 相似文献
2.
Summary Break in bud dormancy in virus-infected stem cuttings ofEuphorbia pulcherrima occurs because of the higher quantity of gibberellins present in them than in healthy cuttings in the dormant period of the plant. 相似文献
3.
Gibberellins and the break of bud dormancy in virus-infected stem cuttings of Euphorbia pulcherrima.
Break in bud dormancy in virus-infected stem cuttings of Euphorbia pulcherrima occurs because of the higher quantity of gibberellins present in them than in healthy cuttings in the dormant period of the plant. 相似文献
4.
Summary 2,4-dinitrophenol enhanced root formation on dark-grown hypocotyl cuttings ofPhaseolus mungo. This effect is probably related to uncoupling of oxidative phosphorylation and not through IAA-metabolism as is evident from studies with respiratory inhibitors (Cd2+) and non-phenolic uncouplers of oxidative phosphorylation (arsenate).The research has been financed by a grant from United States Department of Agriculture. 相似文献
5.
R. N. Chibbar K. Gurumurti K. K. Nanda 《Cellular and molecular life sciences : CMLS》1979,35(2):202-203
Summary IAA oxidase activity increased concomitant with root initiation during 16–52 h, in all cultures, thus showing the necessity of an active IAA oxidase for root initiation inPhaseolus mungo hypocotyl cuttings. The increase being very sharp in IAA alone, but less in all other cultures. The role of sucrose in root initiation via IAA oxidase activity has been discussed.The research has been partly financed by a grant from the US Department of Agriculture. One of us (R.N.C.) is thankful to the CSIR, India, for financial assistance. 相似文献
6.
A. Beqqali W. van Eldik C. Mummery R. Passier 《Cellular and molecular life sciences : CMLS》2009,66(5):800-813
Studies on identification, derivation and characterization of human stem cells in the last decade have led to high expectations
in the field of regenerative medicine. Although it is clear that for successful stem cell-based therapy several obstacles
have to be overcome, other opportunities lay ahead for the use of human stem cells. A more immediate application would be
the development of human models for cell-type specific differentiation and disease in vitro. Cardiomyocytes can be generated from stem cells, which have been shown to follow similar molecular events of cardiac development
in vivo. Furthermore, several monogenic cardiovascular diseases have been described, for which in vitro models in stem cells could be generated. Here, we will discuss the potential of human embryonic stem cells, cardiac stem
cells and the recently described induced pluripotent stem cells as models for cardiac differentiation and disease.
Received 07 August 2008; received after revision 26 September 2008; accepted 03 October 2008 相似文献
7.
Sheila Bhattacharya N. C. Bhattacharya K. K. Nanda 《Cellular and molecular life sciences : CMLS》1976,32(10):1301-1303
Summary Exogenously supplied DNA and RNA hastened root initiation and also increased the formation of roots on hypocotyl cuttings ofImpatients balsamina with intact apex and cotyledons. IAA appreciably increased the nucleic acid-caused enhancement in root formation. In combination with lowe concentrations of nucleic acids, it event stimulated the growth of roots as well as of hypocotyls. Higher concentrations of nucleic acids were, however, toxic.The research has been partly financed by a grant from the United States Department of Agriculture. One of us (SB) is thankful to the Deparmtent of Atomic Engery of the Government of India for financial assistance. 相似文献
8.
Summary
Zizyphus jujuba Lamk. stem galls incited byEriophyes cernuus Massee were induced aseptically on stem segments cultured on auxin and kinetin-free modifiedMurashige andSkoog's nutrient medium by 1. gall callus graft, 2. gall tissue extract and 3. incorporation of NAA into the medium. 相似文献
9.
Stem cells and their niche: a matter of fate 总被引:4,自引:0,他引:4
Embryonic stem cells provide an in vitro model for developmental biologists to study cell fate decisions during ontogenesis, while somatic stem cells allow physiologists
to understand tissue homeostasis in the adult. The behavior of stem cells is dependent on an intimate relationship with a
supportive niche. This brief review highlights some of the most important recent trends in stem cell biology, focusing in
particular on the supportive microenvironments for both embryonic and adult stem cells. Known intrinsic and extrinsic molecular
players from the best-characterized stem cell types are summarized, illuminating a number of shared environmental cues among
tissues originating from all three embryonic germ layers.
Received 6 October 2005; received after revision 27 December 2005; accepted 17 January 2006 相似文献
10.
V. M. Koritsas J. A. Lewis G. R. Fenwick 《Cellular and molecular life sciences : CMLS》1989,45(5):493-495
Summary Infestation of oilseed rape (Brassica napus L.) by the cabbage stem flea beetle (Psylliodes chrysocephala L.) leads to an overall reduction in the levels of aliphatic (alkenyl- and hydroxyalkenyl-) glucosinolates in the damaged tissue (lamina, petiole, stem) and a massive accumulation of indole glucosinolates. Whilst artificial damage (puncturing), with and without associated bacterial infection with an isolate fromP. chrysocephala, led to such accumulation, this was less than that observed in the insect-infected situation. 相似文献
11.
Coaxing bone marrow stromal mesenchymal stem cells towards neuronal differentiation: progress and uncertainties 总被引:8,自引:0,他引:8
Multipotent adult stem cells capable of developing into particular neuronal cell types have great potential for autologous
cell replacement therapy for central nervous system neurodegenerative disorders and traumatic injury. Bone marrow-derived
stromal mesenchymal stem cells (BMSCs) appear to be attractive starting materials. One question is whether BMSCs could be
coaxed to differentiate in vitro along neuronal or glial lineages that would aid their functional integration post-transplantation, while reducing the risk
of malignant transformation. Recent works suggest that BMSCs could indeed be differentiated in vitro to exhibit some cellular and physiological characteristics of neural cell lineages, but it is not likely to be achievable
with simple chemical treatments. We discussed recent findings pertaining to efforts in neuronal differentiation of BMSCs in vitro, and results obtained when these were transplanted in vivo.
Received 19 January 2006; received after revision 24 February 2006; accepted 12 April 2006 相似文献
12.
Summary A naturally regenerated young-growth in the Buchser Hochwald area in the Canton of St. Gallen, Switzerland, was used to determine the silviculturally permissible browsing limit for sycamore maple (Acer pseudoplatanus). The investigated area is situated at an altitude ranging from 1280 to 1310 m a.s.l. on anAbieti-Fagetum typicum site. Browsing was done by red deer (Cervus elaphus) and roe deer (Capreolus capreolus). A total of 57 sycamore maples, 1.30 m high, were examined. The actual browse impact on these plants was assessed by determining the frequency of browsing marks on the stem axis. To this end, the plants were cut into sections of 5 cm each and then split radially. On this basis it was possible to calculate permissible shares of browsed plants for four different size categories between 0.10 and 1.30 m. The permissible share of plants with two or more visible browsing marks on the stem axis amounted to 37.8% as an average value for the total risk period. This corresponds to a quota of 26.9% browsed terminal shoots per annum. 相似文献
13.
Summary
Agrobacterium tumefaciens A208 with nopaline plasmid pTiT37 was used to obtain stem tumors on plantlets ofFagraea fragrans grown in vitro. Bacterial elimination and tissue proliferation were simultaneously achieved by growing tumors on cefatoxime medium. After some tissue growth the shoots regenerated. An examination of these showed the presence of nopaline, indicating genetic transformation by T-DNA. 相似文献
14.
B. Diallo M. Vanhaelen O. P. Gosselain 《Cellular and molecular life sciences : CMLS》1995,51(1):95-97
A phytochemical survey of several plant species used in sub-Saharan Africa for the treatment of pottery, as well as some coating experiments carried out with purified extracts ofBridelia ferruginea stem bark, indicated that procyanidin fractions play a predominant role in the coating properties of the plant extracts. The analysis by high performance gel permeation chromatography of organic compounds isolated from the vessel walls suggested that products deriving from pyrolysis of procyanidins are detectable both in contemporary and older pottery, and their analysis could be useful for archaeological purposes. 相似文献
15.
G. Alleweldt 《Cellular and molecular life sciences : CMLS》1960,16(4):153-154
Summary Rindite and ethylene chlorhydrin have a promotive effect on breaking dormant buds of grape cuttings and of one year old pot-grown plants. The optimal dosis was approximately 6 mg Rindite per bud. 相似文献
16.
Human bystin was identified as a cytoplasmic protein directly binding to trophinin, a cell adhesion molecule potentially involved
in human embryo implantation. Although the trophinin gene is unique to mammals, the bystin gene (BYSL) is conserved across eukaryotes. Recent studies show that bystin plays a key role during the transition from silent trophectoderm
to an active trophoblast upon trophinin-mediated cell adhesion. Bystin gene knockout and knockdown experiments demonstrate
that bystin is essential for embryonic stem cell survival and trophectoderm development in the mouse. Furthermore, biochemical
analysis of bystin in human cancer cells and mouse embryos indicates a function in ribosomal biogenesis, specifically in processing
of 18S RNA in the 40S subunit. Strong evidence that BYSL is a target of c-MYC is consistent with a role for bystin in rapid protein synthesis, which is required for actively growing
cells.
Received 30 June 2007; received after revision 7 August 2007; accepted 29 August 2007 相似文献
17.
Summary Extracts of root, stem, leaf and inflorescence ofLantana camara Linn., (Verbenaceae) inhibited exine bursting, rhizoid initiation and protonemal initiation of spores of the fernCyclosorus dentatus (Forsk.) Ching. The leaf extract was found to be qualitatively and quantitatively most potent in its inhibitory effect. Attention is drawn to the fact that further spread ofLantana camara at Mt. Abu, Rajasthan, India may lead to the complete destruction, of the sizeable pteridophytic component in this locality, the richest vegetationally in Rajasthan. 相似文献
18.
19.
Bernd Kaina Geoffrey P. Margison Markus Christmann 《Cellular and molecular life sciences : CMLS》2010,67(21):3663-3681
O
6-methylguanine-DNA methyltransferase (MGMT) repairs the cancer chemotherapy-relevant DNA adducts, O
6-methylguanine and O
6-chloroethylguanine, induced by methylating and chloroethylating anticancer drugs, respectively. These adducts are cytotoxic,
and given the overwhelming evidence that MGMT is a key factor in resistance, strategies for inactivating MGMT have been pursued.
A number of drugs have been shown to inactivate MGMT in cells, human tumour models and cancer patients, and O
6-benzylguanine and O
6-[4-bromothenyl]guanine have been used in clinical trials. While these agents show no side effects per se, they also inactivate
MGMT in normal tissues and hence exacerbate the toxic side effects of the alkylating drugs, requiring dose reduction. This
might explain why, in any of the reported trials, the outcome has not been improved by their inclusion. It is, however, anticipated
that, with the availability of tumour targeting strategies and hematopoetic stem cell protection, MGMT inactivators hold promise
for enhancing the effectiveness of alkylating agent chemotherapy. 相似文献
20.
Yeung TM Chia LA Kosinski CM Kuo CJ 《Cellular and molecular life sciences : CMLS》2011,68(15):2513-2523
The gastrointestinal epithelium is a highly organised tissue that is constantly being renewed. In order to maintain homeostasis,
the balance between intestinal stem cell (ISC) self-renewal and differentiation must be carefully regulated. In this review,
we describe how the intestinal stem cell niche provides a unique environment to regulate self-renewal and differentiation
of ISCs. It has traditionally been believed that the mesenchymal myofibroblasts play an important role in the crosstalk between
ISCs and the niche. However, recent evidence in Drosophila and in vertebrates suggests that epithelial cells also contribute to the niche. We discuss the multiple signalling pathways
that are utilised to regulate stemness within the niche, including members of the Wnt, BMP and Hedgehog pathways, and how
aberrations in these signals lead to disruption of the normal crypt–villus axis. Finally, we also discuss how CDX1 and inhibition
of the Notch pathway are important in specifying enterocyte and goblet cell differentiation respectively. 相似文献