Studies of Cytokinin Action and Metabolism Using Tobacco Plants Expressing either the ipt or the GUS Gene Controlled by a Chalcone Synthase Promoter. IIipt and GUS Gene Expression, Cytokinin Levels and Metabolism

1997 ◽  
Vol 24 (5) ◽  
pp. 673 ◽  
Author(s):  
Jian Wang ◽  
D. S. Letham ◽  
Edwina Cornish ◽  
K. Wei ◽  
C. H. Hocart ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chalcone Synthase ◽  
Hormonal Control ◽  
Mature Leaf ◽  
Cytokinin Oxidase ◽  
Endogenous Cytokinin ◽  
Gus Gene ◽  
Ipt Gene ◽  
Cytokinin Level ◽  
Gus Gene Expression

The expression of GUS and ipt genes under control of a chalcone synthase (chs) promoter (PCHS) has been determined in tobacco (Nicotiana tabacum L.) plants and related to the development of plants expressing the chimaeric PCHS -ipt gene. GUS gene expression, which served as a model for the expression of the ipt gene, was highest in the internal phloem tissue of stems, in mature leaf laminae and in the upper part of corollas when fully open. Expression of the PCHS -ipt gene was assessed by quantifying the cytokinins produced, by determining incorporation of [3H]adenine into cytokinins and by quantifying ipt mRNA. Results from these studies were in general agreement with those based on expression of the PCHS -GUS gene. The chs promoter controlled expression of the ipt gene with some degree of tissue and temporal specificity. Expression of the ipt gene markedly elevated the cytokinin level in mature leaf laminae and the upper stems of flowering plants. The former was associated with retardation of leaf senescence and increased rates of transpiration due to changes in number, size and aperture of stomata, while the latter was associated with development of lateral shoots. In shoot tip cultures, 2-fold elevations in endogenous cytokinin level caused clear changes in development and this is discussed in relation to current concepts concerning the hormonal control of plant development. Using the transgenic tobacco tissues, it was shown that cis-zeatin is a substrate for cytokinin oxidase, that cis-zeatin is not converted to trans-zeatin in these tissues and that the endogenous cytokinin level influences the level of cytokinin oxidase activity in tissue and the rate of degradation of exogenous zeatin riboside to adenosine.

Studies of Cytokinin Action and Metabolism Using Tobacco Plants Expressing either the ipt or the GUS Gene Controlled by a Chalcone Synthase Promoter. I. Developmental Features of the Transgenic Plants

1997 ◽  
Vol 24 (5) ◽  
pp. 661 ◽  
Author(s):  
Jian Wang ◽  
D. S. Letham ◽  
Edwina Cornish ◽  
K. R. Stevenson
Keyword(s):  
Plant Development ◽  
Chalcone Synthase ◽  
Leaf Shape ◽  
Primary Root ◽  
Diffusion Resistance ◽  
Endogenous Cytokinin ◽  
Ipt Gene ◽  
Node Number ◽  
Transformed Plants ◽  
Developmental Features

A chimaeric cytokinin biosynthetic gene was constructed by placing the coding region of the bacterial ipt gene under the control of a chalcone synthase (chs) promoter (PCHS) from Antirrhinum majus. The PCHS-ipt gene was transferred to tobacco (Nicotiana tabacum L.). To provide control plants for studies of the effect of expression of this gene on plant development, a PCHS β-glucuronidase gene fusion was also introduced into tobacco. Expression of the PCHS-ipt gene caused release of axillary buds, inhibition of root development, retardation of leaf senescence, elevation of chlorophyll levels, delay in onset of flowering and retardation of flower development. These effects, which were quantified in PCHS- ipt plants, have previously been associated with expression of ipt genes controlled by heat shock or other promoters. Additional effects of ipt gene expression characterised in PCHS-ipt plants included growth of leafy shoots from the primary root, change in leaf shape with the production of broader and larger leaves, induction of expansion of excised leaf discs and development of leaves with an enlarged midrib and enlarged veins. A particularly striking effect of the expression of the PCHS-ipt gene was development of thicker stems due mainly to increase of pith tissue caused by an enhancement of both cell division and cell enlargement. Node number per primary stem was also increased. Endogenous cytokinin and applied auxin interacted antagonistically to affect both root and stem development in plants cultured in vitro. The leaves of PCHS -ipt transformed plants exhibited increased transpiration rates and reduced diffusion resistance associated with increased number of stomata and modified stomatal dimensions. The above changes, which were associated with elevated endogenous cytokinin levels, are discussed in relation to previous studies with ipt gene transformed plants and to some aspects of normal plant development.

Transient GUS gene expression in Brassica napus electroporated microspores

Plant Science ◽  
1993 ◽  
Vol 93 (1-2) ◽  
pp. 177-184 ◽  
Author(s):  
Marie-Françoise Jardinaud ◽  
André Souvré ◽  
Gilbert Alibert
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Gus Gene ◽  
Gus Gene Expression

scholarly journals STUDI PERBANDINGAN METODE TRANSFORMASI DNA MENGGUNAKAN VEKTOR Agrobacterium tumefaciens PADA TANAMAN TEBU (Sacharum hybrid)

2007 ◽  
Vol 13 (1) ◽  
pp. 39-44
Author(s):  
Sri Setyati ◽  
Purnama Oktaviandari ◽  
Muhammad Hazmi ◽  
Bambang Sugiharto
Keyword(s):  
Gene Expression ◽  
Embryogenic Callus ◽  
Multiple Shoots ◽  
Suspension Cultures ◽  
Gus Gene ◽  
In Vitro Plants ◽  
Histochemical Observation ◽  
Selection Medium ◽  
Gus Gene Expression

In order to compare transient expression of gus gene driven by CaMV 35S and rice ubiquitin RUBQ2 promoters, a DNA transformation was conducted using embryogenic callus and suspension cultures of sugarcane. The transient gus expression was observed by histochemical staining method. The histochemical observation of GUS activity after co-cultivation showed that RUBQ2 promoter produced high level of clear blue spots both in embryogenic callus and suspension cultures, while the CaMV35S promoter was not detected. The suspension cultures slightly increased transient gus gene expression compared to embryogenic callus. However, the histochemical analysis of regenerated putative transformant plants after 5 successive cycles on the selection medium showed no blue spots of gus gene expression. PCR amplification of DNA for CaMV35 or nptII in putative transformant plants confirmed that there was no integration of the transformed gene in the genome DNA. The results suggested a possibility of somaclonal variation with callus propagation, thus did not produce transformed plants. To avoid the somaclonal variation, the transformation was conducted using in vitro plants and multiple shoots without intervening callus phase. Histochemical observation of infected materials after co-cultivation showed that almost all of the infected materials partially exhibited blue color in the basal region. In case of in vitro plants, they rapidly grow and multiplied in the selection medium, thus the method provided an excellent system for the transformation in sugarcane. The results suggest that in vitro plants as well as multiple shoots need further investigation to be used as target tissues for Agrobacteriummediated transformation in sugarcane.

scholarly journals GUS Gene expression and plant regeneration via somatic embryogenesis in cucumber (Cucumis sativus L.)

2008 ◽  
Vol 35 (4) ◽  
pp. 275-280 ◽  
Author(s):  
Hyun-A Kim ◽  
Boo-Youn Lee ◽  
Jin-Jung Jeon ◽  
Dong-Woog Choi ◽  
Pil-Son Choi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Somatic Embryogenesis ◽  
Plant Regeneration ◽  
Cucumis Sativus ◽  
Gus Gene ◽  
Cucumis Sativus L ◽  
Gus Gene Expression
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