Poduction and Use of Isogenic Lines

Wenzel, G.; Foroughi‐Wehr, B.

doi:10.1007/978-94-017-2681-8_7

Cited by 4 publications

(4 citation statements)

References 36 publications

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“…Individual plants of the same DH lines are expected to be genetically identical (Wenzel and Foroughi‐Wehr, 1994). However, this study showed variation in TE expression among plants within each of the eight DH lines carrying the bay‐TE or the cuphea‐TE transgenes.…”

Section: Resultsmentioning

confidence: 99%

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Stability of the Expression of Acyl‐ACP Thioesterase Transgenes in Oilseed Rape Doubled Haploid Lines

2004

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stable for more than five generations, without any apparent genetic instability or loss of the transgenic pheno-Transgene stability in doubled haploid (DH) lines is an important type. However, instability in the expression of other consideration for transgenic cultivar development programs. The objective of this study was to assess the expression stability of acyl-acyl transgenes has been observed in some studies (Assaad carrier protein (ACP) thioesterase (TE) transgenes in oilseed rape Scheid et al., 1991; Zhong et al., 1999). For (Brassica napus L.) DH lines. The DH lines were developed from example, in a population of Arabidopsis thaliana (L.) microspores of F 1 plants from the crosses between transgenic parents Heynh. plants transgenic for a hygromycin resistance carrying the bay-TE (Uc FatB1), elm-TE (Ua FatB1), nutmeg-TE gene (hpt), 50% of the plants failed to transmit the (Mf FatB1), or cuphea-TE (Ch FatB1) transgenes and three nontransresistance trait to the progeny, although the complete genic cultivars having distinct seed oil fatty acid compositions. Of 333 transgene was detected in all the plants (Scheid et al., DH 1 plants developed from microspore-derived embryos that had 1991). undergone selection for kanamycin resistance (the selectable marker) Unstable expression of transgenes has been associated with bay-TE F 1 and cuphea-TE F 1 plants as the microspore donors, with gene silencing (Charrier et al., 2000; Meyer and 20 plants did not show TE transgene expression. Polymerase chain reaction (PCR) and Southern blotting analyses confirmed that the Saedler, 1996; Scott et al., 1998). Gene silencing is due absence of TE transgene expression in these 20 DH 1 plants was due to somatically or meiotically heritable repression of gene to escape of embryos from kanamycin selection or existence of an expression that is potentially reversible and is not due to incomplete T-DNA copy without the TE transgene. No DH 1 plant mutation (Kaeppler et al., 2000). Gene silencing could with completely silenced TE transgenes was detected. Thirty of 34 result from the blocking of transcription initiation, trantransgenic DH lines showed a stable level of the target fatty acid, scriptional gene silencing (TGS), or from the degradation lauric acid (C12:0) for the bay-TE and palmitic acid (C16:0) for the of mRNA after transcription, posttranscriptional gene other three TE transgenes, over the two or three consecutive generasilencing (PTGS) (Chandler and Vaucheret, 2001; Matzke tions tested (DH 2 , DH 3 , and/or DH 4 plants). Target fatty acids were and Matzke, 1998; Wassenegger, 2000). Possible factors significantly affected by temperature during seed development. DH inducing gene silencing include growth conditions of the lines carrying the elm-TE or the cuphea-TE transgene grown under high temperature conditions (25/20؇C, day/night) during seed develop-

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Section: Resultsmentioning

confidence: 99%

“…Influence of temperature on the fatty acid composi-to be genetically identical (Wenzel and Foroughi-Wehr, 1994). However, this study showed variation in TE ex-tion of the seed oil of nontransgenic oilseed rape culti- 1997).…”

Section: Variation Within Te Transgenic Dh Linesmentioning

confidence: 99%

Stability of the Expression of Acyl‐ACP Thioesterase Transgenes in Oilseed Rape Doubled Haploid Lines

2004

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“…The capacity for uninucleate microspores to undergo a developmental switch has been exploited to form haploid embryos in vitro (Guha and Maheshwari 1964) while microspores from other stages of pollen development are less likely to form embryos (Wenzel and Foroughi-Wehr 1994). The efficiency of embryogenesis in in vitro culture of anthers is also affected by harvest season with a maximum response occurring in anthers collected in spring and autumn than in winter or summer (reviewed in Smykal 2000).…”

Section: Discussionmentioning

confidence: 99%

Mammalian neurohormones: potential significance in reproductive physiology of St. John's wort (Hypericum perforatum L.)?

Murch

Saxena

2002

Naturwissenschaften

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Melatonin and serotonin are indoleamine neurohormones that function as photoperiod signals in many species and have recently been found in St. John's wort, a medicinal plant used in the treatment of depression. There is no known role for melatonin in higher plants but melatonin functions as a signal of changes in photoperiod in other species. In the current study, serotonin and melatonin were quantified during flower development. Higher concentrations of serotonin were found in flower buds at the tetrad stage of microspore development and higher melatonin concentrations were detected during uninucleate mircosporogenesis. Additionally, the regeneration potential of isolated anthers was highest in the same stage that had elevated melatonin concentrations. These data provide the first evidence of the presence of melatonin during flower development and raise many questions about the potential roles of serotonin and melatonin as regulatory molecules in the reproductive flexibility of higher plants.

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“…Cold inhibited embryo formation and this response was only observed when anthers containing tetrads or uninucleate pollen where cultured in the presence of IBA : BA or IAA : BA ratios of 25 or 10 to 5. Although the beneficial effect of cold treatment is well established for many species, in others, a negative effect has been reported (Wenzel and Foroughi-Wehr, 1994). The developmental stage of the microspores at the time of culture has also been cited as one of the most important factors for successful anther culture (Chen, 1987).…”

Section: Propagation and Tissue Culturementioning

confidence: 99%

Callus and Somatic Embryogenesis from Cultured Anthers of Service Tree (Sorbus domestica L.)

Arrillaga¹,

Lerma²,

Pérez‐Bermúdez³

et al. 1995

HortSci

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The effects of stage of microspore development, cold pretreatment, and growth regulators on the embryogenic response of anthers from service tree (Sorbus domestica L.) are reported. Callus proliferation required the presence of growth regulators in the culture medium, best results being obtained with combinations of auxins and BA. Microspore embryogenesis was only induced when anthers containing tetrads or uninucleate pollen were cultured on BA-supplemented media containing IBA or IAA. A cold pretreatment before anther culture elicited a significant decrease in callus formation and inhibited embryogenesis. Chemical names used: benzyladenine (BA), indole-3-butyric acid (IBA), indole-3-acetic acid (IAA).

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Poduction and Use of Isogenic Lines

Cited by 4 publications

References 36 publications

Stability of the Expression of Acyl‐ACP Thioesterase Transgenes in Oilseed Rape Doubled Haploid Lines

Stability of the Expression of Acyl‐ACP Thioesterase Transgenes in Oilseed Rape Doubled Haploid Lines

Mammalian neurohormones: potential significance in reproductive physiology of St. John's wort (Hypericum perforatum L.)?

Callus and Somatic Embryogenesis from Cultured Anthers of Service Tree (Sorbus domestica L.)

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