Limits...
Developmentally early and late onset of Rps10 silencing in Arabidopsis thaliana: genetic and environmental regulation.

Majewski P, Wołoszyńska M, Jańska H - J. Exp. Bot. (2009)

Bottom Line: Transgene dosage, silencing competence of the transgene loci, and photoperiod conditions were found to regulate the onset and efficiency of Rps10 silencing in two independent transgenic lines of Arabidopsis thaliana.P1 plants either died during the vegetative growth phase or were rescued by reversion resulting from inactivation of silencing.The most severe and early was the P2 phenotype found in only one transgenic line and most probably resulting from high competence of the transgene loci.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular Cell Biology, Faculty of Biotechnology, University of Wroclaw, ul. Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.

ABSTRACT
Transgene dosage, silencing competence of the transgene loci, and photoperiod conditions were found to regulate the onset and efficiency of Rps10 silencing in two independent transgenic lines of Arabidopsis thaliana. The Rps10 gene encodes the S10 protein which is part of the small subunit of mitochondrial ribosomes. Homozygous plants presented developmentally early onset of silencing, a very efficient decrease in the level of Rps10 transcripts, as well as a severe and uniform phenotype called P1. P1 plants either died during the vegetative growth phase or were rescued by reversion resulting from inactivation of silencing. A wide variety of morphological and developmental abnormalities observed within the hemizygous transformants allowed their classification into three categories P2, P3, and P4. The most severe and early was the P2 phenotype found in only one transgenic line and most probably resulting from high competence of the transgene loci. Developmentally late onset of silencing occurred only in the short day photoperiod and was characteristic for the P3 and P4 plants. This phenomenon was attributed to conditions favourable to silencing achieved in the short day photoperiod, e.g. a greatly prolonged vegetative phase accompanied by a gradual increase of the level of Rps10 transcripts. To the best of our knowledge, this is the first report indicating that the onset of silencing depends on the photoperiod conditions in A. thaliana.

Show MeSH

Related in: MedlinePlus

Correlation between severity of the P1 and P2 phenotype categories and efficiency of silencing. The Rps10 transcript level was compared in 8-week-old homozygous P1 plants and hemizygous P2 plants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC2657537&req=5

fig8: Correlation between severity of the P1 and P2 phenotype categories and efficiency of silencing. The Rps10 transcript level was compared in 8-week-old homozygous P1 plants and hemizygous P2 plants.

Mentions: On the other hand, the correlation between severity of phenotype and efficiency of silencing was observed when homozygous and hemizygous plants were compared. The Rps10 mRNA level in four 8-week-old dying P1 plants varied in the range of 2–12% (average 6%) of the control level (Fig. 8). The Rps10 transcript level was also measured in the hemizygous P2 plants capable of surviving the vegetative growth phase. When compared with the control plants, the P2 plants contained between 10% and 28% (average 18%) of the Rps10 transcripts. These data indicated that silencing efficiency was generally higher in homozygous than in hemizygous plants.


Developmentally early and late onset of Rps10 silencing in Arabidopsis thaliana: genetic and environmental regulation.

Majewski P, Wołoszyńska M, Jańska H - J. Exp. Bot. (2009)

Correlation between severity of the P1 and P2 phenotype categories and efficiency of silencing. The Rps10 transcript level was compared in 8-week-old homozygous P1 plants and hemizygous P2 plants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2657537&req=5

fig8: Correlation between severity of the P1 and P2 phenotype categories and efficiency of silencing. The Rps10 transcript level was compared in 8-week-old homozygous P1 plants and hemizygous P2 plants.
Mentions: On the other hand, the correlation between severity of phenotype and efficiency of silencing was observed when homozygous and hemizygous plants were compared. The Rps10 mRNA level in four 8-week-old dying P1 plants varied in the range of 2–12% (average 6%) of the control level (Fig. 8). The Rps10 transcript level was also measured in the hemizygous P2 plants capable of surviving the vegetative growth phase. When compared with the control plants, the P2 plants contained between 10% and 28% (average 18%) of the Rps10 transcripts. These data indicated that silencing efficiency was generally higher in homozygous than in hemizygous plants.

Bottom Line: Transgene dosage, silencing competence of the transgene loci, and photoperiod conditions were found to regulate the onset and efficiency of Rps10 silencing in two independent transgenic lines of Arabidopsis thaliana.P1 plants either died during the vegetative growth phase or were rescued by reversion resulting from inactivation of silencing.The most severe and early was the P2 phenotype found in only one transgenic line and most probably resulting from high competence of the transgene loci.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular Cell Biology, Faculty of Biotechnology, University of Wroclaw, ul. Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.

ABSTRACT
Transgene dosage, silencing competence of the transgene loci, and photoperiod conditions were found to regulate the onset and efficiency of Rps10 silencing in two independent transgenic lines of Arabidopsis thaliana. The Rps10 gene encodes the S10 protein which is part of the small subunit of mitochondrial ribosomes. Homozygous plants presented developmentally early onset of silencing, a very efficient decrease in the level of Rps10 transcripts, as well as a severe and uniform phenotype called P1. P1 plants either died during the vegetative growth phase or were rescued by reversion resulting from inactivation of silencing. A wide variety of morphological and developmental abnormalities observed within the hemizygous transformants allowed their classification into three categories P2, P3, and P4. The most severe and early was the P2 phenotype found in only one transgenic line and most probably resulting from high competence of the transgene loci. Developmentally late onset of silencing occurred only in the short day photoperiod and was characteristic for the P3 and P4 plants. This phenomenon was attributed to conditions favourable to silencing achieved in the short day photoperiod, e.g. a greatly prolonged vegetative phase accompanied by a gradual increase of the level of Rps10 transcripts. To the best of our knowledge, this is the first report indicating that the onset of silencing depends on the photoperiod conditions in A. thaliana.

Show MeSH
Related in: MedlinePlus