Arabidopsis mutants impaired in cosuppression

被引：190

作者：

Elmayan, T ^{[1
]}

Balzergue, S ^{[1
]}

Béon, F ^{[1
]}

Bourdon, V ^{[1
]}

Daubremet, J ^{[1
]}

Guénet, Y ^{[1
]}

Mourrain, P ^{[1
]}

Palauqui, JC ^{[1
]}

Vernhettes, S ^{[1
]}

Vialle, T ^{[1
]}

Wostrikoff, K ^{[1
]}

Vaucheret, H ^{[1
]}

机构：

[1] INRA, Biol Cellulaire Lab, F-78026 Versailles, France

来源：

PLANT CELL | 1998年 / 10卷 / 10期

关键词：

D O I：

10.1105/tpc.10.10.1747

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Post-transcriptional gene silencing (cosuppression) results in the degradation of RNA after transcription. A transgenic Arabidopsis line showing post-transcriptional silencing of a 35S-uidA transgene and uidA-specific methylation was mutagenized using ethyl methanesulfonate. Six independent plants were isolated in which uidA mRNA accumulation and beta-glucuronidase activity were increased up to 3500-fold, whereas the transcription rate of the 35S-uidA transgene was increased only up to threefold. These plants each carried a recessive monogenic mutation that is responsible for the release of silencing. These mutations defined two genetic loci, called sgs1 and sgs2 (for Suppressor of gene Silencing). Transgene methylation was distinctly modified in sgs1 and sgs2 mutants. However, methylation of centromeric repeats was not affected, indicating that sgs mutants differ from ddm (for decrease in DNA methylation) and som (for somniferous) mutants. Indeed, unlike ddm and som mutations, sgs mutations were not able to release transcriptional silencing of a 35S-hpt transgene. Conversely, both sgs1 and sgs2 mutations were able to release cosuppression of host Nia genes and 35S-Nia2 transgenes. These results therefore indicate that sgs mutations act in trans to impede specifically transgene-induced post-transcriptional gene silencing.

引用

页码：1747 / 1757

页数：11

共 38 条

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