Post‐transcriptional silencing of chalcone synthase in <i>Petunia</i> by inverted transgene repeats

Stam, Maike; Bruin, R de; Kenter, Susan; Hoorn, R.A.L. van der; Blokland, Rik van; Mol, J.A.; Kooter, Jan M.

doi:10.1046/j.1365-313x.1997.12010063.x

Cited by 170 publications

(138 citation statements)

References 47 publications

Supporting

Mentioning

131

Contrasting

Unclassified

Order By: Relevance

“…It has been shown in IR-induced PTGS in transgenic P. hybrida that a high level of transcription of CHS genes is not essential (Stam et al, 1997(Stam et al, , 2000. However, the increase in total CHS mRNA levels in the seed coats of both the i i !…”

Section: Existence Of Tandem Chs Clusters In the Different I Locus Ismentioning

confidence: 98%

“…Many of the IRs are dominant silencing loci, and palindromic sequences up to 15 kb in mice and Petunia hybrida (petunia) appear to be relatively stable (Ehrlich, 1989;Stam et al, 1997). Silencing of CHS expression and consequential abrogation of seed coat pigmentation in G. max by the dominant I and i i loci is an example of an endogenous inverted repeat locus associated with gene silencing (Todd and Vodkin, 1996).…”

Section: Existence Of Tandem Chs Clusters In the Different I Locus Ismentioning

confidence: 99%

See 1 more Smart Citation

Tissue-Specific Gene Silencing Mediated by a Naturally Occurring Chalcone Synthase Gene Cluster inGlycine max [W]

et al. 2004

View full text Add to dashboard Cite

Chalcone synthase, a key regulatory enzyme in the flavonoid pathway, constitutes an eight-member gene family in Glycine max (soybean). Three of the chalcone synthase (CHS) gene family members are arranged as inverted repeats in a 10-kb region, corresponding to the I locus (inhibitor). Spontaneous mutations of a dominant allele (I or i i ) to a recessive allele (i) have been shown to delete promoter sequences, paradoxically increasing total CHS transcript levels and resulting in black seed coats. However, it is not known which of the gene family members contribute toward pigmentation and how this locus affects CHS expression in other tissues. We investigated the unusual nature of the I locus using four pairs of isogenic lines differing with respect to alleles of the I locus. RNA gel blots using a generic open reading frame CHS probe detected similar CHS transcript levels in stems, roots, leaves, young pods, and cotyledons of the yellow and black isolines but not in the seed coats, which is consistent with the dominant I and i i alleles mediating CHS gene silencing in a tissue-specific manner. Using real-time RT-PCR, a variable pattern of expression of CHS genes in different tissues was demonstrated. However, increase in pigmentation in the black seed coats was associated with release of the silencing effect specifically on CHS7/CHS8, which occurred at all stages of seed coat development. These expression changes were linked to structural changes taking place at the I locus, shown to encompass a much wider region of at least 27 kb, comprising two identical 10.91-kb stretches of CHS gene duplications. The suppressive effect of this 27-kb I locus in a specific tissue of the G. max plant represents a unique endogenous gene silencing mechanism.

show abstract

Section: Existence Of Tandem Chs Clusters In the Different I Locus Ismentioning

confidence: 98%

Section: Existence Of Tandem Chs Clusters In the Different I Locus Ismentioning

confidence: 99%

Tissue-Specific Gene Silencing Mediated by a Naturally Occurring Chalcone Synthase Gene Cluster inGlycine max [W]

et al. 2004

View full text Add to dashboard Cite

show abstract

“…The following day, the RNA was fixed to the membrane by UV cross-linking (0.120 J; Stratalinker). The RNA gel blots were hybridized essentially as described by Stam et al (1997) using probes recognizing the coding regions of the b1 or Sam gene. The probes were generated by PCR (see Supplemental Table 2 online for the primer sequences) using plasmid DNA as template.…”

Section: Rna Gel Blot Analysismentioning

confidence: 99%

Tissue- and Expression Level–Specific Chromatin Looping at Maizeb1Epialleles

et al. 2009

Self Cite

View full text Add to dashboard Cite

This work examines the involvement of chromatin looping in the transcriptional regulation of two epialleles of the maize (Zea mays) b1 gene, B-I and B'. These two epialleles are tissue-specifically regulated and are involved in paramutation. B-I and B' are expressed at high and low levels, respectively. A hepta-repeat ;100 kb upstream of the transcription start site (TSS) is required for both paramutation and high b1 expression. Using chromosome conformation capture, we show that the heptarepeat physically interacts with the TSS region in a tissue-and expression level-specific manner. Multiple repeats are required to stabilize this interaction. High b1 expression is mediated by a multiloop structure; besides the hepta-repeat, other sequence regions physically interact with the TSS as well, and these interactions are epiallele-and expression levelspecific. Formaldehyde-assisted isolation of regulatory elements uncovered multiple interacting regions as potentially regulatory.

show abstract

“…Transcriptional gene silencing has been hypothesized to involve DNA/DNA pairing, DNA methylation or heterochromatinization (Kumpatla et al, 1997;Neuhuber, 1995;Park et al, 1996). Repeated DNA has a tendency to undergo transcriptional silencing, which may be associated with changes in chromatin structure (Meyer, 1996;Ye and Signer, 1996), as well as to induce certain types of posttranscriptional silencing (Stam et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Gene silencing from plant DNA carried by a Geminivirus

et al. 1998

View full text Add to dashboard Cite

SummaryThe geminivirus tomato golden mosaic virus (TGMV) replicates in nuclei and expresses genes from high copy number DNA episomes. The authors used TGMV as a vector to determine whether episomal DNA can cause silencing of homologous, chromosomal genes. Two markers were used to assess silencing: (1) the sulfur allele (su) of magnesium chelatase, an enzyme required for chlorophyll formation; and (2) the firefly luciferase gene (luc). Various portions of both marker genes were inserted into TGMV in place of the coat protein open-reading frame and the constructs were introduced into intact plants using particle bombardment. When TGMV vectors carrying fragments of su (TGMV::su) were introduced into leaves of wild-type Nicotiana benthamiana, circular, yellow spots with an area of several hundred cells formed after 3-5 days. Systemic movement of TGMV::su subsequently produced variegated leaf and stem tissue. Fragments that caused silencing included a 786 bp 5Ј fragment of the 1392 bp su cDNA in sense and anti-sense orientation, and a 403 bp 3Ј fragment. TGMV::su-induced silencing was propagated through tissue culture, along with the viral episome, but was not retained through meiosis. Systemic downregulation of a constitutively expressed luciferase transgene in plants was achieved following infection with TGMV vectors carrying a 623 bp portion of luc in sense or anti-sense orientation. These results establish that homologous DNA sequences localized in nuclear episomes can modulate the expression of active chromosomal genes.

show abstract

Post‐transcriptional silencing of chalcone synthase in Petunia by inverted transgene repeats

Cited by 170 publications

References 47 publications

Tissue-Specific Gene Silencing Mediated by a Naturally Occurring Chalcone Synthase Gene Cluster inGlycine max [W]

Tissue-Specific Gene Silencing Mediated by a Naturally Occurring Chalcone Synthase Gene Cluster inGlycine max [W]

Tissue- and Expression Level–Specific Chromatin Looping at Maizeb1Epialleles

Gene silencing from plant DNA carried by a Geminivirus

Contact Info

Product

Resources

About