Three transgenic lines of squash hemizygous for the coat protein genes of squash mosaic virus (SqMV) were shown previously to have resistant (SqMV-127), susceptible (SqMV-22) or recovery (SqMV-3) phenotypes. Post-transcriptional gene silencing (PTGS) was the underlying mechanism for resistance of SqMV-127. Here, experiments conducted to determine the mechanism of the recovery phenotype and whet...

The intensity of flower colour, mainly determined by the amount of anthocyanin, is an important horticultural trait. To modulate flower colour intensity, post-transcriptional gene silencing (PTGS)-based technology has been widely used. The constraint of PTGS, however, is that it requires a high degree of conservation in the nucleotide sequences of the target and the silencer. Further, it is dif...

Post-transcriptional gene silencing (PTGS) involving small interfering RNA (siRNA)-directed degradation of RNA transcripts and transcriptional silencing via DNA methylation have each been proposed as mechanisms of genome defence against invading nucleic acids, such as transposons and viruses. Furthermore, recent data from plants indicates that many transposons are silenced via a combination of ...

Phloem-mobile endogenous RNA is trafficked selectively into the shoot apex. In contrast, most viruses and long-distance post-transcriptional gene silencing (PTGS) signals are excluded from the shoot apex. These observations suggest the operation of an underlying regulatory mechanism. To examine this possibility, a potexvirus movement protein, known to modify cell-to-cell trafficking and PTGS, w...

Post-transcriptional gene silencing (PTGS) pathways play a role in genome defence and have been extensively studied, yet how repetitive elements in the genome are identified is still unclear. It has been suggested that they may produce aberrant transcripts (aRNA) that are converted by an RNA-dependent RNA polymerase (RdRP) into double-stranded RNA (dsRNA), the essential intermediate of PTGS. Ho...

The term 'gene silencing' refers to transcriptional and post-transcriptional control of gene expression. Related processes are found across kingdoms in plants and animals. We intended to test whether particular RNA constituents of a silenced plant can induce silencing in an animal. We generated Nicotiana benthamiana lines that expressed green fluorescent protein (GFP) from a transgene. Plants i...

Specific silencing of target genes can be induced in a variety of organisms by providing homologous double-stranded RNA molecules. In vivo, these molecules can be generated either by transcription of sequences having an inverted-repeat (IR) configuration or by simultaneous transcription of sense-antisense strands. Since IR constructs are difficult to prepare and can stimulate genomic rearrangem...

BACKGROUND The association between DNA methylation and gene silencing has long been recognized; however, signals that initiate de novo methylation are largely unknown. In plants, recognition of RNAs that are inducers of posttranscriptional gene silencing (PTGS) can result in sequence-specific DNA methylation, and the aim of this work was to investigate whether heritable epigenetic changes can o...

The 2b protein encoded by cucumber mosaic cucumovirus (Cmv2b) acts as an important virulence determinant by suppressing post-transcriptional gene silencing (PTGS), a natural plant defence mechanism against viruses. We report here that the tomato aspermy cucumovirus 2b protein (Tav2b), when expressed from the unrelated tobacco mosaic tobamovirus (TMV) RNA genome, activates strong host resistance...

The first step of the benzoxazinoid (BX) synthesis pathway is catalyzed by an enzyme with indole-3-glycerol phosphate lyase activity encoded by 3 genes, Bx1, TSA and Igl. A gene highly homologous to maize and wheat Bx1 has been identified in rye. The goal of the study was to analyze the gene and to experimentally verify its role in the rye BX biosynthesis pathway as a rye ortholog of the Bx1 ge...