SUMMARY Agrobacterium tumefaciens tumorigenesis is initiated by the horizontal transfer of a suite of oncogenes that alter hormone synthesis and sensitivity in infected plant cells. Transgenic plants silenced for the iaaM and ipt oncogenes are highly recalcitrant to tumorigenesis, and present a unique resource to elucidate fundamental questions related to Agrobacterium biology and post-transcri...

Although many subviral RNAs reduce or intensify disease symptoms caused by the helper virus, only recently have clues concerning the mechanism of disease modulation been revealed. New models for DI RNA-mediated reduction in helper virus levels and symptom attenuation include DI RNA enhancement of posttranscriptional gene silencing (PTGS), which is an antiviral defense mechanism in plants. Sympt...

one of the most efficient mechanisms by which plants protect themselves from invading virusesis the specific rna-dependent silencing pathway termed post-transcriptional gene silencing(ptgs). in this mechanism, resistance to a virus is engineered through the expression of asegment of the virus genomein transgenic plants. potato virusy (pvy) is one of the mostdamaging viruses of potato, infecting...

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...

BACKGROUND The injection of double-stranded RNA (dsRNA) has been shown to induce a potent sequence-specific inhibition of gene function in diverse invertebrate and vertebrate species. The homology-dependent posttranscriptional gene silencing (PTGS) caused by the introduction of transgenes in plants may be mediated by dsRNA. The analysis of Caenorhabditis elegans mutants impaired with dsRNA-medi...

In animals, double-stranded short interfering RNA (siRNA) and single-stranded microRNA (miRNA) regulate gene expression by targeting homologous mRNA for cleavage or by interfering with their translation, respectively. siRNAs are processed from injected or transgene-derived, long, perfect double-stranded RNA (dsRNA), while miRNAs are processed from short, imperfect dsRNA precursors transcribed f...

RNA silencing has an important role in defending against virus infection in plants. Plants with the deficiency of RNA silencing components often show enhanced susceptibility to viral infections. RNA-dependent RNA polymerase (RDRs) mediated-antiviral defense has a pivotal role in resistance to many plant viruses. In RDR6-mediated defense against viral infection, a plant-specific RNA binding prot...

and everybody will be able to enjoy the book, and not RNAi was coined half a dozen years ago to describe just those who are quite happy primarily going through a completely mysterious phenomenon in C. elegans the book by jumping from one tremendously good figure whereby injection of either sense or antisense RNA effi-to another. ciently inhibited gene function. The following year Andy As all go...

efg1 transcription factor is believed to be the main regulator of hyphal formation under many different conditions. in addition, it is responsible for positive regulation of the expression of several hyphal-specific genes. sap5, which encodes secreted aspartic proteinase, is one of the mentioned genes and is crucial for pathogenicity properties. in the present work we have established the exper...

In plants, silencing is usually accompanied by DNA methylation and heterochromatic histone marks. We studied these epigenetic modifications in different epialleles of 35S promoter (P35S)-driven tobacco transgenes. In locus 1, the T-DNA was organized as an inverted repeat, and the residing neomycin phosphotransferase II reporter gene (P35S-nptII) was silenced at the posttranscriptional (PTGS) le...