Bernard Carrol - Systemic RNA silencing in plants
July 2017
- Datum: 05.07.2017
- Uhrzeit: 14:00 - 15:30
- Vortragende(r): Bernard Carrol
- Ort: Central Building
- Raum: Seminar Room
- Gastgeber: Friedrich Kragler
Post-transcriptional gene silencing (PTGS) is
graft-transmissible and involves abundant 21 nt siRNAs and low abundance 22 nt
siRNAs produced by DCL4 and DCL2, respectively. We developed a reporter line
expressing double-stranded RNA (dsRNAs) specifically in the root tip, which
then required RNA-dependent RNA polymerase 6 (RDR6) for PTGS to spread from the
root tip to throughout the plant. This reporter line was used in a genetic
screen to identify mutants impaired in systemic PTGS. As expected, the screen
identified new alleles of rdr6 and other genes known to be required for
RDR6-dependent PTGS. Surprisingly, however, we also recovered dcl2 but
not dcl4 mutants. Thus, even though DCL4 outcompetes DCL2 for siRNA
biogenesis in wild-type plants, DCL2 is crucial for systemic RDR6-dependent
PTGS. Other genes required for systemic PTGS will also be discussed. Finally, the
potential of topical application of double-stranded RNA for inducing systemic
RNA silencing in plants will be discussed.