Mar 2023
Host: Professor Brande Wulff
Abstract:
The
execution of developmental programs requires genetic control exerted
both at transcriptional and post-transcriptional levels. Two key
mechanisms of post-transcriptional gene regulation involve small
non-coding RNAs and mRNA methylation. Small non-coding RNAs are produced
by DICER-LIKE ribonucleases and act to program RNA Induced Silencing
Complexes to repress complementary mRNAs. In addition to its key role in
developmental control, the small RNA machinery is essential for basal
antiviral defense that requires the DICER-LIKE ribonucleases DCL2 and
DCL4 in higher plants. mRNA methylation acts by generating binding sites
for specialized RNA binding proteins that stimulate cell division in
organ primordia in largely unknown ways. Viral RNA can also be
methylated and can serve to limit viral infectivity. I will discuss
evidence that advances our understanding of how both
post-transcriptional regulatory systems work in the crossroads of growth
and defense regulation. Particular focus will be given to evidence
indicating that basal antiviral defense mediated by DICER-LIKE proteins
is brought about by combining direct small RNA-mediated targeting of
viral RNA with sensing of double-stranded RNA to switch on innate immune
responses. I will also discuss our advances on understanding the
principles underlying RNA-methylation-dependent basal antiviral defense
in plants.
BIO:
Principal investigator at the University of Copenhagen, Denmark, since 2011, full professor
since 2020. Research focus on gene regulation via small non-coding RNAs
and covalent mRNA modifications in plants, including links to control
of the innate immune system. Post doctoral researcher and senior
scientist at the Institut de Biologie Moléculaire des Plantes du CNRS,
Strasbourg, France, 2004-2010. Research focus on mechanisms of microRNA
function in plants.