High temperature-responsive poplar lncRNAs modulate target gene
expression by RNA interference or acting as RNA scaffolds enhancing heat
tolerance
Abstract
High temperature stress increasingly threatens plant development and
survival. Long noncoding RNAs (lncRNAs) participate in plant stress
responses, but their functions in the complex stress-responsive network
remain elusive. Poplar is one of the most widely planted trees in the
world and contributes to terrestrial ecological stability. In this
study, we identified 261 high temperature-responsive lncRNAs in poplar
(Populus simonii). These lncRNAs were predicted to target a total of 353
target genes of which 163 are cis-targets and 190 trans-targets. To
determine the function of select heat-responsive lncRNAs, transient
overexpressed and repressed lncRNA were implemented in poplar leaves and
roots. As expected, the abundance of lncRNA target transcripts were
altered. One such lncRNA TCONS_00202587 binds to upstream sequences of
targets via its secondary structure and interfere with the target gene
transcription. Another lncRNA TCONS_00260893 could enhance Ca2+ influx
in response to high-temperature treatment by interfering with a specific
variant/isoform of the target gene. Two lncRNA targets overexpressed
experiment revealed heat tolerance in Arabidopsis. These results
revealed lncRNAs could regulate their targets genes by acting as
potential RNA scaffolds or through RNA interference pathway. It is
indicated a new layers of highly complex RNA-based gene regulation in
heat tolerance of perennial plants.