PT  - JOURNAL ARTICLE
AU  - Kindgren, Peter
AU  - Ard, Ryan
AU  - Ivanov, Maxim
AU  - Marquardt, Sebastian
TI  - Transcriptional read-through of the long non-coding RNA <em>SVALKA</em> governs plant cold acclimation
AID  - 10.1101/287946
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 287946
4099  - http://biorxiv.org/content/early/2018/03/23/287946.short
4100  - http://biorxiv.org/content/early/2018/03/23/287946.full
AB  - Most DNA in the genomes of higher organisms does not encode proteins, but is transcribed by RNA polymerase II (RNAPII) into long non-coding RNA (lncRNA). The biological significance of most lncRNA is largely unclear. Here, we identify a lncRNA (SVALKA) in a cold-sensitive region of the Arabidopsis genome. Mutations in SVALKA affect the timing of maximal CBF1 expression and freezing tolerance. RNAPII read-through transcription of SVALKA results in a cryptic lncRNA overlapping CBF1 on the antisense strand, termed asCBF1. asCBF1 transcription is anti-correlated with CBF1 expression. Our molecular dissection reveals that CBF1 is suppressed by RNAPII collision stemming from the SVALKA-asCBF1 lncRNA cascade. The SVK-asCBF1 cascade provides a mechanism to tightly control CBF1 expression and timing that could be exploited to maximize freezing tolerance with mitigated fitness costs. Inversion of the transcriptional direction of a lncRNA cascade relative to the genes in a co-regulated cluster provides an elegant inbuilt negative feedback for cluster expression. Our results provide a compelling example of local gene regulation by lncRNA transcription having a profound impact on the ability of plants to appropriately acclimate to suboptimal environmental conditions.