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Nature Communications：lncRNA SVALKA调控拟南芥的低温适应

已有 4745 次阅读 2018-11-2 08:50 |个人分类:每日摘要|系统分类:论文交流

Transcriptional read-through of the long non-coding RNA SVALKA governs plant cold acclimation

First author: Peter Kindgren; Affiliations: University of Copenhagen (哥本哈根大学): Bulowsvej, Denmark

Corresponding author: Sebastian Marquardt

Most DNA in the genomes of higher organisms does not encode proteins, yet much is transcribed by RNA polymerase II (RNAPII) into long non-coding RNAs (lncRNAs). The biological significance of most lncRNAs is largely unclear. Here, we identify a lncRNA (SVALKA) in a cold-sensitive region of the Arabidopsis genome. Mutations in SVALKA affect CBF1 expression and freezing tolerance. RNAPII read-through transcription (通读转录) of SVALKA results in a cryptic lncRNA overlapping CBF1 on the antisense strand, termed asCBF1. Our molecular dissection reveals that CBF1 is suppressed by RNAPII collision (碰撞) stemming from the SVALKA-asCBF1 lncRNA cascade. The SVALKA-asCBF1 cascade provides a mechanism to tightly control CBF1 expression and timing that could be exploited to maximize freezing tolerance with mitigated fitness costs. Our results provide a compelling (令人信服的) example of local gene regulation by lncRNA transcription having a profound impact on the ability of plants to appropriately acclimate to challenging environmental conditions.

高等生物基因组上大多数的DNA都不编码蛋白，但也能够被RNA聚合酶II（RNAPII）转录成长链非编码RNA，即lncRNA。大多数lncRNA的生物学功能还不清楚。本文在拟南芥基因组上的低温敏感区域鉴定了一个叫SVALKA的lncRNA。SVALKA上的突变会影响CBF1基因的表达和植物的冷害抗性。RNAPII通读转录（转录于终止子并不停止，继续转录下去）SVALKA基因会在反义链上产生一个覆盖CBF1的lncRNA，叫做asCBF1。进一步的分子试验显示CBF1会被SVALKA-asCBF1 lncRNA级联导致的RNAPII碰撞所抑制。SVALKA-asCBF1级联能够严格调控CBF1基因的表达，并且以最小的适应改变最大化植物的低温耐受性。本文的研究结果揭示了植物中lncRNA转录调控本身基因的表达，进而有助于植物对于恶劣环境的适应。