Control of seed dormancy in Arabidopsis by a cis-acting noncoding antisense transcript
Control of seed dormancy in Arabidopsis by a cis-acting noncoding antisense transcript
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DOI：
10.1073/pnas.1608827113
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发表时间：
2016-11-29
影响因子：
11.1
通讯作者：
Swiezewski, Szymon
中科院分区：
文献类型：
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作者：
Fedak, Halina;Palusinska, Malgorzata;Swiezewski, Szymon
种子休眠是植物生命周期中最重要的过程之一。其萌发时间受延迟萌发1基因（DOG1）表达水平的严格控制。DOG1是拟南芥种子休眠的主要数量性状位点，并已被证明在许多其他植物物种中控制休眠。这反映在功能短的DOG1 mRNA的选择性聚腺苷化形式的进化保守性上。值得注意的是，DOG1的3'区，包括未包含在该转录异构体中的最后一个外显子，在DNA水平上显示出高度的保守性，但编码的多肽保守性较差。在这里，我们证明了DOG1的这个区域包含一个非编码反义RNA的转录启动子，如DOG1，它是5'帽，聚腺苷化，相对稳定。这个启动子是自主的，asDOG1的表达谱与已知的DOG1转录本不同。通过几种方法，我们发现asDOG1在顺式基因的种子成熟过程中强烈抑制DOG1的表达，但在反式基因中却不能。因此，顺式中asDOG1对种子休眠的负调控导致等位基因特异性抑制DOG1的表达，促进萌发。鉴于asDOG1启动子的进化保守性，我们认为这种顺式约束的非编码rna介导的机制限制了十字花科植物种子休眠功能的持续时间。
Seed dormancy is one of the most crucial process transitions in a plant's life cycle. Its timing is tightly controlled by the expression level of the Delay of Germination 1 gene (DOG1). DOG1 is the major quantitative trait locus for seed dormancy in Arabidopsis and has been shown to control dormancy in many other plant species. This is reflected by the evolutionary conservation of the functional short alternatively polyadenylated form of the DOG1 mRNA. Notably, the 3' region of DOG1, including the last exon that is not included in this transcript isoform, shows a high level of conservation at the DNA level, but the encoded polypeptide is poorly conserved. Here, we demonstrate that this region of DOG1 contains a promoter for the transcription of a noncoding antisense RNA, asDOG1, that is 5' capped, polyadenylated, and relatively stable. This promoter is autonomous and asDOG1 has an expression profile that is different from known DOG1 transcripts. Using several approaches we show that asDOG1 strongly suppresses DOG1 expression during seed maturation in cis, but is unable to do so in trans. Therefore, the negative regulation of seed dormancy by asDOG1 in cis results in allele-specific suppression of DOG1 expression and promotes germination. Given the evolutionary conservation of the asDOG1 promoter, we propose that this cis-constrained noncoding RNA-mediated mechanism limiting the duration of seed dormancy functions across the Brassicaceae.