Retrotransposon-mediated DELLA transcriptional reprograming underlies semi-dominant dwarfism in foxtail millet
Retrotransposon-mediated DELLA transcriptional reprograming underlies semi-dominant dwarfism in foxtail millet
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逆转录转座子介导的 DELLA 转录重编程是谷子半显性矮化的基础
DOI：
10.1016/j.cj.2018.12.008
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发表时间：
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通讯作者：
Xianmin Diao
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作者：
Meicheng Zhao;Hui Zhi;Xue Zhang;Guanqing Jia;Xianmin Diao
逆转录转座子占基因组和基因组变异的很大比例and.play许多真核生物中创造新基因和使基因组多样化方面发挥着关键作用。尽管反转录转座子在植物中大量存在，但由于缺乏研究，其作用一直被低估。本文报道了谷子赤霉素不敏感矮化突变体84133的特征。基于图位的克隆揭示了在DWARF 1（D1）中的5.5-kb Copia样反转录转座子插入，其编码DELLA蛋白。转录分析表明，Copia逆转录转座子介导了D1的转录重编程，导致一个新的N端缺失的截短DELLA转录本，即D1-TT和另一个嵌合转录本，该转录本由Copia的LTR驱动。通过蛋白质免疫检测分析证实了D1-TT的存在。此外，与完整的DELLA蛋白相比，D1-TT蛋白对GA 3处理具有抗性，这是由于其不能与GA受体SiGID 1相互作用。在谷子中过量表达D1-TT导致植株矮化，证实它决定了84133的矮化性。因此，我们的研究文件。长末端重复序列（LTR）反转录转座子介导的转录。在植物王国的一个罕见的实例。这些结果揭示了LTR反转录转座子在产生新基因功能和遗传多样性中的作用。
Retrotransposons account for a large proportion of the genome and genomic variation, and.play key roles in creating novel genes and diversifying the genome inmany eukaryotic species..Although retrotransposons are abundant in plants, their roles had been underestimated.because of a lack of research. Here, we characterized a gibberellin Acid (GA)-insensitive dwarf.mutant, 84133, in foxtail millet. Map-based cloning revealed a 5.5-kb Copia-like.retrotransposon insertion in DWARF1 (D1), which encodes a DELLA protein. Transcriptional.analysis showed that the Copia retrotransposonmediated the transcriptional reprogramming.of D1 leading to a novel N-terminal-deleted truncated DELLA transcript that was putatively.driven by Copia's LTR, namely D1-TT, and another chimeric transcript. The presence of D1-TT.was confirmed by protein immunodetection analysis. Furthermore, D1-TT protein was.resistant to GA3 treatment compared with the intact DELLA protein due to its inability to.interact with the GA receptor, SiGID1. Overexpression of D1-TT in foxtail millet resulted in.dwarf plants, confirming that it determines the dwarfismof 84133. Thus, our study documents.a rare instance of long terminal repeat (LTR) retrotransposon-mediated transcriptional.reprograming in the plant kingdom. These results shed light on the function of LTR.retrotransposons in generating new gene functions and genetic diversity.