LTR retrotransposons, handy hitchhikers of plant regulation and stress response
LTR retrotransposons, handy hitchhikers of plant regulation and stress response
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DOI：
10.1016/j.bbagrm.2014.07.017
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发表时间：
2015-04-01
影响因子：
4.7
通讯作者：
Grandbastien, Marie-Angele
中科院分区：
文献类型：
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作者：
Grandbastien, Marie-Angele
LTR 逆转录转座子是植物基因组的主要组成部分。它们受到各种外部压力和组织培养条件的调节，对这些刺激表现出精细的反应，主要以上调的形式。除了应激条件和组织培养之外，分生组织也允许 LTR 逆转录转座子表达，这表明去分化细胞状态可能代表一种频繁的激活条件。 LTR 区域具有高度可塑性，并且包含与细胞基因相似的调控基序。 LTR 反转录转座子的激活是表观遗传沉默的释放与 LTR 招募特定调节因子之间相互作用的结果。尽管LTR反转录转座子在驱动植物基因组多样化方面发挥着重要作用，但LTR反转录转座子主要动员的令人信服的证据仍然比大量转录上调爆发的观察结果要少得多。目前的证据表明，LTR 逆转录转座子的表达可能与宿主功能可塑性有关，作为分散的调节模块，能够将应激刺激重定向到邻近的植物基因。这对于无法逃避压力并进化出复杂且高度协调的外部挑战反应的植物来说可能至关重要。本文是题为“压力作为细胞可塑性的基本主题”的特刊的一部分。 (C) 2014 Elsevier B.V. 保留所有权利。
LTR retrotransposons are major components of plant genomes. They are regulated by a diverse array of external stresses and tissue culture conditions, displaying finely tuned responses to these stimuli, mostly in the form of upregulation. Second to stress conditions and tissue culture, meristems are also permissive for LTR retrotransposon expression, suggesting that a dedifferentiated cell status may represent a frequent activating condition. LTR regions are highly plastic and contain regulatory motifs similar to those of cellular genes. The activation of LTR retrotransposons results from interplay between the release of epigenetic silencing and the recruitment by LTRs of specific regulatory factors. Despite the role of LTR retrotransposons in driving plant genome diversification, convincing evidence for major mobilizations of LTR retrotransposons remains much rarer than observations of massive bursts of transcriptional upregulation. Current evidence suggests that LTR retrotransposon expression may be involved in host functional plasticity, acting as dispersed regulatory modules able to redirect stress stimuli to adjacent plant genes. This may be of crucial importance for plants that cannot escape stress, and have evolved complex and highly coordinated responses to external challenges. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity. (C) 2014 Elsevier B.V. All rights reserved.