Neighbor Detection Induces Organ-Specific Transcriptomes, Revealing Patterns Underlying Hypocotyl-Specific Growth
Neighbor Detection Induces Organ-Specific Transcriptomes, Revealing Patterns Underlying Hypocotyl-Specific Growth
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DOI：
10.1105/tpc.16.00463
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发表时间：
2016-12-01
期刊：
影响因子：
11.6
通讯作者：
Fankhauser, Christian
中科院分区：
文献类型：
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作者：
Kohnen, Markus V.;Schmid-Siegert, Emanuel;Fankhauser, Christian
响应于邻近，植物增加特定器官的生长（例如，下胚轴），以增加对阳光的接触。遮荫通过从光敏色素B介导的抑制中释放这些bHLH转录因子来增强光敏色素相互作用因子（PIF）的活性。PIF通过诱导子叶中生长素的产生来促进伸长。为了阐明时空方面的邻居邻近反应，我们分别分析了基因表达模式的主要光敏感器官（子叶）和迅速伸长的下胚轴的拟南芥。PIFs在15分钟内启动两个器官的转录重编程，包括几个早期生长素反应基因的调节表达。这表明，下胚轴生长引起的本地和远端生长素信号。我们表明，子叶来源的生长素是必要的，足以启动下胚轴生长，但我们也提供了证据的功能的重要性，当地PIF诱导的反应。随着时间的推移，器官之间的转录反应越来越不同。我们确定的基因，其差异表达可能是器官特异性延伸的基础。最后，我们发现了不同发育调节的生长过程和不同器官对环境的反应之间共享的生长促进基因表达特征。
In response to neighbor proximity, plants increase the growth of specific organs (e.g., hypocotyls) to enhance access to sunlight. Shade enhances the activity of Phytochrome Interacting Factors (PIFs) by releasing these bHLH transcription factors from phytochrome B-mediated inhibition. PIFs promote elongation by inducing auxin production in cotyledons. In order to elucidate spatiotemporal aspects of the neighbor proximity response, we separately analyzed gene expression patterns in the major light-sensing organ (cotyledons) and in rapidly elongating hypocotyls of Arabidopsis thaliana. PIFs initiate transcriptional reprogramming in both organs within 15 min, comprising regulated expression of several early auxin response genes. This suggests that hypocotyl growth is elicited by both local and distal auxin signals. We show that cotyledon-derived auxin is both necessary and sufficient to initiate hypocotyl growth, but we also provide evidence for the functional importance of the local PIF-induced response. With time, the transcriptional response diverges increasingly between organs. We identify genes whose differential expression may underlie organ-specific elongation. Finally, we uncover a growth promotion gene expression signature shared between different developmentally regulated growth processes and responses to the environment in different organs.