A specific variant of the PHR1 binding site is highly enriched in the Arabidopsis phosphate- responsive phospholipase DZ2 coexpression network
A specific variant of the PHR1 binding site is highly enriched in the Arabidopsis phosphate- responsive phospholipase DZ2 coexpression network
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DOI：
10.4161/psb.20749
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发表时间：
2012-01-01
影响因子：
2.9
通讯作者：
Herrera-Estrella, Luis
中科院分区：
文献类型：
--
作者：
Acevedo-Hernandez, Gustavo;Oropeza-Aburto, Araceli;Herrera-Estrella, Luis
PLDZ2是拟南芥磷脂酶D基因家族的一员，在磷（Pi）饥饿下在茎和根中均被诱导。最近，通过对PLDZ2启动子的删除和功能获得分析，我们发现了一个65 bp的区域（命名为增强子EZ2），能够对最小的非活性启动子赋予组织特异性和低pi响应。EZ2元件包含两个P1BS基序，每个基序都是PHR1和相关转录因子的结合位点。这种结构组织在蔷薇枝的同源启动子中是进化保守的。为了确定EZ2是否在与PLDZ2共表达的拟南芥基因中显著过度表达，我们构建了一个包含26个基因的PLDZ2共表达网络，其中几乎一半的基因编码参与Pi循环的酶或调节蛋白。在这些共表达基因的启动子区域中发现了P1BS基序的一个变体，在其中7个基因中显示出ez2样排列。其他基序均未显著富集。在与PLDZ2共表达的基因启动子中，P1BS基序的EZ2排列的过度表达表明，在Pi限制条件下，该单元在参与磷脂和其他分子释放Pi的共表达网络中具有特别重要的调控元件作用。
PLDZ2 is a member of the Arabidopsis phospholipase D gene family that is induced in both shoot and root in response to phosphate (Pi) starvation. Recently, through deletion and gain-of-function analyses of the PLDZ2 promoter, we identified a 65 bp region (denominated enhancer EZ2) capable of conferring tissue-specific and low-Pi responses to a minimal inactive promoter. The EZ2 element contains two P1BS motifs, each of which is the binding site for PHR1 and related transcription factors. This structural organization is evolutionarily conserved in orthologous promoters within the rosid clade. To determine whether EZ2 is significantly over-represented in Arabidopsis genes coexpressed with PLDZ2, we constructed a PLDZ2 coexpression network containing 26 genes, almost half of them encoding enzymes or regulatory proteins involved in Pi recycling. A variant of the P1BS motif was found to be highly enriched in the promoter regions of these coexpressed genes, showing an EZ2-like arrangement in seven of them. No other motifs were significantly enriched. The over-representation of the EZ2 arrangement of P1BS motifs in the promoters of genes coexpressed with PLDZ2, suggests this unit has a particularly important role as a regulatory element in a coexpression network involved in the release of Pi from phospholipids and other molecules under Pi-limiting conditions.