PETAL LOSS, a trihelix transcription factor gene, regulates perianth architecture in the Arabidopsis flower
PETAL LOSS, a trihelix transcription factor gene, regulates perianth architecture in the Arabidopsis flower
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DOI：
10.1242/dev.01279
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发表时间：
2004-08-01
期刊：
影响因子：
4.6
通讯作者：
Smyth, DR
中科院分区：
文献类型：
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作者：
Brewer, PB;Howles, PA;Smyth, DR
花被发育在花瓣丢失（PTL）基因突变体中特别受到破坏，特别是花瓣的起始和定向。我们克隆了 PTL，并证明它编码植物特有的三螺旋转录因子，这是以前仅被称为光控基因调节因子的家族之一。在早期发育的花、起始萼片之间的四个区域及其发育边缘中检测到 PTL 转录本。 PTL 在一系列组织中的强烈错误表达普遍会导致生长抑制，表明其正常作用是抑制起始萼片之间的生长，确保它们保持分离。与此一致的是，萼片有时在 ptl 单突变体中融合，但在与器官边界基因杯形子叶 1 或 2 的双突变体中更常见。 PTL 在新出现的萼片内的表达显然被 PINOID 生长素反应基因阻止。令人惊讶的是，在花瓣发育的早期阶段无法检测到 PTL 表达，因此与 PTL 功能丧失相关的花瓣缺陷可能是间接的，可能涉及该区域过度生长导致的信号传导过程中断。 PTL 驱动的报告基因表达也在后期在扩张的萼片、花瓣和雄蕊的边缘以及叶缘中检测到；因此，PTL 可能会过度抑制这些器官的横向生长，帮助确定它们的最终形状。
Perianth development is specifically disrupted in mutants of the PETAL LOSS (PTL) gene, particularly petal initiation and orientation. We have cloned PTL and show that it encodes a plant-specific trihelix transcription factor, one of a family previously known only as regulators of light-controlled genes. PTL transcripts were detected in the early-developing flower, in four zones between the initiating sepals and in their developing margins. Strong misexpression of PTL in a range of tissues universally results in inhibition of growth, indicating that its normal role is to suppress growth between initiating sepals, ensuring that they remain separate. Consistent with this, sepals are sometimes fused in ptl single mutants, but much more frequently in double mutants with either of the organ boundary genes cup-shaped cotyledon1 or 2. Expression of PTL within the newly arising sepals is apparently prevented by the PINOID auxin-response gene. Surprisingly, PTL expression could not be detected in petals during the early stages of their development, so petal defects associated with PTL loss of function may be indirect, perhaps involving disruption to signalling processes caused by overgrowth in the region. PTL-driven reporter gene expression was also detected at later stages in the margins of expanding sepals, petals and stamens, and in the leaf margins; thus, PTL may redundantly dampen lateral outgrowth of these organs, helping define their final shape.