BRACTEOMANIA, AN INFLORESCENCE ANOMALY, IS CAUSED BY THE LOSS OF FUNCTION OF THE MADS-BOX GENE SQUAMOSA IN ANTIRRHINUM-MAJUS
BRACTEOMANIA, AN INFLORESCENCE ANOMALY, IS CAUSED BY THE LOSS OF FUNCTION OF THE MADS-BOX GENE SQUAMOSA IN ANTIRRHINUM-MAJUS
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DOI：
10.1002/j.1460-2075.1992.tb05168.x
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发表时间：
1992-04-01
期刊：
影响因子：
11.4
通讯作者：
SOMMER, H
中科院分区：
文献类型：
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作者：
HUIJSER, P;KLEIN, J;SOMMER, H
Antirrhinum majus突变体squamosa （squa）的异常开花的特点是苞片形成过多，花相对较少，通常畸形或不完整。为了研究鳞状体在花序侧分生组织对花发育的承诺中的功能，克隆了该基因，并确定了其基因组结构以及四个突变等位基因的基因组结构。SQUA是一个转录因子家族的成员，该家族含有MADS-box，这是一个保守的DNA结合域。此外，我们还分析了squa基因的时空表达模式。在苞片和花序下方的叶片中可以检测到低的squa转录活性。在苞片腋部形成的花序侧分生组织中，可以看到高水平的正方形转录物。除雄蕊分化外，Squa的转录活性持续到花形态发生的后期。虽然对于形成正常的总状花序是必要的，但对于花的发育并不是绝对必要的。我们讨论了该基因在开花过程中的功能，它可能的功能冗余，以及它可能与其他参与花形成遗传控制的基因的相互作用。
Anomalous flowering of the Antirrhinum majus mutant squamosa (squa) is characterized by excessive formation of bracts and the production of relatively few and often malformed or incomplete flowers. To study the function of squamosa in the commitment of an inflorescence lateral meristem to floral development, the gene was cloned and its genomic structure, a well as that of four mutant alleles, was determined. SQUA is a member of a family of transcription factors which contain the MADS-box, a conserved DNA binding domain. In addition, we analysed the temporal and spatial expression pattern of the squa gene. Low transcriptional activity of squa is detectable in bracts and in the leaves immediately below the inflorescence. High squa transcript levels are seen in the inflorescence lateral meristems as soon as they are formed in the axils of bracts. Squa transcriptional activity persists through later stages of floral morphogenesis, with the exception of stamen differentiation. Although necessary for shaping a normal racemose inflorescence, the squa function is not absolutely essential for flower development. We discuss the function of the gene during flowering, its likely functional redundancy and its possible interaction with other genes participating in the genetic control of flower formation in Antirrhinum.