The Maize aberrant pollen transmission 1 Gene Is a SABRE/KIP Homolog Required for Pollen Tube Growth
The Maize aberrant pollen transmission 1 Gene Is a SABRE/KIP Homolog Required for Pollen Tube Growth
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DOI：
10.1534/genetics.105.050237
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发表时间：
2006-02
期刊：
影响因子：
3.3
通讯作者：
Zhennan Xu;H. Dooner
中科院分区：
文献类型：
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作者：
Zhennan Xu;H. Dooner
玉米（Zea mays）花粉管在花柱中以>1 μm/sec的速率生长。我们在这里描述一个基因需要达到的打击率。玉米花粉传递异常基因apt 1在杂合子中存在一个Ac-taged突变，导致花粉传递功能严重缺失。通过对Ac纯合子进行表型选择，可以回收罕见的apt 1纯合子。杂合花粉和纯合花粉中各有一半萌发出短而扭曲的花粉管。apt 1基因长26 kb，由22个外显子拼接成8.6 kb的花粉特异性转录物，编码2607个氨基酸的蛋白质。APT 1蛋白分别与拟南芥中参与根皮层细胞和花粉管伸长的功能未知的蛋白SABRE和KIP同源。亚细胞定位分析表明，APT 1共定位与高尔基体蛋白标记在生长烟草花粉管。我们推测，APT 1蛋白是参与膜运输，并需要在花粉管尖端生长的高分泌需求。apt 1-m1（Ac）突变等位基因是一个很好的工具，选择Ac转座，因为强大的负选择压力对父母的Ac网站。
Maize (Zea mays) pollen tubes grow in the styles at a rate of >1 μm/sec. We describe here a gene required to attain that striking rate. The aberrant pollen transmission 1 (apt1) gene of maize was identified by an Ac-tagged mutation that displayed a severe pollen transmission deficit in heterozygotes. Rare apt1 homozygotes can be recovered, aided by phenotypic selection for Ac homozygotes. Half of the pollen in heterozygotes and most of the pollen in homozygotes germinate short and twisted pollen tubes. The apt1 gene is 26 kb long, makes an 8.6-kb pollen-specific transcript spliced from 22 exons, and encodes a protein of 2607 amino acids. The APT1 protein is homologous to SABRE and KIP, Arabidopsis proteins of unknown function involved in the elongation of root cortex cells and pollen tubes, respectively. Subcellular localization analysis demonstrates that APT1 colocalizes with a Golgi protein marker in growing tobacco pollen tubes. We hypothesize that the APT1 protein is involved in membrane trafficking and is required for the high secretory demands of tip growth in pollen tubes. The apt1-m1(Ac) mutable allele is an excellent tool for selecting Ac transpositions because of the strong negative selection pressure operating against the parental Ac site.