Gibberellin-responsive genes: high level of transcript accumulation in leaf sheath meristematic tissue from Zea mays L.
Gibberellin-responsive genes: high level of transcript accumulation in leaf sheath meristematic tissue from Zea mays L.
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DOI：
10.1023/a:1006291917591
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发表时间：
1999-07
影响因子：
5.1
通讯作者：
Mikihiro Ogawa;T. Kusano;N. Koizumi;M. Katsumi;H. Sano
中科院分区：
文献类型：
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作者：
Mikihiro Ogawa;T. Kusano;N. Koizumi;M. Katsumi;H. Sano
为了鉴定与玉米（Zea mays L.）中的赤霉素（GA）反应相关的基因，通过荧光差异显示比较了野生型和单基因矮化突变体D5和D8的mRNA种类。d5突变体不能产生具有生物活性的GA，但在外源GA的应用下恢复其高大的身材。D8对GA不敏感，但积累了大量的内源GA，表明它是一个受体突变体或信号转导途径的突变体。在筛选7000个cDNA群体后，分离出一个克隆，其转录本在d5芽中很少，但在GA3施用后1 h内积累。该克隆命名为ZmGR 1a，编码相对分子质量约为1000的多肽。13 kDa，这显示出显着的同源性，从几种植物富含脯氨酸的蛋白质。用D8进行的类似实验鉴定出一个克隆ZmGR 2a，其转录水平较低，但在GA 3处理d5芽后6小时内积累。ZmGR 2a编码相对分子质量约为100的多肽。19 kDa，其显示与任何已知蛋白没有显著同源性。Southern杂交分析表明，ZmGR 1a和ZmGR 2a在玉米基因组中形成一个小的多基因家族。与野生型幼苗的原位杂交结果表明，在叶鞘分生组织，其中GA增强细胞伸长和细胞分裂都是丰富的成绩单。
In order to identify genes that are related to the gibberellin (GA) response in maize (Zea mays L.), mRNA species from wild-type and single-gene dwarf mutants, d5 and D8, were compared by fluorescent differential display. The d5 mutant is unable to produce biologically active GA, but recovers its tall stature on exogenous application of GA. D8 is insensitive to GA, despite the accumulation of a high level of endogenous GA, suggesting it to be a receptor mutant or a mutant in signal transduction pathway(s). After screening 7000 cDNA populations, one clone was isolated, for which transcripts were rare in d5 shoots but accumulated within 1 h after GA3application. This clone, designated as ZmGR1a, encodes a polypeptide with a relative molecular mass of ca. 13 kDa, which shows significant homology to proline-rich proteins from several plant species. A similar experiment with D8 identified a clone, ZmGR2a, with low transcript levels, but accumulation within 6 h after GA3treatment of d5 shoots. ZmGR2a encodes a polypeptide with a relative molecular mass of ca. 19 kDa, which shows no significant homology with any known protein. Southern blot analysis indicated that ZmGR1a and ZmGR2a form a small multigene family within the maize genome. In situ hybridization with wild-type seedlings showed transcripts on both to be abundant in leaf sheath meristematic tissue, in which GA enhances cell elongation and cell division.