A FLOWER-SPECIFIC CDNA-ENCODING A NOVEL THIONIN IN TOBACCO
A FLOWER-SPECIFIC CDNA-ENCODING A NOVEL THIONIN IN TOBACCO
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DOI：
10.1007/bf00272349
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发表时间：
1992-07-01
期刊：
影响因子：
--
通讯作者：
CHEUNG, AY
中科院分区：
文献类型：
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作者：
GU, Q;KAWATA, EE;CHEUNG, AY
我们从烟草中分离到一个花特异的c DNA，FST(Flower-Special thitin)，它编码一种新的硫素。硫蛋白是一种碱性和富含半胱氨酸(Cys)的低分子蛋白质，存在于许多植物中。它们被认为在植物抵御病原体方面发挥了作用。FST蛋白的中心结构域与三个伽马硫蛋白有同源性。与其他硫素前体一样，FST蛋白具有信号肽的N-末端结构域和酸性的C-末端结构域。FST mRNA在花的发育过程中特异积累，随着花的成熟，FST的表达水平下降。转录本存在于花瓣、雄蕊和雌蕊中，但在萼片中检测不到。原位杂交结果表明，FST基因在花瓣近轴面的表皮细胞、心皮和花药壁的表层细胞层中含量最高。如果FST蛋白确实在花中起到保护作用，那么FST mRNA的这种空间分布模式似乎会最大化这种对两个内部生殖轮生的影响。对FST可能的生物学作用进行了讨论。
We isolated a flower-specific cDNA, FST (flower-specific thionin), which encodes a novel thionin from tobacco. Thionins are basic and cysteine (Cys)-rich, low molecular weight proteins found in many plants. They are believed to play a role in plant defense against pathogens. The central domain of the FST protein shares homology with three gamma-thionins. Like other thionin precursors, the FST protein has an N-terminal domain characteristic of a signal peptide and an acidic C-terminal domain. FST mRNA accumulates specifically in developing flowers and its level drops as flowers mature. Transcripts are present in petals, stamens and pistil but are not detectable in sepals. In situ hybridization revealed that FST mRNA is most abundant in the epidermal cells along the adaxial surface of petals, and in the surface cell layers of the carpel and anther walls. If the FST protein indeed has a protective role in flowers, this pattern of spatial distribution of FST mRNA would appear to maximize this effect on the two internal reproductive whorls. A possible biological role for FST is discussed.