Differential expression and turnover of the tomato polyphenol oxidase gene family during vegetative and reproductive development
Differential expression and turnover of the tomato polyphenol oxidase gene family during vegetative and reproductive development
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DOI：
10.1104/pp.113.3.707
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发表时间：
1997-03-01
期刊：
影响因子：
7.4
通讯作者：
Steffens, JC
中科院分区：
文献类型：
--
作者：
Thipyapong, P;Joel, DM;Steffens, JC
多酚氧化酶（Polypolyphenol oxidases，PPOs）是番茄（Lycopersicon esculentum）第8染色体上一个高度保守的基因家族，由7个成员组成。利用能够区分PPO A/C、PPO B、PPO D和PPO E/F的基因特异性探针，我们研究了该基因家族在营养和生殖发育过程中的空间和时间表达。使用这些探针的RNA印迹和原位杂交表明，虽然PPO的表达主要局限于早期的发展阶段，这些基因的稳态mRNA水平受到复杂的模式的空间和时间调节在营养和生殖器官。番茄幼叶和花具有最丰富的PPO转录本。PPO B在幼叶中含量最高，而在花序中PPO B和E/F转录本占优势。在各种毛状体类型中也观察到PPO的差异表达。PPO A/C在I型和IV型毛状体中特异性表达。相反，PPO D仅在VI型毛状体中表达。I、IV和VI型毛状体具有PPO E/F转录物。免疫定位验证了翻译活性的PPO确定原位杂交和建议细胞类型特异性，发育编程PPO营业额。此外，免疫定位证明了PPO在茎、叶和果实的特定异源细胞中的积累。
Polyphenol oxidases (PPOs) are encoded by a highly conserved, seven-member gene family clustered within a 165-kb locus on chromosome 8 of tomato (Lycopersicon esculentum). Using gene-specific probes capable of differentiating between PPO A/C, PPO B, PPO D, and PPO E/F, we examined the spatial and temporal expression of this gene family during vegetative and reproductive development. RNA blots and in situ hybridization using these probes showed that although PPO expression is primarily confined to early stages of development, the steady-state mRNA levels of these genes are subject to complex patterns of spatial and temporal regulation in vegetative and reproductive organs. Young tomato leaves and flowers possess the most abundant PPO transcripts. PPO B is the most abundant in young leaves, whereas in the inflorescence PPO B and E/F transcripts are dominant. Differential expression of PPOs is also observed in various trichome types. PPO A/C are specifically expressed in type I and type IV trichomes. In contrast, PPO D is only expressed in type VI trichomes. Type I, IV, and VI trichomes possess PPO E/F transcripts. Immunolocalization verified the translational activity of PPOs identified by in situ hybridization and suggested cell-type-specific, developmentally programmed PPO turnover. In addition, immunolocalization demonstrated the accumulation of PPO in specific idioblast cells of stems, leaves, and fruits.