Phillips J, Artsaenko O, Fiedler U, Horstmann C, Mock H P, Müntz K, Conrad U
Institut für Pflanzengenetik und Kulturpflanzenforschung Gatersleben, Germany.
EMBO J. 1997 Aug 1;16(15):4489-96. doi: 10.1093/emboj/16.15.4489.
A single-chain Fv antibody (scFv) gene, which has previously been used to immunomodulate abscisic acid (ABA) activity in transgenic tobacco to create a 'wilty' phenotype, was put under control of the seed-specific USP promoter from Vicia faba and used to transform tobacco. Transformants were phenotypically similar to wild-type plants apart from their seeds. Anti-ABA scFv embryo development differed markedly from wild-type embryo development. Seeds which accumulated similar levels of a scFv that binds to oxazolone, a hapten absent from plants, developed like wild-type embryos. Anti-ABA scFv embryos developed green cotyledons containing chloroplasts and accumulated photosynthetic pigments but produced less seed storage protein and oil bodies. Anti-ABA scFv seeds germinated precociously if removed from seed capsules during development but were incapable of germination after drying. Total ABA levels were higher than in wild-type seeds but calculated free ABA levels were near-zero until 21 days after pollination. We show for the first time seed-specific immunomodulation and the resulting switch from the seed maturation programme to a germination programme. We conclude that the immunomodulation of hormones can alter the development programme of target organs, allowing the study of the directly blocked endogenous molecules and manipulation of the system concerned.
一种单链Fv抗体（scFv）基因，此前已被用于在转基因烟草中免疫调节脱落酸（ABA）活性以产生“萎蔫”表型，该基因置于来自蚕豆的种子特异性USP启动子的控制下，并用于转化烟草。除种子外，转化体在表型上与野生型植物相似。抗ABA scFv胚胎发育与野生型胚胎发育明显不同。积累了与恶唑酮（一种植物中不存在的半抗原）结合的相似水平scFv的种子，其发育方式与野生型胚胎相同。抗ABA scFv胚胎发育出含有叶绿体的绿色子叶并积累光合色素，但产生的种子贮藏蛋白和油体较少。抗ABA scFv种子如果在发育过程中从种荚中取出会早熟萌发，但干燥后无法萌发。总ABA水平高于野生型种子，但计算得出的游离ABA水平在授粉后21天之前接近零。我们首次展示了种子特异性免疫调节以及由此导致的从种子成熟程序向萌发程序的转变。我们得出结论，激素的免疫调节可以改变靶器官的发育程序，从而能够研究直接被阻断的内源性分子并操纵相关系统。
