Functional conservation and maintenance of expression pattern of FIDDLEHEAD-like genes in Arabidopsis and Antirrhinum
Functional conservation and maintenance of expression pattern of FIDDLEHEAD-like genes in Arabidopsis and Antirrhinum
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DOI：
10.1007/s11103-004-5576-y
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发表时间：
2004-11-01
影响因子：
5.1
通讯作者：
Yephremov, A
中科院分区：
文献类型：
--
作者：
Efremova, N;Schreiber, L;Yephremov, A
在拟南芥中，编码推定的β-酮脂酰-CoA合酶的表皮特异性FDH基因的功能丧失导致突变体中的异位器官融合。金鱼草没有相应的突变体，然而，使用化学遗传学方法，β-酮脂酰辅酶A酶的氯乙酰胺抑制剂可以在两个物种中诱导器官融合。我们从金鱼草中分离出FDH的直系同源物，即金鱼草FIDDLEHEAD（AFI）基因，并表明当在FDH启动子的控制下在表皮中表达时，AFI与FDH互补。像FDH一样，AFI基因表现出原皮和表皮特异性表达，并且其启动子指导报告基因在转基因金鱼草和拟南芥中表皮的表达。我们证明了下调的FDH启动子在表皮的子房隔膜，从而支持的假设，FDH样基因可能直接促进细胞间的相互作用，需要发生在心皮融合和花粉管生长。另一方面，FDH在气孔中的上调为其可能参与花药开裂过程中的细胞分离提供了证据。在转基因拟南芥中观察到隔片中FDH和AFI启动子的下调，但在金鱼草植物中没有观察到。这可能反映了这两个物种之间的卵巢隔膜的个体发育的差异。我们还表明，表皮特异性FDH样基因可能无法有效地延长脂肪酸链时，在种子中错误表达。
In Arabidopsis, loss of function of the epidermis-specific FDH gene coding for a putative beta-ketoacyl-CoA synthase results in ectopic organ fusions in mutants. Corresponding mutants are not available for Antirrhinum majus, however, organ fusions can be induced in both species by chloroacetamide inhibitors of beta-ketoacyl-CoA synthases using a chemical genetics approach. We isolated the ortholog of FDH from Antirrhinum majus, the ANTIRRHINUM FIDDLEHEAD (AFI) gene, and showed that AFI complements fdh when expressed in the epidermis under control of the FDH promoter. Like FDH, the AFI gene exhibits protodermis- and epidermis-specific expression, and its promoter directs the expression of reporter genes to the epidermis in transgenic Antirrhinum and Arabidopsis. We demonstrate down-regulation of the FDH promoter in the epidermis of the ovary septum, thereby supporting the assumption that FDH-like genes may directly facilitate the cell - cell interactions that need to occur during carpel fusion and pollen tube growth. Up-regulation of FDH in the stomium, on the other hand, provides evidence for its possible involvement in cell separation during anther dehiscence. Down-regulation of the FDH and AFI promoters in the septum is observed in transgenic Arabidopsis but not in Antirrhinum plants. This probably reflects differences in the ontogeny of the ovary septum between the two species. We also show that epidermis-specific FDH-like genes may not be able to efficiently elongate fatty acid chains when misexpressed in seeds.