Watson John M, Brill Elizabeth M
CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia. Corresponding author; email:
CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
Funct Plant Biol. 2004 May;31(3):225-234. doi: 10.1071/FP03181.
In a search for Eucalyptus grandis Hill ex Maiden MADS-box genes involved in floral initiation and development, we isolated two cDNAs (EgrMADS 3 and EgrMADS 4), which are functional orthologues of the Arabidopsis thaliana (L.) Heynh. floral activator gene SOC1. These two E. grandis genes are equally and most-actively expressed in vegetative tissues such as apical shoots and young leaves. The two genes are less actively, but differentially expressed in roots and unopened flowers. Ectopic expression of EgrMADS 3 or EgrMADS 4 in the late-flowering A. thaliana Ler soc1 (agl20) derivative complemented the phenotype of this mutant, and some of these transgenic lines flowered significantly earlier than the wild-type Ler ecotype. Overexpression of EgrMADS 3 or EgrMADS 4 in A. thaliana ecotype Columbia accelerated flowering time under short-day conditions. However, under the same conditions the flowering time of A. thaliana ecotype C24 was altered by the ectopic expression of EgrMADS 3, but not that of EgrMADS 4.The nucleotide sequence data reported will appear in the EMBL and GenBank Nucleotide Databases under the accession numbers AY263807 (EgrMADS 3) and AY263808 (EgrMADS 4).
为了寻找参与花起始和发育的巨桉（Eucalyptus grandis Hill ex Maiden）MADS-box基因，我们分离出了两个cDNA（EgrMADS 3和EgrMADS 4），它们是拟南芥（Arabidopsis thaliana (L.) Heynh.）花激活基因SOC1的功能直系同源基因。这两个巨桉基因在诸如顶芽和幼叶等营养组织中同等且最活跃地表达。这两个基因在根和未开放的花中表达活性较低，但存在差异表达。在晚花拟南芥Ler soc1（agl20）衍生物中异位表达EgrMADS 3或EgrMADS 4可互补该突变体的表型，并且其中一些转基因株系比野生型Ler生态型开花显著更早。在短日条件下，在拟南芥生态型哥伦比亚中过表达EgrMADS 3或EgrMADS 4可加速开花时间。然而，在相同条件下，拟南芥生态型C24的开花时间因EgrMADS 3的异位表达而改变，但不受EgrMADS 4的影响。所报道的核苷酸序列数据将以登录号AY263807（EgrMADS 3）和AY263808（EgrMADS 4）出现在EMBL和GenBank核苷酸数据库中。
