The Arabidopsis ELF3 gene regulates vegetative photomorphogenesis and the photoperiodic induction of flowering.
The Arabidopsis ELF3 gene regulates vegetative photomorphogenesis and the photoperiodic induction of flowering.
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DOI：
10.1046/j.1365-313x.1996.10040691.x
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发表时间：
1996-10
期刊：
影响因子：
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通讯作者：
M. Zagotta;Karen A. Hicks;Carolyn I. Jacobs;Jeff C. Young;R. Hangarter;D. Meeks-Wagner
中科院分区：
文献类型：
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作者：
M. Zagotta;Karen A. Hicks;Carolyn I. Jacobs;Jeff C. Young;R. Hangarter;D. Meeks-Wagner
长日照(Ld)光周期促进拟南芥开花，使生长在Ld光周期中的植株比生长在短日照(SD)光周期中的植株开花更早，产叶更少。拟南芥早花3号(Elf3)突变体对光周期不敏感，对花的启动不敏感，但elf3突变体也在营养体光形态发生的几个方面发生了变化，包括下胚轴伸长。当测定下胚轴伸长抑制时，elf3突变体幼苗对所有波长的光的反应都低于野生型，最明显的是在蓝光和绿光介导的抑制方面存在缺陷。在对开花时间表型进行分析时，elf3对蓝光受体编码基因HY4的突变等位基因具有上位性。然而，当通过引入hy2突变等位基因使elf3突变体缺乏功能光敏色素时，elf3 hy2双突变体表现出比任何一个突变体更早开花的新表型，但仍然表现出光周期不敏感，这表明在elf3单突变体中，光敏色素介导的调控花起始的途径仍然具有功能。此外，elf3 hy2双突变体的一个等位基因组合的花序形成了与tfk1单突变体相似的顶花结构。这些结果表明，控制拟南芥光周期的信号转导途径之一至少部分地受光敏色素以外的光感受器的调控，拟南芥花序和花分生组织识别基因的活性可能受同一途径的调控。
Flowering in Arabidopsis thaliana is promoted by longday (LD) photoperiods such that plants grown in LD flower earlier, and after the production of fewer leaves, than plants grown in short-day (SD) photoperiods. The early-flowering 3 (elf3) mutant of Arabidopsis, which is insensitive to photoperiod with regard to floral initiation has been characterized elf3 mutants are also altered in several aspects of vegetative photomorphogenesis, including hypocotyl elongation. When inhibition of hypocotyl elongation was measured, elf3 mutant seedlings were less responsive than wild-type to all wavelengths of light, and most notably defective in blue and green light-mediated inhibition. When analyzed for the flowering-time phenotype, elf3 was epistatic to mutant alleles of the blue-light receptor encoding gene, HY4. However, when elf3 mutants were made deficient for functional phytochrome by the introduction of hy2 mutant alleles, the elf3 hy2 double mutants displayed the novel phenotype of flowering earlier than either single mutant while still exhibiting photoperiod insensitivity, indicating that a phytochrome-mediated pathway regulating floral initiation remains functional in elf3 single mutants. In addition, the inflorescences of one allelic combination of elf3 hy2 double mutants form a terminal flower similar to the structure produced by tfk1 single mutants. These results suggest that one of the signal transduction pathways controlling photoperiodism in Arabidopsis is regulated, at least in part, by photoreceptors other than phytochrome, and that the activity of the Arabidopsis inflorescence and floral meristem identity genes may be regulated by this same pathway.