Halliday K, Devlin P F, Whitelam G C, Hanhart C, Koornneef M
Department of Botany, University of Leicester, UK.
Plant J. 1996 Mar;9(3):305-12. doi: 10.1046/j.1365-313x.1996.09030305.x.
A novel elongated mutant has been isolated from EMS-mutagenized populations of the Arabidopsis thaliana ga4 mutant. After backcrossing with the Landsberg erecta (Ler) wild-type (WT) followed by selfing, the mutant phenotype was identified in the GA4 background. Seedlings of the mutant, which has been named elg (elongated), are characterized by elongated hypocotyls and petioles, leaves that are narrow and somewhat epinastic and early flowering. Allelism tests with the hy1-hy5 mutants indicate that elg is not allelic with any of these long-hypocotyl mutants. From linkage analyses, the location of elg on chromosome 4, between cer2 and ap2 has been established. The pleiotropic phenotype of elg seedlings is suggestive of a disruption of phytochrome and/or gibberellin (GA) function. Although the elg mutant displays a light-dependent long-hypocotyl phenotype, elg seedlings retain a full range of photomorphogenic responses and the elg mutation acts additively with the photomorphogenic mutants phyB, hy1 and hy2. This suggests that ELG acts independently of phytochrome action. The elg mutation partially suppresses the effect of GA-deficiency on elongation growth, and, although elg ga1 seedlings are more elongated than ga1 seedlings, both genotypes respond in the same way to applied GA. That applied GA and the elg mutation interact additively suggests that ELG acts independently of GA action.
从拟南芥ga4突变体的EMS诱变群体中分离出一种新型的细长型突变体。与直立型野生型（Ler）回交后再进行自交，在GA4背景中鉴定出该突变体表型。已将该突变体命名为elg（elongated，细长型），其幼苗的特征是下胚轴和叶柄细长，叶片狭窄且有点向下弯曲，并且开花较早。与hy1 - hy5突变体进行的等位性测试表明，elg与这些长下胚轴突变体中的任何一个都不等位。通过连锁分析，已确定elg位于第4号染色体上cer2和ap2之间。elg幼苗的多效表型表明其光敏色素和/或赤霉素（GA）功能受到破坏。尽管elg突变体表现出光依赖性的长下胚轴表型，但elg幼苗保留了完整的光形态建成反应范围，并且elg突变与光形态建成突变体phyB、hy1和hy2呈累加作用。这表明ELG的作用独立于光敏色素作用。elg突变部分抑制了GA缺乏对伸长生长的影响，并且尽管elg ga1幼苗比ga1幼苗更长，但两种基因型对施加的GA的反应方式相同。施加的GA与elg突变呈累加相互作用，这表明ELG的作用独立于GA作用。
