Hiratsu Keiichiro, Matsui Kyoko, Koyama Tomotsugu, Ohme-Takagi Masaru
Gene Function Research Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, Tsukuba 305-8566, Japan.
Plant J. 2003 Jun;34(5):733-9. doi: 10.1046/j.1365-313x.2003.01759.x.
The redundancy of genes for plant transcription factors often interferes with efforts to identify the biologic functions of such factors. We show here that four different transcription factors fused to the EAR motif, a repression domain of only 12 amino acids, act as dominant repressors in transgenic Arabidopsis and suppress the expression of specific target genes, even in the presence of the redundant transcription factors, with resultant dominant loss-of-function phenotypes. Chimeric EIN3, CUC1, PAP1, and AtMYB23 repressors that included the EAR motif dominantly suppressed the expression of their target genes and caused insensitivity to ethylene, cup-shaped cotyledons, reduction in the accumulation of anthocyanin, and absence of trichomes, respectively. This chimeric repressor silencing technology (CRES-T), exploiting the EAR-motif repression domain, is simple and effective and can overcome genetic redundancy. Thus, it should be useful not only for the rapid analysis of the functions of redundant plant transcription factors but also for the manipulation of plant traits via the suppression of gene expression that is regulated by specific transcription factors.
植物转录因子基因的冗余性常常妨碍人们识别此类因子生物学功能的努力。我们在此表明，与EAR基序（仅由12个氨基酸组成的抑制结构域）融合的四种不同转录因子，在转基因拟南芥中作为显性抑制因子发挥作用，即使存在冗余转录因子，也能抑制特定靶基因的表达，从而产生显性功能丧失表型。包含EAR基序的嵌合EIN3、CUC1、PAP1和AtMYB23抑制因子分别显性抑制其靶基因的表达，并导致对乙烯不敏感、子叶呈杯状、花青素积累减少以及无表皮毛。这种利用EAR基序抑制结构域的嵌合抑制因子沉默技术（CRES-T）简单有效，能够克服基因冗余。因此，它不仅应有助于快速分析冗余植物转录因子的功能，还应有助于通过抑制由特定转录因子调控的基因表达来操控植物性状。
