Interaction between the GROWTH-REGULATING FACTOR and KNOTTED1-LIKE HOMEOBOX Families of Transcription Factors1[W]
Interaction between the GROWTH-REGULATING FACTOR and KNOTTED1-LIKE HOMEOBOX Families of Transcription Factors1[W]
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DOI：
10.1104/pp.113.222836
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发表时间：
2014-04-01
期刊：
影响因子：
7.4
通讯作者：
Ouwerkerk, Pieter B. F.
中科院分区：
文献类型：
--
作者：
Kuijt, Suzanne J. H.;Greco, Raffaella;Ouwerkerk, Pieter B. F.
KNOX基因是分生组织功能的重要调控因子，复杂的转录因子网络确保了其表达的严格控制。在这里，我们表明生长调节因子（GRF）家族的成员在这个网络中扮演着角色。利用来自水稻（Oryza sativa）的KNOX基因Oskn 2的上游序列进行酵母（Saccharomyces cerevisiae）单杂交筛选，导致OsGRF 3和OsGRF 10的分离。通过酵母和体外结合试验证实了与Oskn 2的非翻译前导序列中的一个区域的特异性结合。ProOskn 2：OsGRF 3和OsGRF 10在体内下调β-葡萄糖醛酸酶报告基因的表达，提示这些蛋白具有转录抑制因子的功能。同样，我们发现，来自大麦（Hordeum vulgare）的GRF蛋白BGRF 1可以作为KNOX基因Hooded/Barley Knotted 3（Bkn 3）中内含子序列的阻遏物，并且来自拟南芥（Arabidopsis thaliana）的AtGRF 4、AtGRF 5和AtGRF 6可以抑制来自拟南芥的KNOTTED-LIKE 2（KNAT 2）启动子活性。水稻中OsGRF过表达表型与异常的分生活性一致，显示分蘖和节间的形成减少以及节上大量的不定根/芽形成。这些作用与OsGRF 3下调内源性Oskn 2表达有关。相反，OsGRF 3、OsGRF 4和OsGRF 5的RNA干扰沉默导致矮化、生长和花序形成延迟以及Oskn 2的上调。这些数据表明，在单子叶植物和双子叶植物的转录因子的GRF和KNOX家族之间的保守的相互作用。
KNOTTED1-LIKE HOMEOBOX (KNOX) genes are important regulators of meristem function, and a complex network of transcription factors ensures tight control of their expression. Here, we show that members of the GROWTH-REGULATING FACTOR (GRF) family act as players in this network. A yeast (Saccharomyces cerevisiae) one-hybrid screen with the upstream sequence of the KNOX gene Oskn2 from rice (Oryza sativa) resulted in isolation of OsGRF3 and OsGRF10. Specific binding to a region in the untranslated leader sequence of Oskn2 was confirmed by yeast and in vitro binding assays. ProOskn2: beta-glucuronidase reporter expression was down-regulated by OsGRF3 and OsGRF10 in vivo, suggesting that these proteins function as transcriptional repressors. Likewise, we found that the GRF protein BGRF1 from barley (Hordeum vulgare) could act as a repressor on an intron sequence in the KNOX gene Hooded/Barley Knotted3 (Bkn3) and that AtGRF4, AtGRF5, and AtGRF6 from Arabidopsis (Arabidopsis thaliana) could repress KNOTTED-LIKE FROM ARABIDOPSIS THALIANA2 (KNAT2) promoter activity. OsGRF overexpression phenotypes in rice were consistent with aberrant meristematic activity, showing reduced formation of tillers and internodes and extensive adventitious root/shoot formation on nodes. These effects were associated with down-regulation of endogenous Oskn2 expression by OsGRF3. Conversely, RNA interference silencing of OsGRF3, OsGRF4, and OsGRF5 resulted in dwarfism, delayed growth and inflorescence formation, and up-regulation of Oskn2. These data demonstrate conserved interactions between the GRF and KNOX families of transcription factors in both monocot and dicot plants.