Interacting transcription factors from the three-amino acid loop extension superclass regulate tuber formation
Interacting transcription factors from the three-amino acid loop extension superclass regulate tuber formation
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DOI：
10.1104/pp.103.022434
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发表时间：
2003-07-01
期刊：
影响因子：
7.4
通讯作者：
Hannapel, DJ
中科院分区：
文献类型：
--
作者：
Chen, H;Rosin, FM;Hannapel, DJ
利用酵母双杂交系统和马铃薯（Solanum tuberosum）KNOX蛋白（命名为POTH 1）作为诱饵，我们从马铃薯匍匐茎文库中鉴定了7个不同的相互作用蛋白。所有七个cDNA都是BEL 1样转录因子家族的成员。在这些蛋白质中，存在至少四个高度序列保守的区域，包括同源结构域、脯氨酸-酪氨酸-脯氨酸三氨基酸环延伸、SKY盒和同源结构域上游的120个氨基酸区域。通过缺失分析，我们确定了一个蛋白结合域存在于羧基端的KNOX结构域的POTH 1。BEL 1蛋白中的蛋白结合结构域位于BELs的120个残基保守区的氨基末端的一半。RNA印迹分析表明，不同模式的RNA积累的贝尔在不同的马铃薯器官。StBEL 5 mRNA的水平增加响应于短日照在叶片和匍匐茎。类似的POTH 1的正义突变体，过表达StBEL 5的转基因株系表现出增强的块茎形成，即使在非诱导条件下。然而，与POTH 1有义系不同，这些BEL系没有表现出KNOX过表达者的极端叶和茎形态特征，并且显示出比对照植物更快的生长速率。StBEL 5和POTH 1正义系都表现出茎尖中细胞分裂素水平的增加。StBEL 5株系也表现出GA 20-oxidase 1 mRNA在长日照植物匍匐茎顶端的水平下降。我们的研究结果表明，KNOX和BEL 1样转录因子的马铃薯，可能潜在地调节发育过程之间的相互作用。
Using the yeast (Saccharomyces cerevisiae) two-hybrid system and a potato (Solanum tuberosum) KNOX protein, designated POTH1, as bait, we have identified seven distinct interacting proteins from a stolon library of potato. All seven cDNAs are members of the BEL1-like family of transcription factors. Among these proteins, there are at least four regions of high sequence conservation including the homeodomain, the proline-tyrosine-proline three-amino acid loop extension, the SKY box, and a 120-amino acid region upstream from the homeodomain. Through deletion analysis, we identified a protein-binding domain present in the carboxy end of the KNOX domain of POTH1. The protein-binding domain in the BEL1 protein is located in the amino-terminal one-half of the 120-residue conserved region of the BELs. RNA-blot analysis showed differential patterns of RNA accumulation for the BELs in various potato organs. The level of StBEL5 mRNA increased in response to a short-day photoperiod in both leaves and stolons. Similar to sense mutants of POTH1, transgenic lines that overexpressed StBEL5 exhibited enhanced tuber formation even under noninductive conditions. Unlike POTH1 sense lines, however, these BEL lines did not exhibit the extreme leaf and stern morphology characteristic of KNOX overexpressers and displayed a more rapid rate of growth than control plants. Both StBEL5 and POTH1 sense lines exhibited an increase in cytokinin levels in shoot tips. StBEL5 lines also exhibited a decrease in the levels of GA 20-oxidase1 mRNA in stolon tips from long-day plants. Our results demonstrate an interaction between KNOX and BEL1-like transcription factors of potato that may potentially regulate processes of development.