Molecular genetic study on degenerate signal transduction pathway of auxin by the use of activation tagging

通过使用激活标签载体，我们已经建立了大约12,000个独立的拟南芥转基因系。我们还从每个100个品系池中准备了DNA，这样我们就可以通过用聚合酶链式反应检查任何感兴趣的基因来识别T-DNA标签品系。我们已经分离到一个显性突变体cdg1-D，它在几乎所有的气生器官中都显示出结构性差异生长。我们已经证明该突变是由编码丝氨酸/苏氨酸蛋白激酶的CDG1基因的过度表达引起的。CDG1是拟南芥RLCKVII亚家族约50个基因之一。在CDG1-D中，细胞伸长不是以协调的方式发生的，导致许多器官的异常差异生长。Cdg1-D细胞伸长的光调节也受到影响。我们分离到了另一个半显性突变体sls1，它在短日照条件下不表现晚花。SLS1编码一种RNA结合蛋白。这些结果表明，激活标记是识别退化信号转导途径中的因素的有力工具。

We have created about 12,000 independent transgenic lines of Arabidopsis by the use of an activation tagging vector. We have also prepared DNA from each pool of 100 lines so that we can identity a T-DNA tagged line by checking any gene of interest by PCR. We have isolated a dominant mutant, cdg1-D, which shows constitutive differential growth in almost all aerial organs. We have shown that the mutation is caused by overexpression of CDG1 gene that encodes a Ser/Thr protein kinase. CDG1 is one of about 50 genes of RLCKVII subfamily in Arabidopsis. Cell elongation does not occur in a concerted manner in cdg1-D, resulting in an aberrant differential growth in many organs. Light regulation of cell elongation is also affected in cdg1-D. We have isolated another semi-dominant mutant, sls1, that does not show late-flowering in a short-day condition. SLS1 encodes an RNA-binding protein. These results indicate that activation tagging is a powerful tool to identify factors in a degenerate pathway of signal transduction.