Song Sang-Kee, Kwak Su-Hwan, Chang Soo Chul, Schiefelbein John, Lee Myeong Min
Department of Biology, Chosun University, Gwangju 501-759, Republic of Korea.
Department of Biology, Long Island University, 1 University Plaza, Brooklyn, NY, USA.
Biochem Biophys Res Commun. 2015 Nov 6;467(1):94-100. doi: 10.1016/j.bbrc.2015.09.115. Epub 2015 Sep 25.
In multicellular organisms, cell fates are specified through differential regulation of transcription. Epidermal cell fates in the Arabidopsis thaliana root are precisely specified by several transcription factors, with the GLABRA2 (GL2) homeodomain protein acting at the farthest downstream in this process. To better understand the regulation of GL2 expression, we ectopically expressed WEREWOLF (WER) and ENHANCER OF GLABRA3 (EGL3) in various tissues and examined GL2 expression. Here we show that WER expressed ubiquitously in the root induced GL2 expression only in the root epidermis, whereas co-expression of WER and EGL3 induced GL2 expression in the corresponding tissues. We also found that GL3 accumulated in the nucleus at the early meristematic region and EGL3 accumulated later in the nucleus of epidermal cells. We further found that ectopic expression of WER and EGL3 in ground tissues inhibited GL2 expression in the epidermis. Our results suggest that the co-expression of WER and EGL3 is sufficient for driving GL2 and CPC expression.
在多细胞生物体中，细胞命运是通过转录的差异调控来确定的。拟南芥根中的表皮细胞命运由几种转录因子精确确定，其中GLABRA2（GL2）同源结构域蛋白在此过程中作用于最下游。为了更好地理解GL2表达的调控，我们在各种组织中异位表达了WEREWOLF（WER）和GLABRA3增强子（EGL3），并检测了GL2的表达。我们发现，在根中普遍表达的WER仅在根表皮中诱导GL2表达，而WER和EGL3的共表达则在相应组织中诱导GL2表达。我们还发现，GL3在早期分生组织区域的细胞核中积累，而EGL3则在后期在表皮细胞的细胞核中积累。我们进一步发现，在基本组织中异位表达WER和EGL3会抑制表皮中GL2的表达。我们的结果表明，WER和EGL3的共表达足以驱动GL2和CPC的表达。
