Identification of Transcription Factors Involved in Rice Secondary Cell Wall Formation
Identification of Transcription Factors Involved in Rice Secondary Cell Wall Formation
复制标题
DOI：
10.1093/pcp/pct122
复制
发表时间：
2013-11-01
影响因子：
4.9
通讯作者：
Matsuoka, Makoto
中科院分区：
文献类型：
--
作者：
Hirano, Ko;Kondo, Mari;Matsuoka, Makoto
利用共表达网络分析，我们鉴定了123个水稻次生细胞壁调节因子的候选转录因子。为了验证这些TF是否与次生细胞壁的形成有关，我们在水稻中过表达或下调了6个属于MYB、NAC或含有同源结构域的TF家族的TF基因。除OsMYB 58/63-RNAi植株外，所有转基因植株均表现出可能与次生细胞壁改变有关的表型，如矮化、叶片窄而暗的绿色，并改变了水稻肉桂醇脱氢酶2（OsCAD 2）基因的表达和木质素含量。这些结果表明，123个候选的次生细胞壁调节TF中的许多可能在水稻次生细胞壁形成中起作用。对OsMYB 55/61和OsBLH 6 TF进行进一步分析，前者是已知拟南芥直向同源物参与木质素生物合成的TF（AtMYB 61），后者是先前甚至在拟南芥中也没有报道参与细胞壁形成的TF（BLH 6）。OsMYB 55/61和OsBLH 6-GFP融合蛋白定位于洋葱表皮细胞的细胞核。此外，当OsMYB 55/61或OsBLH 6瞬时表达时，由OsCAD 2启动子驱动的报告基因在水稻愈伤组织中的表达增强，表明它们在次生细胞壁形成中起作用。这些结果显示了利用水稻共表达网络分析鉴定水稻中潜在次生细胞壁转录因子的有效性。
Using co-expression network analysis, we identified 123 transcription factors (TFs) as candidate secondary cell wall regulators in rice. To validate whether these TFs are associated with secondary cell wall formation, six TF genes belonging to the MYB, NAC or homeodomain-containing TF families were overexpressed or downregulated in rice. With the exception of OsMYB58/63-RNAi plants, all transgenic plants showed phenotypes possibly related to secondary cell wall alteration, such as dwarfism, narrow and dark green leaves, and also altered rice cinnamyl alcohol dehydrogenase 2 (OsCAD2) gene expression and lignin content. These results suggest that many of the 123 candidate secondary cell wall-regulating TFs are likely to function in secondary cell wall formation in rice. Further analyses were performed for the OsMYB55/61 and OsBLH6 TFs, the former being a TF in which the Arabidopsis ortholog is known to participate in lignin biosynthesis (AtMYB61) and the latter being one for which no previous involvement in cell wall formation has been reported even in Arabidopsis (BLH6). OsMYB55/61 and OsBLH6-GFP fusion proteins localized to the nucleus of onion epidermal cells. Moreover, expression of a reporter gene driven by the OsCAD2 promoter was enhanced in rice calli when OsMYB55/61 or OsBLH6 was transiently expressed, demonstrating that they function in secondary cell wall formation. These results show the validity of identifying potential secondary cell wall TFs in rice by the use of rice co-expression network analysis.