Wang Shucai, Li Eryang, Porth Ilga, Chen Jin-Gui, Mansfield Shawn D, Douglas Carl J
1] Key Laboratory of Molecular Epigenetics of MOE & Key Laboratory of Vegetation Ecology of MOE, Northeast Normal University, Changchun, 130024, China [2] Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada [3].
1] Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada [2].
Sci Rep. 2014 May 23;4:5054. doi: 10.1038/srep05054.
Poplar has 192 annotated R2R3 MYB genes, of which only three have been shown to play a role in the regulation of secondary cell wall formation. Here we report the characterization of PtrMYB152, a poplar homolog of the Arabidopsis R2R3 MYB transcription factor AtMYB43, in the regulation of secondary cell wall biosynthesis. The expression of PtrMYB152 in secondary xylem is about 18 times of that in phloem. When expressed in Arabidopsis under the control of either 35S or PtrCesA8 promoters, PtrMYB152 increased secondary cell wall thickness, which is likely caused by increased lignification. Accordingly, elevated expression of genes encoding sets of enzymes in secondary wall biosynthesis were observed in transgenic plants expressing PtrMYB152. Arabidopsis protoplast transfection assays suggested that PtrMYB152 functions as a transcriptional activator. Taken together, our results suggest that PtrMYB152 may be part of a regulatory network activating expression of discrete sets of secondary cell wall biosynthesis genes.
杨树有192个注释的R2R3 MYB基因，其中只有三个已被证明在次生细胞壁形成的调控中发挥作用。在此，我们报道了PtrMYB152的特性，它是拟南芥R2R3 MYB转录因子AtMYB43的杨树同源物，在次生细胞壁生物合成调控中发挥作用。PtrMYB152在次生木质部中的表达量约为韧皮部中的18倍。当在35S或PtrCesA8启动子的控制下在拟南芥中表达时，PtrMYB152增加了次生细胞壁厚度，这可能是由木质化增加所致。相应地，在表达PtrMYB152的转基因植物中观察到次生壁生物合成中一系列酶编码基因的表达升高。拟南芥原生质体转染试验表明PtrMYB152作为转录激活因子发挥作用。综上所述，我们的结果表明PtrMYB152可能是激活离散次生细胞壁生物合成基因集表达的调控网络的一部分。
