Golfier Philippe, Ermakova Olga, Unda Faride, Murphy Emily K, Xie Jianbo, He Feng, Zhang Wan, Lohmann Jan U, Mansfield Shawn D, Rausch Thomas, Wolf Sebastian
Centre for Organismal Studies Heidelberg, Heidelberg University, 69120 Heidelberg, Germany.
Department of Wood Science, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Int J Mol Sci. 2021 Nov 17;22(22):12395. doi: 10.3390/ijms222212395.
Cell wall recalcitrance is a major constraint for the exploitation of lignocellulosic biomass as a renewable resource for energy and bio-based products. Transcriptional regulators of the lignin biosynthetic pathway represent promising targets for tailoring lignin content and composition in plant secondary cell walls. However, knowledge about the transcriptional regulation of lignin biosynthesis in lignocellulosic feedstocks, such as Miscanthus, is limited. In Miscanthus leaves, and are expressed at growth stages associated with lignification. The ectopic expression of and in leaves was sufficient to trigger secondary cell wall deposition with distinct sugar and lignin compositions. Moreover, RNA-seq analysis revealed that the transcriptional responses to and overexpression showed an extensive overlap with the response to the NAC master transcription factor MsSND1, but were distinct from each other, underscoring the inherent complexity of secondary cell wall formation. Furthermore, conserved and previously described promoter elements as well as novel and specific motifs could be identified from the target genes of the three transcription factors. Together, MsSCM1 and MsMYB103 represent interesting targets for manipulations of lignin content and composition in Miscanthus towards a tailored biomass.
细胞壁顽抗性是将木质纤维素生物质作为能源和生物基产品的可再生资源加以利用的主要限制因素。木质素生物合成途径的转录调节因子是调整植物次生细胞壁中木质素含量和组成的有前景的靶点。然而，关于芒草等木质纤维素原料中木质素生物合成的转录调控的知识有限。在芒草叶片中，[此处原文缺失两个基因名称]在与木质化相关的生长阶段表达。[此处原文缺失两个基因名称]在[此处原文缺失植物名称]叶片中的异位表达足以引发具有不同糖和木质素组成的次生细胞壁沉积。此外，RNA测序分析表明，对[此处原文缺失两个基因名称]过表达的转录反应与对NAC主转录因子MsSND1的反应有广泛重叠，但彼此不同，这突出了次生细胞壁形成的内在复杂性。此外，从这三个转录因子的靶基因中可以鉴定出保守的和先前描述的启动子元件以及新的和特定的基序。总之，MsSCM1和MsMYB103是操纵芒草中木质素含量和组成以获得定制生物质的有趣靶点。
