Payyavula Raja S, Badmi Raghuram, Jawdy Sara S, Rodriguez Miguel, Gunter Lee, Sykes Robert W, Winkeler Kimberly A, Collins Cassandra M, Rottmann William H, Chen Jin-Gui, Yang Xiaohan, Tuskan Gerald A, Kalluri Udaya C
BioEnergy Science Centre, Center for Bioenergy Innovation and Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA.
The Biosciences Center National Renewable Energy Laboratory Golden Colorado USA.
Plant Direct. 2022 Aug 12;6(8):e419. doi: 10.1002/pld3.419. eCollection 2022 Aug.
Woody biomass is an important feedstock for biofuel production. Manipulation of wood properties that enable efficient conversion of biomass to biofuel reduces cost of biofuel production. Wood cell wall composition is regulated at several levels that involve expression of transcription factors such as wood-/secondary cell wall-associated NAC domains (WND or SND). In , regulates cell wall composition through activation of its down-stream targets such as MYBs. The functional aspects of homologs in the woody have been studied through transgenic manipulation. In this study, we investigated the role of , sequence ortholog, in wood formation using transgenic manipulation through over-expression or silencing under the control of a vascular-specific coumarate ligase () promoter. As compared with control plants, -RNAi plants were shorter in height, with significantly reduced stem diameter and dry biomass, whereas there were no significant differences in growth and productivity of over-expression plants. Conversely, over-expression lines showed a significant reduction in cellulose and increase in lignin content, whereas there was no significant impact on lignin content of downregulated lines. Stem carbohydrate composition analysis revealed a decrease in glucose, mannose, arabinose, and galactose, but an increase in xylose in the over-expression lines. Transcriptome analysis revealed upregulation of several downstream transcription factors and secondary cell wall related structural genes in the over-expression lines, partly explaining the observed phenotypic changes in cell wall chemistry. Relative to the control, glucose release efficiency and ethanol production from stem biomass was significantly reduced in over-expression lines. Our results show that is an important factor determining biomass productivity, cell wall chemistry and its conversion to biofuels in .
木质生物质是生物燃料生产的重要原料。对有助于生物质高效转化为生物燃料的木材特性进行调控可降低生物燃料的生产成本。木材细胞壁的组成在多个层面受到调控，这涉及转录因子的表达，如木材/次生细胞壁相关的NAC结构域（WND或SND）。在[具体植物名称未给出]中，[具体基因未给出]通过激活其下游靶点（如MYB）来调节细胞壁组成。通过转基因操作对[具体植物名称未给出]中[具体基因未给出]同源物的功能方面进行了研究。在本研究中，我们利用转基因操作，通过在维管束特异性香豆酸连接酶（[具体基因未给出]）启动子的控制下过表达或沉默，研究了[具体基因未给出]（[具体植物名称未给出]的序列直系同源物）在木材形成中的作用。与对照植物相比，[具体基因未给出]-RNAi植物高度更矮，茎直径和干生物量显著降低，而过表达植物的生长和生产力没有显著差异。相反，[具体基因未给出]过表达株系的纤维素含量显著降低，木质素含量增加，而下调株系的木质素含量没有显著影响。茎碳水化合物组成分析显示，过表达株系中葡萄糖、甘露糖、阿拉伯糖和半乳糖减少，但木糖增加。转录组分析显示，[具体基因未给出]过表达株系中几个下游转录因子和次生细胞壁相关结构基因上调，部分解释了观察到的细胞壁化学表型变化。相对于对照，过表达株系中茎生物质的葡萄糖释放效率和乙醇产量显著降低。我们的结果表明，[具体基因未给出]是决定[具体植物名称未给出]生物量生产力、细胞壁化学及其向生物燃料转化的重要因素。
