Improved lignocellulose saccharification of aMiscanthusreddish stem mutant induced by heavy-ion irradiation
Improved lignocellulose saccharification of aMiscanthusreddish stem mutant induced by heavy-ion irradiation
复制标题
重离子辐照诱导芒草红色茎突变体木质纤维素糖化的改善
DOI：
10.1111/gcbb.12748
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发表时间：
2020-10-04
影响因子：
5.6
通讯作者：
Zhou, Gongke
中科院分区：
文献类型：
--
作者：
Wang, Congpeng;He, Guo;Zhou, Gongke
芒草是一种很有前景的木质纤维素生物能源作物，用于生产纤维素乙醇。木质纤维素的顽抗性阻碍了芒草生物质向可发酵糖的有效转化。因此，筛选具有增强木质纤维素糖化效率的芒草种质对于芒草生物质生产纤维素乙醇具有重要意义。在本研究中，我们利用重离子辐照诱变技术建立了芒草突变体库，并筛选了具有提高木质纤维素糖化效率的红茎（rs）突变体。 rs突变体的特征是韧皮部和维管束鞘中的各种木质化细胞壁显着呈红色，而生物量产量并未受到影响。呈红色的原因是几种酚类化合物的掺入量减少，包括 3-咖啡酰奎宁酸、二氢黄酮醇和原花青素 A，它们与通过苯丙素途径进行木质素单木质醇生物合成具有共同的前体。相应地，与对照植物相比，rs突变体的木质素含量降低了10.2%，纤维素含量随之增加了9.5%。同时，当木质纤维素生物质用或不用1.5% H2SO4预处理时，rs突变体的糖化效率比对照显着提高了22.4%–25.6%。这里鉴定的 rs 突变体具有作为纤维素生物乙醇生产中理想候选原料的潜在用途。
Miscanthus is a promising lignocellulosic bioenergy crop for the production of cellulosic ethanol. The recalcitrance of lignocellulose hampers the efficient conversion of Miscanthus biomass to fermentable sugars. Therefore, screening of Miscanthus germplasms with enhanced lignocellulose saccharification efficiency is of important significance to the cellulosic ethanol production from Miscanthus biomass. In this study, we utilize heavy‐ion irradiation mutagenesis to establish a mutant library of Miscanthus lutarioriparius, and screened a reddish stem (rs) mutant with improved lignocellulose saccharification efficiency. The rs mutant was characterized by a noticeable reddish coloration in various lignified cell walls in phloem and vascular bundle sheath, whereas the biomass yield was not compromised. The reddish coloration was attributed to the reduced incorporation of several phenolic compounds including 3‐caffeoylquinic acid, dihydroflavonol and proanthocyanin A, which shared common precursors with lignin monolignol biosynthesis via the phenylpropanoid pathway. Correspondingly, the lignin content was decreased by 10.2% and the cellulose content was concomitantly increased by 9.5% in rs mutant compared with the control plant. Meanwhile, the saccharification efficiency was substantially improved by 22.4%–25.6% in rs mutant compared to the control, when the lignocellulosic biomass was pretreated with or without 1.5% H2SO4. The rs mutant identified here holds a potential utilization as an ideal candidate feedstock in cellulosic bioethanol production.