文献类型： 外文期刊

作者： Wu, Leiming ¹ ; Zhang, Mingliang ¹ ; Zhang, Ran ¹ ; Yu, Haizhong ³ ; Wang, Hailang ¹ ; Li, Jingyang ¹ ; Wang, Youmei ¹ ; Hu, Zhen ¹ ; Wang, Yanting ¹ ; Luo, Zi ² ; Li, Lin ² ; Wang, Lingqiang ¹ ; Peng, Liangcai ¹ ; Xia, Tao ¹ ;

作者机构： 1.Huazhong Agr Univ, Coll Plant Sci & Technol, Biomass & Bioenergy Res Ctr, Wuhan 430070, Peoples R China

2.Huazhong Agr Univ, Natl Key Lab Crop Genet Improvement, Wuhan, Peoples R China

3.Hubei Univ Arts & Sci, Coll Food Sci & Chem Engn, Lab Biomass Engn & Nanomat Applt Automobiles, Xiangyang, Peoples R China

4.Chinese Acad Trop Agr Sci, Haikou Expt Stn, Haikou 570102, Hainan, Peoples R China

5.Guangxi Univ, Coll Agr, State Key Lab Conservat & Utilizat Subtrop Agrobi, Nanning, Peoples R China

6.Huazhong Agr Univ, Coll Life Sci & Technol, Wuhan 430070, Peoples R China

关键词： Cellulose synthesis; Cellulose polymerization; Microfibril assembly; OsMYBs; Multi-omics; Biomass saccharification; Fragile culm; Rice

期刊名称：BIOTECHNOLOGY FOR BIOFUELS （ 影响因子：7.67； 五年影响因子：7.862 ）

ISSN：

年卷期： 2021 年 14 卷 1 期

页码：

收录情况： SCI

摘要： Background As a major component of plant cell walls, cellulose provides the most abundant biomass resource convertible for biofuels. Since cellulose crystallinity and polymerization have been characterized as two major features accounting for lignocellulose recalcitrance against biomass enzymatic saccharification, genetic engineering of cellulose biosynthesis is increasingly considered as a promising solution in bioenergy crops. Although several transcription factors have been identified to regulate cellulose biosynthesis and plant cell wall formation, much remains unknown about its potential roles for genetic improvement of lignocellulose recalcitrance. Results In this study, we identified a novel rice mutant (Osfc9/myb103) encoded a R2R3-MYB transcription factor, and meanwhile generated OsMYB103L-RNAi-silenced transgenic lines. We determined significantly reduced cellulose levels with other major wall polymers (hemicellulose, lignin) slightly altered in mature rice straws of the myb103 mutant and RNAi line, compared to their wild type (NPB). Notably, the rice mutant and RNAi line were of significantly reduced cellulose features (crystalline index/CrI, degree of polymerization/DP) and distinct cellulose nanofibers assembly. These alterations consequently improved lignocellulose recalcitrance for significantly enhanced biomass enzymatic saccharification by 10-28% at p < 0.01 levels (n = 3) after liquid hot water and chemical (1% H2SO4, 1% NaOH) pretreatments with mature rice straws. In addition, integrated RNA sequencing with DNA affinity purification sequencing (DAP-seq) analyses revealed that the OsMYB103L might specifically mediate cellulose biosynthesis and deposition by regulating OsCesAs and other genes associated with microfibril assembly. Conclusions This study has demonstrated that down-regulation of OsMYB103L could specifically improve cellulose features and cellulose nanofibers assembly to significantly enhance biomass enzymatic saccharification under green-like and mild chemical pretreatments in rice. It has not only indicated a powerful strategy for genetic modification of plant cell walls in bioenergy crops, but also provided insights into transcriptional regulation of cellulose biosynthesis in plants.