title: High-level hemicellulosic arabinose predominately affects lignocellulose crystallinity for genetically enhancing both plant lodging resistance and biomass enzymatic digestibility in rice mutants.
abstract: Rice is a major food crop with enormous biomass residue for biofuels. As plant cell wall recalcitrance basically decides a costly biomass process, genetic modification of plant cell walls has been regarded as a promising solution. However, due to structural complexity and functional diversity of plant cell walls, it becomes essential to identify the key factors of cell wall modifications that could not much alter plant growth, but cause an enhancement in biomass enzymatic digestibility. To address this issue, we performed systems biology analyses of a total of 36 distinct cell wall mutants of rice. As a result, cellulose crystallinity (CrI) was examined to be the key factor that negatively determines either the biomass enzymatic saccharification upon various chemical pretreatments or the plant lodging resistance, an integrated agronomic trait in plant growth and grain production. Notably, hemicellulosic arabinose (Ara) was detected to be the major factor that negatively affects cellulose CrI probably through its interlinking with β-1,4-glucans. In addition, lignin and G monomer also exhibited the positive impact on biomass digestion and lodging resistance. Further characterization of two elite mutants, Osfc17 and Osfc30, showing normal plant growth and high biomass enzymatic digestion in situ and in vitro, revealed the multiple GH9B candidate genes for reducing cellulose CrI and XAT genes for increasing hemicellulosic Ara level. Hence, the results have suggested the potential cell wall modifications for enhancing both biomass enzymatic digestibility and plant lodging resistance by synchronically overexpressing GH9B and XAT genes in rice.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China; Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, China; College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Fengcheng
authors.initials: F
authors.lastname: Li
authors.forename: Mingliang
authors.initials: M
authors.lastname: Zhang
authors.forename: Kai
authors.initials: K
authors.lastname: Guo
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hu
authors.forename: Ran
authors.initials: R
authors.lastname: Zhang
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Feng
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yi
authors.forename: Weihua
authors.initials: W
authors.lastname: Zou
authors.forename: Lingqiang
authors.initials: L
authors.lastname: Wang
authors.forename: Changyin
authors.initials: C
authors.lastname: Wu
authors.forename: Jinshan
authors.initials: J
authors.lastname: Tian
authors.forename: Tiegang
authors.initials: T
authors.lastname: Lu
authors.forename: Guosheng
authors.initials: G
authors.lastname: Xie
authors.forename: Liangcai
authors.initials: L
authors.lastname: Peng
mesh_terms: D001089:Arabinose / Q000378:metabolism*; D018533:Biomass; D002473:Cell Wall / Q000201:enzymology / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D017343:Genes, Plant; D008031:Lignin / Q000378:metabolism*; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*
chemical_list: D004798:Enzymes; D011134:Polysaccharides; C036909:lignocellulose; C007916:hemicellulose; D008031:Lignin; D001089:Arabinose
keywords: GH9B and XAT; biomass digestibility; cell wall; genetic modification; lodging resistance; rice