title: Screening of rice mutants with improved saccharification efficiency results in the identification of CONSTITUTIVE PHOTOMORPHOGENIC 1 and GOLD HULL AND INTERNODE 1.
abstract: The screening of rice mutants with improved cellulose to glucose saccharification efficiency (SE) identifies reduced xylan and/or ferulic acid, and a qualitative change of lignin to impact SE. To ensure the availability of sustainable energy, considerable effort is underway to utilize lignocellulosic plant biomass as feedstock for the production of biofuels. However, the high cost of degrading plant cell wall components to fermentable sugars (saccharification) has been problematic. One way to overcome this barrier is to develop plants possessing cell walls that are amenable to saccharification. In this study, we aimed to identify new molecular factors that influence saccharification efficiency (SE) in rice. By screening 22 rice mutants, we identified two lines, 122 and 108, with improved SE. Reduced xylan and ferulic acid within the cell wall of line 122 were probable reasons of improved SE. Line 108 showed reduced levels of thioglycolic-released lignin; however, the amount of Klason lignin was comparable to the wild-type, indicating that structural changes had occurred in the 108 lignin polymer which resulted in improved SE. Positional cloning revealed that the genes responsible for improved SE in 122 and 108 were rice CONSTITUTIVE PHOTOMORPHOGENIC 1 (OsCOP1) and GOLD HULL AND INTERNODE 1 (GH1), respectively, which have not been previously reported to influence SE. The screening of mutants for improved SE is an efficient approach to identify novel genes that affect SE, which is relevant in the development of crops as biofuel sources.
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, 464-8601, Japan. khirano@nuagr1.agr.nagoya-u.ac.jp.
authors.forename: Ko
authors.initials: K
authors.lastname: Hirano
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Masuda
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Wakana
authors.initials: W
authors.lastname: Takase
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, 464-8601, Japan.|Zensho Holdings Co., Ltd., Tokyo, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Morinaka
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Kawamura
authors.affiliation: Rice Breeding Research Team, NARO Institute of Crop Science, Tsukuba, Ibaraki, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takeuchi
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takagi
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yaegashi
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Natsume
authors.affiliation: Iwate Biotechnology Research Center, Kitakami, Iwate, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Terauchi
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Saitama, Japan.|Institute for Environmental Science and Technology, Saitama University, Saitama, Japan.
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Kotake
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sazuka
mesh_terms: D018533:Biomass; D002482:Cellulose / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism
chemical_list: D003373:Coumaric Acids; D010940:Plant Proteins; D002482:Cellulose; D008031:Lignin; C004999:ferulic acid
keywords: Cellulose; Ferulic acid; Lignin; Rice mutant; Xylan