Identification of lignin-deficient Brachypodium distachyon (L.) Beauv. mutants induced by gamma radiation.
BACKGROUND
Brachypodium distachyon (L.) Beauv. is a monocotyledonous model plant that has been studied to understand a range of biological phenomena for lignocellulosic bioethanol feedstocks and other cereal crops. The lignin makes its cell walls recalcitrant to saccharification, constituting the main barrier to lignocellulosic bioethanol production. In this study, lignin-deficient mutants of B. distachyon induced by chronic radiation were selected and the effects of the mutants on fermentable glucose production were identified.


RESULTS
Brachypodium distachyon M2mutants induced by chronically irradiated gamma radiation were screened by the Wiesner test. Lignin-deficient M2mutants were further confirmed in subsequent M3and M4generations by determining acetyl bromide-soluble lignin. The lignin content was significantly reduced in mutant plants 135-2 (by 7.99%), 142-3 (by 13.8%) and 406-1 (by 8.13%) compared with the wild type. Moreover, fermentable glucose was significantly higher in 135-2 (by 23.91%) and 142-3 (by 36.72%) than in the wild type after 72 h of enzymatic hydrolysis.


CONCLUSIONS
Three lignin-deficient B. distachyon mutants induced by chronically irradiated gamma radiation were obtained. This study will provide fundamental understanding of the B. distachyon cell wall and could contribute to increases in bioethanol production using bioenergy crops. © 2016 Society of Chemical Industry.
Department of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul, 136-713, Korea.
Man Bo
MB
Lee
Department of Biosystems and Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul, 136-713, Korea.
Jae Yoon
JY
Kim
Department of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul, 136-713, Korea.|Department of Biosystems and Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul, 136-713, Korea.
Yong Weon
YW
Seo
D056804:Biofuels; D058431:Brachypodium / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects*; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D005720:Gamma Rays; D008031:Lignin / Q000032:analysis* / Q000378:metabolism; D009154:Mutation; D018547:Plant Stems / Q000528:radiation effects
D056804:Biofuels; D008031:Lignin
Brachypodium distachyon; enzyme hydrolysis; gamma radiation; lignin; lignocellulosic bioethanol; mutation