학술논문

Sugar release and growth of biofuel crops are improved by downregulation of pectin biosynthesis
Document Type
Report
Source
Nature Biotechnology. March 2018, Vol. 36 Issue 3, p249, 9 p.
Subject
Biomass -- Chemical properties
Biosynthesis -- Observations
Cell walls -- Chemical properties
Plant cells -- Chemical properties
Pectin -- Chemical properties
Biotechnology industry
Business
Observations
Chemical properties
Language
English
ISSN
1087-0156
Abstract
Cell walls in crops and trees have been engineered for production of biofuels and commodity chemicals, but engineered varieties often fail multi-year field trials and are not commercialized. We engineered reduced expression of a pectin biosynthesis gene (Galacturonosyltransferase 4, GAUT4) in switchgrass and poplar, and find that this improves biomass yields and sugar release from biomass processing. Both traits were maintained in a 3-year field trial of GAUT4-knockdown switchgrass, with up to sevenfold increased saccharification and ethanol production and sixfold increased biomass yield compared with control plants. We show that GAUT4 is an [alpha]-1,4-galacturonosyltransferase that synthesizes homogalacturonan (HG). Downregulation of GAUT4 reduces HG and rhamnogalacturonan II (RGII), reduces wall calcium and boron, and increases extractability of cell wall sugars. Decreased recalcitrance in biomass processing and increased growth are likely due to reduced HG and RGII cross-linking in the cell wall.
Author(s): Ajaya K Biswal [1, 2, 3]; Melani A Atmodjo [1, 2, 3]; Mi Li [3, 4, 5]; Holly L Baxter [3, 6]; Chang Geun Yoo [3, 4, 5]; Yunqiao [...]