Loosening xyloglucan accelerates the enzymatic degradation of cellulose in wood.
In order to create trees in which cellulose, the most abundant component in biomass, can be enzymatically hydrolyzed highly for the production of bioethanol, we examined the saccharification of xylem from several transgenic poplars, each overexpressing either xyloglucanase, cellulase, xylanase, or galactanase. The level of cellulose degradation achieved by a cellulase preparation was markedly greater in the xylem overexpressing xyloglucanase and much greater in the xylems overexpressing xylanase and cellulase than in the xylem of the wild-type plant. Although a high degree of degradation occurred in all xylems at all loci, the crystalline region of the cellulose microfibrils was highly degraded in the xylem overexpressing xyloglucanase. Since the complex between microfibrils and xyloglucans could be one region that is particularly resistant to cellulose degradation, loosening xyloglucan could facilitate the enzymatic hydrolysis of cellulose in wood.
Kaida
Rumi
R
Kyoto University, RISH, Gokasho, Uji, Kyoto 611-0011, Japan.
Kaku
Tomomi
T
Baba
Kei'ichi
K
Oyadomari
Masafumi
M
Watanabe
Takashi
T
Nishida
Koji
K
Kanaya
Toshiji
T
Shani
Ziv
Z
Shoseyov
Oded
O
Hayashi
Takahisa
T
D044602:Cellulases / Q000235:genetics / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D043364:Endo-1,4-beta Xylanases / Q000235:genetics / Q000378:metabolism; D005936:Glucans / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D018625:Microscopy, Atomic Force; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D032107:Populus / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D014934:Wood / Q000378:metabolism*; D014961:X-Ray Diffraction; D014990:Xylans / Q000378:metabolism*; D052584:Xylem / Q000201:enzymology / Q000648:ultrastructure; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D005936:Glucans; D014990:Xylans; C029353:xyloglucan; D002482:Cellulose; D044602:Cellulases; D006026:Glycoside Hydrolases; C072818:xyloglucan endo(1-4)-beta-D-glucanase; D001616:beta-Galactosidase; D043364:Endo-1,4-beta Xylanases