Enhancement of growth and cellulose accumulation by overexpression of xyloglucanase in poplar

Received 11 February 2004; received in revised form 19 March 2004; accepted 19 March 2004.

Abstract

Because the loosening of xyloglucan in the cell wall promotes plant growth (Takeda et al. (2002) Proc. Natl. Acad. Sci. USA 99, 9055–9060; Park et al. (2003) Plant J. 33, 1099–1106), we expressed Aspergillus xyloglucanase constitutively in Populus alba. The expression increased the length of stem even in the presence of sucrose. Increased stem growth was accompanied by a decrease in Young’s elastic modulus in the growth zone but an increased elasticity in mature tissue. The increased internode length corresponded to an increase in cellulose content as well as specific gravity, showing that the removal of xyloglucan might cause an increase in cellulose density in the secondary xylem.

Keywords: Cellulose deposition, Secondary wall, Transgenic poplar, Xyloglucan, Xyloglucanase

a Wood Research Institute, Kyoto University, Gokasho, Uji 611-0011, Japan

b Biological Function Science Course, Kyoto Prefectural University, Shimogamo-nakaragi-cho, Sakyo-ku, Kyoto 606-8522, Japan

c Department of Forest Science, Kochi University, Nangoku 783-8502, Japan

d Department of Applied Biochemistry, Osaka Prefectural University, 1-1 Gakuen-cho, Sakai 599-8531, Japan

Corresponding author. Fax: (81)-774-38 3618

PII: S0014-5793(04)00346-1

doi:10.1016/S0014-5793(04)00346-1

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