The mechanical properties of xylem tissue from tobacco plants (Nicotiana tabacum 'Samsun')

Abstract

Tobacco plants (Nicotiana tabacum 'Samsun') have been grown with an antisense CAD (cinnamyl alcohol dehydrogenase) gene. This modifies lignin production, resulting in lignin with a greater aldehyde content which is easier to extract chemically. This lignin probably has a reduced crosslink density. The changed properties of the lignin affect the longitudinal tensile modulus of the xylem tissue (wood), reducing it by one third, from 2·8 GPa to 1·9 GPa. Tobacco xylem tissue cell walls are more sensitive to changes in the properties of the matrix than can be predicted using current cell wall mechanical models.