Transgenic Arabidopsis thaliana plants expressing cel1 antisense exhibit reduced levels of cel1 mRNA and protein compared with wild-type plants. The former display significant alterations in their phenotype. cel1 antisense plants have shorter stems and roots and are mechanically weaker than their wild-type counterparts. In cel1 antisense plants, the cell wall structure is markedly disrupted: both fluorescent confocal microscopy and scanning electron microscopy revealed 'wrinkled' cell walls, thus indicating that CEL1 plays an important role in cell wall relaxation during cell growth and expansion. In cel1 antisense plants, the number of xylem elements per bundle is smaller than in the wild-type. In addition, both xylem elements and interfascicular fibers are significantly less lignified in the former. It is suggested that in A. thaliana, abnormal cell wall deposition affected by CEL1 depletion is associated not only with cell growth, but also with the differentiation process in the vascular and supporting tissues.
- Cell wall