Polynucleotide, DNA constructs and methods are disclosed for the modification ofcellulose content in plant tissues. Plants are transformed with constructs encodingeither an active Anabaena sp. sucrose synthase gene or a soybean nodule sucrosesynthase gene, which leads to increased cellulose content when over-expressed underthe control of a cambium/xylem preferred promoter. Plant transformants harboringan Anabaena sp. or a soybean nodule sucrose synthase gene demonstrated increasedcontent of cellulose, a trait that is thought to improve woody trees for celluloseextraction during pulping and papermaking.
