Characterisation of the cDNA clones of two beta-tubulin genes and their expression in the potato plant (Solanum tuberosum L.).

The cDNA clones of two potato beta-tubulin genes were isolated from a tuberising stolon tip library. Analysis of 20 positive clones showed that they represented one or another of two different but very similar beta-tubulin genes, designated TUBST1 and TUBST2. The expression pattern of beta-tubulin genes in the potato plant was investigated by RNA blot analysis and by RT-PCR. Southern analysis of potato genomic DNA with coding and non-coding beta-tubulin probes revealed that there are multiple beta-tubulin genes in the potato genome and that there is likely to be considerable divergence in the 3' non-coding sequences. Phylogenetic analysis of plant beta-tubulin genes is described.