CHARACTERIZATION OF THE CDNA CLONES OF 2 BETA-TUBULIN GENES AND THEIREXPRESSION IN THE POTATO PLANT (SOLANUM-TUBEROSUM L.)

The cDNA clones of two potato beta-tubulin genes were isolated from a tuberising stolen tip library. Analysis of 20 positive clones showed t hat they represented one or another of two different but very similar beta-tubulin genes, designated TUBST1 and TUBST2. The expression patte rn of beta-tubulin genes ill the potato plant was investigated by RNA blot analysis and by RT-PCR. Southern analysis of potato genomic DNA w ith coding and non-coding beta-tubulin probes revealed that there are multiple beta-tubulin genes in the potato genome and that there is lik ely to be considerable divergence in the 3' non-coding sequences. Phyl ogenetic analysis of plant beta-tubulin genes is described.