A retrotransposon-like sequence linked to the S-locus of Nicotiana alata is expressed in styles in response to touch

Abstract

We have identified a family of repetitive sequences in the genome of Nicotiana alata named Tna1 (Transposon of N. alata). The first element we characterised was on a genomic clone for the N. alata S6-ribonuclease (S6-RNase), a gene required for self-incompatibility in this species. The DNA sequence of this element resembles the integrase domain of retrotransposons of the gypsy class and is most similar to a retrotransposon from Lilium henryi. A transcript present in N. alata styles (self-incompatibility genotype S6S6) hybridized to Tna1 and accumulated in the style following either pollination or touching. This transcript was cloned from a cDNA library and was encoded by a second, partial Tn..