Identification of the tobacco and Arabidopsis homologues of the pollen-expressed LAT59 gene of tomato.

We describe the complete genomic sequences for the tobacco and Arabidopsis homologues of tomato LAT59, a previously described member of a family of pectate lyase-like genes. Translation of the tobacco gene, Nt59, predicts a protein with 93.5% overall amino acid similarity to LAT59. Nt59 has two introns whose positions are exactly conserved with the two introns of LAT59. Both LAT59 and Nt59 are specifically expressed in pollen and their promoter and 5'-UTR sequences are highly similar. Furthermore, two promoter elements shown to be important for pollen expression of LAT59 are conserved in the Nt59 promoter. The Arabidopsis homologue, At59, was found by examination of four candidates. At59 has 72.6% amino acid similarity to LAT59 and the position of one of its two introns is conserved with one of the LAT59 introns. At59 is also pollen-expressed and although its promoter sequence is quite different from the Nt59 and LAT59 promoters, the two promoter elements are somewhat conserved.