Expression patterns of the genes that encode lectin or lectin-related polypeptides in Robinia pseudoacacia

Three genomic clones (Rplec2, Rplec5 and Rplec6) and a cDNA clone (LECRPA4) that encoded lectin or lectin-related polypeptides were isolated from Robi nia pseudoacacia L.A comparison of the nucleotide sequences of Rplec2 and a previously reported cDNA for the subunit indicated that Rplec2 encoded the 29 kDa subunit of the inner-bark lectin RPbAI. Rplec5 encoded a polypeptid e whose deduced amino acid sequence was 96.1% identical to that of a subuni t of seed lectin. The amino acid sequence deduced from the open reading fra me of Rplec6 showed 61.1% identity to that encoded by Rplec5. LECRPA4 was i solated from an inner bark cDNA library and appeared to encode the 26 kDa s ubunit of inner-bark lectin RPbAII. The expression patterns of the various genes in tissues were examined by the reverse transcriptase-polymerase chai n reaction (RT-PCR) with appropriate primers. Rplec2 transcripts were detec ted in the inner bark and roots. Rplec5 transcripts were detected in the in ner bark, seeds and roots. No Rplec6 transcripts were detected in all tissu es examined. LECRPA4 transcripts were found in leaves and in the inner bark . The level of expression of Rplec2 in the inner bark appeared to be simila r in samples collected in different years and from different trees, whereas levels of expression of Rplec5 and LECRPA4 varied. These results suggest t he differential regulation of expression of members of the lectin gene fami ly in tissues of R. pseudoacacia.