Identification of new nodulin cDNAs from yellow lupine by differential display

In this study several sequences that represent yellow lupine nodulin genes are identified. Four different cDNA clones were isolated from a lupine nodu le cDNA. library and sequenced. Database search revealed that the deduced a mino acid of one clone, DD3A20, shows near 80% amino acid similarity to pla nt stearoyl-acyl carrier protein desaturases and contains crucial amino aci ds in the fatty acid binding domain which are characteristic for stearoyl-A CP desaturases. The other sequences seem to be unique. Nearly identical sig nal peptide sequences are present at the N-termini of the DD4A9 and DD2T15 putative proteins. Northern analysis indicated that the pattern of expressi on of the Lldd4A9, Lldd2A18 and Lldd2T15 genes is the same as that of the l upine leghemoglobin gene LllbII, while the desaturase gene Ll3A20 is turned on at least 3 days earlier. Ll3A20 is also expressed in lupine fruits. RT- PCR analysis of the Lldd3A20 and Lldd2T15 expression confirmed organ-specif ic and temporal pattern of expression in nodules. (C) 2000 Published by Els evier Science Ireland Ltd. All rights reserved.