The promoter of a Brassica napus lipid transfer protein gene is active in a range of tissues and stimulated by light and viral infection in transgenic Arabidopsis

cDNA and genomic clones encoding Brassica napus non-specific lipid transfer proteins (LTP) were isolated and sequenced. The encoded amino acid sequenc es were very similar to those reported previously for LTPs from B. napus an d other species. Sequence information indicates that B. napus contains an L TP gene family. The 5'-flanking region of one gene, designated BnLTP, was f used to GUS and the fusion introduced into Arabidopsis. LTP transcripts and BnLTP-Gus expression were present predominantly in the epidermis of leaf a nd stem, consistent with the hypothesised function of LTPs in the depositio n of cuticular or epicuticular waxes. However, GUS activity was detected in other tissues, including lateral root initials, anthers, stigmas and vascu lar tissues, which may suggest additional functions. LTP transcript levels in B. napus and Arabidopsis and BnLTP-GUS expression in transgenic Arabidop sis were stimulated by blue and red light but not UV-B. BnLTP promoter acti vity was also stimulated upon viral infection, at a time when the virus had spread systemically. No increase in expression was observed in response to cold or wounding.