Research note: High efficiency transformation of the diatom Phaeodactylum tricornutum with a promoter from the diatom Cylindrotheca fusiformis

Abstract

A high efficiency transformation system was established for the pennate diatom Phaeodactylum tricornutum Bohlin using a plasmid containing fucoxanthin chlorophyll a/c binding protein (fcp) promoter/terminator and nitrate reductase (NR) promoter/terminator that are derived from the pennate diatom Cylindrotheca fusiformis. The plasmid that contains the zeocin resistance gene (ble) with the fcp promoter and enhanced green fluorescent protein gene (egfp) with the NR promoter was introduced into P. tricornutum using microparticle bombardment. Transformants (650 ± 58 per 108 cells) were obtained. The yield of transformants was between 1.5 and 130 times higher than previously reported P. tricornutum transformation systems. Four to seven copies of the ble gene were integrated into genomic DNA of the transformants. This high efficiency transformation system of P. tricornutum is expected to provide a powerful tool for high-throughput analysis of gene function using homologous recombination or RNAi. © 2009 Japanese Society of Phycology.