Isolation of the 3-phosphoglycerate kinase gene of the arbuscular mycorrhizal fungus Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe

The 3-phosphoglycerate: kinase (PGK) gene of the arbuscular mycorrhizal fun gus Glomus mosseae has beer; isolated by differential RNA display (DD). Exp erimentally, the technique of DD was utilized to simultaneously compare the mRNA transcript populations from Lycopersicon esculentum root systems colo nized by the arbuscular mycorrhizal fungus G. mosseae; and non-mycorrhizal plants. A differentially expressed band was isolated and cloned from mycorr hizal tissue. The isolated DD fragment was screened and sequenced. A revers e transcription-PCR (RT-PCR) technique detected transcripts in germinated s pores and G. mosseae-colonized root systems hut not in uncolonised root sys tems. The full-length cDNA was isolated by RACE and corresponded to the 3-p hosphoglycerate kinase gene of G, mosseae. The cDNA encodes a polypeptide o f 416 amino acids, with a predicted molecular weight of 44764 Ba. The PGK p roteins shows high homology to those PGKs of other fungi and the phylogenet ic relationship among 14 isolated fungal PGK sequences is illustrated.