Gene mpl1, activated during mating in Phytophthora infestans: similar to genes encoding pectate lyases

Abstract

Clones of genes activated in mating cultures of A1 and A2 mating-type strains of Phytophthora infestans were isolated using the cDNA-representational difference analysis subtraction method. Clone cET58 was selected based on its accumulation in mating cultures and then was used as a probe to isolate cDNA clone cET58L2 from a cDNA library that was constructed from mycelia grown under mating conditions. Sequence analysis revealed that cET58L2 was 1043 bp long and contained a complete open reading frame of 789 bp. The amino acid sequence of the putative protein was similar to a pectate lyase, PLD, of Fusarium solani f. sp. pisi. The central region of the predicted protein was highly similar to the sequence of other pectate lyases. The gene from which the cDNA clones were derived was designated mpl1. A probe corresponding to the protein-coding region of mpl1 was prepared (probe p58L) for Northern and Southern analyses. The maximum rate of oogonia increase and mpl1 transcript accumulation reached a maximum after 5 days in mating culture. More than 13 genes with sequences similar to that of mpl1 were found in the genome, revealing mpl1 to be a multicopy gene. The mpl1 may be a pectate lyase gene that is activated in P. infestans during mating.