Stage-specific gene expression during sexual development in Phytophthora infestans.
Eight genes that are upregulated during sexual development in the heterothallic oomycete, Phytophthora infestans, were identified by suppression subtractive hybridization. Two genes showed very low but detectable expression in vegetative hyphae and became induced about 40- to >100-fold early in mating, before gametangial initials appeared. The remaining six loci were not induced until later in mating, coincident with the formation of gametangia and oospores, with induction levels ranging from 60- to >100-fold. Five genes were single copy, and three were members of families. Sequence analysis revealed that the predicted products of three of the genes had similarity to proteins that influence RNA stability, namely a ribonuclease activator, the pumilio family of RNA-binding proteins and RNase H. The products of two other mating-induced genes resembled two types of Phytophthora proteins previously shown to elicit plant defence responses. Each mating-induced gene was also expressed in a self-fertile strain, which was shown to be a heterokaryon. However, quantitative and qualitative differences existed in their expression in normal matings and in the self-fertile heterokaryon. Besides the mating-induced genes, two extrachromosomal RNA elements were identified.
Department of Plant Pathology, University of California, Riverside, CA 92521, USA.
Anna-Liisa
AL
Fabritius
Cristina
C
Cvitanich
Howard S
HS
Judelson
D000595:Amino Acid Sequence; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010838:Phytophthora / Q000235:genetics* / Q000254:growth & development*; D012331:RNA, Fungal / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013382:Subtraction Technique
D012331:RNA, Fungal