DIFFERENTIAL DISPLAY ANALYSIS OF THE EARLY COMPATIBLE INTERACTION BETWEEN SOYBEAN AND THE SOYBEAN CYST-NEMATODE

The marked cellular changes during feeding site formation of the soybe an cyst nematode (Heterodera glycines) indicate major changes in soybe an gene expression. We used differential display of mRNA to detect hos t gene expression changes during the early compatible interaction betw een soybean and H, glycines, Fifteen cDNA clones corresponding to mRNA s with different abundances in N, glycines-infected versus uninfected roots were identified. Differential display results indicated that abu ndances of five mRNAs increased in infected roots, whereas abundances of 10 mRNAs decreased. Transcripts for nine of these 15 cDNAs could be detected on RNA blots, and their hybridization signals confirmed the differential display results for eight of these nine cDNAs, Sequence a nalyses identified five cDNAs with decreased mRNA levels in infected r oots as corresponding to two putative aldolase genes, a transcription- factor TFIIA homologue, the soybean small GTP-binding protein gene sra 1, and the soybean auxin down-regulated gene ADR12. RNA blot analyses of other auxin down-regulated genes revealed a decrease in their mRNA abundances in H, glycines-infected roots as well.