GeneChip profiling of transcriptional responses to soybean cyst nematode, Heterodera glycines, colonization of soybean roots.

Soybean cyst nematode (SCN) is currently the most devastating pathogen of soybean. SCN penetrates the root and migrates toward the central vascular bundle where it establishes a complex multinucleated feeding structure that provides plant-derived nutrients to support the development and growth of the nematode. To identify host genes that play significant roles in SCN development in susceptible roots, RNA from SCN-inoculated and non-inoculated root pieces were hybridized to the Affymetrix soybean genome GeneChips.

Gene expression profiles for cell wall-modifying proteins associated with soybean cyst nematode infection, petiole abscission, root tips, flowers, apical buds, and leaves.

Changes in transcript accumulation for cell wall-modifying proteins were examined in excised soybean root pieces colonized by soybean cyst nematodes (SCN), Heterodera glycines, using RT-PCR and soybean Affymetrix GeneChips. Sequence-specific PCR primer pairs were prepared from sequence data for core sequences in the GenBank soybean database and consensus sequences derived from the assembly of soybean ESTs. In addition, to identify previously uncharacterized soybean transcripts, degenerate primers were prepared for conserved motifs in cellulases (endo-1,4-beta-glucanases, EGases) and polygalacturonases (PGs) and these were used to amplify segments of transcripts that were then extended with 3' and 5' RACE.

Characterization of Several Heterodera glycines mRNA that Encode Small Proteins with Putative Signal Peptides.

Two subtraction libraries were prepared from RNA extracted at early and late stages in the development of soybean cyst nematodes (SCN), Heterodera glycines, in soybean roots. The cDNA from inoculated roots were subtracted with cDNA prepared from non-inoculated roots and SCN eggs, and 384 clones from each library were sequenced. BLAST searches revealed that 191 of the cDNA in the late library were most probably of nematode origin.