Name the accession number for  rhodopseudomonas palustris
CREATE TABLE "homologs" (
  "genus_species" text,
  "gene_name" text,
  "accession_number" text,
  "sequence_length" text,
  "sequence_similarity" real
);
SELECT "accession_number" FROM "homologs" WHERE "genus_species"='Rhodopseudomonas palustris';