Abstract: Rosa multiflora 'Inermis 4' is a crown gall disease resistant ecotype. Suppression subtractive hybridization (SSH) was utilized to identify the host genes that were differentially expressed in the host-pathogen interactions. In vitro cultured shoots inoculated with Agrobacterium tumefaciens were used as "tester" and needle pricking shoots as "driver". Subtractive cDNA library was constructed, which enriched for resistance-related genes to A. tumefaciens. Ninety-two cDNA clones were sequenced after differential screening through cDNA macroarray. After removing redundant and bacteria cDNA fragments, 53 unique cDNA clones were obtained. The putative function of these genes involved in:（1）cell division and growth and chaperones;（2）defense/stress, signaling, hormone regulation;（3）primary and secondary metabolism. Ten clones were designated as unknowns, these clones had either substantial similarity to genes with unknown functions, or only low similarity matches to GenBank database sequences. Furthermore, the probable molecular mechanism of R. multiflora 'Inermis 4' resistance to crown gall development was discussed according to the sequencing and blasting results.

Key words: Rosa multiflora, Suppression subtractive hybridization (SSH), cDNA macroarray, Bacteria-induced genes