Previously we reported that a highly-conserved single-stranded DNA-binding protein (Ssbx) of Xanthomonas species, secreted by the type-Ⅲ secretion system (T3SS), acts as harpin-like proteins to elicit hypersensitive response (HR) in nonhost tobacco.In this study, we cloned ssbXoc gene from X.oryzae pv.oryzicola (Xoc) that causes bacterial leaf streak in rice, into tobacco (cv.Xanthi) via Agrobacterium-mediated transformation.The ssbXoc transgenic tobacco showed smaller phenotype in whole life cycle, including stems, roots.Moreover, HRs occurred earlier in ssbXoc transgenic tobacco than the wild-type and the empty vector (EV) plants when SsbXoc and Hpa1 (a harpin protein of Xoc)were infiltrated.