In the present study,the phosphorus-deficiency tolerance introgression line IL171 and its parents (Oryza sativa cv.‘Xieqingzao B’ and Dongxiang wild rice) were used to investigate the differential expression genes at early seedling stage by cDNA-AFLP technique under the phosphorus-deficiency stress condition.Real-time fluorescent quantitative PCR was used to verify the differentially expressed genes.(1)cDNA-AFLP analysis revealed that numerous cDNA fragments (20-159) were obtained in each material under the phosphorus-deficiency condition compared to the control (normal phosphorus level).(2)Compared with ‘Xieqingzao B’,36 and 61 cDNA fragments were differentially up- and down-regulated in IL171,respectively.In Dongxiang wild rice line,79 and 136 cDNA fragments were differentially up- and down-regulated,respectively.Further analysis showed that IL171 and Dongxiang wild rice shared the same expression pattern at 13 up-regulated loci and 15 down-regulated loci.(3)Among the 60 recovered and sequenced TDFs (transcript-derived fragments),50 of them were obtained and their functions were determined through Blast search against the RAP-DB database.The functions of them were grouped into eight classes,including energy and metabolism,regulating genes,signal transduction and transcription factors et al.(4)Six above functional genes were subjected to real-time fluorescentquantitative PCR (qRT-PCR) analysis which was all in agreement with those of the cDNA-AFLP analysis,comfirming that cDNA-AFLP was reliable in detecting differentially expressed gens involved in responding to the phosphorus-deficiency stress.The results in this study suggested that partial alien DNA fragments of Dongxiang wild rice related to phosphorus-deficiency tolerance has been transferred into the introgression lines and they could be acted as excellent bridging germplasm in exploring and utilizing the phosphorus-deficiency tolerant genes in rice.In additon,the introgression linses derived from Dongxiang wild rice can be used a good experimental system for understanding the molecular mechanism to tolerate phosphorus-deficiency stress in wild rice.