Abstract: ObjectiveIn order to provide candidate genes for improving drought resistance of sugarcane,the gene expression profiles in Saccharum spontaneum leaf under drought stress were analyzed for screening drought resistant genes.MethodS. spontaneum GX83-10 was used as material to design two treatments viz. normal watering(control, CK)and drought stress(T),and their equal quantity mixed solutions of total RNA were constructed to establish gene ex-pression profiles in response to drought stress at elongation stage of GX83-10 by using cDNA-SCoT differential display technology.The transcript derived fragments(TDFs)were screened and isolated for sequencing,followed by the BLAST homology searching in NCBI database to deduce gene function based on homological genes. Furthermore,the related genes of drought resistance were analyzed by real time fluorescence quantitative PCR(qRT-PCR).ResultIn this study, 120 up-regulated TDFs were successfully cloned and sequenced.Among them,53 had higher similarity than others with the accessed genes in NCBI database,and these TDFs could be classified into 10 functional groups,including associated-functional protein related genes(20.75%),metabolism related genes(13.21%),communication and signal transduction related genes(13.21%),transcription regulated factor related genes(13.21%),transport pathway related genes(11.32%), environmental interaction related genes(9.43%),energy metabolism related genes(7.55%),protein synthesis related genes (3.77%),defense related genes(3.77%)and cell component biological synthesis related gene(3.77%).Transport factor 2 family protein,RING/U-box superfamily protein,22 kD drought-inducible protein,tubulin alpha-3 chain and plasma-membrane H+-ATPase were selected to conduct qRT-PCR analysis,and the results confirmed that all five genes were up-regulated in expressions at varying degrees under drought stress.ConclusionUnder drought stress,it is feasible to screen the drought resistance related genes in S.spontaneum from gene expression profiles constructed by applying cDNA-SCoT differential display technology.The drought resistance and water efficient utilization genes,which were excavated from S. spontaneum leaf,will provide more candidate genes for sugarcane breeding research using wild germplasm re-sources to improve sugarcane drought resistance and broaden the genetic library of sugarcane breeding.