Abstract: Microarray technology plays increasing roles in the study of plant gene function. By using BLAST biosoftware and data from GenBank, the specific primers for key metabolism enzyme genes in cucumberwere designed, and the specific fragments amp lified by RT-PCR were cloned and sequenced. A total of
432 cDNA sequences corresponding to genes involved in photochewistry, carbon fixation, carbohydrate metabolism, water-water cycle, signal transduction , hormone metabolism, defense, photoresp iration and amino acid
metabolism were obtained and categorized. At last, a cDNA microarraywith 423 cDNA fragments and 9 quality control cDNA fragments were built. The microarray was then used to study the changes of gene expression
profiles of cucumber plants after exposure to magnesium starvation. The results showed that 10 genes were down regulated, while 12 genes were up regulated in magnesium deficiency p lants. This microarray will provide us a powerful tool for the study of gene function in response to a series of stresses.

Key words: Cucumber, cDNA microarray, Magnesium deficiency, Gene expression profile