Abstract: 【Objective】Introns widely exist in the DNA region of non-encoding proteins and it could effectually regulate the gene expression in the eukaryote. The objective of this paper is to study the number and structure of the introns of the chloroplastic stroma HSP70 (CSHSP70) gene in the cucumber. 【Method】Primers were designed according to the cDNA sequence from cucumber CSHSP70 gene and cucumber CSHSP70 gene was cloned from gDNA with polymerase chain reaction (PCR) technique. The existence of introns was proven by reverse transcription polymerase chain reaction (RT-PCR) technique. 【Result】After sequencing the three fragments cloned from cucumber CSHSP70 gene, a 4056bp cucumber CSHSP70 gene with seven introns was obtained. Analysis of those introns indicated that they are rich in A•T, have similar structure of promoter and core structure of the HSE. Comparative analysis of the CSHSP70 sequence in cucumber, melon and luffa indicated its nature of conservative among those cucurbit crops. 【Result】The results obtained in this study are useful in revealing the introns function of the cucumber CSHSP70 gene and understanding the molecular mechanism of heat injury and heat tolerance.

Key words: Cucumis sativus L, CSHSP70 gene, intron