Abstract: To reveal the role of chloroplast in the PCD of cucumber induced by salicylic acid (SA),10 mmol/L salicylic acid was added to the leaves of cucumber seedlings at the four-leaf period,and the samples were collected at the location where SA was added. ROS in situ detection,Trypan blue staining,PI and FDA staining,and TUNEL detection were performed. These results showed that SA could induce PCD process in cucumber. According to the results of high-throughput sequencing,15 genes annotated with chloroplast were screened out among 1 759 differentially expressed genes. These genes were expressed in cucumber leaves treated with SA was confirmed by RT-PCR. It was preliminarily identified that these genes were involved in the PCD process induced by SA in cucumber. According to the expression of qRT-PCR,the 15 genes played a role of positive regulation or negative regulation in PCD induced SA in cucumber,upon regulating characteristics five kinds of genes were raised:Probable thylakoidal processing peptidase 1 gene, 6-phosphogluconate dehydrogenase gene, Probable fructose-bisphosphate aldolase 3 gene, Alpha-glucan water dikinase 1 gene and Allene oxide cyclase 4 gene, down-regulated expression of 10 genes were:Betaine aldehyde dehydrogenase 1 gene, Calcium sensing receptor gene, Pheophorbide a oxygenase gene, Probable chlorophyll(ide) b reductase1 gene, Sigma factor binding protein 1 gene, NADPH-protochlorophyllide oxidoreductase gene, 2-succinylbenzoate-CoA ligase gene, ATP-dependent zinc metallopro-tease FtsH1 gene, Nicotinamide adenine dinucleotide transporter 1 gene and CBS domain-containing protein1 gene. It lays a foundation for further revealing the role of chloroplast in cucumber PCD induced by SA.

Key words: Cucumber, Salicylic acid, Programmed cell death, Gene expression

CLC Number: 

• Q78

• S642.03