关键词: 柿, 果实, 软化, EG基因, 实时荧光定量PCR

Abstract: A full length of endo-1,4-β-glucanase gene was isolated from mature persimmon（Diospyros kaki L.‘Fuping Jianshi’）fruit by RT-PCR and RACE（rapid amplification of cDNA ends）method，and its mRNA expression level of different treatments（GA3，ABA，1-MCP at room temperature）on persimmon fruits were further investigated by the Real-time fluorescence qPCR. The results showed that the obtained EG gene，named DKEG1（GenBank accession number：HQ222561），was 2 011 bp in length，and encoded 545 amino acid，with CBD residue in the deduced EG protein. Real-time fluorescence qPCR（RT-qPCR）showed that the expression of DKEG1 in control fruits increased to maximum at 3 d after harvest，then decreased rapidly and rised to a second expression peak at 12 d after harvest；While in GA3 treatment，it was suppressed obviously through the whole ripening and softening progress. Though its expression level increased at 6 d after harvest，generally it’s still lower than that of control. The DKEG1 was abundantly expressed in ABA treatment from 6 to 18 days after harvest with an expression peak at 9 d after harvest，but it didn’t show an expression peak at 3 d after harvest as the control. The expression peak of DKEG1 in 1-MCP treatment was delayed 9 days than the control，and its expression were significantly inhibited at earlier stage but increased at later stage. Therefore，the expression of DKEG1 in persimmon fruits is concluded to be regulated by ethylene and the ethylene signal transduction，and then participates in the ripening and softening progress.

Key words: persimmon, fruit, softening, endo-1, 4-β-glucanase gene, real-time quantitative PCR