Isolation and characterization of isopentenyl transferase gene in Cucumis sativus(CsIPT2)

To analyze the role of isopentenyl transferase gene in Cucumis sativus(CsIPT2) during fruit development of cucumber and response after different hormones treatment,based on cloning and sequence analysis of CsIPT2 gene,parthenocarpic line EC1 and non-parthenocarpic line 8419s-1 were used for real-time RT-PCR analysis. The results showed that the length of CsIPT2 gene was843 bp,encoding 280 amino acids. The protein structure model was extremely similar to IPT protein of hop(Humulus lupulus L.).The expression of gene was higher during the fruit development of cucumber after pollination. At the same time the expression of CsIPT2 was higher at the early stage of natural parthenocarpic fruit and the late stage of artificially induced parthenocarpic fruit.Therefore,it was speculated that CsIPT2 might play an important role in promoting parthenocarpy of cucumber. Moreover,the five hormones(GA,ET,6-BA,ABA and NAA) were able to up-regulate the expression of the gene. The highest expression of ET,6-BA,ABA and NAA appeared 6 h after treatment,while only GA did 3 h after treatment. The higher the concentration the higher the expression during the NAA treatment.