บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Expression of ACC synthase and ACC oxidase genes in melons harvested at different stages of maturity

Shiomi, S., Yamamoto, M., Nakamura, R. and Inaba, A.

Journal of the Japanese Society for Horticultural Science Year: 1999 Vol: 68 Issue: 1 Pages: 10-17.

1999

บทคัดย่อ

Expression of ACC synthase and ACC oxidase genes in melons harvested at different stages of maturity.

 

Biochemical and molecular aspects of ethylene production were studied in fruits of the melon cultivars Andes and Earl's Favourite which produce relatively high and low amounts of ethylene, respectively. Ethylene biosynthetic activity in the peel, mesocarp and placenta of Earl's Favourite fruits harvested at different stages of maturity remained low even at commercial harvest maturity (CHM), and ethylene production in the intact fruits was also low. In Andes, 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) activity and ACC content in the mesocarp and placenta and ethylene production in intact fruits increased markedly at CHM. Northern blot analysis using mRNA extracted from the respective tissues of fruits at different stages of maturity indicated that CMe-ACS1 mRNA accumulated in the mesocarp and placenta of Andes fruits at CHM, whereas in Earl's Favourite there was no accumulation in any of the tissues at any maturity. In ACC oxidase (ACO) genes, mRNA for ACO1 accumulated in the meso

carp and placenta of both cultivars at CHM, and that for ACO2 was almost constitutively expressed. Exogenous application of ethylene to fruits at the preclimacteric stage, slightly induced CMe-ACS1 mRNA accumulation in Andes but not in Earl's Favourite fruits, whereas wounding induced CMe-ACS1 transcripts accumulation in both cultivars. The accumulation of ACO1 mRNA in the 2 cultivars was greatly stimulated by ethylene and wounding treatments. When Andes fruits at the climacteric stage were treated with 1-methylcyclopropene (MCP), an inhibitor of ethylene action, transcripts for CMe-ACS1, ACO1 and ACO2 were barely detectable. These results suggest that the difference in the ethylene-forming capability between the 2 cultivars may result from the expression of CMe -ACS1 mRNA during natural fruit ripening and in response to exogenous ethylene.