REGULATION OF ETHYLENE BIOSYNTHESIS BY O_2 AND CO_2 IN THE DISCS OF LAIYANG PEAR FRUIT
Liu Yu;Y. Liu;Li Zhen-guo;Wu You-mei;Xu Rong-jiang;Gu Wen-mao;Gao Jin-cheng Shanghai Institute of Plant Physiology, Academia Sinica Shanghai Fruit Company
In the climacteric Laiyang pear (Pyrus bretschneider Rehd) fruit, the ethyleneproduction of discs in 12 h-incubation period was decreased by decreasing concentra-tion of O_2 in the incubation atmosphere from 21% (air) and ACC content in discsincreased correspondingly. When the discs were returned to air after 12 h-treat-ment, ethylene production rose again, even higher than before the treatment andcorresponded to the ACC content in discs, except the treatment of 0% O_2. Dualeffict of CO_2 on ethylene biosynthesis was observed in this system. CO_2 promotedethylene production at the beginning of treatment, especially in the case of low O_2concentration, but later inhibited it, the inhibition was enhanced with the advanceof time. The inhibition of ethylene production increased with increasing CO_2concentration. However, no correspondence was found between the changes ofACC content and the decrease ih ethylene production and ethylene production couldnot recover after CO_2 treatment.