Inhibition of ethylene biosynthesis in pear fruit by carbon dioxide: the mode of action.
de Wild H.P.J.
5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004. page 10.
2004
บทคัดย่อ
Inhibition of ethylene biosynthesis in pear fruit by carbon dioxide: the mode of action.
High CO2 can inhibit ethylene production of pear (Pyrus communis L.).The mode of CO2 action is still unknown.In several experiments it was shown that CO2 inhibits ethylene production other than through inhibition of ethylene perception.In these experiments, 1-MCP was used to block the ethylene receptor binding site. (1) in climacteric pears, the reduction of ethylene production by CO2 was similar for 1-MCP treated and untreated pears; (2) in the case of pears that had been stored for a period of 25 weeks, CO2 only had a clear effect after 1-MCP treatment, and (3) ethylene production of pre-climacteric pears was stimulated by 1-MCP, but unaffected or ingibited by CO2.The effect of CO2 on ethylene production of pear depended on the applied CO2 level and the duration of exposure.Elevated CO2 initially stimulated ethylene production, which may reflect a fast derect effect on ACC oxidase.Later, CO2 inhibited ethylene production which points to a relatively slow in direct effect or CO2 regarding inhibiting properties, for instance, an effect on gene regulation.Differences in ethylene production in response to various CO2 partial pressures were not accompained by differences in respiration.
In conclusion, the ethylene receptor binding site is not the primary site at which CO2 inhibits ethylene production.Inhibition of ethylene production by CO2 cannot be explained via an effect of CO2 on respiration.The most likely action site of CO2 is the conversion of SAM to ACC catalysed by ACC synthase.