香梨果实发育、成熟期间乙烯、ACC、MACC变化及相互关系

The Changs in Contents of Ethylene,ACC and MACC of Fragrant Pear Fruits during Developing,Ripening and Senescing

香梨是典型的呼吸跃变型果实 ,采后乙烯释放持续上升。果实采前含有相当数量的内源ACC ,但未有乙烯形成。内源MACC含量采前高于采后 ,表明发生了ACC→MACC转化 ,MACC可抑制其果实发育中乙烯的形成。采后果实成熟衰老过程中 ,MACC含量急剧下降至低水平 ,ACC含量明显上升 ,表明发生了MACC→ACC转化 ,从而催化乙烯大量释放。

Fragrant pear(Pyrus sinkiangensis Yü)fruit belong to typical climacteric fruit.Postharvest ethylene content in the fruit succe- ssively increases;The ACC content in the preharvested fruit was quite high,but no ethylene was detected.Indigenous MACC content was also higher in preharvested fruits,which indicated that there was a conversion of ACC to MACC,while MACC might inhibit the formation of ethylene in the period of fruit development.The content of MACC dropped dramatically whereas ACC content went up evidently during the ripening and senescing periods after harvest,showing that there was a conversion of ACC to MACC,which catalyzed ethylene synthesis and accelerated the process of fruit’s mature and senescence.