摘要
从成熟中华猕猴桃果实中克隆到了一个 β 半乳糖苷酶基因cDNA片段 ,其长度为 747bp ,有一由 2 49个氨基酸组成的开放阅读框架 ,它与苹果、芦笋、绿花椰菜、番茄中 β 半乳糖苷酶基因cDNA相应区段的核苷酸同源性为 6 7.3 %～ 70 .3 %,氨基酸同源性为6 9.1%～ 72 .7%。用该片段为探针进行Northern分析表明 ,果实采收时 ,β 半乳糖苷酶mRNA水平最高 ,随后呈下降变化 ,同时 β 半乳糖苷酶基因的表达可为外源乙烯所诱导 ,但在果实乙烯跃变期间 β 半乳糖苷酶基因的表达信号无显著变化。文中对 β
We cloned an 747 bp long cDNA fragment encoding part of the β galactosidase protein by PCR from ripening Actinidia chinensis fruit (Figs.1,2). The fragment has an open reading frame containing 249 amino acids (Fig.3). Comparisons between the β galactosidase sequence from kiwifruit and others from apple, asparagus, broccoli and tomato indicated a nucleic acid homology between 67.3% and 70.3 %, and amino acid identity between 69.1% and 72.7 % (Table 1). Northern analysis showed that β galactosidase mRNA was abundant in the fruit at harvest time and then went down. The mRNA level was the lowest at the stage of 24 h ethylene treatment. A transient increase in the mRNA level was seen after 24h ethylene treatment and no significant change during ethylene climacteric in ripening fruit (Fig.4). The significance of these results is discussed.
基金
国家自然科学基金
浙江省自然科学基金资助项目
