五十多年来,科学家一直认为果实在成熟时变软,是由于聚半乳糖醛酶分解细胞壁的果胶所致。一些果实成熟时聚半乳糖醛酶的数量和活性均增加,实验室也证明聚半乳糖醛酶能破坏细胞壁的结构。然而某些果实,如草莓、苹果等的果实中不含聚半乳糖醛酶,将具活性的聚半乳糖醛酶注入未成熟的果实,不能促进其软化,说明软化还有其它原因。 For more than fifty years, scientists have long believed that fruit softens at maturity due to the breakdown of the cell wall by polygalacturonase. Some fruits mature polygalacturonase quantity and activity are increased, the laboratory also proved that polygalacturonase can destroy the cell wall structure. However, some fruits, such as strawberries, apples and other fruits without polygalacturonase, the activity of polygalacturonase into immature fruit, can not promote its softening, indicating there are other reasons softening.