摘要
β-D-木聚糖苷酶是细胞壁半纤维素中阿拉伯木聚糖和木聚糖残基降解的主要酶,对香蕉贮藏过程中果皮、果肉中β-D-木聚糖苷酶活性以及果实硬度、呼吸强度和乙烯释放量的变化进行测定分析。结果显示:β-D-木聚糖苷酶活性在果实贮藏初期的变化很小,到果实硬度开始急剧下降时迅速增加,其增加量在果皮和果肉中分别为12和22倍以上,且果肉中的酶活性大于果皮中;乙烯吸收剂处理延缓了香蕉果实呼吸和乙烯的高峰出现以及果实硬度、果肉和果皮中β-D-木聚糖苷酶活性变化的速度和幅度,但并不改变其活性的变化趋势。结果证明,β-D-木聚糖苷酶能诱导香蕉果实成熟,在果实软化中起着十分重要的作用,且其活性受乙烯的调节。
The cell wall modifications of ripening fruit are mediated by cell wall-degrading enzymes, including β-D-xylosidase,which participates in the breakdown of xylans and arabinoxylans in hemicellulose of cell wall. To elucidate the softening mechanism of banana fruit,β-D-xylosidase activities in peel and flesh,fruit firmness, respiration rate and ethylene release rate were assayed during banana softening. The results showed that β-D-xylosidase activities in banana flesh and peel increased slightly at the beginning and increased rapidly when the fruit firmness decreased drastically during storage. β-D-xylosidase activities increased to approximately 12 and 22 fold in peel and flesh respectively,and the activities in flesh were higher than that in peel. Treatment of banana fruit with ethylene absorbent postponed the decrease of fruit firmness and the increase of β-D-xylosidase activity,but it did not alter the changing pattern of β-D-xylosidase activity in treatment. The results suggested that β-D-xylosidase was induced specifically for fruit ripening and played an important role in banana fruit softening, and its activity was regulated by ethylene.
出处
《西北植物学报》
CAS
CSCD
北大核心
2007年第7期1394-1398,共5页
Acta Botanica Boreali-Occidentalia Sinica
基金
农业部科技项目(2006-G32)
广东省自然科学基金团队项目(06200670)
作者简介
苏菁（1973-）,女（汉族）,博士,主要从事生物化学与分子生物学研究.E-mail：bsujing@126.com
陈维信,教授,博士生导师,主要从事果蔬贮藏保鲜研究. 通讯作者
