番木瓜果实中芥子酶基因组织差异表达和酶活性研究

Expression and Enzymatic Analysis of Myrosinases in Carica papaya Fruit

检测了番木瓜果实3个发育时期(Ⅰ、Ⅱ、Ⅲ)的果皮(外果皮)、果肉(内果皮)及种子中芥子酶的活性,并通过RT-PCR分析CpTGG1、CpTGG2和CpTGG3三个番木瓜芥子酶基因在番木瓜果实各组织的差异性表达情况。结果表明,番木瓜果皮及种子中均有明显的芥子酶活性,但在果肉中无法检测出芥子酶活性;成熟后(Ⅲ期)番木瓜果皮的芥子酶活性相比未成熟前提高了6.6倍,而不同发育时期种子中的芥子酶并不表现出显著差异性。RT-PCR分析结果表明,番木瓜芥子酶基因在番木瓜果实中的表达存在显著时空差异性。其中,CpTGG1在番木瓜果皮及种子中均有表达,且表达量无明显差异,在果肉中完全无表达;CpTGG2在番木瓜果实的各个组织中均无表达;CpTGG3在果皮及种子中也均有表达,成熟果皮(Ⅲ期)和Ⅰ期种子中表达量比较强,并随着果实的发育成熟而呈现梯度变化。

Using the method of myrosinase activity detecting and reverse transcription-polymerase chain reaction（RT-PCR） analysis,we took the peel,pulp and seeds into study,which from three different development stage papaya fruit.The result showed that there was significantly myrosinase activity found in peel and seeds,no myrosinase activity in pulp,and the myrosinase activity in the peel of ripening fruit increase in amounts of 6.6 times than the green one.RT-PCR analysis revealed that CpTGG1 was expressed in peel and seeds differ little from different development stage;CpTGG2 was turned off in all the tissues in papaya fruit of any stage;while CpTGG3 was expressed in peel and seeds with a gradual change,suggesting that myrosinase genes in papaya are spatially regulated.