扁桃酸性转化酶在生理落果期的特征分析及与落果的关系

Characteristics of Acid Invertase(AcAI) and Its Relationship with Fruit Drop during the Physiological Fruit Drop of Almond

酸性转化酶是果实蔗糖代谢关键酶之一,扁桃幼果脱落期酸性转化酶基因(AcAI)的表达模式及其与糖组分含量和酶活性之间的关系,对于揭示扁桃幼果生理脱落机理具有重要的意义。本研究以新疆主栽品种‘纸皮’扁桃生理落果期的正常果和即将脱落果实为试材,采用qRT-PCR方法分析正常果和即将脱落果中AcAI基因的时空表达模式,同时分别测定幼果生理脱落期正常果和即将脱落果糖组分含量和酸性转化酶活性,并分析三者之间的关系。结果表明,扁桃果实(正常果和即将落果)AcAI基因在不同发育期均有表达且在落果高峰期表达量均达最低值,而后逐渐升高;果实中糖组分为明显上升趋势,AI活性则呈持续下降趋势,即将落果中蔗糖积累量和酶活性始终高于正常果,且在落果高峰期蔗糖积累量降低、AI酶活性明显升高。说明AI在果实发育、糖分积累的过程中发挥作用,且参与调控幼果生理脱落。

Acid invertase(AcAI)is one of the key enzymes of sucrose metabolism in fruit.The expression pattern of AcAI gene during the physiological fruit drop of almond and its relations with sugar content and enzyme activities have great significance to reveal the physiological mechanism of fruit drop of almond.In this research,the normal fruit and fruit about to drop in the physiological fruit drop of'Zhi pi'almond,which is the main planting almond varieties in Xinjiang,was selected as target material,and the temporal spatial expression patterns of AcAI gene was analyzed by qRT-PCR method.At the same time,the sugar content and AcAI activities in normal fruit and fruit about to drop were also measured and the relations between those were discussed.Results showed that AcAI gene was expressed at different developmental stages of almond fruit(normal fruit and fruit about to drop)and the expressions reached the lowest level at the drop peak stage,after then increased gradually.The sugar components in fruits showed a significant upward trend,while AI activity showed a continuous downward trend,and the sucrose accumulation and the enzyme activities in fruit about to drop were always higher than that in normal fruit.At the peak of fruit drop,the sucrose accumulation has decreased,and the AI enzyme activities have increased significantly.Results indicated that AI enzyme would play an important role in fruit development and sugar accumulation process,and participate in regulating the physiological fruit drop of almond.