套袋对梨果皮AsA积累和相关酶活性的影响

Effects of bagging on As A accumulation and related enzyme activities of pear peel

【目的】探讨套袋对梨果皮中As A代谢的影响。【方法】以‘满天红’和‘翠冠’梨为试材,研究了果实套袋后果皮中As A含量及其代谢相关酶活性的变化。【结果】在果实发育过程中,As A、T-As A和DHA的含量在2个梨品种中变化趋势一致,均是在幼果果皮中最高,在成熟果果皮中最低;套袋显著降低了果皮中的As A和T-As A含量。此外,对参与As A代谢的酶活性测定发现GLDH、Gal DH、DHAR和MDHAR的活性均在幼果果皮中最高,成熟果果皮中最低,这与As A含量的变化趋势一致;同时套袋降低了GLDH、DHAR和MDHAR的活性。果实发育过程中,‘满天红’的GLDH活性高于‘翠冠’的GLDH活性,而其他酶活性在这2个品种中差异不显著。【结论】品种间As A含量的差异可能主要受GLDH调控;套袋通过抑制GLDH、DHAR和MDHAR的活性,从而导致梨果皮中As A含量的降低。

【Objective】The aim of the study is to investigate the effect of bagging treatment on the metabo-lism of As A.【Methods】In this study,bagging treatment was employed to investigate the relationship be-tween As A content and related metabolizing enzymes,by using‘Mantianhong＇and‘Cuiguan＇pear peelas materials.【Results】Results showed that the content of As A,T-As A and DHA in these two varietiesreached a maximum value 20 days after full bloom,then decreased to the minimum when the fruit wasripe. The bagging treatment could reduce As A and T-As A content compared with the control. Further-more,GLDH,DHAR,MDHAR and GR enzyme activities involved in As A metabolism were also highestin the young fruit peel and were lowest in the mature fruit peel,and the trends of these enzyme activitieswere consistent with the trends of As A content. Moreover,the bagging treatment decreased GLDH,DHAR,and MDHAR activities. In addition,GLDH activity of Mantianhong was higher than that of Cui-guan,while the differences of other enzyme activities in these two varieties were not significant.【Conclu-sion】The difference of As A content between‘Mantianhong＇and‘Cuiguan＇might be regulated byGLDH;the bagging influenced DHAR,MDHAR and GLDH enzyme activities,thereby reduced the As Acontent of pear peel.