拮抗贪噬菌R1对采后苹果糖代谢的调控

Effects of antagonistic Variovorax sp.R1 on sugar metabolism in postharvest apple

采用拮抗贪噬菌Variovorax sp.R1发酵液作为保鲜剂,干预采后乔纳金苹果果实中正常的糖代谢,观察其保鲜效果。结果表明,在整个贮藏期间,Variovorax sp.R1发酵液处理维持了苹果果实中较高的蔗糖、果糖、葡萄糖、总糖含量,7 d时实验组蔗糖含量是对照组的1.89倍。同时,蔗糖代谢酶活性被抑制,1 d时酸性转化酶和中性转化酶均达到最低值,抑制率分别为38.5%和57.6%;蔗糖合成酶活性也被抑制,5 d时两组酶活性差距最大;与对照组相比,实验组蔗糖磷酸合成酶活性增强,3 d增至对照组的7.83倍。Variovorax sp.R1发酵液处理还能够增强苹果果实的抗性,延缓果实硬度的下降速率,降低果实失重率,减轻病情指数,对采后苹果果实具有保鲜效果。

The fermentation broth of the antagonistic Variovorax sp.R1 were used as a preservative to interfere with the normal sugar metabolism in the postharvest Jona Gold apple fruits,observing the fresh-keeping effects.The results showed that during the whole storage period,the contents of sucrose,fructose,glucose and total sugar in apple fruit were maintained by the treatment of Variovorax sp.R1 fermentation broth.The content of sucrose in the experimental group was 1.89 times higher than that in the control group in 7 d.The activities of sucrose metabolizing enzyme were inhibited.The acid invertase and neutral invertase decreased to the lowest in 1 d,and the inhibition rates were 38.5%and 57.6%,respectively.The activity of sucrose synthase was also inhibited,and the differences between the two groups reached to the maxium in 5 d.Compared with the control group,the activity of sucrose phosphate synthase in the experimental group increased to 7.83 times higher than that in the control group after 3 d.Variovorax sp.R1 fermentation liquid treatment can also enhance the resistance of apple fruit,delay the decline rate of fruit hardness,reduce the weight loss rate of fruit,reduce the disease index,and have a fresh-keeping effect on postharvest apple fruit.