1-甲基环丙烯处理对桃果实花青素代谢的影响

Effect of 1-Methylcyclopropene Treatment on Anthocyanin Metabolism of Peach Fruit During Storage

以‘白凤’水蜜桃为试材,研究1-甲基环丙烯(1-Methylcyclopropene, 1-MCP)处理对其在贮藏期间花青素代谢及转色的影响。以浓度为10 mg/kg的1-MCP熏蒸桃果实12 h,不做任何处理的桃果实作为对照,然后在室温下贮藏9 d,分别于第0、3、5、7、9天取样,测定桃果实的硬度、总酚、总黄酮、总花青素含量和苯丙氨酸解氨酶(Phenylalanine ammonia lyase, PAL)活性的变化。此外,测定花青素合成途径基因表达的变化,包括编码PAL酶、查尔酮合酶(Chalcone synthase,CHS)、查尔酮异构酶(Chalcone isomerase, CHI)、黄烷酮-3-羟化酶(Flavanone-3-hydroxylase, F3H)、花青素合成酶(Anthocyanin synthetase, ANS)和UDP-葡萄糖:类黄酮3-O-葡糖基转移酶(UDP-glucose:flavonoid 3-O-glucosyltransferase, UFGT)的基因。实验结果表明,1-MCP处理能够通过刺激Ppa PAL基因表达激活PAL酶活性,进而促进总酚、总黄酮和花青素的合成,提高桃果实的抗氧化能力,延缓桃果实的贮藏期,提升贮藏品质。1-MCP处理通过刺激花青素合成途径关键基因Ppa CHS、Ppa F3H和Ppa UFGT的表达来促进花青素物质的累积,进而影响果实后期的转色。

In this study,the effect of 1-Methylcyclopropene(1-MCP)on color change and anthocyanin metabolism of peach fruit was examined.‘Baifeng'peach was taken as experimental material,treated with 10 mg/kg 1-MCP for 12 h,then stored at room temperature(25±1)℃for 9 d.Samples were taken every two days of storage time.Fruit without any treatment was taken as control.The changes of hardness,total phenols,total flavonoids,total anthocyanins content and phenylalanine ammonia lyase(PAL)activity were determined.In addition,changes of gene expressions in anthocyanin synthesis pathway,including PAL,chalcone synthase(CHS),chalcone isomerase(CHI),flavanone-3-hydroxylase(F3H),anthocyanin synthetase(ANS),and UDP-glucose:flavonoid 3-O-glucosyltransferase(UFGT)were measured.Result shows that 1-MCP treatment can activate the activities of PAL by stimulating PpaPAL expression,further elevate the contents of total phenols,flavonoids and anthocyanins content.1-MCP treatment can enhance anthocyanin accumulation by stimulating the gene expression of PpaCHS,PpaF3H,PpaUFGT in the anthocyanin synthesis pathway,thus promote the color transformation of peach fruit duringstorage.