遮光性套袋对黄肉桃类胡萝卜素合成及相关基因表达的影响  

Effects of Shading Fruit with Opaque Paper Bag on Carotenogenesis and Related Gene Expression in Yellow-flesh Peach

作　　者：董新甜 曹洪波[1] 张飞燕[1] 韩艳[1] 贾浩[1] 李丹[1] 张学英[1] 陈海江[1] 

机构地区：[1]河北农业大学园艺学院,河北保定071000

出　　处：《园艺学报》2015年第4期633-642,共10页Acta Horticulturae Sinica

基　　金：国家现代农业产业技术体系建设专项资金项目(CARS-31-3-02);河北省教育厅青年基金项目(QN2014006)

摘　　要：以‘金童6号’和‘金童8号’黄肉桃为试材,于花后60 d时套袋对果实进行遮光处理,研究遮光对果实叶绿素和类胡萝卜素积累的影响,以及类胡萝卜素合成关键基因的表达差异。结果表明:伴随果实成熟,叶绿素含量逐渐降低,且3个采样时期套袋果实中的叶绿素含量均显著低于不套袋的对照;类胡萝卜素含量逐渐升高,但未成熟期套袋果实低于对照,成熟期则显著高于对照。利用高效液相色谱(HPLC)对果肉类胡萝卜素组分的分析表明:在黄肉桃果实未成熟期,类胡萝卜素以叶黄素和β–胡萝卜素积累为主,表现出叶绿体合成途径特征;进入成熟期,有色体类胡萝卜素合成途径占据优势,形成更为稳定的酯化类隐黄质和紫黄质,并且套袋果实中酯化类胡萝卜素的积累水平明显高于对照果实。此外,分子证据表明伴随果实成熟,类胡萝卜素合成关键基因HDR(羟甲基丁烯基–4–二磷酸还原酶)、PSY1(八氢番茄红素合成酶1)、PSY2(八氢番茄红素合成酶2)、PDS(八氢番茄红素脱氢酶)和HYB(β–胡萝卜素羟化酶基因)在套袋和不套袋果实中均呈现上调表达趋势。值得注意的是,DXS(1–脱氧–D–木酮糖–5–磷酸合成酶基因)、PSY2和PDS基因在成熟期套袋果实中的表达水平低于对照,而HYB基因的表达水平显著高于对照。Effects of shading fruit with opaque paper bag on the accumulations of chlorophylls and carotenoids,as well as on the carotenogenesis related gene expression,were studied in two yellow-flesh peach(Prunus persica L. Batsch)cultivars:‘Babygold 6'and‘Babygold 8'. The results showed that contents of chlorophyll were declined gradually both in peel and flesh,and they were significantly lower in the bagged fruits compared with the non-bagged fruits in each sampling period;The contents of carotenoid were increased during the fruit development and ripening. Compared with the non-bagged flesh tissues,the bagged flesh tissues accumulated less carotenoids at the immature stage,but they accumulated a significantly higher level of carotenoid at the mature stage. HPLC analysis indicated that carotenoids in the immature flesh tissues were mainly composed of lutein and β-carotene, which represented a chloroplast-specific carotenoid biosynthesis pathway; Chromoplast-specific carotenoid biosynthesis pathway was preponderant in the mature flesh tissue,characterized by abundant accumulation of stable estered cryptoxanthin and violaxanthin. In addition,it was noted that there were more carotenoid eaters in the bagged fruits than in the non-bagged fruits. Furthermore,transcriptional analysis revealed that,consistently in the bagged fruit and non-bagged control, genes encoding enzymes for HDR(hydroxymethylbutenyl 4-diphosphate reductase),PSY1(phytoene synthase 1),PSY2(phytoene synthase 2),phytoene desaturase(PDS),and HYD(β-carotene hydroxylase)showed higher expressive levels in the mature flesh than in the immature flesh. It was noted that,compared to the non-bagged control,DXS(1-deoxy-D-xylulose 5-phosphate synthase),PSY2 and PDS genes showed the significantly down-regulated expression in the bagged mature fruit,HYD gene was expressed at a significantly higher level in the bagged mature fruit.

关 键 词：桃 遮光 套袋 类胡萝卜素 叶绿素 

分 类 号：S662.1[农业科学—果树学]