‘果真好1号’与其亲本‘大五星’枇杷果实苹果酸代谢差异比较  

Comparison of Malic Acid Metabolism between ′Guozhenhao 1′ and Its Parent ′Dawuxing′ Loquat Fruits

作　　者：周甲云 张坤 王羊 宋潘晖 张慧芬 罗弦 郝宇轩 邓群仙 ZHOU Jiayun;ZHANG Kun;WANG Yang;SONG Panhui;ZHANG Huifen;LUO Xian;HAO Yuxuan;DENG Qunxian(College of Horticulture,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学园艺学院,成都611130

出　　处：《四川农业大学学报》2024年第3期546-553,共8页Journal of Sichuan Agricultural University

基　　金：四川省科技支撑计划“十四五”育种攻关项目(2021YFYZ0023-07);国家现代化农业产业技术体系四川水果创新团队项目(sccxtd-2024-04);四川省自然科学基金(2022NSFSC0092)。

摘　　要：【目的】研究‘果真好1号’及亲本‘大五星’枇杷果实主要有机酸——苹果酸代谢差异,明确其积累规律、相关酶活性及相关基因表达的差异,以期为枇杷生产过程中有机酸的调控与低酸新品种的培育提供理论依据。【方法】以‘大五星’和‘果真好1号’枇杷不同发育时期的果实为材料,测定可滴定酸含量、有机酸组分及其含量、苹果酸相关酶活性以及代谢相关基因表达量。【结果】2个枇杷品种的果实发育前期主要积累酒石酸和琥珀酸,发育后期主要积累苹果酸,苹果酸含量均随果实发育呈先上升后下降的趋势。与‘大五星’相比,‘果真好1号’成熟期时可滴定酸、有机酸、苹果酸含量分别显著增加了17.6%、25.2%和35.6%,苹果酸合成酶NAD-MDH活性显著提高和降解酶NADP-ME活性显著降低。基因的相对表达量结果表明,EjPEPC、EjMDH和EjNADP-ME的表达水平在成熟‘果真好1号’果实中较‘大五星’显著上调,而EjNADP-ME4显著下调。相关性分析表明,2个枇杷品种的苹果酸含量均与NAD-MDH活性和EjNAD-MDH的表达水平呈显著正相关,与EjPEPC2和EjNADP-ME4的表达水平呈显著负相关。【结论】成熟期‘果真好1号’中EjNAD-MDH的高表达提高了NAD-MDH活性,‘大五星’EjNADP-ME4的高表达提高了NADP-ME活性,导致‘果真好1号’苹果酸合成速率增快而降解速率减慢,最终导致其苹果酸含量高于‘大五星’。【Objective】The differences in organic acid metabolism between′Dawuxing′and its parent′Guozhenhao 1′loquat fruits were studied,to clarify the differences in their accumulation patterns,related enzyme activities and related gene expressions,in order to provide a theoretical basis for the regulation of organic acids in the loquat production process and the cultivation of new low-acid varieties.【Method】The differences in organic acid contents and expression levels of metabolism-related genes in′Dawux⁃ing′and′Guozhenhao 1′fruits at different developmental stages were analyzed to determine the differ⁃ences in organic acids.【Result】The fruits of the two loquat varieties mainly accumulated tartaric acid and succinic acid in the early stage of development,and malic acid in the late stage of development,and malic acid content increased first and then decreased with fruit development.Compared with the′Dawux⁃ing′,the contents of titrable acid,organic acid and malic acid in the maturation stage of′Guozhenhao 1′were significantly increased by 17.6%, 25.2% and 35.6%, respectively. Additionally, the activity of ma⁃ late synthetase NAD-MDH was significantly increased, while the activity of degradation enzyme NADP ME was significantly decreased in ‘Guozhenhao 1’. The relative expression levels of EjPEPC, EjMDH and EjNADP-ME were significantly up-regulated compared with ′Dawuxing′ in mature ′Guozhenhao 1′ fruit, while EjNADP-ME4 was significantly down-regulated. Correlation analysis showed that malic acid content was positively correlated with the activity of NAD-MDH and the expression levels of EjNAD-MDH, while significantly negatively correlated with the expression levels of EjPEPC2 and EjNADP-ME4 in both loquat varieties. 【Conclusion】 The high expression of EjNAD-MDH in ′Guozhenhao 1′ at the ma⁃ turity stage led to an increase in NAD-MDH activity , while the high expression of EjNADP-ME4 in ′Dawuxing′ led to an increase in NADP-ME activity. This ultimately led

关 键 词：枇杷果实 有机酸 苹果酸代谢 基因表达 

分 类 号：S667.3[农业科学—果树学]