浙江农业学报 ›› 2024, Vol. 36 ›› Issue (11): 2510-2520.DOI: 10.3969/j.issn.1004-1524.20231338

• 园艺科学 • 上一篇    下一篇

桃溪蜜柚果实贮藏期有机酸含量变化及相关基因表达分析

赵凌吉1(), 廖香娇1, 刘德春1, 胡威1, 匡柳青1, 宋杰1, 易明亮2, 刘勇1,*(), 杨莉1,*()   

  1. 1.江西农业大学 农学院,江西 南昌 330045
    2.吉安市井冈蜜柚发展服务中心,江西 吉安 343099
  • 收稿日期:2023-11-27 出版日期:2024-11-25 发布日期:2024-11-27
  • 作者简介:赵凌吉(1998—),男,山西晋中人,硕士研究生,主要从事果树生理品质研究。E-mail:1219980160@qq.com
  • 通讯作者: *刘勇, E-mail:liuyongjxau@163.com;杨莉, E-mail: yangli526526@126.com
  • 基金资助:
    江西省重点研发计划揭榜挂帅项目(20223BBF61009);江西省柑橘产业技术体系项目(JXARS-07-栽培岗位)

Changes of organic acid content in Taoxi pomelo fruits during the storage period and citric acid related gene expression analysis

ZHAO Lingji1(), LIAO Xiangjiao1, LIU Dechun1, HU Wei1, KUANG Liuqing1, SONG Jie1, YI Mingliang2, LIU Yong1,*(), YANG Li1,*()   

  1. 1. College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China
    2. Ji’an Jinggang Pomelo Development Service Center, Ji’an 343099, Jiangxi, China
  • Received:2023-11-27 Online:2024-11-25 Published:2024-11-27

摘要:

为明确江西省地方特色品种-桃溪蜜柚果实常温贮藏期间有机酸的变化规律,初步探讨引起桃溪蜜柚贮藏期有机酸变化的原因,研究以桃溪蜜柚贮藏期果实为材料,应用高效液相色谱技术(HPLC)测定采后贮藏0~150 d果实中有机酸组分及含量,并通过实时荧光定量PCR(qRT-PCR)分析柠檬酸合成、降解和转运相关基因表达量的变化。结果表明:桃溪蜜柚果实在贮藏期间大部分时期的总有机酸含量高于贮藏0 d,而糖酸比在整个贮藏期间低于贮藏0 d,存在果实“返酸”现象,这可能是桃溪蜜柚采后贮藏品质下降的主要原因。桃溪蜜柚柠檬酸含量占总有机酸含量的 78.51%~80.32%,且二者变化趋势一致。柠檬酸含量在贮藏初期存在较大的变化波动,在贮藏后40 d达到最大值。柠檬酸合成基因PEPC1/2及CS1、液泡 H+-ATPase质子泵基因CmVHA-c4和液泡 H+-焦磷酸酶质子泵基因CmVHP2与柠檬酸积累大致呈现相似的变化趋势,而柠檬酸降解基因CmGAD5和阳离子/H+交换基因CmCHX与柠檬酸积累呈现相反的变化趋势,这可能与桃溪蜜柚贮藏初期柠檬酸积累有关。因此,桃溪蜜柚贮藏期间有机酸含量增加、糖酸比下降造成了果实“返酸”现象,而柠檬酸在其中起到了重要作用,其在贮藏期间的积累主要与柠檬酸合成相关基因CmPEPC1/2和CmCS1、降解相关基因CmGAD5以及转运相关基因CmCHXCmVHA-c4和CmVHP2有关。

关键词: 桃溪蜜柚, 果实贮藏, 柠檬酸, 基因表达

Abstract:

This study mainly clarified the variation rule of organic acids in the fruit of Taoxi pomelo which is a local characteristic variety in Jiangxi Province during the room temperature storage period, the causes of organic acid changes in Taoxi pomelo during storage were discussed. The study took the fruits of Taoxi pomelo during the storage period as materials, and applied high performance liquid chromatography (HPLC) to determine the components and contents of organic acids in the fruits stored from 0 d to 150 d after picking, and analyzed the changes in the expression of citric acid synthesis, degradation and transport-related genes by real-time fluorescence quantitative PCR (qRT-PCR). The results showed that it was found that the total organic acid content of Taoxi pomelo fruits was higher than that of storage 0 d during most of the storage period, while the sugar-acid ratio was lower than that of storage 0 d during the whole storage period, and there existed the phenomenon of fruit “returning to acidity”, which may be the main reason for the decline in the quality of Taoxi pomelo fruits in post-harvest storage. The citric acid content of Taoxi pomelo accounted for 78.51%-80.32% of the total organic acid content, and the trends of both changes were consistent. The citric acid content fluctuated greatly at the beginning of storage, reached the maximum value at 40 d after storage. The qRT-PCR analysis of genes related to citric acid synthesis (CmCS, CmPEPC), degradation (CmACL, CmAco3, CmNAD-IDH, CmGS, CmGAD, and CmGABA), and transport (CmCHX, CmDIC, CmVHA, and CmVHP) revealed that the citric acid synthesis genes PEPC1/2 and CS1, the vesicular H+-ATPase proton pump gene CmVHA-c4 and the vesicular H+-pyrophosphatase proton pump gene CmVHP2 showed broadly similar trends with citric acid accumulation, whereas the citric acid degrading gene GAD5 and the cation/H+ exchanging gene CmCHX showed opposite trends with citric acid accumulation, which might be related to the accumulation of citric acid during the early stage of Taoxi pomelo storage. Therefore, the increase in organic acid content and the decrease in sugar-acid ratio during storage of Taoxi pomelo caused the phenomenon of fruit “returning to acidity”, and citric acid plays an important role in this, and its accumulation in the early stage of storage is mainly related to the citric acid synthesis-related genes CmPEPC1/2 and CmCS1, the degradation-related gene CmGAD5, as well as the transporter-related genes CmCHX, CmVHA-c4, and CmVHP2.

Key words: Taoxi pomelo, fruit storage, citric acid, gene expression

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