中国农业科学 ›› 2022, Vol. 55 ›› Issue (9): 1831-1845.doi: 10.3864/j.issn.0578-1752.2022.09.012

• 园艺 • 上一篇    下一篇

高茶氨酸茶树新品系‘福黄1号’黄化变异机理

林馨颖1(),王鹏杰1,杨如兴2,*(),郑玉成1,陈潇敏1,张磊2,邵淑贤1,叶乃兴1,*()   

  1. 1福建农林大学园艺学院/茶学福建省高校重点实验室,福州 350002
    2福建省农业科学院茶叶研究所,福州 350013
  • 收稿日期:2021-09-02 修回日期:2021-11-01 出版日期:2022-05-01 发布日期:2022-05-19
  • 通讯作者: 杨如兴,叶乃兴
  • 作者简介:林馨颖,E-mail: 12565769@qq.com
  • 基金资助:
    福建省“2011协同创新中心”中国乌龙茶产业协同创新中心专项(闽教科〔2015〕75号);福建省属公益类科研院所基本科研专项(2021R1029001);茶学福建省高校重点实验室开放项目(KLTS2018001);福建张天福茶叶发展基金会科技创新基金(FJZTF01)

The Albino Mechanism of a New High Theanine Tea Cultivar Fuhuang 1

LIN XinYing1(),WANG PengJie1,YANG RuXing2,*(),ZHENG YuCheng1,CHEN XiaoMin1,ZHANG Lei2,SHAO ShuXian1,YE NaiXing1,*()   

  1. 1College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science at Universities in Fujian, Fuzhou 350002
    2Tea Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013
  • Received:2021-09-02 Revised:2021-11-01 Online:2022-05-01 Published:2022-05-19
  • Contact: RuXing YANG,NaiXing YE

摘要:

【目的】分析茶树黄化变异相关的代谢和转录机制,探究高茶氨酸茶树新品系‘福黄1号’的黄化变异和高茶氨酸形成机理。【方法】以茶树‘福安大白茶’及其黄化突变种质‘福黄1号’为试验材料,利用超微电镜、广泛靶向代谢组学、靶向代谢组学及转录组学联合分析,确定茶树黄化变异相关的色素、代谢物及转录组数据。【结果】超微结构显示,‘福黄1号’的叶绿体类囊体呈现丝状,基粒片层排列散乱不规则,片层间疏松,存在许多异常的囊泡。色素含量测定表明,叶绿素a和叶绿素b含量显著下降,叶绿素a/b比率下降,相关基因SGR表达显著下调,黄化叶片中光捕获叶绿素a/b蛋白(LHC)表达显著下调。类胡萝卜素总含量虽然差异不大,但各组分含量显著变化,玉米黄质为唯一显著增加的组分,其调控基因VDE表达显著上调,其余组分含量均下降。与‘福安大白茶’相比,‘福黄1号’中共鉴定到680个差异表达基因(DEGs)和57个显著变化的代谢物(SCMs)。KEGG富集分析表明,SCMs和DEGs显著富集到氨基酸生物合成、谷胱甘肽代谢以及TCA循环等途径。此外,与碳和氮代谢相关的通路也被激活。通过靶向测定,共鉴定到19种游离氨基酸,新品系‘福黄1号’游离氨基酸含量显著高于‘福安大白茶’,达到97.13 mg∙g-1,其中茶氨酸为66.90 mg∙g-1,占氨基酸含量的68.89%,而精氨酸含量达到8.46 mg∙g-1,是‘福安大白茶’的56.4倍。调控氨基酸合成的GOGATGLU的表达量上调1.17倍和3.17倍。【结论】‘福黄1号’的芽叶色泽主要受叶绿素、类胡萝卜素和类黄酮等色素代谢的影响,SGR和4种LHCs的共同作用也可能影响叶绿体的生物合成来调节叶片色泽。‘福黄1号’茶氨酸含量显著高于‘福安大白茶’的原因主要是泛素化相关的蛋白质水解酶表达上调蛋白降解能力加强,叶绿素和其他含氮分子生物合成的减少,以及黄化叶中碳骨架的缺乏,氨基和氮资源被更有效地储存,使得与氨基酸合成相关的氮代谢激活,茶氨酸合成前体物质之一的谷氨酸积累,这可能促使茶氨酸成为黄化叶中显著积累的含氮化合物。

关键词: 茶树, 福黄1号, 黄化, 代谢, 转录, 组学技术

Abstract:

【Objective】 The aim of this study was to analyze metabolic and transcriptional mechanism of etiolated variation in tea plant, and to explore the albino mutation of a new homotheanine tea cultivar Fuhuang 1 and its formation mechanism of homotheanine. 【Method】 The experimental materials were Fuan Dabaicha and Fuhuang 1. The combined analysis of ultramicroelectron microscopy, widely targeted metabolism, targeted metabolomics and transcriptomics was used to clarify the pigments, metabolism and transcriptome data related to the albino tea.【Result】The results of ultrastructure showed that the chloroplast thylakoids of Fuhuang 1 was filamentous, with irregular arrangement of basal granule lamellae and many abnormal vesicles. Chlorophyll a and chlorophyll b content, chlorophyll a/b ratio, SGR gene expression and light-harvesting chlorophyll a/b protein (LHC) expression were significantly reduced in yellow leaves. Although the total content of carotenoids did not change significantly, the content of each component changed significantly. Zeaxanthin was the only component with significant increase, and the expression of its regulatory gene VDE was significantly up-regulated, and the content of other components decreased. Compared with Fuan Dabaicha, 680 differentially expressed genes (DEGs) and 57 significantly changed metabolites (SCMs) were identified in Fuhuang 1. KEGG enrichment analysis showed that SCMs and DEGs were significantly enriched in pathways related to amino acid biosynthesis, glutathione metabolism and TCA cycle. In addition, the pathways related to carbon and nitrogen metabolism were also activated. A total of 19 free amino acids were identified by targeted determination. The free amino acid content of Fuhuang 1 was 97.13 mg∙g-1, which was significantly higher than that of Fuan Dabaicha. Theanine content was 66.90 mg∙g-1, accounting for 68.89% of amino acids, while the content of arginine was 8.46 mg∙g-1, which was 56.4 times as more as that of Fuan Dabaicha. The expression levels of GOGAT and GLU, which regulated amino acid synthesis, were up-regulated in Fuhuang 1 by 1.17 and 3.17 times higher than that in Fuan Dabaicha. 【Conclusion】 The leaf color of Fuhuang 1 was mainly influenced by chlorophyll, carotenoids and flavonoids. The combined action of SGR and the four LHCs might also affect chloroplast biogenesis to regulate leaf color. The content of theanine in Fuhuang 1 was significantly higher than that in Fuan Dabaicha. The main reason was that the up-regulation of ubiquitination-related protein hydrolase activity and the enhanced protein degradation ability. The biosynthesis of chlorophyll and other nitrogen-containing molecules was reduced, the carbon skeleton in yellow leaves was lacking, amino and nitrogen resources were stored more effectively. The activation of nitrogen metabolism associated with amino acid synthesis led to the accumulation of glutamate, one of the precursors of theanine synthesis. Theanine accumulated significantly in yellow leaves.

Key words: tea plant, Fuhuang 1(Camellia sinensis), albino, metabolomics, transcriptomics, omics technology