Transcriptome Analysis on the Underlying Physiological Mechanism of Calcium and Magnesium Resolving “Sugar Receding” in ‘Feizixiao’ Litchi Pulp
Transcriptome Analysis on the Underlying Physiological Mechanism of Calcium and Magnesium Resolving “Sugar Receding” in ‘Feizixiao’ Litchi Pulp
复制标题
DOI：
10.3390/horticulturae8121197
复制
发表时间：
2022-12
期刊：
影响因子：
3.1
通讯作者：
Junjie Peng;Jingjia Du;Wuqiang Ma;Tiantian Chen;Xian Shui;Haizhi Liao;Xiaokai Lin;Kaibing Zhou
中科院分区：
文献类型：
--
作者：
Junjie Peng;Jingjia Du;Wuqiang Ma;Tiantian Chen;Xian Shui;Haizhi Liao;Xiaokai Lin;Kaibing Zhou
对‘妃子笑’荔枝(Litchi chinensis Sonn.)成熟后下降；钙(Ca)和镁(Mg)叶面肥可以解决这种“糖消退”。为探讨钙镁叶面肥缓解‘妃子笑’荔枝果肉“糖退”现象的生理机制，用0.3%CaCl2+0.3%MgCl2叶面喷施或浇水处理16年生荔枝果肉。我们在2020年和2021年分两年测定了果肉含糖量。2020年提取果肉总RNA进行转录组测序，利用实时荧光定量聚合酶链式反应验证了10个差异表达基因(DEG)在2020年和2021年的表达模式。结果表明，化肥处理显著提高了两年成熟期果肉果糖和总可溶性糖含量。根据基因本体论(GO)功能富集法将155个DEG分为35个GO类，其中49个DEG根据京都基因与基因组百科全书(KEGG)途径富集法分为49条途径。我们分离了与糖代谢相关的酶基因，包括蔗糖合成酶(SS)、酸性转化酶(AI)、中性转化酶(NI)、蔗糖磷酸合成酶(SPS)和己糖激酶(HK)。所有蔗糖代谢相关酶(NI、AI、SS、SPS)基因均下调，7个HK基因中有6个基因下调。用实时荧光定量聚合酶链式反应验证了10个DEGS的表达模式，结果显示它们之间存在显著的线性关系(r2020=0.9127，r2021=0.8705)。综上所述，施肥处理通过下调SS、SPS和HK基因的表达，抑制了蔗糖的合成和己糖的磷酸化，从而提高了‘妃子笑’荔枝的果糖和总可溶性糖含量。
The sugar contents of ‘Feizixiao’ litchi (Litchi chinensis Sonn.) decrease at full maturity; calcium (Ca) and magnesium (Mg) foliar fertilizer can resolve this “sugar receding”. To investigate the physiological mechanism of Ca and Mg foliar fertilizer used to resolve the “sugar receding” phenomenon in ‘Feizixiao’ litchi pulp, 16-year-old litchi trees were treated with 0.3% CaCl2 + 0.3% MgCl2 foliar spraying or water as a control. We determined the pulp sugar content over a two-year period in 2020 and 2021. Pulp total RNA was extracted for transcriptome sequencing in 2020, and the expression pattern of 10 differentially expressed genes (DEGs) was verified by real-time PCR in 2020 and 2021. The results showed that the fertilizer treatment significantly increased pulp fructose and total soluble sugar contents at maturity in both years. According to Gene Ontology (GO) functional enrichment analysis, there were 155 DEGs divided into 35 GO categories, among which 49 DEGs were divided into 49 pathways according to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We isolated sugar-metabolism-related enzyme genes, including sucrose synthase (SS), acid invertase (AI), neutral invertase (NI), sucrose phosphate synthase (SPS), and hexokinase (HK). All sucrose-metabolism-related enzyme (NI, AI, SS, SPS) genes were downregulated, and six of the seven HK genes were downregulated. The expression patterns of the 10 DEGs were verified by real-time PCR, which showed significant linear relationships (r2020 = 0.9127, r2021 = 0.8705). In conclusion, the fertilizer treatment inhibited the synthesis of sucrose and phosphorylation of hexose by downregulating the expression of the SS, SPS, and HK genes, thus increasing the fructose and total soluble sugar contents in ‘Feizixiao’ litchi.