柑橘基因组中核因子-Y（NF-Y）家族的全基因组特征鉴定出参与果糖和葡萄糖积累的 CgNF-YB9。

Genome-wide characterization of the NUCLEAR FACTOR-Y (NF-Y) family in Citrus grandis identified CgNF-YB9 involved in the fructose and glucose accumulation.

机构信息

Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical, Hainan University, Haikou, 570228, Hainan, China.

出版信息

Genes Genomics. 2019 Nov;41(11):1341-1355. doi: 10.1007/s13258-019-00862-2. Epub 2019 Aug 29.

DOI:10.1007/s13258-019-00862-2

PMID:31468348

Abstract

BACKGROUND

Nuclear factor Y (NF-Y) is increasingly known to be involved in many aspects of plant growth and development. To date, the systematic characterization of NF-Y family has never been reported in Citrus grandis.

OBJECTIVE

Genome-wide characterization of C. grandis NF-Y (CgNF-Y) family and analysis of their role in sucrose metabolism.

METHODS

NF-Y conserved models were employed to identify CgNF-Y genes from genomic data. Phylogenetic tree was generated by the neighbor-joining method using program MEGA 7.0. Based on our previous transcriptomic data, the transcription levels were calculated by RSEM software and were clustered by ShortTime-series Expression Miner. The plant expression vector of CgNF-YB9 was constructed using In-Fusion Cloning and transferred into tobacco by leaf disc transformation method. Soluble sugars and gene expressions were analysis by HPLC and qRT-PCR, respectively.

RESULTS

A total of 24 CgNF-Y genes (6 CgNF-YAs, 13 CgNF-YBs and 5 CgNF-YCs) were identified with conserved domains. Phylogenetic analysis of the NF-Y proteins indicated that NF-YA, NF-YB and NF-YC could be categorized into four, five and three clades, respectively. Expression profiling analysis reflected spatio-temporally distinct expression patterns for CgNF-Y genes. Importantly, we observed a positive correlation between the expression level of CgNF-YB9 and the content of soluble sugar. Moreover, CgNF-YB9-corelated genes were enriched in carbohydrate metabolism. In CgNF-YB9 overexpression lines, sucrose content showed a decrease, whereas glucose and fructose contents displayed an increase. As expected, the transcription levels of sucrose-phosphate synthase and vacuolar invertase in transgenic Line 3 were observed with significantly down- and up-regulated, respectively.

CONCLUSIONS

The structure, phylogenetic relationship and expression pattern of 24 CgNF-Y genes were identified, and CgNF-YB9 was involved in sucrose metabolism.

摘要

背景

核因子 Y（NF-Y）越来越多地参与植物生长和发育的许多方面。迄今为止，尚未在甜橙中对 NF-Y 家族进行系统的特征描述。

目的

对甜橙 NF-Y（CgNF-Y）家族进行全基因组鉴定，并分析其在蔗糖代谢中的作用。

方法

使用 NF-Y 保守模型从基因组数据中鉴定 CgNF-Y 基因。使用程序 MEGA 7.0 通过邻接法生成系统发育树。根据我们之前的转录组数据，使用 RSEM 软件计算转录水平，并使用 ShortTime-series Expression Miner 进行聚类。使用 In-Fusion 克隆构建 CgNF-YB9 的植物表达载体，并通过叶盘转化法将其转入烟草。通过高效液相色谱法（HPLC）和 qRT-PCR 分别分析可溶性糖和基因表达。

结果

共鉴定出 24 个 CgNF-Y 基因（6 个 CgNF-YA、13 个 CgNF-YB 和 5 个 CgNF-YC），具有保守结构域。NF-Y 蛋白的系统发育分析表明，NF-YA、NF-YB 和 NF-YC 可分为四个、五个和三个分支。表达谱分析反映了 CgNF-Y 基因在时空上的不同表达模式。重要的是，我们观察到 CgNF-YB9 的表达水平与可溶性糖含量呈正相关。此外，CgNF-YB9 相关基因富集在碳水化合物代谢中。在 CgNF-YB9 过表达株系中，蔗糖含量下降，而葡萄糖和果糖含量上升。正如预期的那样，在转基因株系 3 中观察到蔗糖磷酸合酶和液泡转化酶的转录水平分别显著下调和上调。