| 摘要: |
| 【目的】鉴别不同花色甘蓝型油菜花瓣花青素合成相关差异表达基因（DEGs），为油菜花色形成机理研究奠定基础。【方法】以甘蓝型红花油菜与黄花油菜杂交和回交获得的B1C1群体为材料，分别用Na（NO2）2-Al（NO3）3-NaOH显色法和pH示差法测定红花和黄花总黄酮和总花青素含量。取7月份油菜初花期花瓣，分别构建黄花和红花cDNA文库，利用高通量测序技术获得其转录组数据，筛选DEGs,随后利用生物信息学方法对DEGs进行GO和KEGG分析；用MapMan注释和鉴别出花瓣花青素合成相关基因；并用qRT-PCR技术进行验证。【结果】甘蓝型黄花油菜花瓣中的总黄酮和总花青素含量明显低于红花油菜。经转录组分析，从黄花油菜和红花油菜初花期花瓣中共获得2 824个DEGs，其中红花油菜花瓣中多数基因负调控表达。KEGG富集分析显示，2 368个DEGs显著富集到124个KEGG代谢通路，其中代谢途径的差异基因最多（461个），次生代谢的生物合成差异基因次之（266个）；GO富集分析显示，2 824个DEGs注释到分子功能、细胞组分和生物过程3种功能类型,其中生物过程中的细胞过程、代谢过程、刺激反应和生物调节的DEGs分别有1 546，1 198，983和704个基因。MapMan分析结果显示，花青素生物合成途径差异表达的结构基因有34个，其中7个上调表达，27个下调表达，表达倍数均达极显著水平。相关转录因子鉴定结果显示，参与花青素合成的转录因子有56个，其中MYB家族转录因子34个，bHLH家族转录因子22个，未找到WD40。对鉴定出的花青素合成相关的5个基因（3个结构基因和2个转录因子）进行qRT PCR验证，结果与转录组分析结果一致。【结论】甘蓝型油菜花瓣的黄色与红色是由其内总黄酮和总花青素含量不同所致；甘蓝型油菜黄色花瓣和红色花瓣中鉴别出的差异表达结构基因和转录因子是导致不同花色花瓣总黄酮和总花青素含量差异的关键基因；甘蓝型红花油菜的花青素合成途径中仅有MYB和bHLH转录因子发挥作用。 |
| 关键词: 甘蓝型油菜 转录组学 花色 花青素 总黄酮 |
| DOI：10.13207/j.cnki.jnwafu.2024.09.006 |
| 分类号: |
| 基金项目:青海省科技厅项目“彩色油菜种质资源创新及利用”（2020-ZJ-745） |
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| Preliminary analysis of transcriptomes of different Brassica napus petals |
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GAO Haoran, TENG Shoulian, LUO Yuxiu
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College of Ecological and Environmental Engineering,Qinghai University,Xining,Qinghai 810016,China
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| Abstract: |
| 【Objective】This study identified differentially expressed genes (DEGs) related to anthocyanin synthesis in petals of Brassica napus with different flower colors to lay the foundation for studying rape flower color formation.【Method】Contents of total flavonoids and total anthocyanins in the B1C1 population obtained from crossing and backcrossing of safflower rapeseed and yellow rapeseed were determined by Na(NO2)2-Al(NO3)3-NaOH and pH difference methods,respectively.Yellow flower and safflower phase cDNA libraries were constructed from July rape petals,and transcriptome data were obtained by high throughput sequencing technology.DEGs were screened,and then bioinformatics were used for GO and KEGG analysis.The genes related to anthocyanin synthesis were annotated and identified by MapMan and verified by qRT-PCR.【Result】Contents of total flavonoids and total anthocyanins in petals of Brassica napus were significantly lower than those of safflower rapeseed.By transcriptome analysis,a total of 2 824 DEGs were obtained from petals of yellow and safflower rapeseed at the beginning of flowering,and most genes in safflower rapeseed were negatively regulated.KEGG enrichment analysis showed that the 2 368 differential genes were significantly enriched into 124 KEGG metabolic pathways,and the metabolic pathway had the most differential genes (461),followed by the secondary metabolic biosynthesis (266).GO enrichment analysis showed that the 2 824 differential genes annotated three types of molecular functions,cell components and biological processes.There were 1 546,1 198,983 and 704 genes of DEGs in cellular,metabolic,stimulatory and bioregulatory processes,respectively.MapMan analysis showed that there were 34 differentially expressed structural genes in anthocyanin biosynthesis pathway,of which 7 were up regulated and 27 were down-regulated with extremely significant expression multiples.The identification of related transcription factors showed that there were 56 transcription factors involved in anthocyanin synthesis,among which 34 were MYB family transcription factors,22 were bHLH family transcription factors,and WD40 was not found. Five genes (3 structural genes and 2 transcription factors) related to anthocyanin synthesis were identified by qRT-PCR,and the results were consistent with the transcriptome analysis.【Conclusion】The yellow and red colors of Brassica napus petals were caused by different contents of total flavonoids and total anthocyanins in Brassica napus.The differentially expressed structural genes and transcription factors in yellow and safflower petals were identified as the key genes for the differences of total flavonoids and total anthocyanins with different flower colors.Only MYB and bHLH transcription factors played a role in anthocyanin synthesis pathway of safflower rapeseed. |
| Key words: Brassica napus transcriptomic flower color anthocyanin total flavone |
