黑果枸杞不同发育时期果实花色苷合成的转录组分析

Transcriptome Analysis of the Anthocyanin Biosynthesis in the Fruit Development Processes of Lycium ruthenicum Murr.

【目的】探究黑果枸杞果实发育过程中花色苷合成的分子机制,对深入理解黑果枸杞花色苷合成调控网络具有重要意义。【方法】选取青果期、转色初期、转色后期、成熟期和完全成熟期的黑果枸杞果实进行转录组测序,挖掘与黑果枸杞果实花色苷合成相关的候选基因。【结果】随黑果枸杞果实发育,花色苷含量逐渐升高,成熟期及完全成熟期果实中的花色苷含量显著高于青果期、转色初期及转色后期。5个发育时期共筛选出13540个差异表达基因(differentially expressed genes,DEGs),以青果期为对照,随果实发育,各阶段DEGs数量逐渐增多。GO分析发现,DEGs共同富集的子集有苯丙烷代谢过程、多糖分解代谢过程、苯丙烷生物合成过程、类黄酮生物合成过程、细胞壁大分子代谢过程、膜锚定成分和营养库活性通路。KEGG分析表明,DEGs显著富集于类黄酮生物合成、苯丙烷生物合成、植物激素信号转导、二苯乙烯类、二芳基庚烷类和姜辣素生物合成及角质和木栓质和蜡质的生物合成通路。分析DEGs表达量与花色苷含量相关性,筛选出参与黑果枸杞果实发育过程花色苷合成的候选基因36个,主要包括10个花色苷合成通路结构基因,4个转录因子,9个ABA、8个GA及5个JA信号转导通路基因。RT-qPCR验证其中10个基因的表达趋势,与转录组数据一致。【结论】黑果枸杞果实发育过程中,花色苷合成途径的结构基因、转录因子及ABA、GA和JA信号转导通路中基因的表达调控果实着色。

【Objective】To explore the molecular mechanism involved in anthocyanin biosynthesis during the fruit development of Lycium ruthenicum Murr.is important for deeply understanding the regulatory network of anthocyanin biosynthesis.【Method】Transcriptome sequencing was performed on the samples at the five stages of fruit development:green fruit,early color-changing,late color-changing,ripeness,and complete ripeness.The candidate genes related to anthocyanin biosynthesis were mined.【Result】With the development of L.ruthenicum Murr.fruit,the anthocyanin content gradually increased.The anthocyanin content in the fruits at the ripeness and complete ripeness stages were significantly higher than that at the green fruit,early color-changing,and late color-changing stages.A total of 13540 differentially expressed genes(DEGs)were identified from the five stages of fruit development.Using the green fruit stage as a control,the number of DEGs gradually increased with the development of the fruit.GO analysis showed that DEGs were co-enriched GO terms including phenylpropanoid metabolic process,polysaccharide catabolic process,phenylpropanoid biosynthetic process,flavonoid biosynthetic process,cell wall macromolecule metabolic process,anchored component of membrane,and nutrient reservoir activity.KEGG analysis indicated the significant enrichment of DEGs in flavonoid biosynthesis,phenylpropanoid biosynthesis,plant hormone signal transduction,stilbenoid,diarylheptanoid and gingerol biosynthesis,as well as cutin,suberine,and wax biosynthesis.The correlation between DEGs expression and anthocyanin content was performed and 36 candidate genes involved in anthocyanin biosynthesis during the L.ruthenicum fruit development were screened,including ten structural genes of anthocyanin biosynthesis pathway,four genes of transcription factors,nine,eight,and five genes of ABA,GA,and JA signal transduction pathway.Ten DEGs were selected for RT-qPCR analysis,and the results were consistent with RNA-seq data.【Conclusion】DEGs related to structural genes and transcription factors involved in anthocyanin biosynthesis,as well as genes involved in the ABA,GA,and JA signal transduction pathways,affect fruit coloration during the development of L.ruthenicum Murr.fruit.