摘要
为探明蔗糖饲喂对菊花脑花苞总黄酮积累的影响及其机制,以中国特有的菊属野生二倍体物种菊花脑(Chrysanthemum nankingense)为试材,对其离体花苞进行蔗糖饲喂,测定饲喂后0、12、36和60 h管状花和舌状花总黄酮和总酚的动态变化,并对管状花进行转录组测序。结果发现:蔗糖饲喂24 h以内菊花脑管状花类黄酮和总酚的含量显著增加,而同类物质在舌状花中变化较为平缓。蔗糖饲喂60h与同时间无蔗糖饲喂相比,转录组分析仅获得3 423个差异表达基因;而与0 h无蔗糖饲喂相比,可获得最多的差异表达基因(9 135个),说明随饲喂时间的增加,管状花在生化层面上对蔗糖的响应程度增加。经KEGG分析,类黄酮生物合成途径被显著富集,32个类黄酮生物合成结构基因具有差异表达。相关性分析表明转录因子MYB、WRKY和MADS-box与类黄酮生物合成结构基因表达具有较强的共表达关系。在上述差异基因中随机挑选9个进行qRT-PCR验证,结果表明转录组数据具有较高的准确性;并对其中2个转录因子的编码基因进行了时空表达分析和蛋白亚细胞定位,为从代谢工程的角度研究菊花脑次生代谢筛选了目标基因。
To explore effects of sucrose feeding on the accumulation of total flavonoids in Chrysanthemum nankingense capitula and the underlying mechanism,Chrysanthemum nankingense,a unique wild diploid species of chrysanthemum in China,was used as the test material,and its detached capitula were fed with sucrose.The dynamic changes of total flavonoids and total phenols in disc and ray florets were determined at 0,12,36 and 60 h after sucrose feeding,and transcriptome sequencing of disc florets was performed.The results confirmed that sucrose feeding could increase the content of flavonoids and total phenols in disc florets within 24 h.However,in ray florets,these compounds changed slightly.A total of 9135 differentially expressed genes(DEGs),which was also the maximum number of DEGs identified between treatments,were obtained by transcriptome analysis of disc florets sucrose-fed for 60 h and 0 h,while only 3423 differentially expressed genes were obtained by transcriptome analysis of disc florets sucrose-fed for 60 h and no sucrose-fed for 60 h.These data indicate that the response degree of disc florets to sucrose increased with the increase of feeding time on the biochemistry level.KEGG analysis indicated that the flavonoid biosynthesis pathway was significantly enrichedand 32 flavonoid biosynthetic structural genes were differentially expressed.Correlation analysis showed that transcription factors MYBs,WRKYs and MADS-boxes had a strong co-expression relationship with flavonoid biosynthetic structural gene expression in disc florets in response to sucrose feeding.Nine DEGs were randomly selected for qRT-PCR,indicating that the transcriptome data were accurate.Spatio-temporal expression and subcellular localization of the encoding genes of two transcription factors were further analyzed to confirm the findings.Genes screened out from this study can offer potential targets for further efforts of metabolic engineering aiming to probe secondary metabolism in Chrysanthemum nankingense.
作者
王稳
张鹏
王志敏
刘根忠
包志龙
马方放
WANG Wen;ZHANG Peng;WANG Zhimin;LIU Genzhong;BAO Zhilong;MA Fangfang(State Key Laboratory of Crop Biology,College of Horticulture Science and Engineering,Shandong Agricultural University,Tai’an,Shandong 271018,China)
出处
《园艺学报》
CAS
CSCD
北大核心
2024年第6期1297-1310,共14页
Acta Horticulturae Sinica
基金
泰山学者青年专家项目(tsqn201909073)。
关键词
菊花脑
蔗糖响应
类黄酮生物合成
差异表达基因
管状花
Chrysanthemum nankingense
response to sucrose
flavonoid metabolism
differentially expressed genes
disc florets
