摘要：

为了探明设施内铺设反光膜对果实品质的影响和促进着色的机理,以京艳为试材,行间铺设反光膜,监测覆膜后葡萄果实的外观与花色苷含量的变化,利用高通量测序和Illumina Novaseq 6000测序平台对着色差异的果皮进行转录组测序及差异表达基因分析。结果表明,12个样本得到了41 151 986~46 673 908条Clean reads,且Q30都在94%以上、Q20在98%以上。Clean reads与葡萄参考基因组比对总数为92.69%~94.22%。差异表达的基因统计结果显示,CK 0 d~CK 7 d差异表达基因数目是3 768个,上调基因1 488个,下调2 280个;覆膜后RF 0 d~RF 7 d差异表达基因数目是5 129个,其中上调表达2 048个,下调表达3 081个,可见覆膜能够促进基因的差异表达。覆膜7 d后,与对照相比,获得934个差异表达基因,上调表达441个,下调表达493个。KEGG富集分析表明,934个DEGs中,共有179个被注释到64条信号通路上,主要富集在代谢、细胞过程、环境信息处理、遗传信息处理和生物系统五大类代谢途径。其中,苯丙烷生物合成、内质网蛋白加工、植物病菌互作、植物激素信号传导途径多个基因表达出现差异。PAL、F3'H、3GT的多个转录本均上调表达,多个生长素相应蛋白基因下调表达。转录因子WRKY基因以上调表达为主,bHLH、C2H2、NAC、MIKC-MADS、Dof等多是下调表达。综上所述,铺设反光膜可能通过提高苯丙氨酸解氨酶(PAL)的活性,提高相关基因(F3'H、3GT等)的表达,从而促进花色苷合成。转录因子WRKY、bHLH、C2H2、MYB、NAC、MIKC-MADS、Dof也可能发挥重要的调控作用。

关键词: 葡萄, 反光膜, 着色, 转录组, 差异表达基因

Abstract:

To find out the effect of laying reflective film on fruit quality in facilities and the mechanism of promoting coloring,the changes of the appearance and anthocyanin content of Jingyan grape fruits were monitored with the film laid between rows,then transcriptome sequencing and differential expression gene analysis of the peels with different coloring were carried out using high-throughput sequencing and Illumina Novaseq 6000 sequencing platform.Finally,41 151 986—46 673 908 Clean reads were obtained from 12 samples,with Q30 was over 94% and Q20 was over 98%.Besides,the mapping ratio between Clean reads and grape reference genome was 92.69%—94.22%.The analysis results of differentially expressed genes (DEGS) showed that there were 3 768 DEGs in CK 0 d—CK 7 d,with 1 488 up-regulated and 2 280 down-regulated.And 5 129 in RF 0 d—RF 7 d after film mulching,with 2 048 up-regulated and 3 081 down-regulated.It showed that film mulching can increase the differential expression of genes.Compared with CK,934 DEGs were obtained after 7 days mulching,of which 441 genes were up-regulated and 493 were down-regulated.KEGG enrichment analysis showed that,a total of 179 DEGs were annotated on 64 signal pathways,which were mainly enriched in five metabolic pathways:metabolism,cellular process,environmental information processing,genetic information processing and organismal systems.Particularly,many genes vere differentially expressed in benzene propane biosynthesis,endoplasmic reticulum protein processing,plant pathogen interaction and plant hormone signaling pathway.Results showed some transcripts of PAL,F3'H and 3GT were up-expressed,and some auxin-related protein genes were down-regulated.For transcription factors,WRKY gene was mainly up-regulated,while bHLH,C2H2,NAC,MIKC-MADS,Dof were down-regulated.In conclusion,laying reflective film may improve the activity of phenylalanine ammonia-lyase(PAL)and the expression of related genes(F3'H,3GT),thus promoting anthocyanin synthesis.Meanwhile,transcriptional factors WRKY,bHLH,C2H2,MYB,NAC,MIKC-MADS and Dof may also play an important role in regulation.

Key words: Grape, Reflective film, Colour, Transcriptome, DEGs