脱水过程中无核白葡萄转录组测序及膜脂降解代谢中关键基因的筛选

Transcriptome Sequencing and Screening of Key Genes Involved in Membrane Lipid Degradation during Dehydration of Thompson Seedless Grape

该研究以吐鲁番地区无核白葡萄为试验材料,在25℃常温和30℃热风干燥后,取失水25%、50%时褐变和未褐变的样品。利用转录组测序技术筛选出膜脂降解代谢相关的关键基因,并利用实时荧光定量PCR技术对其进行验证,研究结果显示,转录组测序共获得了11.63亿的clean data,当无核白失水50%时未褐变与褐变的相比,在快速脱水组筛选出718个差异表达基因,慢速脱水组2259个。将上述基因进行GO功能富集和KEGG富集分析后,筛选出43个膜脂代谢相关的差异基因,归类于5种代谢途径。从已获得的差异基因中最终筛选出乙醛脱氢酶7B4(Aldehyde Dehydrogenase7B4,ALDH7B4)、双半乳糖甘油二酯合成酶1(Digalactose Diglycerol Synthetase1,DGD1)、脂氧合酶(Lipoxygenase,LOX)、磷脂磷酸水解酶2(Lipid Phosphate Phosphatase2,LPP2)、二酰基甘油激酶5(Diacylglycerol Kinase5,DGK5)、非特异性磷脂酶C4(Non-specific Phospholipase C4,NPC4)、磷脂酶Dα1(Phospholipase Dα1,PLDα1)7个膜脂代谢相关的关键基因,经qRT-PCR验证,基因表达趋势与转录组测序结果基本一致。结果表明,膜脂降解代谢相关基因表达量变化对无核白脱水褐变有一定影响。

In this study,Thompson seedless grapes from Turpan area were used as the experimental materials.After hot-air drying at 25℃and 30℃,the grape samples with/without browning that underwent 25%,and 50%of water loss were withdrwan.Transcriptome sequencing technology was used to screen out the key genes related to membrane lipid degradation and metabolism,and real-time fluorescence quantitative PCR technology was used for verification.The results showed that a total of 1.163 billion clean data were obtained by transcriptome sequencing.When the water loss in Thompson seedless grapes was 50%,the comparison between the non-browning and the browning species revealed 718 differentially expressed genes for the rapid dehydration group and 2259 differentially expressed genes for the slow dehydration group.After the GO function enrichment and KEGG enrichment analyses,43 differential genes related to membrane lipid metabolism were screened,which were classified into 5 metabolic pathways.Seven key genes related to membrane lipid metabolism were screened from the obtained differential genes,including Aldehyde dehydrogenase 7B4(ALDH7B4),Digalactose diglycerol synthetase 1(DGD1),Lipoxygenase(LOX),Lipid phosphate phosphatase 2(LPP2),Diacylglycerol kinase 5(DGK5),Non-specific phospholipase C4(NPC)and Phospholipase Dα1(PLDα1).qRT-PCR verification confirmed the agreement of the gene expression trend with the transcriptome sequencing results.In conclusion,the changes of membrane lipid degradation and metabolism-related gene expression have influence on dehydration-induced browning in Thompson seedless grapes.