水分胁迫下枣裂果的全长转录组分析

Full-length Transcriptome Analysis of Fruit Cracking of Chinese Jujube under Water Stress

为了从转录本水平阐明水分胁迫下的枣裂果的分子机制,以5 a生金丝新4号品种为试验材料进行50 h的喷淋,模拟水分胁迫,处理结束后对喷淋前后的样品在ONT平台进行3代全长转录组测序。6个样品共获得13368条转录本序列,APA事件中鉴定到9178个PolyA位点,并找到78个显著富集的PolyA信号(PAS)motif,预测到7321个SSR和114个lncRNA;对照组和处理组分别鉴定到239,189个可变剪接事件;差异分析共得到248个差异转录本,参与的主要转录本包括钙网蛋白、钙联蛋白、热激蛋白、微管蛋白、果糖激酶等。GO富集显示,差异转录本主要参与了翻译、有丝分裂、冷适应等生物学过程,相应地细胞组分为细胞质和核糖体,富集的分子功能为核糖体成分、木葡糖基转移酶活性等;通过KEGG富集分析发现,上调表达的转录本主要参与了内质网蛋白加工、吞噬体、氨基糖与核糖代谢以及淀粉和蔗糖代谢通路;下调转录本主要参与了内质网蛋白加工、氮代谢和光合作用-天线蛋白通路等过程。差异转录本编码的蛋白之间存在复杂的互作网络。水分胁迫下的裂果机制可能包括可变剪接事件的减少、钙网蛋白和钙调蛋白对钙离子的调节、持续喷淋后冷应激造成热激蛋白上调及细胞壁组分合成相关基因的上调等。

In order to illuminate the mechanisms of fruit cracking of Chinese jujube under water stress,5 a Jinsi novel No.4 Chinese jujube was chosen.The trees were spayed for 50 hours to simulate water stress.Fruits before and after treatment were sequenced on the ONT third-generation sequencing platform.There were totally 13368 transcripts obtained from 6 samples.9178 PolyA sites were identified in the APA event.78 significantly enriched PolyA signals(PAS)motif were found.7321 SSRs and 114 lncRNAs were predicted.239,189 alternative splicing events were identified in the control and treatment group,respectively.There were 248 differentially expressed transcripts(DETs)between the two groups.DETs mainly encoded calnexin,calreticulin,heatshock proteins,microtube proteins fructokinase and so on.GO enrichment showed that DETs were mainly involved in the biological processes such as translation,positive regulation of mitotic centrosome separation and cold acclimation.Cellular components participating those processes included cytosol and cytosolic large ribosomal subunit etc.Enriched molecular functions included structural constituent of ribosome and xyloglucosyl transferase activity,etc.KEGG enrichment analysis showed that up-regulated DETs were involved in protein processing in endoplasmic reticulum,phagosome,amino sugar and nucleotide sugar metoboism,starch and sucrose metabolism,etc.Down-regulated DETs took part in protein processing in endoplasmic reticulum,nitrogen metabolism,photosynthesis-antenna proteins and so on.The mechanisms of fruit cracking of Chinese jujube under water stress might include decrease of alternative splicing events,regulation of Ca2+by calnexin and calreticulin,up-regulation of heat shock proteins resulting from cold stress by continuous spaying,and up-regulation of cell wall biosynthesis related transcripts.