转录组与蛋白质组关联分析鉴定桑树硬枝扦插皮部生根相关功能基因

Identification of Functional Genes Related to Cortex Rooting on Mulberry Hardwood Cuttings Using Transcriptom e-proteome Correlation Analysis

前期以桑品种育711号硬枝扦插皮部生根的插穗为材料,对扦插生根过程起始阶段(S0)、根原基形成阶段(S1)和不定根伸长阶段(S2)的插穗基部皮层进行了转录组与蛋白质组测序。在此基础上对差异表达基因与蛋白质(差异系数>1.5,错误发现率≤0.05)做关联分析。结果显示:不同阶段插穗基部皮层的基因和蛋白质表达趋势总体上呈正相关,关联系数分别为0.470 3(S0-vs-S1)与0.113 0(S1-vs-S2);基因与蛋白质表达趋势相反的关联数量较少,关联系数分别为-0.319 9(S0-vs-S1)与-0.107 1(S1-vs-S2);基因与蛋白质表达趋势相同的关联数量相对较多,关联系数分别为0.855 4(S0-vs-S1)与0.834 6(S1-vs-S2),均呈强相关。在关联分析表达趋势相同组中筛选鉴定出21个差异表达基因,并进行功能注释与信号通路分析。其中,有5个基因在生根过程中持续上调表达,主要包括酚氧化酶(PPO)、马铃薯糖蛋白(Patatin)、生长素酰胺水解酶(ILL)、肌氨酸氧化酶(SOX)的编码基因;有13个基因在根原基形成期上调表达,在不定根伸长期下调表达,主要包括赤霉素双加氧酶(GA3OX4)、12-氧植物二烯酸还原酶(OPR)、内切葡聚糖酶(EG)和吲哚乙酸氨基化合成酶(GH3)的编码基因;有3个基因在根原基形成期下调表达,在不定根伸长期上调表达,分别为细胞膜相关钙结合蛋白(PCa P)、肌肉LIM蛋白(MLP)和膜联蛋白(ANX)的编码基因。上述关联分析的结果为深入认识桑树插穗皮部生根过程的生理机制提供了相关功能基因信息。

Hardwood cuttings of mulberry variety Yu 711 with cortex rooting were previously used as materials for transcriptome sequencing and proteome sequencing at initial stage（S0）,root primordium formation stage（S1）and adventitious root elongation stage（S2）of rooting process.Based on the sequence data,correlation analysis was conducted to differentially expressed genes and proteins（variation coefficient〉1.5,false discovery rate≤0.05）.The analysis results showed that,in general,expression tendencies of genes and proteins were positively correlated at different stages,in which the correlation coefficient was 0.470 3（S0-vs-S1）and 0.113 0（S1-vs-S2）.There were relatively less genes having reverse expression trend with proteins,in which the correlation coefficient was-0.319 9（S0-vs-S1）and-0.107 1（S1-vs-S2）.In contrast,there were relatively more genes having the same expression trend with proteins,in which the correlation coefficient was 0.855 4（S0-vs-S1）and 0.834 6（S1-vs-S2）,showing strong correlation.Twenty-one differentially expressed genes were identified from correlative groups showing the same expression trend in correlation analysis and subject to functional annotation and signal pathway analysis.Among them,five genes,encoding polyphenol oxidase（PPO）,Patatin,IAA-leucine resistant1-like hydrolase（ILL）and sarcosine oxidase（SOX）,were continually up-regulated in the whole rooting process.Thirteen genes encoding proteins including gibberellin 3-beta-dioxygenase 4（GA3OX4）,12-oxophytodienoate reductase（OPR）,endoglucanase（EG）and indole-3-acetic acid-amido synthetase（GH3）etc were up-regulated in root primordium formation stage and down-regulated in adventitious root elongation stage.Three genes,encoding plasma-membrane associated cation-binding protein（PCa P）,muscle LIM protein（MLP）and annexin（ANX）,were downregulated in root primordium formation stage and up-regulated in adventitious root elongation stage.The above correlation analysis results provide useful information of functional genes for further exploration on physiological mechanism in cortex rooting process of mulberry cuttings.