铅锌胁迫下山苍子雌雄花蕾转录组测序分析

Analysis of Pb and Zn Stress on Transcriptome Sequencing of Male and Female Flower Buds in Litsea cubeba(Lour.)Pers.

为研究山苍子雌雄株的花蕾在铅锌胁迫下基因表达模式的差异,本试验以铅锌尾矿区中无污染和铅锌污染样地的山苍子雌雄株的花蕾作为试验材料,对无污染土地(CK)和铅锌污染土地的山苍子雌雄株的花蕾进行转录组测序,共设置4个差异分组,即无污染雌组、无污染雄组、铅锌污染雌组和铅锌污染雄组。测序结果显示,共获得88.41 Gb的Clean data,Q 30碱基大于94.30%,平均GC含量为45.81%,样品间进行差异基因筛选,得到差异基因的数量分别为3204、4698、5038和4124条。经GO数据库对其注释,结果表明4个比较组的差异基因大量参与生物过程部分,而极少量差异基因参与分子功能部分。根据KEGG通路富集分析可得出,山苍子响应铅锌复合胁迫的主要代谢途径有苯丙素生物合成、植物病原菌互作、次生代谢物生物合成以及芪类,二苯基庚酮和姜酚生物合成等,而山苍子雌雄株间差异主要体现在苯丙素生物合成、淀粉和蔗糖代谢、次生代谢物生物合成以及新陈代谢等代谢通路上。本研究通过对铅锌胁迫下山苍子雌雄株的花蕾进行高通量测序,揭示铅锌复合胁迫对山苍子雌雄花蕾发育和重金属富集在基因层面上的影响及差异,并对后期进行重金属污染区山苍子良种选育以及雌雄株栽植配比具有重要的指导意义。

In order to study the differences of gene expression patterns in male and female flower buds of Litsea cubeba under lead-zinc stress the male and female flower buds of L.cubeba from pollution-free sample area(CK)and lead-zinc polluted sample area in lead-zinc tailing area were used as test materials for transcriptome sequencing.A total of 4 difference groups were set up,that is,the pollution-free female group,pollution-free male group,lead-zinc contaminated female group and lead-zinc contaminated male group.Sequencing results showed that a total of 88.41 Gb clean data were obtained,the Q30 base was greater than 94.30%and the average GC content was 45.81%.The number of DEGs obtained by differential gene screening among samples were 3204,4698,5038 and 4124,respectively.GO analysis showed that four comparison groups involved more differential gene in biological processes,and less in molecular functions.KEGG analysis revealed that lead and zinc stress had distinct effects on phenylpropanoid biosynthesis,plant-pathogen interaction,biosynthesis of secondary metabolites and stilbenoid,diarylheptanoid and gingerol biosynthesis in L.cubeba.Significant differences between female and male flower buds were obtained in phenylpropanoid biosynthesis,starch and sucrose metabolism,biosynthesis of secondary metabolites and metabolic pathways under lead and zinc stress.In this study,high throughput sequencing was conducted on the male and female flower buds of L.cubeba under lead-zinc stress,revealing the genetic effects and differences of the combined lead-zinc stress on the development of male and female flower buds and heavy metal enrichment of L.cubeba,which has important guiding significance for the breeding of improved varieties of L.cubeba in heavy metal polluted areas and the planting ratio of male and female plants.