NaCl胁迫下红砂种子萌动期差异表达基因的转录组分析

Transcriptome analysis of differentially expressed genes in Reaumuria soongorica seeds germination under NaCl stress

【目的】筛选NaCl胁迫下红砂萌发期的差异表达基因,为耐盐碱树种选育提供基因资源。【方法】以前期拟合的萌发阈值浓度(273 mmol/L,记为M)、最适萌发浓度(43 mmol/L,记为L)、蒸馏水(记为C)处理红砂种子,每个处理3次重复,待胚根突破种皮,不超过2 mm时取出,进行转录组测序。【结果】分别在L与C对比组(记为LvsC)、M与C对比组(记为MvsC)、M与L对比组(记为MvsL)中筛选出210、2 273、2 888个差异表达基因,其中LvsC中116个上调表达,94个下调表达;MvsC中1 781个上调表达,492个下调表达; MvsL中2 165个上调表达,723个下调表达;上调表达基因在KEGG富集中主要集中在核糖体、碳代谢、细胞色素P450代谢、谷胱甘肽代谢等途径,下调表达基因主要富集在蔗糖淀粉代谢、内质网蛋白质加工等过程。【结论】盐胁迫条件下,差异基因诱导相关反应协同发挥作用,最终使胚轴细胞伸长,突破种皮完成萌发。

【Objective】Screen differentially expressed genes(DEG) at the germination stage of Reaumuria soongorica under NaCl stress and provide genetic resources for the breeding of salt-tolerant species.【Method】The R. soongorica seeds were treated with pre-fitting germination threshold concentration(273 mmol/L, marked as M), optimum germination concentration(43 mmol/L, marked as L) and distilled water(marked as C), and each treatment was repeated three times. The seeds were taken out when the radicle broke through the seed coat but not more than 2 mm, and the transcriptome sequencing was performed.【Result】There were 210, 2 273 and 2 888 DEG screened out in comparison group of L and C(LvsC), M and C(MvsC), M and L(MvsL), respectively, of which 116 were up-regulated and 94 were down-regulated in LvsC, 1 781 were up-regulated and 492 were down-regulated in MvsC, and 2 165 were up-regulated and 723 were down-regulated in MvsL. These up-regulated genes are mainly enriched in ribosome, carbon metabolism, cytochrome P450 metabolism, glutathione metabolism and other pathways in KEGG, down-regulated genes are mainly enriched in sucrose and starch metabolism, endoplasmic reticulum protein processing and other processes.【Conclusion】Under stress conditions, the DEG induce related reactions synergistic responses, which ultimately lengthen the hypocotyl cells and break through the seed coat to complete germination.