不同纬度来源结缕草叶片响应低温胁迫的转录组分析

Transcriptomic Analysis of Leave in Two Zosiagrass Genotypes Native from Different Latitudes in Response to Low Temperature Stress

为探讨不同纬度来源结缕草(Zoysia japonica)对低温的响应,以结缕草种质ZG-36(高纬度)和ZG-32(低纬度)为材料,分析了适温(30℃/25℃)、冷害(8℃/2℃)和冻害(2℃/-4℃)3种温度下叶片的转录组变化。结果表明,在常温、冷害、冻害下,不同来源结楼草差异表达基因数量存在差异,冷害胁迫下ZG-32中差异表达的基因数量显著多于ZG-36,而冻害胁迫下后者多于前者;在功能分类及代谢通路富集分析中,叶片差异表达基因在生物学过程(Biological process,BP)、细胞组分(Celluar component,CC)与分子功能(Molecular function,MF)等3大分类中均有富集,但富集的组分和程度不同;ZG-36的差异表达转录因子(Transcription factor,TF)显著多于ZG-32。冷害、冻害条件下,差异表达的胚胎发育晚期丰富蛋白(Late embriogenesis abundant protein,LEA)在ZG-36中上调表达的数量显著多于ZG-32,而ZG-32中下调表达的LEA显著多于ZG-36,表明LEA基因对结缕草适应低温起了重要作用。

In order to explore the response mechanism of Zoysia japonica from different latitudes to low temperature stress,ZG-36(high latitude)and ZG-32(low latitude)from different latitudes were used as materials to analyze the changes of transcriptome of zoysiagrass leaves under three temperatures:optimum(30℃/25℃),chilling(8℃/2℃)and freezing(2℃/-4℃).The results showed that there were differences in the number of differentially expressed genes between the two genotypes under optimum,cold and freezing temperature.The number of differentially expressed genes in ZG-32 under cold injury stress was significantly higher than that in ZG-36,while the latter was more than the former under cold injury stress;In gene ontology(GO)functional classification and KEGG metabolic pathway enrichment analysis,differentially expressed genes in leaves were enriched in three major classifications:biological process(BP),cellular component(CC),and molecular function(MF),but the enriched components and degrees were different.The differentially expressed transcription factor(TF)analysis showed that ZG-36 was significantly higher than ZG-32.Under cold and freezing conditions.The number of up-regulated late embriogenesis abundant protein(LEA)in ZG-36 was significantly higher than that of ZG-32,while downregulated LEA in ZG-32 was significantly higher than that of ZG-36.Those results indicated that LEA may play an important role in cold adaptation in zoysiagrass under low temperature.