盐胁迫下7个刺榆无性系的叶片转录组分析

Transcriptome Analysis of Leaves of Seven Hemiptelea davidii Clones under Salt

[目的]从转录组水平上探究刺榆叶片对盐胁迫的响应机制,筛选耐盐基因。[方法]本研究以7个不同耐盐能力刺榆无性系的扦插苗为试验材料,对0、100、150、200 mmol·L^(-1) NaCl溶液处理15 d的叶片进行了转录组测序与分析。[结果](1)除DW1上调数量略多于下调数量外,其他无性系核心差异基因下调数量均多于上调数量,且各无性系在200 mmol·L^(-1)盐溶液处理时差异表达基因数量最多,对盐胁迫的响应最为强烈。GO富集分析显示细胞壁等功能类别基因对盐胁迫的响应较强。KEGG富集分析显示植物激素信号转导等代谢通路在7个无性系响应盐胁迫时发挥了重要作用。(2)强耐盐型的无性系DJ1、DJ3与弱耐盐型的无性系DW1、DY1在200 mmol·L^(-1)盐溶液处理时的4个对比组合共有的差异基因数量为1406个,共同上调基因393个、共同下调基因996个,其中脱落酸调节因子蛋白磷酸酶PP2C基因AHG1、ABI2,乙烯受体基因ERS1、ETR2,以及环核苷酸门控离子通道基因CNGC10和CNGC15可能与DJ1、DJ3较强的耐盐能力有关。[结论]盐胁迫引起刺榆转录水平上功能类别基因与代谢通路的响应,其中6个显著差异表达基因将作为候选耐盐基因。本研究为揭示刺榆响应盐胁迫的转录组特征与筛选耐盐基因提供了理论参考,为进一步开展刺榆种质资源的研究与应用奠定了基础。

[Objective]To investigate the response mechanism of Hemiptelea davidii leaves under salt stress at the transcriptome level and screen for salt tolerance genes.[Methods]Based on seven different H.davidii cuttings,transcriptome sequencing and analysis were performed on leaves treated with 0,100,150,and 200 mmol·L^(-1) NaCl solution for 15 days.[Results](1)The screening results of core differentially expressed genes(DEGs)in seven clones showed that except for the DW1,which had slightly more upregulated genes than downregulated genes,all other clones had more downregulated genes than upregulated genes.Moreover,when treated with 200 mmol·L^(-1) salt solution,each strain had the highest number of DEGS and the strongest response to salt stress.GO enrichment analysis showed that functional genes such as cell wall,had strong responses to salt stress.KEGG enrichment analysis showed that metabolic pathways such as hormone signal transduction,played important roles in the response of 7 clones to salt stress.(2)The four comparative combinations of stronger salt tolerant clones DJ1 and DJ3 and weak salt tolerant clones DW1 and DY1 had a total of 1406 DEGs,including 393 upregulated genes and 996 downregulated genes.Among them,the abscisic acid regulatory factor protein phosphatase 2C(PP2C)genes AHG1,ABI2,ethylene receptor genes ERS1,ETR2,and cyclic nucleotide gated channel genes CNGC10 and CNGC15 might be related to the strong salt tolerance of DJ1 and DJ3.[Conclusion]Salt stress causes the response of functional genes and metabolic pathways in H.davidii.Six significantly DEGs will be served as candidate salt tolerant genes.This study provides a theoretical reference for revealing the transcriptome characteristics of H.davidii in response to salt stress and screening salt tolerant genes,laying a foundation for further research and application of H.davidii germplasm resources.