燕麦盐胁迫响应基因的差异表达与生理响应的关系

Exploring the Relationship of Differentially Expressed Genes and Physiological of Oats in Response to Salt Stress

以耐盐燕麦品种VAO-9为材料,通过Illumina测序与数字基因表达谱技术对300mmol/L NaCl处理前后的叶片cDNA文库进行RNA-Seq与DGE分析,同时测定0(CK)、100、200、250、300mmol/L NaCl胁迫下VAO-9幼苗叶片的相对电导率、丙二醛含量和脯氨酸含量,探讨燕麦盐胁迫响应基因的差异表达与生理响应的关系。结果表明:(1)RNA-Seq分析得到Unigenes 65 801条,其基因表达呈现高度的不均一性和冗余性;若差异基因表达谱鉴定分析以log2Ratio≥2且FDR值≤0.001为选择标准,则发现上调和下调表达基因在胁迫0.5h时分别有306和64个,在胁迫3h时分别有639和290个,胁迫24h时分别有1 488和882个。(2)KEGG代谢分析显示,有23 652条Unigenes比对到KEGG中的128条代谢途径,包括与逆境胁迫相关的植物激素信号转导途径、ABC转运蛋白途径、肌醇磷酸代谢途径、渗透调节途径等。(3)在300mmol/L NaCl处理下燕麦叶片的相对电导率、丙二醛含量、脯氨酸含量等生理指标的变化与相关差异表达基因的变化趋势基本一致,说明基因差异表达量与生理反应密切相关。研究认为,在相同的栽培及胁迫处理条件下,可根据植物盐响应生理指标的变化判断耐盐基因的表达情况。

In this study,a salt tolerant variety VAO-9 was used to analyse leaf cDNA library of oat treated with 300 mmol/L NaCl by Illumina sequencing and in silico expression profile.At the same time,relative conductivity,MDA,and proline content of leaves under 0（CK）,100,200,250 and 300 mmol/L NaCl stressed were determined,probed the relationship between the differentially expressed of genes and physiological response to salt stress.The results showed that：（1）transcriptome sequencing get 65 801 Unigenes,and the gene expression in oat transcriptome showed high nonhomogeneity and redundancy.FDR value ≤0.001 and log2 Ratio≥2 as the selection criteria when identify and analyze differentially expressed genes （DEGs）,compared with the control,there were 306 and 64 genes up-and down-regulated expressed respectively coercion 0.5 h;coercion 3 h,there were 639 genes up-regulated,290 genes down-regulated;stressed 24 h,1488 genes up-regulated and 882 genes down-regulated.（2）The KEGG pathway analysis indicated there are 23 652 unigenes comparison to the 128 KEGG metabolic pathways,including abiotic stress-related pathways,such as plant hormone signaling pathways,ABC transporter protein pathway,inositol phosphate pathway,osmotic adjustment,and so on.The changing trends of the physiological indicators（relative conductivity,MDA,and proline contents in oat leaves） were the same as the differentially expressed genes under 300 mmol/L NaCl stressed,which indicated that the amount of differentially expressed genes is closely related to the physiological responses.Thus,salt tolerance genes expression can be judged according to the physiological indicators of plant salt response.