盐胁迫下栽培大豆与野生大豆根系离子流及转录组分析

Ion flux and transcriptome analysis of roots of cultivated and wild soybean under salt stress

为揭示栽培大豆和野生大豆盐胁迫下根系离子流变化及内在分子响应机制,挖掘大豆耐盐基因,以普通栽培大豆(Glycine max,Gm)和滩涂野生大豆(Glycine soja,Gs)为试验材料,通过设置100 mmol·L^(-1)NaCl盐胁迫处理,用非损伤微测技术(NMT)检测大豆根系离子流对盐胁迫的响应,并用高通量测序技术对栽培大豆及野生大豆盐胁迫24 h后根系的转录组进行分析,以寻找离子转运体相关的耐盐基因。结果表明:与对照相比,100 mmol·L^(-1)NaCl胁迫10 d后栽培大豆鲜重下降41.5%,而野生大豆鲜重下降29.2%。根系离子流测定结果显示,盐胁迫24 h后野生大豆比栽培大豆Na+外排量高46.3%,K+损失量少33.0%,且H+吸收量高93.9%。转录组分析结果显示,野生大豆阳离子/H+反向转运体CHX20和钠钾根缺陷NaKR2显著下调,K+/H+逆向转运体KEA2、KEA3和K+转运体KT1、KT2显著上调。综上,野生大豆比栽培大豆具有更强的耐盐能力,根系离子流与植株耐盐能力间存在较好的一致关系,通道控制基因参与了大豆耐盐能力的调控,这一研究为进一步探讨野生大豆耐盐机制及筛选耐盐基因提供了依据。

In order to explore the salt tolerance genes related to ion transporters of wild soybean in tidal flat,ion flux and differentially expressed genes(DEGs)of the root system of cultivated and wild soybean after salt stress were analyzed by None-invasive Micro-test Technology(NMT)and transcriptome sequencing,respectively.The results showed that fresh weight of cultivated soybean and wild soybean decreased significantly by 41.5%and 29.2%under salt stress for 10 days,compared with the control.Root ion flux for 24 h under salt stress measured by NMT indicated that the Na~+efflux of wild soybean was 46.3%higher,the K~+loss was 33.0%lower,and H~+influx was 93.9%higher than those of cultivated soybean.Transcriptional analysis showed that cation/H~+antiporter 20(CHX20)and sodium potassium root defective 2(NaKR2)were significantly down-regulated under salt stress,while K~+/H~+antiporter(KEA2,KEA3)and K~+transporters(KT1,KT2)were significantly up-regulated.In summery,these data indicated that the salt tolerance of wild soybean was stronger than that of cultivated soybean.There was a consistent relationship between root ion flux and salt tolerance.The genes controlling ion channel were involved in the regulation of salt tolerance in soybean.This study provides a basis for the further investigation of mechanism and screening of candidate genes of salt tolerance in wild soybean.