花生根部耐盐相关miRNAs的鉴定与功能分析

Identification and Functional Characterization of Salt Tolerance Related microRNAs in Roots of Peanut(Arachis hypogaea L.)

miRNAs作为一种基因表达调控子在植物应答胁迫的过程中起着重要的作用,当花生受到盐胁迫时,也会有相应的miRNAs参与基因表达调控应答胁迫。本研究对200份花生品种进行萌发期耐盐性鉴定,获得了高耐盐花生品种3份,中耐盐花生品种5份,盐高敏感品种4份。并对不同耐盐性花生品种在盐胁迫处理条件下进行了抗氧化酶活性(SOD,POD,CAT)和MDA含量的测定。结果表明,耐盐性花生品种清除活性氧的能力大于盐敏感型。盐胁迫条件下,耐盐性花生植株MDA含量较少,受到的伤害相对较小,而盐敏感植株的受伤害程度最大,也证明了耐盐性花生品种在受到盐胁迫伤害时植物体内存在更强大的保护作用。通过小RNA测序及对靶基因序列进行功能分析和同源序列功能检索,获得了8条花生耐盐相关保守miRNAs序列,miR159-1,miR159-2,miR159-3,miR164-2,miR167-3,miR319-1,miR319-2,miR2111-1。荧光定量PCR测定结果表明,这些花生保守miRNAs受盐胁迫诱导,并调控其靶基因的应答反应。

miRNAs as a gene expression regulator plays an important role in the process of plant response to stress.When peanut suffered from salt stress,there will be the corresponding miRNAs involved in the regulation of gene expression responding to stresses.3salt-tolerant,5moderate salttolerant and 4high salt-sensitive peanut varieties were screened out from 200 peanut germplasm resources in germination and seedling stage.The results of antioxidase activities and malondialdehyde content indicated that the salt-tolerant plant had stronger ability to eliminate reactive oxygen species.And the salt-tolerant plants suffered less from salt treatment than the salt-sensitive ones,which also showed the self protective response.Through miRNA sequencing and Gene Ontology（GO）functional annotation of target gene sequences,eight salt tolerance related miRNA sequences（miR159-1,miR159-2,miR159-3,miR164-2,miR167-3,miR319-1,miR319-2,miR2111-1）were obtained.qRTPCR analyses demonstrated that these peanut miRNAs are regulated by salt stress,resulting in appropriate biological responses of their target genes.