转PeDREB2a和KcERF基因紫花苜蓿的表型及抗旱耐盐性

PeDREB2a,KcERF enhance drought and salt tolerance in transgenic alfalfa

以紫花苜蓿(Medicago sativa)‘中苜1号’为受体材料,通过根癌农杆菌介导法将抗旱基因PeDREB2a、KcERF转入‘中苜1号’,获得转基因抗性苗66株,基因组PCR检测阳性率为93.94%,RT-PCR检测表明目的基因在转录水平上能够稳定表达;利用Taqman PCR方法检测目的基因的拷贝数,结果表明PeDREB2a、KcERF基因在转基因株系Z6、Z7、Z9中均为单拷贝。在正常生长条件下,转基因株系Z6和Z7株高、分枝数、叶片吲哚乙酸含量、纤维素含量均显著高于野生型,而叶片乙烯含量显著低于野生型(P<0.05)。用20%PEG-3350和250 mmol·L^(-1)NaCl胁迫处理进行表型观测和抗逆生理指标检测,表明转基因株系与野生型相比抗旱、耐盐能力明显增强。本研究为进一步培育抗逆优质高产苜蓿新品种提供了新种质。

Alfalfa(Medicago sativa)Zhongmu No.1 was used as the experimental material and leaves were used as explants.The target genes PeDREB2a,KcERF were transferred into alfalfa mediated by Agrobacterium tumefaciens LBA4404.Sixtysix transgenic resistance(Kan)lines were obtained.The positive rate of PCR detection was 93.94%.PeDREB2a and KcERF genes were determined to be single copy in transgenic lines Z6,Z7,and Z9 by digital PCR.RT-PCR showed that the transgene positive plants could be stably expressed at the transcription level.Under normal conditions,the plant height,branch number,and contents of indole acetic acid and cellulose in Z6 and Z7 were significantly higher than those in wild type,and the ethylene content in Z6 and Z7 was significantly lower than that in wild type.With 20%PEG-3350 and 250 mmol·L^(-1)NaCl stress treatment and physiological indicators,transgenic plants were more resistant under drought and salt stress compared with the wild-type.This provides a new germplasm for further cultivating new alfalfa varieties with stress resistance,high quality,and high yield.