转CkLEA4基因拟南芥种子萌发期的抗逆性分析

该研究在实验室前期研究的基础上,将受脱水、盐胁迫和ABA诱导的柠条锦鸡儿CkLEA4基因转入野生型拟南芥,并利用实时荧光定量PCR从8株纯合体中筛选出3个表达量不同的株系,比较野生型和转CkLEA4基因过表达拟南芥种子在不同胁迫处理下的萌发率,以探讨CkLEA4基因在植物抵抗逆境胁迫中的功能。结果发现:(1)在不同浓度NaCl、甘露醇及ABA处理下,转CkLEA4基因过表达拟南芥种子的萌发率均高于野生型,随着NaCl、甘露醇及ABA浓度增加,各株系萌发率均降低,但野生型的萌发率下降幅度均高于3个过表达株系,并且在200mmol/L NaCl和400mmol/L甘露醇处理下,过表达株系子叶绿化率均显著高于野生型。(2)在低浓度ABA处理下,CkLEA4过表达植株子叶的绿化率也高于野生型。研究表明,柠条锦鸡儿CkLEA4基因提高了拟南芥种子萌发阶段对盐、ABA及渗透胁迫的耐受性。

Stress Tolerance of Transgenic Arabidopsis Expressing CkLEA4 Gene during Seed Germination Stage

Based on our previous study,CkLEA4,a Caragana korshinskii LEA gene induced by dehydration,salt and ABA treatments,was transferred into Arabidopsis. The transgene expression of eight T₃ transgenic plants was detected by quantitative real time PCR and three independent overexpression lines with different transgene expression level were selected for further analysis.For the germination assays,CkLEA4 overexpression lines germinated more quickly than that of wild type on medium containing different concentrations of NaCl,mannitol or ABA.The germination rate of wild type and CkLEA4 overexpression lines were all decreased with the increased concentrations of NaCl,mannitol or ABA,while the germination rate of wild type decreased more dramatically than that of the overexpression lines.The cotyledon greening rates of CkLEA4 overexpression lines were also higher than those of wild type under 200 mmol/L NaCl,400 mmol/L mannitol or low concentrations of ABA.Altogether,our results suggested that CkLEA4 improved Arabidopsis tolerance to salt,ABA and osmotic stress during seed germination stage.