转CkLEA4基因拟南芥种子萌发期的抗逆性分析

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

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。

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 trans- genic 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 con- centrations of NaCl,mannitol or ABA. The germination rate of wild-type and CkLEA4 overexpression lines were all decreased with the increased concentrations of NaC1, 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 NaC1, 400 mmol/L mannitol or low concentrations of ABA. Altogether, our results suggested that CkLEA4 im- proved Arabidopsis tolerance to salt,ABA and osmotic stress during seed germination stage.