摘要
为了解钾和油菜素内酯(BRs)在调控植物抗逆境胁迫中的作用,以超量表达K+吸收基因NsAKT1及BRs合成基因AtDWF4的转基因烟草为材料,分析PEG渗透胁迫对其形态及抗性指标等的影响。结果表明,PEG胁迫3 d时,转基因烟草SOD活性即达到极值且显著高于非转基因烟草(Wt),其中以共转AKT1/DWF4植株中SOD活性最高;而PEG胁迫1 d时,3种转基因植株的POD活性均显著(p<0.05)高于Wt植株,且共转AKT1/DWF4植株中POD活性分别是单转AKT1植株的1.28倍、单转DWF4植株的1.40倍和Wt植株的1.90倍;PEG胁迫第3天时,共转AKT1/DWF4植株中CAT活性增幅最大,达59.18%,显著高于其他2种转基因烟草。同时,H2O2和MDA含量测定表明,PEG处理后Wt中MDA和H2O2含量均在第5天时达极值,分别为58.52 nmol/g和38.21μg/g,均显著高于转基因烟草。另外,特征基因表达分析表明,NsAKT1和AtDWF4可能协同调控共转AKT1/DWF4烟株对PEG渗透胁迫的抗性。本研究为进一步揭示K和BRs协同介导的烟草抗逆境胁迫应答机制以及创制优良的烟草新种质奠定理论依据。
In order to study the role of potassium and BRs in regulating plant resistance to stresses,the transgenic tobaccos overexpressing the K+absorption gene NsAKT1 and the BRs synthetic gene AtDWF4 were used to analyze the effects of PEG osmotic stress on morphology and resistance-related physicochemical indexes of transgenic tobaccos.The results showed that SOD activities of the transgenic tobacco plants reached the maximum values at 3 d after PEG treatment,which was significantly higher than that of non-transgenic tobacco(Wt).Among them,the highest SOD enzyme activity was in plants co-transformed with AKT1/DWF4.The POD enzyme activities of the three transgenic plants were significantly higher than that of Wt plants at 1 d after PEG stress(p<0.05),and the POD enzyme activities in the AKT1/DWF4 co-transformed tobacco plants were 1.28 folds,1.40 folds and 1.90 folds higher than that of trans-AKT1 plants,trans-DWF4 plants and Wt plants,respectively.Three days after PEG treatment,CAT enzyme activities in the AKT1/DWF4 plants increased the most,up to 59.18%,which was significantly higher than the other two transgenic tobaccos.Meanwhile,the determination of H2O2 and MDA contents showed that the maximum values of MDA and H2O2 in Wt were 58.52 nmol/g and 38.21μg/g,respectively.Five days after PEG stress,these values were significantly higher than those in transgenic tobacco plants.Additionally,the expression analysis of characteristic genes indicated that NsAKT1 and AtDWF4 might synergistically regulate the resistance to PEG osmotic stress of the AKT1/DWF4 tobacco lines.The results of this study provided a theoretical basis for further understanding of the mechanism of K and BRs synergistically mediated tobacco response to stresses and the creation of excellent new tobacco germplasm.
作者
韦春
秦利军
WEI Chun;QIN Lijun(Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region(Ministry of Education)and College of Life Sciences,Guizhou University,Guiyang 550025,China)
出处
《中国烟草科学》
CSCD
北大核心
2020年第6期7-16,共10页
Chinese Tobacco Science
基金
贵州省科技计划项目“烟草钾离子通道蛋白及BR对植株抗非生物胁迫研究”{黔科合LH[2016]7449号}
贵州大学人才培育项目“油菜素内酯介导的烟草抗TMV机理研究”{黔科合平台人才[2018]5781号}。
关键词
烟草
AKT1
DWF4
抗旱性
Nicotiana tabacum
AKT1
DWF4
drought-resistance
