过表达马铃薯StuPPO9基因对烟草抗旱能力的影响

Impact of potato StuPPO9 gene overexpression on drought resistance in Nicotiana benthamiana

为鉴定马铃薯多酚氧化酶基因StuPPO9在干旱胁迫响应中的功能,本研究以利用农杆菌介导法获得的过表达StuPPO9基因的本氏烟草为材料,通过盆栽试验模拟自然干旱胁迫,对比转基因株系和空载转化(WT)烟草植株干旱胁迫0 d、3 d、6 d、9 d、12 d的生长形态,测定叶绿素、丙二醛、脯氨酸含量和抗氧化酶活性等生理指标以及抗旱相关基因的表达情况。结果表明,干旱处理后过表达株系叶片的相对含水量、叶绿素、脯氨酸含量以及SOD、POD活性均显著高于WT,而丙二醛含量则显著低于WT。RT-qPCR分析发现,活性氧(reactive oxygen species, ROS)清除系统基因SOD、POX, ABA生物合成基因NCED、RD29A,脯氨酸生物合成基因P5CS以及其他应激反应基因LEA、ADC、SAMDC等的表达量明显升高。本研究表明,StuPPO9基因增强了烟草植株对干旱的耐受性,为探明StuPPO9基因调控干旱胁迫响应的功能提供理论依据。

To investigate the role of the potato polyphenol oxidase gene StuPPO9 in response to drought stress,we utilized the overexpression of the StuPPO9 gene in Nicotiana benthamiana through Agrobacterium-mediated transformation as the experi-mental material.Pot experiments were conducted to simulate natural drought stress,and various physiological indicators including growth morphology,chlorophyll content,malondialdehyde and proline levels,antioxidant enzyme activity,and expression of re-lated resistance genes were compared and measured in transgenic and wild-type tobacco plants under drought stress for 0,3,6,9 and 12 days.The results revealed that following the drought treatment,the transgenic strains exhibited significantly higher relative water content,chlorophyll content,proline levels,and superoxide dismutase(SOD)and peroxidase(POD)activities compared to the wild-type plants.Conversely,the malondialdehyde content was significantly lower in the transgenic strains compared to the wild-type.RT-qPCR analysis demonstrated a significant upregulation of expression levels in ROS scavenging system genes(SOD,POX),ABA biosynthesis genes(NCED,RD29A),proline biosynthesis gene(P5CS),and other stress response genes(LEA,ADC,SAMDC).These findings suggest that the overexpression of the StuPPO9 gene enhances drought tolerance in tobacco plants,pro-viding a theoretical foundation for further exploration of StuPPO9’s role in regulating drought stress response.