马铃薯抗晚疫病转基因材料的获得及活性氧清除酶系与抗病过程关系分析

Transgenic Potato Lines Conferring Resistance to Late Blight and the Relationship Between Resistance and Active Oxygen Scavenging-Enzymes

【目的】获得马铃薯抗晚疫病转基因材料,初步分析活性氧清除酶系与抗病过程的关系。【方法】通过农杆菌介导的方法,以茎段为外植体,将抗晚疫病基因R1、R3a和RB分别转化马铃薯感病栽培品种Desiree,并通过特异PCR扩增目的基因、无菌苗快速抗病鉴定和离体叶片接种鉴定、RT-PCR分析来筛选阳性转化株系。并测定转基因株系和野生型接种晚疫病原菌生理小种89148-9后,体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性变化。【结果】结果证明,3个抗晚疫病基因都已经整合进入马铃薯基因组中并稳定表达,所获得的转基因株系接种小种89148-9后其抗性有不同程度的提高,大部分表现为高抗或抗病,有明显的HR反应;转基因株系在接种小种89148-9后3种酶的活性都升高,且活性高峰比野生型早。【结论】获得了一批高抗或抗晚疫病的马铃薯转基因材料;活性氧清除酶系可能参与了R基因介导的抗病过程。

【Objective】The aim of the study is to obtain the transgenic potato lines conferring resistance to late blight and to study the relationship between resistance and active oxygen scavengers.【Method】Resistance genes（R1,R3a and RB） were separately introduced into potato susceptible cultivar Desiree via Agrobacterium tumefaciens-mediated transformation and confirmed by gene specific PCR,in vitro inoculation and detached leaf assay,RT-PCR analysis.Activities of superoxidase（SOD）,peroxidase（POD） and catalase（CAT） of transgenic potato lines and non-transgenic line were measured after inoculation of P.infestans strain 89148-9.【Result】The results indicated that three resistance genes were integrated into the potato genome and expressed stably.Transgenic potato lines had higher disease resistance than that of the non-transgenic ones,most of them showed localized hypersensitive necrosis to the avirulent strain.The SOD,POD and CAT activities of transgenic potato lines were higher than that of non-transgenic potato line and showed a peak earlier than that of non-transgenic potato line.【Conclusion】Some transgenic lines highly resistant or resistant to P.infestans strains had been obtained.The result also suggested that the scavenging-enzymes may involve in potato’s resistance to P.infestances.