etr1-1在矮牵牛中诱导表达可提高叶片对灰霉病的抗性  

Induced etr1-1 Expression in Petunias is Responsible for Its Tolerance to Botrytis cinerea

作　　者：王宏[1] 蔺经[1] 刘刚[2] 李春霞[2] 罗昌国 李刚波[2] 章镇[2] 常有宏[1] 

机构地区：[1]江苏省农业科学院园艺研究所/江苏省高效园艺作物遗传改良重点实验室,南京210014 [2]南京农业大学园艺学院,南京210095 [3]贵州果树科学研究所,贵阳550006

出　　处：《中国农业科学》2014年第8期1502-1511,共10页Scientia Agricultura Sinica

基　　金：国家自然科学基金项目(31300469)

摘　　要：【目的】研究etr1-1诱导表达对矮牵牛抗灰霉病的作用。【方法】以转GVG:etr1-1矮牵牛为材料,地塞米松(DEX)处理,接种灰霉病菌,通过调查发病程度和定量半定量基因表达分析揭示etr1-1在矮牵牛抗灰霉病中的作用。【结果】与对照叶片相比,DEX处理的矮牵牛叶片表现出延缓衰老和减轻病害的症状。接种病原菌后,DEX处理的叶片发病率增加比例为0,对照叶片为66.77%;DEX处理的叶片平均病斑扩展速率为4.69 mm·d-1,对照叶片为6.29 mm·d-1。qRT-PCR和semi-qRT-PCR基因表达分析表明,DEX处理的叶片etr1-1与Bcact表达呈相反趋势。在DEX处理叶片中,DEX诱导了叶片etr1-1表达,随着诱导时间延长,基因相对表达量上升,诱导后第3天达到最大,无菌水接种叶片的表达量是病原菌接种叶片的10.71倍。DEX处理的叶片,Bcact在接种后第1天表达量最大;对照叶片,Bcact在接种后第2天表达量最大;其中处理叶片Bcact的最大表达量比对照叶片降低了20倍。在DEX处理的叶片上随着etr1-1表达增强,Bcact表达量下降。DEX处理的叶片,CP10仅在接种后第3天轻微表达;对照叶片上,随接种时间延长,CP10表达量上升,接种后第3天达到最大,处理最大表达量比对照降低了23.6倍。随接种时间延长,DEX处理的叶片和对照叶片,ACO表达均先升高后降低,在第2天达到最大,处理叶片上最大表达量仅为6.75,比对照低7.33倍。DEX处理的叶片,乙烯途径基因ETR2、ERS1、EIL1和EIN2表达受到抑制。ERS1和ETR2在DEX处理和对照叶片上均有表达,并在接种后第3天达到最大,但处理的最大表达量比对照低51倍。DEX处理的叶片,接种后第1—2天EIN2表达被抑制,第3天表达上升,在对照叶片上,EIN2表达量随接种时间而增加,第3天达到最大,DEX处理的叶片EIN2最大表达量比对照低31.58倍;DEX处理的叶片和对照叶片,EIL1与EIN2有相似的表达趋势,且DEX处理的叶片EIL1最大表达量低于对照两�[Objective]The objective of this study is to clarify the effect of induced etr1-1 expression on petunia response to infection by Botrytis cinerea, the causal agent of gray mold disease. [Method]Detached leaves of GVG：etr1-1 transgenic petunias treated by DEX were inoculated with B. cinerea, then the regulation mechanism of etr1-1 was investigated by observing disease symptoms, measuring disease severity and analyzing gene expression by quantitative RT-PCR and semi-quantitative RT-PCR. [Result]Induced etr1-1 expression by dexamethasone resulted in the retarded senescence and reduced disease symptoms on detached leaves. During the period of inoculation, the percentage of increased disease incidence was 0 on DEX-treated leaves, whereas 66.77%on control leaves. The growth rate of the leaf lesions on DEX-treated leaves was 4.69 mm＆#183;d-1, whereas 6.29 mm＆#183;d-1 on control leaves. qRT-PCR and semi-qRT-PCR provided the following results. The extent of decreased disease incidence was negatively correlated with the etr1-1 expression. Following prolonged induction time, the level of etr1-1 expression was enhanced on DEX-treated leaves and obtained the peak at 3rd day after DEX treatment. 10.71-fold changes were increased on mock-inoculating leaves than that on B. cinerea-inoculating leaves. The maximum expression of Bcact was obtained at 1 dpi on DEX-treated leaves, whereas, at 2 dpi on control leaves. The maximum level of Bcact expression was 20-fold lower on DEX-treated leaves than that on control leaves. Infection of B. cinerea activated CP10 expression and caused the senescence symptom. In comparison, 23.6-fold changes were decreased on DEX-treated leaves than on control leaves. The expression of ACO exhibited a decline after an up on both DEX-treated and control leaves. The peak of expression level was observed at 2 dpi. The peak of expression of ACO was only 6.75 on DEX-treated leaves, which suggested 7.33-fold lower than that on control leaves. On DEX-treated leaves with induced etr1-1 expression, represse

关 键 词：矮牵牛'Mitchell diploid’ 灰霉病菌 乙烯 茉莉酸 衰老 防御响应 

分 类 号：S436.81[农业科学—农业昆虫与害虫防治]