Activation tagging of ADR2 conveys a spreading lesion phenotype and resistance to biotrophic pathogens
Activation tagging of ADR2 conveys a spreading lesion phenotype and resistance to biotrophic pathogens
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DOI：
10.1111/j.1469-8137.2009.02902.x
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发表时间：
2009-01-01
期刊：
影响因子：
9.4
通讯作者：
Loake, Gary J.
中科院分区：
文献类型：
--
作者：
Aboul-Soud, Mourad A. M.;Chen, Xinwei;Loake, Gary J.
用激活的T-DNA标签转化拟南芥PR1：：荧光素酶(Luc)转基因株系，筛选出具有组成性Luc活性的显性功能获得突变体，LUC成像检测到激活的抗病2号(Adr2)在没有病原体攻击的情况下表现出缓慢扩散的病变。对该突变体进行了详细的分子、遗传和组织化学分析。adr2植物结构性地表达了防御相关基因和抗氧化基因。此外，该品系积累了更多的水杨酸(SA)，并表现出更高的丝裂原激活蛋白激酶活性。ADR2植株表现出对多种生物营养型病原菌的抗性增强，但对坏死型病原菌的抗性不强。Adr2表型是由于Toll白细胞介素受体(TIR)核苷酸结合位点(NBS)富含亮氨酸重复序列(LRR)基因(At1g56510)过表达所致。在adr2nahG、adr2npr1和adr2eds1双突变体中，结构性PR1表达完全取消。此外，在adr2 nahG和adr2 eds1双突变体中，对拟南芥光肩孢菌Noco2的高度抗性受到了影响，但在adr2 npr1、adr2 coi1或adr2 etr1植株中没有。这些数据表明，adr2介导的抗性是通过增强的疾病敏感性(EDS)和依赖SA的防御信号网络来实现的，该网络独立于COI1或ETR1发挥作用。
An Arabidopsis PR1:: luciferase (LUC) transgenic line was transformed with activation T-DNA tags and the resulting population screened for dominant gain-of-function mutants exhibiting constitutive LUC activity.LUC imaging identified activated disease resistance 2 (adr2), which exhibited slowly spreading lesions in the absence of pathogen challenge. Molecular, genetic and histochemical analysis was employed to characterize this mutant in detail.adr2 plants constitutively expressed defence-related and antioxidant genes. Moreover, this line accrued increased quantities of salicylic acid (SA) and exhibited heightened mitogen-activated protein kinase activity. adr2 plants exhibited increased resistance against numerous biotrophic but not necrotrophic pathogens. The adr2 phenotype resulted from the overexpression of a Toll interleukin receptor (TIR) nucleotide binding site (NBS) leucine rich repeat (LRR) gene (At1g56510). Constitutive PR1 expression was completely abolished in adr2 nahG, adr2 npr1 and adr2 eds1 double mutants. Furthermore, heightened resistance against Hyaloperonospora arabidopsis Noco2 was compromised in adr2 nahG and adr2 eds1 double mutants but not in adr2 npr1, adr2 coi1 or adr2 etr1 plants.These data imply that adr2-mediated resistance operates through an Enhanced Disease Susceptibility (EDS) and SA-dependent defence signalling network which functions independently from COI1 or ETR1.