AtNFXL1, an Arabidopsis homologue of the human transcription factor NF-X1, functions as a negative regulator of the trichothecene phytotoxin-induced defense response
AtNFXL1, an Arabidopsis homologue of the human transcription factor NF-X1, functions as a negative regulator of the trichothecene phytotoxin-induced defense response
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DOI：
10.1111/j.1365-313x.2007.03353.x
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发表时间：
2008-02-01
期刊：
影响因子：
7.2
通讯作者：
Nishiuchi, Takumi
中科院分区：
文献类型：
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作者：
Asano, Tomoya;Masuda, Daisuke;Nishiuchi, Takumi
单端孢霉烯是由植物病原真菌产生的一个密切相关的植物毒素家族。在拟南芥中，AtNFXL 1的表达，一个假定的人类转录抑制因子NF-X1的同源物，显着诱导应用A型拟南芥，如T-2毒素。atnfxl 1突变体生长在培养基上没有表现出任何表型，而在T-2毒素处理的atnfxl 1突变体植物中观察到超敏表型。微阵列分析表明，几个防御相关基因（即WRKYs、NBS-LRR、EDS 5、ICS 1等）与野生型植物相比，在T-2毒素处理的atnfxl 1突变体中上调。此外，在T-2毒素处理的atnfxl 1突变体中观察到水杨酸（SA）积累增强，这表明AtNFXL 1通过SA依赖性信号通路充当这些防御相关基因的负调节因子。我们还发现SA和flg 22处理诱导AtNFXL 1的表达。此外，atnfxl 1突变体是不太敏感的兼容的植物病原体，假单胞菌pv.番茄菌株DC 3000（Pst DC 3000）。综上所述，这些结果表明AtNFXL 1在拟南芥的拟南芥烯反应以及一般防御反应中起着重要作用。
Trichothecenes are a closely related family of phytotoxins that are produced by phytopathogenic fungi. In Arabidopsis, expression of AtNFXL1, a homologue of the putative human transcription repressor NF-X1, was significantly induced by application of type A trichothecenes, such as T-2 toxin. An atnfxl1 mutant growing on medium lacking trichothecenes showed no phenotype, whereas a hypersensitivity phenotype was observed in T-2 toxin-treated atnfxl1 mutant plants. Microarray analysis indicated that several defense-related genes (i.e. WRKYs, NBS-LRRs, EDS5, ICS1, etc.) were upregulated in T-2toxin-treated atnfxl1 mutants compared with wildtype plants. In addition, enhanced salicylic acid (SA) accumulation was observed in T-2 toxin-treated atnfxl1 mutants, which suggests that AtNFXL1 functions as a negative regulator of these defense-related genes via an SA-dependent signaling pathway. We also found that expression of AtNFXL1 was induced by SA and flg22 treatment. Moreover, the atnfxl1 mutant was less susceptible to a compatible phytopathogen, Pseudomonas syringae pv. tomato strain DC3000 (Pst DC3000). Taken together, these results indicate that AtNFXL1 plays an important role in the trichothecene response, as well as the general defense response in Arabidopsis.