Functional characterization of a Nudix hydrolase AtNUDX8 upon pathogen attack indicates a positive role in plant immune responses.
Functional characterization of a Nudix hydrolase AtNUDX8 upon pathogen attack indicates a positive role in plant immune responses.
复制标题
DOI：
10.1371/journal.pone.0114119
复制
发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Dong X
中科院分区：
文献类型：
--
作者：
Fonseca JP;Dong X
Nudix 水解酶由拟南芥中的一个由 29 个成员组成的大基因家族组成，每个基因家族都包含能够水解特定底物（如 ADP-葡萄糖和 NADH）的保守基序。到目前为止，该家族中只有两个成员 AtNUDX6 和 AtNUDX7 已被证明与植物免疫有关。 RPP4 是来自多基因家族的抗性基因，赋予对霜霉病的抗性。在野生型 (WT) 和 rpp4 突变体中接种拟南芥霜霉后进行时程表达谱分析，以鉴定 RPP4 介导的抗性中差异表达的基因。 AtNUDX8 是已确定的几个差异表达、下调基因之一。从 Salk T-DNA 插入集合中获得了 T-DNA 敲除突变体 (KO-nudx8)，该突变体表现出 AtNUDX8 表达的消除。 KO-nudx8突变体与卵菌病原体Hpa和细菌病原体丁香假单胞菌pv分别感染。斑状菌 ES4326。与野生型对照相比，突变体对两种病原体的疾病敏感性显着增强。我们观察到 KO-nudx8 突变体植物在 12/12 小时光周期但不超过 16/8 小时光周期生长时出现小的、发育不良的表型。 AtNUDX8 表达在开灯后 8 小时达到峰值，并且该表达被水杨酸 (SA) 显着抑制四倍。与WT相比，KO-nudx8突变体中三种病原体响应性硫氧还蛋白（TRX-h2、TRX-h3和TRX-h5）的表达在特定时间点下调。此外，KO-nudx8 植物（如 npr1 突变体）表现出 SA 超敏性。 KO-nudx8 突变体中关键的 SA 生物合成基因 ICS1 的表达在特定时间点受到抑制，表明 AtNUDX8 参与植物中的 SA 信号传导。同样，在 KO-nudx8 突变体中，NPR1 和 PR1 转录水平也在特定时间点下调。这项研究表明，AtNUDX8 作为拟南芥防御的正调节因子参与植物免疫。
Nudix hydrolases comprise a large gene family of twenty nine members in Arabidopsis, each containing a conserved motif capable of hydrolyzing specific substrates like ADP-glucose and NADH. Until now only two members of this family, AtNUDX6 and AtNUDX7, have been shown to be involved in plant immunity. RPP4 is a resistance gene from a multigene family that confers resistance to downy mildew. A time course expression profiling after Hyaloperonospora arabidopsidis inoculation in both wild-type (WT) and the rpp4 mutant was carried out to identify differentially expressed genes in RPP4-mediated resistance. AtNUDX8 was one of several differentially expressed, downregulated genes identified. A T-DNA knockout mutant (KO-nudx8) was obtained from a Salk T-DNA insertion collection, which exhibited abolished AtNUDX8 expression. The KO-nudx8 mutant was infected separately from the oomycete pathogen Hpa and the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326. The mutant displayed a significantly enhanced disease susceptibility to both pathogens when compared with the WT control. We observed a small, stunted phenotype for KO-nudx8 mutant plants when grown over a 12/12 hour photoperiod but not over a 16/8 hour photoperiod. AtNUDX8 expression peaked at 8 hours after the lights were turned on and this expression was significantly repressed four-fold by salicylic acid (SA). The expression of three pathogen-responsive thioredoxins (TRX-h2, TRX-h3 and TRX-h5) were downregulated at specific time points in the KO-nudx8 mutant when compared with the WT. Furthermore, KO-nudx8 plants like the npr1 mutant, displayed SA hypersensitivity. Expression of a key SA biosynthetic gene ICS1 was repressed at specific time points in the KO-nudx8 mutant suggesting that AtNUDX8 is involved in SA signaling in plants. Similarly, NPR1 and PR1 transcript levels were also downregulated at specific time points in the KO-nudx8 mutant. This study shows that AtNUDX8 is involved in plant immunity as a positive regulator of defense in Arabidopsis.
登录
查看更多内容
影响因子：
4.9
作者：
Munoz, Francisco Jose;Baroja-Fernandez, Edurne;Pozueta-Romero, Javier
通讯作者：
Pozueta-Romero, Javier
影响因子：
3.5
作者：
Lee, Ok Ran;Kim, Yu-Jin;Yang, Deok-Chun
通讯作者：
Yang, Deok-Chun
DOI：
10.1046/j.1439-0434.2003.00697.x
发表时间：
2003-03-01
期刊：
JOURNAL OF PHYTOPATHOLOGY-PHYTOPATHOLOGISCHE ZEITSCHRIFT
影响因子：
--
作者：
Patykowski, J;Urbanek, H
通讯作者：
Urbanek, H
影响因子：
14.9
作者：
Edgar, R;Domrachev, M;Lash, AE
通讯作者：
Lash, AE
影响因子：
--
作者：
Gunawardana D;Likic VA;Gayler KR
通讯作者：
Gayler KR