Functional analysis of Arabidopsis ethylene-responsive element binding protein conferring resistance to Bax and abiotic stress-induced plant cell death
Functional analysis of Arabidopsis ethylene-responsive element binding protein conferring resistance to Bax and abiotic stress-induced plant cell death
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DOI：
10.1104/pp.105.063586
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发表时间：
2005-07-01
期刊：
影响因子：
7.4
通讯作者：
Uchimiya, H
中科院分区：
文献类型：
--
作者：
Ogawa, T;Pan, L;Uchimiya, H
通过在酿酒酵母中的功能筛选，分离到拟南芥乙烯反应元件结合蛋白（AtEBP）基因，该基因是拟南芥诱导的细胞死亡的抑制因子。为了进一步研究AtEBP在植物细胞中的细胞死亡抑制作用，我们建立了过表达AtEBP的转基因烟草（Nicotiana tabacum）植物以及在地塞米松诱导型启动子下异位表达小鼠Bax蛋白的转基因烟草植物。我们制备了每个转基因植物的选择系的杂交，根据细胞死亡抑制活性对其进行评价。结果表明，AtEBP抑制烟草植物中Bax诱导的细胞死亡，该作用也与降低的离子泄漏水平相关。此外，烟草亮黄-2细胞过表达AtEBP赋予抗过氧化氢（H2 O2）和热处理。AtEBP蛋白定位于细胞核中，并在使用稳定转基因系统的瞬时测定和实验中证实其作为体内转录激活剂。在过量表达AtEBP的转基因拟南芥植株中观察到防御基因的上调。通过对乙烯相关突变体mRNA积累的分析，提出了AtEBP在信号通路中的位置。
Arabidopsis ( Arabidopsis thaliana) ethylene-responsive element binding protein ( AtEBP) gene was isolated as a suppressor of Bax-induced cell death by functional screening in yeast ( Saccharomyces cerevisiae). To further examine the cell death suppressive action of AtEBP in plant cells, we established transgenic tobacco ( Nicotiana tabacum) plants overexpressing AtEBP as well as transgenic tobacco plants ectopically expressing mouse Bax protein under a dexamethasone-inducible promoter. We prepared the crosses of the selective lines of each transgenic plant, which were evaluated in terms of cell death suppression activity. Results indicate that AtEBP suppressed Bax- induced cell death in tobacco plants, an action also associated with a lowered level of ion leakage. Furthermore, tobacco Bright Yellow-2 cells overexpressing AtEBP conferred resistance to hydrogen peroxide ( H2O2) and heat treatments. AtEBP protein localized in the nucleus and functioned as an in vivo transcription activator as confirmed in transient assays and experiments using stable transgenic system. Up-regulation of defense genes was observed in transgenic Arabidopsis plants overexpressing AtEBP. Based on the analysis of mRNA accumulation in ethylene-related mutants, the position of AtEBP in signaling pathway is presented.