Mutational loss of the prohibitin AtPHB3 results in an extreme constitutive ethylene response phenotype coupled with partial loss of ethylene-inducible gene expression in Arabidopsis seedlings
Mutational loss of the prohibitin AtPHB3 results in an extreme constitutive ethylene response phenotype coupled with partial loss of ethylene-inducible gene expression in Arabidopsis seedlings
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DOI：
10.1093/jxb/erm086
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发表时间：
2007-01-01
影响因子：
6.9
通讯作者：
Larsen, Paul B.
中科院分区：
文献类型：
--
作者：
Christians, Matthew J.;Larsen, Paul B.
Eer3-1功能缺失突变体是通过对乙烯反应增强的拟南芥突变体幼苗进行筛选而鉴定的，在肉眼评估时，它既增加了对乙烯的敏感性，又严重夸大了对乙烯的反应，但在分子水平上表现出部分乙烯不敏感。EER3-1突变代表了一种具有乙烯依赖表型的条件等位基因，这是由于先前未知的禁止蛋白AtPHB3中的氨基酸替换而导致的，EER3功能完全丧失，导致空气中极端的结构性乙烯反应。在其他生物中，Prohibitins有不同的作用，包括转录调节，在哺乳动物中与肿瘤形成相关的这一能力的抑制功能的丧失。AtPHB3的亚细胞定位表明，它存在于几个细胞位置，包括细胞核和整个细胞质。遗传分析表明，eer3在ein2下游发挥作用，因为ein2-5；eer3-2双重突变体具有与eer3-2突变体相同的深刻的下胚轴抑制表型。根据目前的工作，AtPHB3可能作为乙烯调节基因的子集以及在乙烯存在下维持生长所需的一组基因表达的正向调节因子。
The eer3-1 loss-of-function mutant, which was identified by screening for Arabidopsis mutant seedlings with an enhanced ethylene tesponse, has both increased sensitivity and profound exaggeration of response to ethylene when visually assessed, yet exhibits partial ethylene insensitivity at the molecular level. The eer3-1 mutation represents a conditional allele with an ethylene-dependent phenotype that results from an amino acid substitution in the previously uncharacterized prohibitin, AtPHB3, with complete loss of EER3 function resulting in an extreme constitutive ethylene response in air. Prohibitins in other organisms have diverse roles including transcriptional regulation, with loss of prohibitin function in this capacity associated with tumour formation in mammals. Subcellular localization of AtPHB3 indicates that it is found in several cellular locations, including the nucleus and throughout the cytoplasm. Genetic analysis demonstrates that EER3 functions downstream of EIN2, since an ein2-5;eer3-2 double mutant has the same profound hypocotyl inhibition phenotype seen with the eer3-2 mutant. Based on the presented work, AtPHB3 probably functions as a positive regulator of expression of a subset of ethylene-regulated genes along with a group of genes required to maintain growth in the presence of ethylene.