Arabidopsis mutant plants with diverse defects in polyamine metabolism show unequal sensitivity to exogenous cadaverine probably based on their spermine content
Arabidopsis mutant plants with diverse defects in polyamine metabolism show unequal sensitivity to exogenous cadaverine probably based on their spermine content
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DOI：
10.1007/s12298-014-0227-5
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发表时间：
2014-04-01
影响因子：
3.5
通讯作者：
Kusano, Tomonobu
中科院分区：
文献类型：
--
作者：
Liu, Taibo;Dobashi, Hayato;Kusano, Tomonobu
拟南芥植物不合成多胺尸胺，一种五碳链二胺和腐胺的结构类似物。多胺代谢基因缺陷的突变体暴露于外源尸胺。精胺缺陷型spms突变体生长良好，而多胺氧化酶（PAO）4的T-DNA插入突变体（pao 4 -1）的根生长受到严重抑制相比，野生型（WT）或其他pao功能丧失突变体。为了理解这种现象的分子基础，分析了用尸胺处理的WT、spms和pao 4 -1植物的多胺含量。腐胺含量在所有三种植物中增加，亚精胺含量在WT和pao 4 -1中降低，但在spms中不增加。WT和pao 4 -1中精胺含量增加。由于腐胺（或精胺）含量与根系生长抑制程度之间存在良好的相关性，因此研究了外源腐胺和精胺的影响。精胺模仿原来的现象，而高水平的腐胺均匀地抑制根的生长，这表明尸胺诱导的精胺积累可以解释这种现象。我们还测试了尸胺处理的WT和pao 4 -1植物对NaCl的生长反应，发现精胺积累的pao 4 -1植物不耐NaCl。在此基础上，讨论了尸胺对拟南芥生长的影响以及聚苯胺在盐胁迫中的作用。
Arabidopsis plants do not synthesize the polyamine cadaverine, a five carbon-chain diamine and structural analog of putrescine. Mutants defective in polyamine metabolic genes were exposed to exogenous cadaverine. Spermine-deficient spms mutant grew well while a T-DNA insertion mutant (pao4-1) of polyamine oxidase (PAO) 4 was severely inhibited in root growth compared to wild type (WT) or other pao loss-of-function mutants. To understand the molecular basis of this phenomenon, polyamine contents of WT, spms and pao4-1 plants treated with cadaverine were analyzed. Putrescine contents increased in all the three plants, and spermidine contents decreased in WT and pao4-1 but not in spms. Spermine contents increased in WT and pao4-1. As there were good correlations between putrescine (or spermine) contents and the degree of root growth inhibition, effects of exogenously added putrescine and spermine were examined. Spermine mimicked the original phenomenon, whereas high levels of putrescine evenly inhibited root growth, suggesting that cadaverine-induced spermine accumulation may explain the phenomenon. We also tested growth response of cadaverine-treated WT and pao4-1 plants to NaCl and found that spermine-accumulated pao4-1 plant was not NaCl tolerant. Based on the results, the effect of cadaverine on Arabidopsis growth and the role of PAO during NaCl stress are discussed.