Characterization of five polyamine oxidase isoforms in Arabidopsis thaliana
Characterization of five polyamine oxidase isoforms in Arabidopsis thaliana
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DOI：
10.1007/s00299-010-0881-1
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发表时间：
2010-06
影响因子：
6.2
通讯作者：
Yoshihiro Takahashi;Runzi Cong;G. Sagor;M. Niitsu;T. Berberich;T. Kusano
中科院分区：
文献类型：
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作者：
Yoshihiro Takahashi;Runzi Cong;G. Sagor;M. Niitsu;T. Berberich;T. Kusano
拟南芥（Arabidopsis thaliana）基因组中含有5个编码多胺氧化酶（PAO）的基因（AtPAO 1 ~ AtPAO 5）。AtPAO 1在花器官中具有特异性表达，AtPAO 2在幼苗的茎分生组织和根尖中表达，在生长后期，AtPAO 2在茎分生组织、叶柄和花药中表达量较高。AtPAO 3基因在花器官中表达量最高，在子叶、根的远端、成熟莲座叶的边缘和花丝中均有表达; AtPAO 4基因在包括根在内的幼苗中表达量最高，AtPAO 5在成熟期普遍表达，在茎中表达量较低，在整个植株的生长过程中都有表达阶段它的最高表达是在花中，特别是在萼片中，但不是在花瓣中。此外，我们确定了AtPAO 1对AtPAO 4的底物特异性。没有一种AtPAO酶识别腐胺（Put）。AtPAO 2和AtPAO 3显示出几乎相似的底物识别模式，其中最优选的底物是亚精胺（Spd），其次是对其他四胺的特异性较低。AtPAO 4似乎是精胺（Spm）特异性的。更有趣的是，AtPAO 1偏好热精胺（T-Spm）和去甲精胺（NorSpm），而不识别Spd。在此基础上，对AtPAOs的个体功能进行了讨论.
The genome ofArabidopsis thalianacontains five genes (AtPAO1toAtPAO5) encoding polyamine oxidase (PAO) which is an enzyme responsible for polyamine catabolism. To understand the individual roles of the five AtPAOs, here we characterized their tissue-specific and space-temporal expression.AtPAO1seems to have a specific function in flower organ.AtPAO2was expressed in shoot meristem and root tip of seedlings, and to a higher extent in the later growth stage within restricted parts of the organs, such as shoot meristem, leaf petiole and also in anther. The expression ofAtPAO3was constitutive, but highest in flower organ.AtPAO3promoter activity was detected in cotyledon, distal portion of root, boundary region of mature rosette leaf and in filaments of flower.AtPAO4was expressed at higher level all over young seedlings including roots, and in the mature stage its expression was ubiquitous with rather lower level in stem.AtPAO5expression was observed in the whole plant body throughout various growth stages. Its highest expression was in flowers, particularly in sepals, but not in petals. Furthermore, we determined the substrate specificity of AtPAO1 to AtPAO4. None of the AtPAO enzymes recognized putrescine (Put). AtPAO2 and AtPAO3 showed almost similar substrate recognition patterns in which the most preferable substrate is spermidine (Spd) followed by less specificity to other tetraamines tested. AtPAO4 seemed to be spermine (Spm)-specific. More interestingly, AtPAO1 preferred thermospermine (T-Spm) and norspermine (NorSpm) to Spm, but did not recognize Spd. Based on the results, the individual function of AtPAOs is discussed.