Peroxidase genes differentially respond to auxin during the formation of adventitious roots in soybean hypocotyl
Peroxidase genes differentially respond to auxin during the formation of adventitious roots in soybean hypocotyl
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DOI：
10.1007/s10725-009-9431-7
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发表时间：
2010-03-01
影响因子：
4.2
通讯作者：
Liu, Zin-Huang
中科院分区：
文献类型：
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作者：
Chou, Chien-Hung;Huang, Yi-Chi;Liu, Zin-Huang
在本研究中，生长素（IAA、IBA和NAA）能有效促进大豆下胚轴的生根。第2天（诱导期）外源生长素显著抑制了阴离子过氧化物酶（POX） （pI 3.7）和阳离子过氧化物酶（POX） （pI 8.5）的活性。当孵育时间延长至第3天和第4天（起始期）时，iba处理组织中某些特定阴离子pox （pI 4.0和pI 5.3）与对照相比显著增加。我们利用PLACE和PlantCARE数据库对pi8.5和pi5.3痘基因的5'-侧翼区域进行测序，以确定几个潜在的顺式调控元件。pi8.5 POX基因启动子包含两个与生长素应答元件同源的位点；图案ARF/AuxRE和CATATGGMSAUR。在诱导期，外源生长素显著抑制了pi8.5 POX的活性。pi8.5痘基因启动子包含ARF/AuxRE和CATATGGMSAUR两个基序，它们对生长素的响应早于pi5.3痘基因。因此，pi8.5 POX基因可能属于生长素反应的初级基因。pi5.3痘痘基因仅含有ARF/AuxRE基序，对生长素的应答要晚一两天。此外，不同于pi8.5和pi3.7的POX受到生长素的抑制，pi5.3的POX受到生长素尤其是IBA的诱导或增强。pi5.3 POX在大豆下胚轴不定根形成的起始阶段产生H2O2，引起生长素诱导的生长。
In our investigation, auxins (IAA, IBA and NAA) effectively promoted rooting in soybean hypocotyls. The activity of anionic peroxidase (POX) (pI 3.7) and cationic POX (pI 8.5) was significantly suppressed by exogenous auxins on day 2 (the inductive phase). Some particular anionic POXs (pI 4.0 and pI 5.3) significantly increased in IBA-treated tissues as compared with the control when the incubation time was prolonged to day 3 and day 4 (the initiation phase). We sequenced 5'-flanking region of pI 8.5 and pI 5.3 POX genes using the PLACE and PlantCARE databases to identify several potential cis-regulatory elements. The pI 8.5 POX gene promoter contained two sites that were homologous to sequences commonly found in auxin response elements; motifs ARF/AuxRE and CATATGGMSAUR. During the inductive phase, the activity of pI 8.5 POX was significantly suppressed by the exogenously applied auxins. The pI 8.5 POX gene promoter contained both ARF/AuxRE and CATATGGMSAUR motifs that responded to auxins earlier than the pI 5.3 POX gene. Hence, the pI 8.5 POX gene might belong to primary auxin response genes. The pI 5.3 POX gene, which responded to auxins a day or two later, contained only ARF/AuxRE motif. Moreover, unlike pI 8.5 and pI 3.7 POXs that were suppressed by auxins, the pI 5.3 POX was induced or enhanced by the applied auxins, especially IBA. The pI 5.3 POX might generate H2O2 which caused the auxin-induced growth at the initiation phase during the formation of adventitious root in soybean hypocotyls.