Gibberellin-Induced Expression of Fe Uptake-Related Genes in Arabidopsis
Gibberellin-Induced Expression of Fe Uptake-Related Genes in Arabidopsis
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DOI：
10.1093/pcp/pct160
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发表时间：
2014-01-01
影响因子：
4.9
通讯作者：
Satoh, Shinobu
中科院分区：
文献类型：
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作者：
Matsuoka, Keita;Furukawa, Jun;Satoh, Shinobu
在双子叶植物中，铁（Fe）通过位于根表皮的IRT 1（铁调节转运蛋白1）和FRO 2（铁还原氧化酶2）从土壤中获得。铁缺乏条件下，IRT 1和FRO 2的表达由拟南芥中的局部和系统信号诱导。在本研究中，赤霉素（GA）缺乏的ga 3 ox 1 ga 3 ox 2突变体的GA（4）处理促进了IRT 1、FRO 2、bHLH 038和bHLH 39的表达（后两者控制IRT 1和FRO 2的表达）。相反，FIT的表达，其编码在Fe缺乏下诱导IRT 1和FRO 2所必需的转录因子，不被GA的应用诱导（4）。即使在fit-2突变体中，也观察到由芽施用GA（4）触发的这些基因的诱导，所述fit-2突变体具有通过用GA生物合成抑制剂多效唑（PBZ）处理引起的内源GA水平降低。这些结果表明，FIT是不是一个关键的调节器在GA的反应，铁充足的条件下。另一方面，在铁吸收相关基因中，在铁充足条件下，与野生型（WT）相比，在ga 3 ox 1 ga 3 ox 2中IRT 1、bHLH 038和bHLH 39的表达较低，但在铁缺乏条件下，所有铁吸收相关基因的表达均降低。此外，PBZ处理在铁缺乏条件下降低WT中的IRT 1表达，但在fit-2突变体中不降低。这些数据表明，在铁充足和铁缺乏的条件下，GA的铁吸收相关基因的诱导的贡献，可能在适合独立和适合依赖的方式，分别。
In dicots, iron (Fe) is acquired from the soil by IRT1 (IRON-REGULATED TRANSPORTER 1) and FRO2 (FERRIC REDUCTION OXIDASE 2) that are localized at the root epidermis. IRT1 and FRO2 expression is induced by local and systemic signals under Fe-deficient conditions in Arabidopsis thaliana. In this study, the expression of IRT1, FRO2, bHLH038 and bHLH39 (the latter two of which control IRT1 and FRO2 expression) was promoted by GA(4) treatment of gibberellin (GA) deficient ga3ox1 ga3ox2 mutants. In contrast, the expression of FIT, which encodes a transcription factor necessary for IRT1 and FRO2 induction under Fe deficiency, was not induced by the application of GA(4). The induction of those genes triggered by shoot-applied GA(4) was observed, even in the fit-2 mutant which had reduced endogenous GA levels caused by treatment with paclobutrazol (PBZ), a GA biosynthesis inhibitor. These results suggested that FIT was not a key regulator in the GA responses under Fe-sufficient conditions. On the other hand, among Fe uptake-related genes, the expression of IRT1, bHLH038 and bHLH39 was lower in ga3ox1 ga3ox2 compared with the wild type (WT) under Fe-sufficient conditions, but the expression of all Fe uptake-related genes decreased under Fe-deficient conditions. Additionally, the PBZ treatment decreased IRT1 expression in the WT under Fe-deficient conditions, but not in the fit-2 mutant. These data suggest the contribution of GA to the induction of Fe uptake-related genes under Fe-sufficient and Fe-deficient conditions, possibly in FIT-independent and FIT-dependent manners, respectively.