Spermine modulates the expression of two probable polyamine transporter genes and determines growth responses to cadaverine in Arabidopsis
Spermine modulates the expression of two probable polyamine transporter genes and determines growth responses to cadaverine in Arabidopsis
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DOI：
10.1007/s00299-016-1957-3
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发表时间：
2016-06-01
影响因子：
6.2
通讯作者：
Kusano, Tomonobu
中科院分区：
文献类型：
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作者：
Sagor, G. H. M.;Berberich, Thomas;Kusano, Tomonobu
两个基因 LAT1 和 OCT1 可能参与拟南芥中的多胺转运。内源精胺水平调节其表达并决定对尸胺的敏感性。拟南芥精胺 (Spm) 合酶 (SPMS) 基因缺陷突变体先前被证明对二胺尸胺 (Cad) 具有相当的抗性。此外，多胺氧化酶 4 基因缺陷的突变体比野生型植物积累了大约两倍的 Spm，显示出对 Cad 的敏感性增加。这表明内源 Spm 含量决定了拟南芥对 Cad 的生长反应。在这里，我们发现用Spm预处理的拟南芥幼苗吸收更多的Cad并且根系生长更短，并且过表达SPMS基因的转基因拟南芥植物对Cad高度敏感，进一步支持了上述观点。过表达 L-氨基酸转运蛋白 1 (LAT1) 的转基因拟南芥吸收了更多的 Cad，并表现出增加的 Cad 敏感性，表明 LAT1 作为 Cad 导入器发挥作用。最近，其他研究小组报道有机阳离子转运蛋白1（OCT1）是决定各种拟南芥种质对Cad敏感性的致病基因。此外，他们的结果表明 OCT1 参与 Cad 外流。因此我们在上述实验中监测了OCT1和LAT1的表达。基于这些结果，我们提出了一个模型，其中Spm含量水平调节OCT1和LAT1的表达，并确定拟南芥的Cad敏感性。
Two genes, LAT1 and OCT1 , are likely to be involved in polyamine transport in Arabidopsis. Endogenous spermine levels modulate their expression and determine the sensitivity to cadaverine.Arabidopsis spermine (Spm) synthase (SPMS) gene-deficient mutant was previously shown to be rather resistant to the diamine cadaverine (Cad). Furthermore, a mutant deficient in polyamine oxidase 4 gene, accumulating about twofold more of Spm than wild type plants, showed increased sensitivity to Cad. It suggests that endogenous Spm content determines growth responses to Cad in Arabidopsis thaliana. Here, we showed that Arabidopsis seedlings pretreated with Spm absorbs more Cad and has shorter root growth, and that the transgenic Arabidopsis plants overexpressing the SPMS gene are hypersensitive to Cad, further supporting the above idea. The transgenic Arabidopsis overexpressing L-Amino acid Transporter 1 (LAT1) absorbed more Cad and showed increased Cad sensitivity, suggesting that LAT1 functions as a Cad importer. Recently, other research group reported that Organic Cation Transporter 1 (OCT1) is a causal gene which determines the Cad sensitivity of various Arabidopsis accessions. Furthermore, their results suggested that OCT1 is involved in Cad efflux. Thus we monitored the expression of OCT1 and LAT1 during the above experiments. Based on the results, we proposed a model in which the level of Spm content modulates the expression of OCT1 and LAT1, and determines Cad sensitivity of Arabidopsis.