Boronic acid treatment phenocopies monopteros by affecting PIN1 membrane stability and polar auxin transport in Arabidopsis thaliana embryos
Boronic acid treatment phenocopies monopteros by affecting PIN1 membrane stability and polar auxin transport in Arabidopsis thaliana embryos
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DOI：
10.1242/dev.131375
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发表时间：
2016-11-01
期刊：
影响因子：
4.6
通讯作者：
Torres-Ruiz, Ramon A.
中科院分区：
文献类型：
--
作者：
Matthes, Michaela;Torres-Ruiz, Ramon A.
多项观察结果表明，微量营养素硼 (B) 在质膜 (PM) 中具有稳定作用，支持 PM 相关（激素）信号传导过程的功能。然而，这个角色的特征却很差。在这里，我们展示了用硼酸（B 的特定竞争者）进行处理，模拟了拟南芥无根模式突变体单翅目。至少部分原因是早期胚胎中苯硼酸 (PBA) 诱导膜局部生长素流出载体 PINFORMED1 (PIN1) 内化。 PIN1 内化会中断涉及植物激素生长素、PIN1 和转录因子基因 MONOPTEROS 的反馈信号转导级联。这会带来多种影响，包括血管细胞前体发育异常、MONOPTEROS下游靶标的抑制以及根生长素最大值的丧失——根生长素最大值是根分生组织发育的重要信号。当 PIN1 被内化时，我们观察到 PBA 对其他蛋白质的不同影响，这些蛋白质要么不受影响，要么被内化，或者像 B 转运蛋白 BOR1 一样，在 PM 处稳定。这些发现表明 PBA 与 B 竞争植物膜蛋白，并可能揭示 B 在 PM 中的功能。
Several observations suggest that the micronutrient boron (B) has a stabilising role in the plasma membrane (PM), supporting functions in PM-linked (hormone) signalling processes. However, this role is poorly characterised. Here we show treatment with boronic acids, specific competitors of B, phenocopies the Arabidopsis thaliana rootless pattern mutant monopteros. At least in part, this is caused by phenylboronic acid (PBA)-induced internalisation of the membrane-localised auxin efflux carrier PINFORMED1 (PIN1) in the early embryo. PIN1 internalisation interrupts the feedback signal transduction cascade involving the phytohormone auxin, PIN1 and the transcription factor gene MONOPTEROS. This entails several effects, including abnormal development of vascular cell precursors, suppression of MONOPTEROS downstream targets and loss of the root auxin maximum - essential signals for root meristem development. While PIN1 is internalised, we observe a differential effect of PBA on other proteins, which are either unaffected, internalised or, as in the case of the B transporter BOR1, stabilised at the PM. These findings suggest acompetition of PBA with B for plant membrane proteins and might shed light on the function of B at the PM.