ABSTRACT Roots grow asymmetrically, sometimes helically, around their growth direction likely to facilitate environmental sensing. We recently demonstrated that nitrate deficiency induces root coiling on horizontal surface through nitrate transporter/sensor NRT1.1 and PIN2- and AUX-mediated polar auxin transport. Here, we show that nitrate deficiency or NRT1.1 loss-of-function induces differential distribution of PIN2 between the future concave and concave sides in root epidermal cells. Treatment with pharmacological drugs suggests that enhanced endocytosis at the future convex side leads to reduced plasma membrane (PM) association of PIN2. A reduction of PIN2 at the PM would maintain a low auxin response to further enhance endocytosis at the convex side, leading to root coiling.

中文翻译：

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硝酸盐缺乏通过 NRT1.1 诱导根中的差异内吞作用

摘要 根围绕其生长方向不对称生长，有时呈螺旋状生长，这可能有助于环境感知。我们最近证明，硝酸盐缺乏通过硝酸盐转运蛋白/传感器 NRT1.1 和 PIN2 和 AUX 介导的极性生长素转运诱导水平表面的根卷曲。在这里，我们表明硝酸盐缺乏或 NRT1.1 功能丧失导致 PIN2 在根表皮细胞未来凹面和凹面之间的差异分布。用药物治疗表明未来凸面的内吞作用增强会导致 PIN2 的质膜 (PM) 关联减少。PM 处 PIN2 的减少将保持低生长素反应，以进一步增强凸侧的内吞作用，导致根卷曲。