• The plant hormone auxin and its directional intercellular transport play a major role in diverse aspects of plant growth and development. The establishment of auxin gradients requires the asymmetric distribution of members of the auxin efflux carrier PIN‐FORMED (PIN) protein family to the plasma membrane. An endocytic pathway regulates the recycling of PIN proteins between the plasma membrane and endosomes, providing a mechanism for dynamic localisation.
• N‐Ethylmaleimide‐sensitive factor adaptor protein receptors (SNAP receptors, SNAREs) mediate fusion between vesicles and target membranes and are classed as Q‐ or R‐SNAREs based on their sequence. We analysed gain‐ and loss‐of‐function mutants, dominant‐negative transgenics and localisation of the Arabidopsis R‐SNARE VAMP714 protein to understand its function.
• We demonstrate that VAMP714 is essential for the insertion of PINs into the plasma membrane, for polar auxin transport, root gravitropism and morphogenesis. VAMP714 gene expression is upregulated by auxin, and the VAMP714 protein co‐localises with endoplasmic reticulum and Golgi vesicles and with PIN proteins at the plasma membrane.
• It is proposed that VAMP714 mediates the delivery of PIN‐carrying vesicles to the plasma membrane, and that this forms part of a positive regulatory loop in which auxin activates a VAMP714‐dependent PIN/auxin transport system to control development.

中文翻译：

---

拟南芥 R-SNARE VAMP714 对于 PIN 蛋白的极化和生长素反应至关重要

• 植物激素生长素及其定向细胞间转运在植物生长发育的各个方面发挥着重要作用。生长素梯度的建立需要生长素流出载体 PIN-FORMED (PIN) 蛋白家族成员在质膜上的不对称分布。内吞途径调节质膜和内体之间 PIN 蛋白的再循环，提供动态定位的机制。
• N-乙基马来酰亚胺敏感因子衔接蛋白受体（SNAP 受体，SNARE）介导囊泡和靶膜之间的融合，根据其序列分为 Q-或 R-SNARE。我们分析了拟南芥 R-SNARE VAMP714 蛋白的获得和丧失功能突变体、显性阴性转基因和定位，以了解其功能。
• 我们证明 VAMP714 对于将 PIN 插入质膜、极性生长素转运、根向地性和形态发生至关重要。VAMP714基因表达被生长素上调，VAMP714 蛋白与内质网和高尔基体囊泡以及质膜上的 PIN 蛋白共定位。
• 有人提出，VAMP714 介导携带 PIN 的囊泡向质膜的传递，这构成了生长素激活依赖 VAMP714 的 PIN/生长素转运系统以控制发育的正调节回路的一部分。