Vieten Anne, Vanneste Steffen, Wisniewska Justyna, Benková Eva, Benjamins René, Beeckman Tom, Luschnig Christian, Friml Jirí
Centre for Molecular Biology of Plants, University Tübingen, Auf der Morgenstelle 3, 72076 Tübingen, Germany.
Development. 2005 Oct;132(20):4521-31. doi: 10.1242/dev.02027.
Plant development displays an exceptional plasticity and adaptability that involves the dynamic, asymmetric distribution of the phytohormone auxin. Polar auxin flow, which requires polarly localized transport facilitators of the PIN family, largely contributes to the establishment and maintenance of the auxin gradients. Functionally overlapping action of PIN proteins mediates multiple developmental processes, including embryo formation, organ development and tropisms. Here we show that PIN proteins exhibit synergistic interactions, which involve cross-regulation of PIN gene expression in pin mutants or plants with inhibited auxin transport. Auxin itself positively feeds back on PIN gene expression in a tissue-specific manner through an AUX/IAA-dependent signalling pathway. This regulatory switch is indicative of a mechanism by which the loss of a specific PIN protein is compensated for by auxin-dependent ectopic expression of its homologues. The compensatory properties of the PIN-dependent transport network might enable the stabilization of auxin gradients and potentially contribute to the robustness of plant adaptive development.
植物发育表现出非凡的可塑性和适应性，这涉及植物激素生长素的动态、不对称分布。生长素极性运输需要PIN家族的极性定位运输促进因子，在很大程度上有助于生长素梯度的建立和维持。PIN蛋白的功能重叠作用介导了多个发育过程，包括胚胎形成、器官发育和向性运动。我们在此表明，PIN蛋白表现出协同相互作用，这涉及在pin突变体或生长素运输受抑制的植物中PIN基因表达的交叉调控。生长素本身通过AUX/IAA依赖的信号通路以组织特异性方式正向反馈调节PIN基因表达。这种调节开关表明了一种机制，即特定PIN蛋白的缺失可通过其同源物的生长素依赖异位表达得到补偿。PIN依赖运输网络的补偿特性可能使生长素梯度得以稳定，并可能有助于植物适应性发育的稳健性。
