Plant hormones coordinate responses to environmental cues with developmental programs 1 , and are fundamental for stress resilience and agronomic yield 2 . The core signalling pathways underlying the effects of phytohormones have been elucidated by genetic screens and hypothesis-driven approaches, and extended by interactome studies of select pathways 3 . However, fundamental questions remain about how information from different pathways is integrated. Genetically, most phenotypes seem to be regulated by several hormones, but transcriptional profiling suggests that hormones trigger largely exclusive transcriptional programs 4 . We hypothesized that protein–protein interactions have an important role in phytohormone signal integration. Here, we experimentally generated a systems-level map of the Arabidopsis phytohormone signalling network, consisting of more than 2,000 binary protein–protein interactions. In the highly interconnected network, we identify pathway communities and hundreds of previously unknown pathway contacts that represent potential points of crosstalk. Functional validation of candidates in seven hormone pathways reveals new functions for 74% of tested proteins in 84% of candidate interactions, and indicates that a large majority of signalling proteins function pleiotropically in several pathways. Moreover, we identify several hundred largely small-molecule-dependent interactions of hormone receptors. Comparison with previous reports suggests that noncanonical and nontranscription-mediated receptor signalling is more common than hitherto appreciated. A systems-level map of the Arabidopsis hormone signalling network, comprising more than 2,000 binary protein–protein interactions, reveals hundreds of interpathway contact points, many of which mediate crosstalk between different hormone pathways.

中文翻译：

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植物激素蛋白网络的广泛信号整合

植物激素通过发育计划 1 协调对环境线索的反应，并且是抗逆力和农艺产量 2 的基础。遗传筛选和假设驱动的方法已经阐明了植物激素影响的核心信号通路，并通过选择通路的相互作用组研究进行了扩展 3。然而，关于如何整合来自不同途径的信息的基本问题仍然存在。从基因上讲，大多数表型似乎受几种激素的调节，但转录谱表明激素触发了主要的排他性转录程序 4。我们假设蛋白质-蛋白质相互作用在植物激素信号整合中具有重要作用。在这里，我们通过实验生成了拟南芥植物激素信号网络的系统级图谱，由超过 2,000 个二元蛋白质-蛋白质相互作用组成。在高度互联的网络中，我们确定了通路群落和数百个以前未知的通路接触，它们代表了潜在的串扰点。七种激素途径中候选物的功能验证揭示了 84% 的候选相互作用中 74% 的测试蛋白质的新功能，并表明大多数信号蛋白在几种途径中发挥多效性。此外，我们确定了数百种主要依赖于小分子的激素受体相互作用。与以前的报告比较表明，非经典和非转录介导的受体信号传导比迄今为止所理解的更为常见。拟南芥激素信号网络的系统级图，包括 2 个以上，