Strigolactones (SLs) are important ex‐planta signalling molecules in the rhizosphere, promoting the association with beneficial microorganisms, but also affecting plant interactions with harmful organisms. They are also plant hormones in‐planta , acting as modulators of plant responses under nutrient‐deficient conditions, mainly phosphate (Pi) starvation. In the present work, we investigate the potential role of SLs as regulators of early Pi starvation signalling in plants. A short‐term pulse of the synthetic SL analogue 2′‐epi ‐GR24 promoted SL accumulation and the expression of Pi starvation markers in tomato and wheat under Pi deprivation. 2′‐epi ‐GR24 application also increased SL production and the expression of Pi starvation markers under normal Pi conditions, being its effect dependent on the endogenous SL levels. Remarkably, 2′‐epi ‐GR24 also impacted the root metabolic profile under these conditions, promoting the levels of metabolites associated to plant responses to Pi limitation, thus partially mimicking the pattern observed under Pi deprivation. The results suggest an endogenous role for SLs as Pi starvation signals. In agreement with this idea, SL‐deficient plants were less sensitive to this stress. Based on the results, we propose that SLs may act as early modulators of plant responses to P starvation.

中文翻译：

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外源性松果内酯会影响根部的代谢谱和磷酸饥饿信号。

松果内酯（SLs）是根际中重要的植物外信号传导分子，促进与有益微生物的缔合，但也影响植物与有害生物的相互作用。它们也是植物体内的植物激素，在营养缺乏的情况下（主要是磷酸盐（Pi）饥饿）充当植物反应的调节剂。在目前的工作中，我们调查了SL作为植物早期Pi饥饿信号的调节因子的潜在作用。合成的SL类似物2'- Epi- GR24的短期脉冲促进了Pi剥夺下番茄和小麦中的SL积累和Pi饥饿标记的表达。2'- Epi‐GR24的施用还增加了SL的产生以及在正常Pi条件下Pi饥饿标记的表达，其作用取决于内源性SL水平。值得注意的是，在这些条件下，2'- Epi- GR24也影响了根部的代谢谱，促进了与植物对Pi限制的反应相关的代谢产物水平，从而部分模仿了Pi剥夺下观察到的模式。结果表明SL作为Pi饥饿信号具有内源性作用。与这个想法一致的是，缺乏SL的植物对这种压力不太敏感。根据结果​​，我们建议SL可以作为植物对P饥饿反应的早期调节剂。