Exogenous strigolactones impact metabolic profiles and phosphate starvation signalling in roots

• Published in: Plant, cell and environment Vol. 43; no. 7; pp. 1655 - 1668
• Main Authors: Gamir, Jordi, Torres‐Vera, Rocío, Rial, Carlos, Berrio, Estefanía, Souza Campos, Pedro M., Varela, Rosa M., Macías, Francisco A., Pozo, María J., Flors, Victor, López‐Ráez, Juan A.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2020; Wiley Subscription Services, Inc
• Subjects: 2′‐epi‐GR24; Deprivation; Heterocyclic Compounds, 3-Ring - pharmacology; Hormones; Lactones - pharmacology; Lycopersicon esculentum - metabolism; Markers; Metabolism; Metabolites; Microorganisms; Mimicry; Modulators; molecular markers; Nutrient deficiency; Phosphate starvation response; Phosphates - deficiency; Phytohormones; Pi starvation; plant responses; Plant Roots - drug effects; Plant Roots - metabolism; Probiotics; Regulators; Rhizosphere; Rhizosphere microorganisms; Signal Transduction - drug effects; Signaling; signalling; strigolactones; Tomatoes; Triticum - metabolism; strigolactones; plant responses; metabolism; molecular markers; 2′-epi-GR24; Pi starvation; signalling
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.13760

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. The current work provides evidences supporting that the phytohormone strigolactones are early modulators of plant responses to low Pi availability and that they impact metabolic profiles in the roots. This knowledge may help to develop new strategies to optimize plant Pi acquisition efficiency and use.