The Apocarotenoid β-Cyclocitric Acid Elicits Drought Tolerance in Plants

Stefano d'Alessandro (1) , Yusuke Mizokami (2) , Bertrand Legeret (3) , Michel Havaux (1, 4)

1 BIAM - Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB)
2 P&E - Photosynthèse & Environnement
3 EBMP - Environnement, Bioénergie, Microalgues et Plantes
4 PEPSS - Plant Environmental Physiology and Stress Signaling

β-Cyclocitral (β-CC) is a volatile compound deriving from 1O21O2^1O_2 oxidation of β-carotene in plant leaves. β-CC elicits a retrograde signal, modulating 1O21O2^1O_2-responsive genes and enhancing tolerance to photooxidative stress. Here, we show that β-CC is converted into water-soluble β-cyclocitric acid (β-CCA) in leaves. This metabolite is a signal that enhances plant tolerance to drought by a mechanism different from known responses such as stomatal closure, osmotic potential adjustment, and jasmonate signaling. This action of β-CCA is a conserved mechanism, being observed in various plant species, and it does not fully overlap with the β-CC-dependent signaling, indicating that β-CCA induces only a branch of β-CC signaling. Overexpressing SCARECROW-LIKE14 (SCL14, a regulator of xenobiotic detoxification) increased drought tolerance and potentiated the protective effect of β-CCA, showing the involvement of the SCL14-dependent detoxification in the phenomenon. β-CCA is a bioactive apocarotenoid that could potentially be used to protect crop plants against drought.

Domaines: Sciences du Vivant [q-bio]; Biochimie, Biologie Moléculaire

Stefano d'Alessandro, Yusuke Mizokami, Bertrand Legeret, Michel Havaux. The Apocarotenoid β-Cyclocitric Acid Elicits Drought Tolerance in Plants. iScience, 2019, 19, pp.461-473. ⟨10.1016/j.isci.2019.08.003⟩. ⟨cea-02272035⟩