Eugenol Confers Cadmium Tolerance via Intensifying Endogenous Hydrogen Sulfide Signaling in Brassica rapa

Abstract

Eugenol, a plant-derived small compound, shows great medicinal potential. However, whether and how eugenol regulates crop physiology remains elusive. Here we reported that eugenol induced Cd (cadmium) tolerance in the root of Brassica rapa. Roots were treated with eugenol and CdCl simultaneously (eugenol + Cd) or pretreated with eugenol followed by CdCl treatment (eugenol → Cd). Eugenol significantly attenuated Cd-induced growth inhibition, ROS accumulation, oxidative injury, and cell death, which were confirmed by in vivo histochemical analysis. Eugenol remarkably decreased free Cd accumulation in root. Eugenol intensified GSH (glutathione) accumulation in roots upon CdCl exposure, which explained the decrease in free Cd and attenuation of oxidative injury. Eugenol stimulated endogenous HS (hydrogen sulfide) generation by upregulating the expression of BrLCD ( l-cysteine desulfhydrase) and BrDCD ( d-cysteine desulfhydrase) as well as their enzymatic activities in CdCl-treated root. Application of HS biosynthesis inhibitor or HS scavenger led to the decrease in endogenous HS level in Cd-treated root, which further compromised all the above effects of eugenol. These findings suggested that eugenol triggered HS → GSH signaling cassette in plants to combat Cd stress, which shed new light on eugenol-modulated plant physiology and the interaction between eugenol and HS.

Functional nano-catalyzed pyrolyzates from branch of Cinnamomum camphora

“…Eugenol (2.00%) is used as a modifier and perfumery fixative. It is perfumed with colored soap and can be prepared and blended with cosmetics (Hu et al, 2018). Octadecanoic acid (1.92%) is the raw material for making cosmetics.…”

Eugenol improves salt tolerance via enhancing antioxidant capacity and regulating ionic balance in tobacco seedlings

“…The anti-inflammatory potential of eugenol has been associated with the regulation of endogenous NO in mammals ( Barboza et al., 2018 ). Eugenol can intensify endogenous H 2 S in rice plants against heavy metal stress ( Hu et al., 2018a ). Therefore, further studying the possible involvement of H 2 S and NO in eugenol-conferred salt tolerance would help reveal eugenol-primed signaling network for plant salt tolerance.…”

“…Eugenol confers drought tolerance in tea plant and heavy metal tolerance in Brassica rapa by modulating antioxidant defense through hydrogen sulfide- and abscisic acid-mediated signaling, respectively (e.g. heavy metal, drought, and cold) ( Hu et al., 2018a ; Zhao et al., 2022 ). These reports imply the potentiality of using eugenol as an environmental-friendly agrichemical to induce plant tolerance.…”

The Defensive Role of Endogenous H2S in Brassica rapa against Mercury-Selenium Combined Stress

“…The chamber for seedling growth was set at photoperiod of 12 h, photosynthetic active radiation of 200 μmol/m 2 /s, and temperature at 25 °C. [ 44 ]. After growing for another 3 days, we selected 30 identical seedlings with root length at 1.5 cm for each treatment.…”