Cinnamaldehyde Ameliorates Cadmium-Inhibited Root Elongation in Tobacco Seedlings via Decreasing Endogenous Hydrogen Sulfide Production

Abstract

Cinnamaldehyde (CA) is natural plant-derived compound that has been highly appreciated for its medicinal properties. However, little information is known about the regulation of plant intrinsic physiology by CA. To address these gaps, physiological, histochemical, and biochemical approaches were applied to investigate CA-facilitated cadmium (Cd) tolerance in the roots of tobacco (Nicotiana tabacum) seedlings. Treatment with CdCl2 at 20 μM for 72 h resulted in the significant decrease in root elongation by 40.39% as compared to control. CA alleviated Cd-inhibited root elongation in dose- and time-dependent manners. The addition of CA at 20 μM induced significant increase in root elongation by 42.58% as compared to Cd treatment alone. CA abolished Cd-induced ROS (reactive oxygen species) accumulation, lipid peroxidation, loss of membrane integrity, cell death, and free Cd2+ accumulation in roots. CA blocked the Cd-induced increase in the endogenous H2S level through the down-regulation of d-cysteine desulfhydrase (DCD) expression. H2S scavenger hypotaurine (HT) or potent H2S-biosynthetic inhibitor dl-propargylglicine (PAG) were able mimic the action of CA on the blockade of Cd-induced H2S accumulation, cell death, and growth inhibition. Enhancement of the endogenous H2S level with NaHS (H2S donor) abrogated all the beneficial capabilities of CA, HT, and PAG. Collectively, these results suggest that CA has great potential to confer plant tolerance against Cd stress, which is closely associated with its capability to inhibit Cd-induced H2S production. This study not only provides evidences for the regulation of plant physiology by CA but also sheds new light on the cross-talk between CA and H2S in physiological modulations.

Hydrogen sulfide (H2S) signaling in plant development and stress responses

“…All of them have been reported to activate the H 2 S response pathway by increasing the activity of H 2 S-producing enzymes or endogenous H 2 S level (Hu et al 2018 ; Kaya et al 2020a ; Kaya and Aslan 2020 ; Qiao et al 2015 ; Zanganeh et al 2019 ; Zhu et al 2015 ). However, cinnamaldehyde was found to alleviate the toxic metal stress in a different action mode, which inhibits the activity of d -CDes in tobacco, and thus, reduces the content of endogenous H 2 S (Ye et al 2017 ).…”

Brassinosteroids in Plants: Crosstalk with Small-Molecule Compounds

“…H 2 S is known to be a poisonous gas, and its toxicity has always been a focus of research. In recent years, research on H 2 S has been increasingly concerned with its roles in plant growth, development, and stress response [ 84 , 85 ]. As a second signaling messenger, the interaction between H 2 S and BRs might play a crucial role in plants.…”

Thymol ameliorates ammonium toxicity via repressing polyamine oxidase-derived hydrogen peroxide and modulating ammonium transporters in rice root

“…•¯( superoxide radical anion), H 2 O 2 , and cell death in root tips were detected in situ using specific fluorescent probe DCFH-DA (2′,7′-dichlorofluorescein diacetate), DHE (dihydroethidium), HPF [3′-(p-hydroxyphenyl) fluorescein], and PI (propidium iodide), respectively, followed by capturing fluorescent images and calculating fluorescent density based on our previously published methods (Ye et al 2017). The fluorescence was observed and captured with a fluorescence microscope (ECLIPSE, TE2000-S, Nikon, Melville, NY, USA) with setting of excitation 480-490 nm/emission 515-525 nm for green fluorescence (DCFH-DA and HPF) and excitation 530-540 nm/emission 610-620 nm for red fluorescence (DHE and PI).…”