Cinnamaldehyde promotes root branching by regulating endogenous hydrogen sulfide.
BACKGROUND
Cinnamaldehyde (CA) has been widely applied in medicine and food preservation. However, whether and how CA regulates plant physiology is largely unknown. To address these gaps, the present study investigated the beneficial effect of CA on root branching and its possible biochemical mechanism.


RESULTS
The lateral root (LR) formation of pepper seedlings could be markedly induced by CA at specific concentrations without any inhibitory effect on primary root (PR) growth. CA could induce the generation of endogenous hydrogen sulfide (H2S) by increasing the activity of L-cysteine desulfhydrase in roots. By fluorescently tracking endogenous H2S in situ, it could be clearly observed that H2S accumulated in the outer layer cells of the PR where LRs emerge. Sodium hydrosulfide (H2S donor) treatment induced LR formation, while hypotaurine (H2S scavenger) showed an adverse effect. The addition of hypotaurine mitigated the CA-induced increase in endogenous H2S level, which in turn counteracted the inducible effect of CA on LR formation.


CONCLUSIONS
CA showed great potential in promoting LR formation, which was mediated by endogenous H2S. These results not only shed new light on the application of CA in agriculture but also extend the knowledge of H2S signaling in the regulation of root branching.
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.|Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, China, 50 Zhongling Street, Nanjing 210014, China.
Yan-Feng
YF
Xue
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.|Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, China, 50 Zhongling Street, Nanjing 210014, China.
Meng
M
Zhang
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.|Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, China, 50 Zhongling Street, Nanjing 210014, China.
Zhong-Qiang
ZQ
Qi
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.|Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, China, 50 Zhongling Street, Nanjing 210014, China.
You-Qin
YQ
Li
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.|Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, China, 50 Zhongling Street, Nanjing 210014, China.
Zhiqi
Z
Shi
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing 210014, China.|Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, China, 50 Zhongling Street, Nanjing 210014, China.
Jian
J
Chen
D000171:Acrolein / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005503:Food Additives / Q000494:pharmacology*; D006801:Humans; D010938:Plant Oils / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development
D005503:Food Additives; D010938:Plant Oils; D000171:Acrolein; C012843:cinnamaldehyde
cinnamaldehyde; hydrogen sulfide; lateral root; pepper; root branching