Inhibition of root growth by narciclasine is caused by DNA damage-induced cell cycle arrest in lettuce seedlings.
Narciclasine (NCS) is an Amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs. Its phytotoxic effects on plant growth were examined in lettuce (Lactuca sativa L.) seedlings. Results showed that high concentrations (0.5-5 μM) of NCS restricted the growth of lettuce roots in a dose-dependent manner. In NCS-treated lettuce seedlings, the following changes were detected: reduction of mitotic cells and cell elongation in the mature region, inhibition of proliferation of meristematic cells, and cell cycle. Moreover, comet assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay indicated that higher levels NCS (0.5-5 μM) induced DNA damage in root cells of lettuce. The decrease in meristematic cells and increase in DNA damage signals in lettuce roots in responses to NCS are in a dose-dependent manner. NCS-induced reactive oxygen species accumulation may explain an increase in DNA damage in lettuce roots. Thus, the restraint of root growth is due to cell cycle arrest which is caused by NCS-induced DNA damage. In addition, it was also found that NCS (0.5-5 μM) inhibited the root hair development of lettuce seedlings. Further investigations on the underlying mechanism revealed that both auxin and ethylene signaling pathways are involved in the response of root hairs to NCS.
State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, People's Republic of China.
Yanfeng
Y
Hu
Jiaolong
J
Li
Lijing
L
Yang
Wenbin
W
Nan
Xiaoping
X
Cao
Yurong
Y
Bi
D047151:Amaryllidaceae Alkaloids / Q000494:pharmacology / Q000633:toxicity*; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D005030:Ethylenes / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D007210:Indoleacetic Acids / Q000378:metabolism; D018545:Lactuca / Q000187:drug effects*; D018519:Meristem / Q000166:cytology / Q000254:growth & development; D008940:Mitotic Index; D018384:Oxidative Stress / Q000187:drug effects; D010617:Phenanthridines / Q000494:pharmacology / Q000633:toxicity*; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development*; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
D047151:Amaryllidaceae Alkaloids; D005030:Ethylenes; D007210:Indoleacetic Acids; D010617:Phenanthridines; D017382:Reactive Oxygen Species; C010753:narciclasine; C036216:ethylene