Exogenous CaCl₂ promoted the indole alkaloid accumulation in seedlings of Catharanthus roseus under NaCl stress

Abstract

A sandy culture experiment was conducted to investigate the effects of exogenous CaCl₂ on the indole alkaloid accumulation in Catharanthus roseus under salt stress. One-month seedlings of C. roseus were treated with the different concentrations of NaCl (0, 50, and 100 mmol l^− 1) and 7.5 mmol l^− 1 CaCl₂. The plant samples were analyzed after 7 days of the treatments. The NaCl-stressed plants showed decrease of fresh and dry weight and increase of malondialdehyde (MDA) content compared to control. Tryptophan decarboxylase (TDC) activity increased significantly under 50 mmol l^− 1 NaCl without CaCl₂ addition, 50 mmol l^− 1 NaCl with 7.5 mmol l^− 1 CaCl₂, and CaCl₂ treatment without NaCl addition. There was a significant increase in peroxidase activity under NaCl stress compared to control. The vindoline, catharanthine, vincristine, and vinblastine contents increased under salt stress (especially with 50 mmol l^− 1 NaCl treatment with or without CaCl₂). Addition of CaCl₂ to NaCl-stressed plants increased biomass, TDC activity, vindoline, and catharanthine contents and lowered MDA and vincirstine contents compared to the plants without CaCl₂. The plants treated with CaCl₂ alone showed higher TDC activity, vindoline, catharanthine, and vinblastine content when compared to control. The results showed that exogenous CaCl₂ could promote the indole alkaloid metabolism under salt stress.

Keywords::

• Catharanthus roseus
• alkaloids
• calcium chloride
• enzymes
• growth
• NaCl stress

Notes

^† Equal first author.

Additional information

Funding

Funding

The authors are grateful for the financial support of the Project of Special Fund for Public Welfare Industrial (Agriculture) Research of China [grant number 200903001-5]; the National Key Project of Scientific and Technical Supporting Programs funded by Ministry of Science & Technology of China [grant number 2011BAD13B09]; the National Key Project of Scientific and Technical Supporting Programs funded by Ministry of Science & Technology of Jiangsu Province [grant number BE2011368]; the Fundamental Research Funds for the Central Universities [grant number Y0201100249]; One Hundred-Talent Plan of Chinese Academy of Sciences (CAS); the CAS/SAFEA International Partnership Program for Creative Research Teams; the Science and Technology Development Plan of Shandong Province [grant number 2010GSF10208]; the Yantai Science and Technology Development Project [grant number 2011016]; and the Yantai Double-hundred High-end Talent Plan [grant number XY-003-02].