Chin J Plan Ecolo ›› 2014, Vol. 38 ›› Issue (7): 749-756.DOI: 10.3724/SP.J.1258.2014.00070

• Research Articles • Previous Articles     Next Articles

The role of chitosan in polyphenols accumulation and induction of defense enzymes in Pinus koraiensis seedlings

LIU Ran, WANG Zhen-Yu*, LI Ting-Ting, WANG Fang, and AN Jing   

  1. College of Forestry, Northeast Forestry University, Harbin 150040, China
  • Received:2014-01-22 Revised:2014-02-28 Online:2014-07-01 Published:2014-07-10
  • Contact: WANG Zhen-Yu

Abstract:

Aims This study aimed to explore the physiological mechanisms of polyphenols synthesis promoted by chitosan elicitor in Pinus koraiensis.
Methods Pinus koraiensis seedlings were cultured for eight days under different chitosan concentrations in the DCR media and the accumulations of polyphenols and proanthocyanidins were measured, in order to determine the chitosan concentration for optimal polyphenols accumulation. The changes in polyphenols accumulation, activities of defense enzymes, and activities of key enzymes for polyphenol synthesis were then studied in P. koraiensis seedlings under the optimal chitosan concentration.
Important findings Results showed that chitosan at the concentration ranging from 50 to 200 mg·L–1 effectively increased the accumulation of polyphenols and proanthocyanidins in P. koraiensis seedlings. The effect of induction by chitosan reached the peak at 100 mg·L–1. The polyphenols accumulation in P. koraiensis seedlings treated with chitosan reached (9.91 ± 0.68) mg·g–1 in fresh mass, which was 1.64 times the content in the control. The accumulation of proanthocyanidins reached (2.52 ± 0.11) mg·g–1 in fresh mass, which was 1.53 times the accumulation in the control. Activities of defense-related enzymes (superoxide dismutase, peroxidase, and catalase) and polyphenol biosynthesis-related enzymes (phenylalanine ammonia-lyse, and cinnamate-4-hydroxylase) in P. koraiensis seedlings were increased significantly by chitosan elicitor at the concentration of 100 mg·L–1. Chitosan could significantly activate defensive response and the phenylpropanoid pathway in P. koraiensis, thus promoting the synthesis and accumulation of polyphenols and enhancing the resistance of P. koraiensis seedlings.