Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (5): 1015-1022.DOI: 10.3773/j.issn.1005-264x.2008.05.006

• Original article • Previous Articles     Next Articles

EFFECTS OF TEMPERATURE AND LIGHT TREATMENT ON VIOLAXANTHIN DE-EPOXIDASE ACTIVITY AND XANTHOPHYLL CYCLE-DEPENDENT ENERGY DISSIPATION IN WHEAT LEAVES

CHEN Hua-Xin1,2, CHEN Wei1,2, JIANG Chuang-Dao3, GAO Hui-Yuan1,2,*(), ZOU Qi1,2   

  1. 1College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong 271018, China
    2State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an, Shandong 271018, China
    3Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2006-07-17 Accepted:2008-01-16 Online:2008-07-17 Published:2008-09-30
  • Contact: GAO Hui-Yuan

Abstract:

Aims Our objective was to explore how temperature and light directly affect activity of violaxanthin de-epoxidase (VDE) in vitro and to clarify the relationship between VDE activity and xanthophyll cycle-dependant energy dissipation.

Methods We investigated VDE activities and energy dissipation in wheat leaves treated with different temperatures (4, 25, 38 and 45 ℃) combined with different light intensities (200, 500, 900 and 1 200 μmol·m -2·s-1).

Important findings Maximum activity of VDE in wheat leaves appeared at 30 ℃, suggesting that this was the optimum temperature for VDE in vitro. Light intensity had no effects on VDE activity in wheat leaves in vitro. Compared with 25 ℃, 4 ℃ treatment exhibited no obvious effect on VDE activity; however, 38 ℃ treatment caused slight increase while 45 ℃ caused dramatic decrease in the VDE activity. With increasing light intensity, non-photochemical quenching (NPQ) and xanthophyll cycle-dependent energy dissipation (qE) increased significantly. However, the ratio qE/NPQ decreased slightly when the temperature increased from 4 ℃ to 38 ℃ and decreased significantly when the temperature was increased to 45 ℃. Under low and moderate light intensity, the VDE activity measured at treatment temperature was in agreement with the qE/NPQ, which is a measure of the capacity of xanthophyll cycle-dependent energy dissipation.

Key words: xanthophyll cycle, violaxanthin de-epoxidase (VDE), photoinhibition, energy dissipation