Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (8): 870-879.DOI: 10.17521/cjpe.2021.0146

Special Issue: 光合作用

• Research Articles • Previous Articles     Next Articles

Relative changes and regulation of photosynthetic energy partitioning components in Artemisia ordosica during growing season

JIN Chuan1,2, LI Xin-Hao1,2, JIANG Yan1,2, XU Ming-Ze1,2, TIAN Yun1,2, LIU Peng1,2, JIA Xin1,2,3, ZHA Tian- Shan1,2,3,*()   

  1. 1School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
    2Yanchi Ecology Research Station of Mau US Desert, Beijing 100083, China
    3Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
  • Received:2021-04-19 Revised:2021-06-26 Online:2021-08-20 Published:2021-07-22
  • Contact: ZHA Tian- Shan
  • Supported by:
    National Natural Science Foundation of China(32071842);National Natural Science Foundation of China(31901366);National Natural Science Foundation of China(32071843);Fundamental Research Funds for the Central Universities(2015ZCQ-SB-02)


Aims This study is to examine the relative changes and regulation in photosynthetic energy partitioning components of a typical desert shrub Artemisia ordosica in Northwest China.
Methods The minimum fluorescence yield (Fo), maximal fluorescence yield (Fm), actual fluorescence yield (Fs), maximal fluorescence yield in the light-adapted state (Fm′), net photosynthetic rate (Pn), dark respiration (Rd), transpiration rate (E) and stomatal conductance (gs) of A. ordosica were investigated from April to October, 2018 using a multi-channel fluorometer and a portable photosynthesis analyzer. The specific leaf area (SLA), nitrogen per leaf area (Narea), chlorophyll content (CChl) and the ratio of chlorophyll a to chlorophyll b content (Chl a/b) were also measured. We analyzed the fraction of energy used for CO2 assimilation (ΦA), the fraction of energy used for photorespiration (ΦPR), the fraction of regulate heat dissipation (ΦNPQ) and the fraction of non-regulate heat dissipation in energy allocation (ΦNO) during the photosynthetic process in A. ordosica and their responses to fluctuating environment.
Important findings The photochemical reaction component (ΦA and ΦPR) and the heat dissipation component (ΦNPQ and ΦNO) showed a negative competition relationship, and exhibited positive synergistic relationship within components. E was positively correlated with ΦA and ΦPR, and negatively correlated with ΦNPQ and ΦNO. Under low soil water content (SWC) and high saturated water vapor pressure (VPD) conditions, ΦA, ΦPR and SLA were significantly decreased, while ΦNPQ and ΦNO were significantly increased. The results indicate that A. ordosica avoids excessive loss of water under the condition of the long drought or high evapotranspiration via reducing SLA. Synergistically, excessive light energy is transferred from photorespiration to thermal dissipation pathway. The relative changes and long-term regulation of photosynthetic energy partitioning in A. ordosica under fluctuating environment, fully reflect the acclimation of plants to adversity via its synergistic morphologic and physiological plasticity.

Key words: desert plant, photosynthesis, energy partitioning, photorespiration, heat dissipation