Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (1): 74-87.DOI: 10.17521/cjpe.2021.0203

Special Issue: 光合作用

• Research Articles • Previous Articles     Next Articles

Photosynthetic physiology and growth adaptation of herbages with different photosynthetic pathways in response to drought-rehydration

Fei LI, Ming-Wei SUN, Shang-Zhi ZHONG, Wen-Zheng SONG, Xiao-Yue ZHONG, Wei SUN()   

  1. Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China
  • Received:2021-05-29 Accepted:2021-09-10 Online:2022-01-20 Published:2022-04-13
  • Contact: Wei SUN
  • Supported by:
    Supported by the National Natural Science Foundation of China(31570470);Supported by the National Natural Science Foundation of China(31870456)


Aims Based on the background of increasing drought frequency and intensity globally, investigating the photosynthetic properties and growth adaptation of annual grasses differed in photosynthetic pathway (C3 and C4) in response to drought-rehydration conditions is useful to predict the changes of grassland ecosystem composition, structure and function in the context of global climate change. Methods The study was conducted as a pot experiment with four annual C3 and three C4 grasses widely grown in the Songnen Grassland. Three water levels were set up including control, moderate drought and severe drought. Plant photosynthetic (leaf gas exchange) and growth (biomass, leaf mass per area etc.) parameters were measured at the end of the drought and during the rehydration periods. Important findings The net photosynthetic rate (A) and stomatal conductance (Gs) of all studied species showed a decreasing trend and water use efficiency showed an increasing trend under the drought conditions. There were functional group differences in the effects of drought on photosynthetic properties of the studied plants. The effects of the severe drought on net photosynthetic rate of the C4 plants are more pronounced than that of the C3 plants, with the C4 plants gradually losing their photosynthetic advantage as drought severity increases. The A of the C4 plants recovered more slowly than that of the C3 plants after the rehydration because of carbon assimilation in the C3 plants was mainly restricted by stomata limitation while it in the C4 plants was mainly restricted by metabolic limitation. The biomass of all studied species decreased, but the root to shoot ratio and leaf mass per area increased, under the drought conditions. The effects of drought on all growth indicators were greater in the C3 plants than in the C4 plants. After the rehydration, the biomass of C3 plants showed a decreasing trend with increasing drought intensity, while the biomass of C4 plants was not significantly different from the control treatment.

Key words: drought, rehydration, functional group, photosynthetic limitation, root to shoot ratio