Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (12): 1718-1727.DOI: 10.17521/cjpe.2022.0448

Special Issue: 光合作用

• Research Articles • Previous Articles     Next Articles

Photochemical reaction of photosystem II in diatoms under phosphorus starvation and its response to high light intensity

LIU Hai-Yan1, ZANG Sha-Sha1,*(), ZHANG Chun-Xia2, ZUO Jin-Cheng1, RUAN Zuo-Xi3, WU Hong-Yan1   

  1. 1College of Life Sciences, Ludong University, Yantai, Shandong 264025, China
    2Tai’an Hydrology Center, Tai’an, Shandong 271000, China
    3Institute of Marine Biology, Shantou University, Shantou, Guangdong 515063, China
  • Received:2022-11-07 Accepted:2023-06-06 Online:2023-12-20 Published:2023-12-22
  • Contact: *(
  • Supported by:
    National Natural Science Foundation of China(42076206);Natural Science Foundation of Shandong Province(ZR2020QC025);Natural Science Foundation of Guangdong Province(2020A1515011073)


Aims As the ocean warms, the upper mixed layer becomes shallower, increasing nutrient limitation and sunlight exposure for diatoms. The photosynthetic yield of diatoms was affected by the dual stress of high light and nutrient limitation. This study mainly explored the photophysiological regulation of diatoms in response to phosphorus starvation and high light stress to further understand the effects of marine environmental changes on diatom photosynthesis.
Methods We cultured the two different-sized diatom species Thalassiosira pseudonana and T. weissflogii under the condition of phosphorus starvation to monitor the changes of photosystem II (PSII) function and to investigate their photophysiological responses to high light.
Important findings Under the condition of phosphorus starvation, the PSII activity of smaller T. pseudonana gradually declined, the electron transport efficiency from plastoquinone QA- which binds to D2 protein to plastoquinone QB which binds to D1 protein descended. Thus, the energy captured for electron transport per unit reaction center decreased, and the non-photoquenched was induced, while the PSII activity of larger T. weissflogii could be maintained for a longer time; T. pseudonana had higher value of PSII photoinactivation cross section (σi) under phosphorus sufficient condition than T. weissflogii, which was prone to photoinhibition and exhibited a higher repair rate for PSII. Phosphorus starvation had no significant effect on its sensitivity to photoinhibition, while T. weissflogii had significantly higher σi under phosphorus starvation condition, and its tolerance to high light intensity was significantly reduced. Under the condition of nutrient limitation and increased light exposure, the larger T. weissflogii may tend to distribute in the lower euphotic layer. In summary, this study suggests that marine environmental changes may change the niche of diatoms with different cell sizes and affect their contribution to primary production.

Key words: diatoms, phosphorus starvation, photosystem II function, photosynthesis