Determinants of photochemical characteristics of the photosynthetic electron transport chain of maize

Xiuping Liu; Yunzhou Qiao; Wangming Zhou; Wenxu Dong; Lianhong Gu

doi:10.3389/fpls.2023.1279963

Determinants of photochemical characteristics of the photosynthetic electron transport chain of maize

Front Plant Sci. 2023 Nov 20:14:1279963. doi: 10.3389/fpls.2023.1279963. eCollection 2023.

Authors

Xiuping Liu¹, Yunzhou Qiao¹, Wangming Zhou², Wenxu Dong¹, Lianhong Gu³

Affiliations

¹ Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
² School of Life Sciences, Anqing Normal University, Anqing, China.
³ Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, United States.

Abstract

Introduction: The photosynthetic electron transport chain (ETC) is the bridge that links energy harvesting during the photophysical reactions at one end and energy consumption during the biochemical reactions at the other. Its functioning is thus fundamental for the proper balance between energy supply and demand in photosynthesis. Currently, there is a lack of understanding regarding how the structural properties of the ETC are affected by nutrient availability and plant developmental stages, which is a major roadblock to comprehensive modeling of photosynthesis.

Methods: Redox parameters reflect the structural controls of ETC on the photochemical reactions and electron transport. We conducted joint measurements of chlorophyll fluorescence (ChlF) and gas exchange under systematically varying environmental conditions and growth stages of maize and sampled foliar nutrient contents. We utilized the recently developed steady-state photochemical model to infer redox parameters of electron transport from these measurements.

Results and discussion: We found that the inferred values of these photochemical redox parameters varied with leaf macronutrient content. These variations may be caused either directly by these nutrients being components of protein complexes on the ETC or indirectly by their impacts on the structural integrity of the thylakoid and feedback from the biochemical reactions. Also, the redox parameters varied with plant morphology and developmental stage, reflecting seasonal changes in the structural properties of the ETC. Our findings will facilitate the parameterization and simulation of complete models of photosynthesis.

Keywords: leaf characteristics; maize; photosynthesis; photosynthetic electron transport; plant growth stages; redox parameters.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was supported by the National Key Research and Development Program of China (2021YFD1901104, 2022YFD1901604), the “Strategic Priority Research Program” of the Chinese Academy of Sciences (XDA28020303, XDA26040103), and the Key Research and Development Program of Hebei Province (22326412D). LG is supported by the U.S. Department of Energy (DOE), Office of Science, Biological and Environmental Research Program. ORNL is managed by UT-Battelle, LLC, for DOE under contract DE-AC05-00OR22725.