Potential metabolic mechanism of increasing global atmospheric CO2 concentration inhibiting photosynthetic nitrogen assimilation in C3 plants

Zhu Xinguang's research team discovered the potential metabolic mechanism of increasing global atmospheric CO2 concentration that inhibits photosynthetic nitrogen assimilation in C3 plants

 

July 29, 2021, State Key Laboratory of Plant Molecular Genetic room Zhu Guang new team through the integration of nearly half a century to about C 3 photosynthesis and nitrogen assimilation and metabolism research breathing in the international community to build its first C 3 photosynthesis The elementary metabolic kinetic system model analyzes the potential metabolic mechanism of the increased atmospheric CO 2 concentration inhibiting the photosynthetic nitrogen assimilation ability of C 3 plants
.

The related research paper "Potential Metabolic Mechanisms for Inhibited Chloroplast Nitrogen Assimilation under High CO 2 " was published online in the international academic journal Plant Physiology

Since the industrial revolution, the global atmospheric CO 2 concentration has continued to rise
.

Increasing atmospheric CO 2 concentration usually promotes the photosynthesis and crop yield of C 3 crops

There is a close interaction between photosynthesis and nitrogen assimilation in plants
.

Photosynthesis requires protein, of which organic nitrogen is obtained through nitrogen assimilation; photosynthesis provides carbon skeleton (α-ketoglutarate), energy (ATP) and reducing power (NAD(P)H) for nitrogen assimilation

In this study, Zhu Xinguang's team constructed the world's first model of the kinetic mechanism of C 3 photosynthetic elementary carbon and nitrogen metabolism
.

The model covers the Calvin-Benson cycle, photorespiration pathway, starch synthesis, glycolysis-gluconeogenesis, tricarboxylic acid cycle, photosynthetic nitrogen assimilation and other metabolic pathways; the model can accurately simulate different light intensities and CO 2 concentrations Photosynthetic rate, mitochondrial respiration rate and photosynthetic nitrogen assimilation rate under the conditions

Research using this model found that if the current atmospheric CO 2 concentration doubles to the level at the end of this century, the C 3 photosynthetic nitrogen assimilation capacity will drop by about 10%
.

The reason for this phenomenon is that when the concentration of CO 2 increases, on the one hand, the ability of the photorespiration pathway to produce α-ketoglutarate is inhibited, which reduces the carbon skeleton content required for nitrogen assimilation, thereby reducing the chloroplast NH 4 + fixed; the other hand, reducing the energy reducing cytoplasm (NADH) concentration, thereby inhibiting NO .

Zhu Xinguang's research group at the State Key Laboratory of Plant Molecular Genetics has graduated with a Ph.
D.
student, Zhao Honglong, as the first author, co-authored with Dr.
Chang Tiangen and Dr.
Xiao Yi, and researcher Zhu Xinguang is the corresponding author
.

The author is particularly grateful to: Dr.

　　Original link:  https://doi.