Nitrogen Deficiency Effects on Photosynthesis in Plants

Nitrogen is integral to photosynthetic machinery, forming the backbone of chlorophyll, key enzymes and amino acids that drive carbon fixation. When nitrogen becomes limiting, plants exhibit reduced chlorophyll content, lower stomatal conductance and impaired electron transport in photosystems. The decline in chlorophyll a and b diminishes light harvesting, while reduced ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) limits carboxylation capacity. Chlorophyll fluorescence parameters such as the maximum quantum yield of photosystem II (Fv/Fm) and electron transport rate (ETR) decline under nitrogen stress, signalling damage to PSII reaction centres and a shift towards energy dissipation. Concurrently, antioxidant-enzyme systems are upregulated to mitigate oxidative stress arising from excess excitation energy. These physiological and biochemical adjustments vary between species and genotypes, influencing growth, yield and nitrogen-use efficiency. A global body of work now links nitrogen deficiency to altered gene expression, metabolic reprogramming and changes in root–shoot allocation, underlining its importance for sustainable crop management and breeding of nitrogen-efficient varieties.

Research from Nature Portfolio

Recent studies have compared rice varieties with contrasting nitrogen-use efficiencies under controlled hydroponic conditions. In one investigation, an efficient genotype maintained higher net photosynthetic rates and biomass under one-quarter to half nitrogen supply, supported by enhanced activities of superoxide dismutase, peroxidases and the ascorbate–glutathione cycle. Reduced declines in Fv/Fm and Pn in the efficient variety reflected better maintenance of PSII photochemistry and protection against oxidative damage.

A foundational field experiment on indica hybrid rice examined the effects of graded nitrogen application rates on photosynthetic pigments, leaf fluorescence and yield components. Results showed that moderate increases in nitrogen enhanced chlorophyll a/b ratios, electron transport efficiency and photochemical quenching (qP) at critical growth stages. Non-photochemical quenching (NPQ) and energy-dissipative measures peaked at intermediate nitrogen levels, indicating dynamic regulation of excess light energy. Correlations between fluorescence traits and yield underscored the capacity of optimised nitrogen supply to improve photochemical efficiency and grain productivity.

Nitrogen Deficiency Effects on Photosynthesis in Plants publication trend

The graph below shows the total number of articles in nitrogen deficiency effects on photosynthesis in plants across all publications each year (not limited to Nature Index journals).

Technical terms

Chlorophyll fluorescence: light re-emitted by chlorophyll molecules during photosynthesis, used to assess PSII efficiency.

Maximum quantum yield of PSII (Fv/Fm): ratio indicating the potential photochemical efficiency of PSII reaction centres.

Photochemical quenching (qP): fraction of open PSII centres engaged in photochemistry.

Non-photochemical quenching (NPQ): mechanism dissipating excess light energy as heat to protect PSII.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco): key enzyme catalysing CO₂ fixation in the Calvin cycle.

References

1. Response of Photosynthesis and Chlorophyll Fluorescence to Nitrogen Changes in Rice with Different Nitrogen Use Efficiencies. Plants (2025).
2. Effects of nitrogen application rate on the photosynthetic pigment, leaf fluorescence characteristics, and yield of indica hybrid rice and their interrelations. Scientific Reports (2021).
3. Effects of low nitrogen on seedling growth, photosynthetic characteristics and antioxidant system of rice varieties with different nitrogen efficiencies. Scientific Reports (2023).