In urban areas, pollution is a major environmental issue affecting lawn establishment and maintenance. Perennial ryegrass, a common grass species, can help mitigate this problem. However, heavy metals such as cadmium (Cd) and nickel (Ni) can significantly limit photosynthetic efficiency and affect plant growth. A recent study by Dąbrowski et al. aimed to investigate the photosynthetic efficiency of perennial ryegrass seedlings under Cd and Ni stress.
The study compared the prompt and delayed chlorophyll-a fluorescence signals and modulated reflectance at 820 nm of two perennial ryegrass cultivars, ‘Niga’ and ‘Nira,’ under Cd and Ni stress. The results showed a decrease in the activity of photosystem II (PSII) and photosystem I (PSI), which was attributed to an increase in nonradiative dissipation of the PSII antenna, a decrease in PSII antenna size, or a decrease in the number of photosynthetic complexes with fully closed PSII RCs. In addition, the efficiency of electron transport was also decreased, indicating a restriction in electron flow from PSII to PSI.
Interestingly, the study found that specific photosynthetic efficiency parameters, such as Area, Fo, Fm, and Fv, were correlated with growth parameters. This suggests that these photosynthetic efficiency parameters could serve as indicators for the early detection of heavy metal effects. By using these parameters, it may be possible to identify stressed plants before visible symptoms of heavy metal toxicity appear, allowing for early intervention to prevent further damage.
In conclusion, the study by Dąbrowski et al. provides essential insights into the effects of Cd and Ni stress on photosynthetic efficiency in perennial ryegrass seedlings. Furthermore, the findings suggest that specific photosynthetic efficiency parameters can be used as early indicators of heavy metal toxicity. This could have important implications for managing lawns and other urban green spaces in polluted environments.