Faculty of Science E-newsletter

Free-air ozone garden has been built at many locations in the US and Europe to measure the effect of ground-level ozone on plant life. Professor Amos Tai of Earth System Science Programme and his team have built “Gene Garden”, the first plant-based measurement of ozone in South China Region, inside CUHK campus since 2019, growing ozone-sensitive and ozone-resistant genotypes of bush bean.

After three months of observation, it was found that the sensitive plants experienced more severe ozone-induced leaf injury from flowering stage onward but a higher yield than the resistant genotype. The result could be explained by stress-induced flowering caused by ozone; ozone, as a source of stresses, triggers plants to produce more flowers and seeds as a coping mechanism for increasing the chance of fertilisation and reproduction.

The findings, recently published in Atmosphere, show that the ozone level in Hong Kong is high enough to cause vital change to plants even in countryside area like CUHK campus. The results not only suggested further investigation into the physiology of the beans under various ozone concentrations in a controlled environment, but also contributed to the current limited studies on how ozone pollution affects the terrestrial ecosystems and vegetation in subtropical areas including Hong Kong.

Further reading:
Leung, F., Pang, J., Tai, A. P., Lam, T., Tao, D. K., & Sharps, K. (2020). Evidence of ozone-induced visible foliar injury in Hong Kong using Phaseolus vulgaris as a bioindicator. Atmosphere, 11(3), 266. DOI: https://doi.org/10.3390/atmos11030266

University Press Release