Effects of Short-term Drought Stress on Chlorophyll Fluorescence and Proline Content of Ficus annulata

Abstract

Drought is still one of the key factors that directly affects the rate of photosynthesis and the reduction of plant growth and yield. This study was carried out to investigate the effect of drought and re-watering trials on the contents of chlorophyll, carotenoids, proline, CO2 fluxes, and the photosynthetic efficiency of Ficus annulata. Treatments included control (no drought) and drought-stressed plants exposed to 21 days of drought followed by re-watering, with four replications conducted over 56 days. The results showed that drought stress greatly reduced the amounts of chlorophyll and carotenoids, with the highest reduction in relative water content (RWC) observed at 76–79% (p ≤ 0.05). Conversely, proline content significantly increased during drought stress, exhibiting the highest value of 108.16 µg/g FW before re-watering (p ≤ 0.05). A 21-day short-term drought had a statistically significant effect on changes in chlorophyll fluorescence parameters and CO2 flux (p ≤ 0.05). However, the overall plant response after re-watering showed no significant difference compared with the control (p > 0.05), suggesting recovery of physiological efficiency. Our findings indicated that F. annulata has the capacity to mitigate carbon dioxide emissions. These physiological responses enhance the plant's suitability for drought resistance, and re-watering supports effective survival under drought stress.