Effect of light on the photosynthetic activity during desiccation of the resurrection plant haberlea rhodopensis

Abstract

The effect of light during desiccation of the resurrection plant Haberlea rhodopensis on the photosynthetic activity and some morphological parameters was evaluated using plants growing at low or high irradiance in natural habitat. Chlorophyll content was not only lower in sun plants compared to shade plants, but it declined to a higher extent when desiccation was carried out at high light irradiance. Regardless of lower chlorophyll content in sun plants their photosynthetic activity (PN) was about 30% higher compared to shade plants. However, during dehydration PN declined more rapidly in sun plants. The mean leaf thickness of fully hydrated leaves from sun plants was larger when compared with shade plants, which was due to higher thickness of the mesophyll. Following rehydration plants rapidly recovered and PN was higher by about 70% in sun than in shade plants. The results showed that the sun-exposed Haberlea plants exhibited good adaptation to desiccation under high irradiance.