Abstract

Aloe barbadensis Miller is adapted to tolerate severe drought and high irradiance levels. Photoprotective, photosynthetic and antioxidative potentials were investigated in plants grown under drought stress. Prolonged periods of drought caused high level accumulation of carotenoids which suggest their role in photoprotection. Due to the presence of strong photoprotective response, plants were found capable to maintain their photosynthetic performance even in severe drought conditions. The high activity of reaction centers, despite their low density in drought stressed plants, indicate strong phytosynthetic plasticity in A. barbadensis. Water deprivation triggered activities of superoxide dismutase (SOD) and catalase (CAT) to minimize the effects of drought-induced photodamage. The present findings indicate that A. barbadensis plants are physiologically quite resistant to extreme water deficit conditions. This study will therefore be useful in transgenics for the development of drought tolerant plants.