Photosynthesis, antioxidant enzyme, and anatomical difference of Sedum kamtschaticum and Hosta longipes to ozone.

Abstract. The objective of this study was to identify the effects of ozone on the two species in controlled environment. Sedum kamtschaticum and Hosta longipes were exposed in both control and ozone chamber to investigate photosynthesis, antioxidant enzyme activity, visible damage, the number and the size of stomata and the plastogloubuli. Ozone was fumigated in the concentration of 200 μg･kg -1 for 8 hours in a day (from 08:00 AM to 04:00 PM). Firstly, net photosynthesis of two species was decreased after ozone fumigation. Secondly, glutathione reductase activities showed significant difference between control and ozone treatment. Thirdly, visible symptoms of leaves were expressed such as chlorosis, necrosis and decoloration. Also, the size of stoma was significantly decreased in ozone-exposed plants. Furthermore, the intercellular space of Hosta longipes showed increased phenomenon because the mesophyll was collapsed. The number and the size of the plastogloubuli were significantly larger in ozone stress.