Photosynthetic Properties and Structure of Leaves of Licorice Seedlings in Response to Drought Stress

Abstract

Licorice (Glycyrrhiza uralensis Fisch.) is a perennial herb that has high drought resistance, and is widely used in food, pharmaceutical and cosmetics industries. Understanding the response mechanism of licorice leaves to drought stress can help to develop drought-tolerant medicinal crops. In this experiment, the changes of photosynthetic parameters and structure of licorice leaves under drought stress were investigated. After 10 days of treatment with different soil containing water of 80, 65, 50 and 35%, the photosynthetic indexes, leaf surface stomata, glands morphology, leaf structure and chloroplast structure of licorice seedlings were measured respectively. The results showed that under light stress (LS), licorice adapted to drought stress by adjusting stomatal number, morphology and gland density, while severe stress (SS) inhibited the electron transfer between photosystems, leading to inactivation of the oxygen emitting complex, destruction of chloroplast structure and insufficient CO2 supply, resulting in the decrease of photosynthesis. This paper explains the response mechanism of licorice leaves to drought stress, which provides a foundation for further exploring its mechanism and improving the yield.