Abstract

Increasing UV-B radiation reaching the earth's surface can affect the growth and development of plants. Glucosinolate metabolism is evolved through plant interactions with the environment and constantly regulated by different environmental factors. We investigated the contents of glucosinolates and the expression of related genes in response to enhanced UV-B radiation (1.55 W·m^-2) and the succeeding dark recovery process in Arabidopsis (Arabidopsis thaliana) rosette leaves. At the initial 1 h of enhanced UV-B radiation, UV-B radiation induced the production of glucosinolates; however, after continuous UV-B exposure for 12 h the expression of glucosinolate metabolism related genes was significantly inhibited and the glucosinolate content was declined, especially that of indolic glucosinolates. Additional analyses indicated that UV-B exposure also led to the cell membrane damage and the decrease of relative water content. Then, the plants irradiated by UV-B radiation were kept in darkness for 12 h so as to the physiological status ofthe leaves could be partially recovered. As a result, both glucosinolate gene expression and the content returned to the control levels.

Key words: UV-B, Arabidopsis, glucosinolates, gene expression.