Responses of glutathione and phytochelatins biosysthesis in a cadmium accumulator of Perilla frutescens (L.) Britt. under cadmium contaminated conditions.

Abstract

Screening new accumulators of heavy metal and identifying their tolerance, enrichment capacity of heavy metals are currently hot issues in phytoremediation research. A series of hydroponic experiments were conducted to analyze the effects of glutathione and phytochelatins in roots, stems, and leaves of Perilla frutescens under cadmium stress. The results showed that the non-protein thiols in roots and stems mainly existed in the form of GSH, PC2, PC3, and PC4 under Cd stress condition, while in leaves they existed in the form of GSH, PC2, and PC3. Furthermore, the contents of GSH and PCs positively correlated with Cd, but negatively correlated with root vigor and chlorophyll content under Cd stress conditions. After 21 days of treatments, the contents of Cd in different parts of the plant were 1465.2-3092.9mg· kg-1 in the roots, 199.6-478.4mg·kg-1 in the stems and 61.3-96.9mg· kg-1 in the leaves at 2, 5, 10mg·L-1 Cd levels respectively, and the amount of Cd uptakes were up to 3547.7-5701.7μg·plant-1. Therefore, P. frutescens performed high capacity in Cd accumulation, and PCs played a key role in Cd tolerance. The application prospect of the plant in phytoremediation Cd polluted soil was also discussed.