Overexpression of Zostera japonica 14-3-3 gene ZjGRF1 enhances the resistance of transgenic Arabidopsis to copper stress.

Abstract

Copper is both a nutrient essential for plant growth and a pollutant. In recent decades, with the rapid development of industrial and agricultural production, copper has been used more and more widely, and its consumption has also increased rapidly. Excessive soil copper contents induce phytotoxicity, affecting plant growth, development and yields. Moreover, copper can accumulate in crops and enter the food chain through enrichment, harming human health. In this study, Arabidopsis wild-type (WT) and Zostera japonica 14-3-3 gene ZjGRF1 overexpression lines were used to explore the physiological function and molecular mechanism of ZjGRF1 in Arabidopsis in the copper stress response. Under copper stress, compared with WT plants, transgenic ZjGRF1 Arabidopsis plants exhibited less inhibition of root growth and development and had higher fresh weights. Under copper stress, the soluble sugar and soluble protein contents in transgenic ZjGRF1 Arabidopsis plants were significantly higher than those in WT plants, while the superoxide dismutase (SOD), peroxidase and catalase (CAT) activities were significantly higher than those in WT plants. Additionally, the malonaldehyde content of transgenic plants was significantly lower than that of WT plants. Furthermore, qRT-PCR results showed that under copper stress, the SOD, CAT1 and HMA5 expression levels in transgenic ZjGRF1 Arabidopsis plants were significantly higher than those in WT plants, while COPT1 expression was significantly lower than that in WT plants. ZjGRF1 enhanced the copper stress resistance of Arabidopsis by maintaining high antioxidant enzyme activity, increasing copper efflux and reducing copper uptake under copper stress.