Overexpression of Zostera japonica J protein gene ZjDjB1 in Arabidopsis enhanced the tolerance to lead stress.

Abstract

Among the heavy metal pollution in soil, lead pollution is particularly prominent. The lead in contaminated soil will not only cause damage to plants, animals and microorganisms, but also seriously affect the progress of the entire ecosystem. Under lead stress, the abundance of DnaJ protein in plants will increase. However, little is known about the role of DnaJ in lead stress. We used transgenic Arabidopsis that overexpressed DnaJ gene ZjDjB1 of Zostera japonica as material to study the role of DnaJ in the mechanism of lead induced stress response. Under lead stress, the seedlings and adult plants of transgenic ZjDjB1 Arabidopsis have higher tolerance to lead stress than wild type. Under lead stress, the content of NO and O2·- free radicals in transgenic ZjDjB1 Arabidopsis was lower than that of wild type. The negative effect of catalase in transgenic ZjDjB1 Arabidopsis under lead stress was weaker than that of wild type. The expression of ABC transporter of mitochondrion 3 (ATM3; systematic name: ABCB25) in transgenic ZjDjB1 Arabidopsis under lead stress was higher than that in wild type. These results confirmed that ZjDjB1, the DnaJ gene of Z. japonica, was involved in the reaction mechanism to lead pollution, which might improve the tolerance of plants to lead stress by maintaining catalase activity and increasing the expression level of ATM3 under lead stress.