Proteomic Profiling of the Interactions of Cd/Zn in the Roots of Dwarf Polish Wheat (Triticum polonicum L.).

Yi Wang,Haiqin Zhang,Chao Wang,Jian Zeng,Xing Fan,Houyang Kang,Fan Peng,Lina Sha,Yonghong Zhou,Xue Xiao,Ruijiao Wang,Xiaolu Wang

doi:10.3389/fpls.2016.01378

Abstract

Cd and Zn have been shown to interact antagonistically or synergistically in various plants. In the present study of dwarf polish wheat (DPW)roots, Cd uptake was inhibited by Zn, and Zn uptake was inhibited by Cd, suggesting that Cd and Zn interact antagonistically in this plant. A study of proteomic changes showed that Cd, Zn, and Cd+Zn stresses altered the expression of 206, 303, and 190 proteins respectively. Among these, 53 proteins were altered significantly in response to all these stresses (Cd, Zn, and Cd+Zn), whereas 58, 131, and 47 proteins were altered in response to individual stresses (Cd, Zn, and Cd+Zn, respectively). Sixty-one differentially expressed proteins (DEPs) were induced in response to both Cd and Zn stresses; 33 proteins were induced in response to both Cd and Cd+Zn stresses; and 57 proteins were induced in response to both Zn and Cd+Zn stresses. These results indicate that Cd and Zn induce differential molecular responses, which result in differing interactions of Cd/Zn. A number of proteins that mainly participate in oxidation-reduction and GSH, SAM, and sucrose metabolisms were induced in response to Cd stress, but not Cd+Zn stress. This result indicates that these proteins participate in Zn inhibition of Cd uptake and ultimately cause Zn detoxification of Cd. Meanwhile, a number of proteins that mainly participate in sucrose and organic acid metabolisms and oxidation-reduction were induced in response to Zn stress but not Cd+Zn stress. This result indicates that these proteins participate in Cd inhibition of Zn uptake and ultimately cause the Cd detoxification of Zn. Other proteins induced in response to Cd, Zn, or Cd+Zn stress, participate in ribosome biogenesis, DNA metabolism, and protein folding/modification and may also participate in the differential defense mechanisms.

Highlights

Environmental toxicity from non-essential heavy metals such as cadmium (Cd), which is released from human activities and other environmental causes, is rapidly increasing (Ahsan et al, 2009)
The Cd concentration in leaves under Cd stress (40.87 ± 3.69 mg/Kg) was significantly higher (P < 0.01) than that in leaves under CdSO4 + μM ZnCl2 (Cd+Zn) stress (9.20 ± 1.24 mg/Kg; Figure 1A). These results indicate that Zn inhibits Cd uptake in roots as well as its transport from roots to shoots
These results suggest that Cd inhibits Zn uptake in roots but does not affect its transport from root to shoot

Summary

Introduction

Environmental toxicity from non-essential heavy metals such as cadmium (Cd), which is released from human activities and other environmental causes, is rapidly increasing (Ahsan et al, 2009). Zinc (Zn), an essential metal and a cofactor of numerous plant proteins and enzymes, plays several crucial roles in protein binding, enzyme activity, transcriptional and translational regulation, and signal transduction (Broadley et al, 2007; Lin and Arats, 2012). Excess Zn can cause toxicity, as it can damage DNA replication and disrupt enzyme activities and protein folding and function, inducing chlorosis and inhibiting plant growth and development (Broadley et al, 2007; Lin and Arats, 2012; Schneider et al, 2013)

Methods

Results

Discussion

Conclusion