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Xin C, Chi J, Zhao Y, He Y, Guo J. Cadmium stress alters cytosine methylation status and expression of a select set of genes in Nicotiana benthamiana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 284:16-24. [PMID: 31084868 DOI: 10.1016/j.plantsci.2019.03.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 05/14/2023]
Abstract
In this paper, we evaluated the genotoxicity of cadmium (Cd) in plants by performing a methylation-sensitive amplification polymorphism (MSAP) on the model plant Nicotiana benthamiana. Among 255 loci examined, 14 genes were found to show altered cytosine methylation patterns in response to Cd stress. Four of those genes (NbMORC3, NbHGSNAT, NbMUT, and NbBG) were selected for further analysis due to their predicted roles in plant development. Cd-induced changes of cytosine methylation status in MSAP fragments of selected genes were confirmed using bisulfite sequencing polymerase chain reaction (BSP). In addition, the expression levels of these genes were found to correlate with cadmium dosage, and a knock-down of these four genes via virus-induced genes silencing (VIGS) led to abnormal development and elevated sensitivity to cadmium stress. Silencing of these four genes resulted in altered cadmium accumulation in different parts of the experimental plants. Our data indicate that cadmium exposure causes dramatic changes in the cytosine methylation status of the plant genome, thus affecting the expression of many genes that are vital for plant growth and are involved in cadmium stress response.
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Affiliation(s)
- Cuihua Xin
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou, 014010, China
| | - Junling Chi
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou, 014010, China
| | - Yibo Zhao
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou, 014010, China
| | - Yindi He
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou, 014010, China
| | - Jiangbo Guo
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou, 014010, China.
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Zhang L, Jin Q, Luo J, Wu J, Wang S, Wang Z, Gong S, Zhang W, Lan X. Intracellular Expression of Antifreeze Peptides in Food Grade Lactococcus lactis and Evaluation of Their Cryoprotective Activity. J Food Sci 2018; 83:1311-1320. [PMID: 29660758 DOI: 10.1111/1750-3841.14117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 02/11/2018] [Accepted: 02/13/2018] [Indexed: 02/06/2023]
Abstract
Antifreeze peptides can protect living organisms from low temperatures by preventing damage or killing due to ice crystal formation between cells. Therefore, antifreeze peptides can be used as a low temperature protectant for cryopreservation of cells and tissues, and also in food production. In this study, a recombinant SF-P gene was constructed and inserted into pNZ8149 to construct a food grade expression vector, which was then electroporated into Lactococcus lactis NZ3900. The expression of the target protein was induced using Nisin, and the optimal expression condition was determined to be a pH of 6.0, Nisin concentration of 25 ng/mL, temperature of 37 °C, and incubation time of 6 hr. Compared to the strain NZ3900 and the recombinant strain SF-P1 without addition of Nisin, the recombinant strain SF-P2 showed the highest cell survival and thermal hysteresis activity, and had a reduction in the changes of activities of extracellular and intracellular lactate dehydrogenase and β-galactosidase after freezing. Moreover, analysis by SEM showed that SF-P2 cells were more completely and regularly shaped than other strains, displayed no obvious leakage of cell contents, and had an intact boundary between cells after freezing. These results indicate that the recombinant strain SF-P2 has a protective effect against freezing. This paper presents a food grade expression system for an antifreeze peptide SF-P using L. lactis as a host, and shows that the intracellular expression of antifreeze peptide could protect the cellular integrity and physiological functions of L. lactis. PRACTICAL APPLICATION The recombinant Lactococcus lactis with intracellular expression of antifreeze peptides SF-P could reduce the damage of bacteria cells induced by freezing or freeze drying, so, it could be applied in the process of freezing food without separation, such as the manufacture of yoghurt ice cream, frozen dough, and so on.
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Affiliation(s)
- Li Zhang
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Quan Jin
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Jing Luo
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Jinhong Wu
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Shaoyun Wang
- College of Biological Science and Technology, Fuzhou Univ., Fuzhou, 350108, China
| | - Zhengwu Wang
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Shengxiang Gong
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Wei Zhang
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
| | - Xiaohong Lan
- Dept. of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong Univ., Shanghai, 200240, China
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Ma J, Zhang X, Wang L. Synergistic effects between [Si-hemicellulose matrix] ligands and Zn ions in inhibiting Cd ion uptake in rice (Oryza sativa) cells. PLANTA 2017; 245:965-976. [PMID: 28138761 DOI: 10.1007/s00425-017-2655-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 01/22/2017] [Indexed: 06/06/2023]
Abstract
Our study demonstrated that Zn alleviated Cd toxicity in the presence of Si in the cell walls by Zn 2+ binding to ligands through the formation of the [Si-hemicellulose matrix]Zn complexes that restrict the uptake of Cd. The plant cell wall exhibits preferential sites for the accumulation of metals at toxic concentrations. Through modification of wall polysaccharide components, elements, such as silicon (Si) and zinc (Zn), may play active roles in alleviating the toxicity of heavy metals, including cadmium (Cd). However, enhanced tolerance for Cd stress may rely on synergistic effects between nutrient elements. Here, we cultured Si-accumulating suspension cells of rice (Oryza sativa) exposed to Cd and Zn treatments, either separately or in combination, and investigated cells using noninvasive microtest technology (NMT), inductively coupled plasma mass spectroscopy (ICP-MS) and atomic force microscopy (AFM). We found that Zn alleviated Cd toxicity in the presence of Si in the cell walls by binding of Zn2+ to ligands through the formation of the [Si-hemicellulose matrix]Zn complexes and co-precipitates to greatly inhibit Cd2+ uptake into cells. This, in turn, induced the lower expression of Cd-related transporters. This synergistic effect could be decisive for the survival of cells under conditions of high Cd concentrations.
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Affiliation(s)
- Jie Ma
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiuqing Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
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