Overexpression of OsLCT2, a Low-Affinity Cation Transporter Gene, Reduces Cadmium Accumulation in Shoots and Grains of Rice

AbstractCadmium (Cd)-contaminated rice is a serious issue affecting food safety. Understanding the molecular regulatory mechanisms of Cd accumulation in rice grains is crucial to minimizing Cd concentrations in grains. We identified a member of the low-affinity cation transporter family, OsLCT2 in rice. It was a membrane protein. OsLCT2 was expressed in all tissues of the elongation and maturation zones in roots, with the strongest expression in pericycle and stele cells adjacent to the xylem. When grown in Cd-contaminated paddy soils, rice plants overexpressing OsLCT2 significantly reduced Cd concentrations in the straw and grains. Hydroponic experiment demonstrated its overexpression decreased the rate of Cd translocation from roots to shoots, and reduced Cd concentrations in xylem sap and in shoots of rice. Moreover, its overexpression increased Zn concentrations in roots by up-regulating the expression of OsZIP9, a gene responsible for Zn uptake. Overexpression of OsLCT2 reduces Cd accumulation in rice shoots and grains by limiting the amounts of Cd loaded into the xylem and restricting Cd translocation from roots to shoots of rice. Thus, OsLCT2 is a promising genetic resource to be engineered to reduce Cd accumulation in rice grains.

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Effects of Silcon on Growth and Cadmium Accumulation by Flue-Cured Tobacco

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1092-1093.608 ◽

2015 ◽

Vol 1092-1093 ◽

pp. 608-612

Author(s):

Yan Fang Ren ◽

Jun Yu He ◽

Dong Liu ◽

Yan Chao Zhang ◽

Hui Qing Chang

Keyword(s):

Nicotiana Tabacum ◽

Leaf Area ◽

Contaminated Soils ◽

Growth Yield ◽

Dry Weight ◽

Cadmium Accumulation ◽

Cadmium Content ◽

Tobacco Plants ◽

Cd Accumulation ◽

Cd Translocation

Tobacco (Nicotiana tabacumL.) is able to accumulate cadmium in leaves and reduction of cadmium content can reduce health hazards to smokers. In the present study, the influence of silicon on the growth, yield and the content and distribution of cadmium (Cd) in flue-cured tobacco plants in the presence of cadmium was investigated by pot experiment. The results showed that Cd reduced the growth of both shoots and roots. Application of Si significantly increased the dry weight of roots and shoots in flue-cured tobacco grown in Cd contaminated soils, but not the largest leaf area. Si reduced the Cd concentration and accumulation in the root, stem and leaf of flue-cured tobacco compared with Cd alone. Si restricted the transport of Cd from roots to shoots. These results demonstrate that 1 and 2 g/kg Si could enhance Cd tolerance in flue-cured tobacco and decrease of Cd accumulation in plant and Cd translocation to shoots.

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Transporters and ascorbate–glutathione metabolism for differential cadmium accumulation and tolerance in two contrasting willow genotypes

Tree Physiology ◽

10.1093/treephys/tpaa029 ◽

2020 ◽

Vol 40 (8) ◽

pp. 1126-1142 ◽

Cited By ~ 1

Author(s):

Xiaojiao Han ◽

Yunxing Zhang ◽

Miao Yu ◽

Jin Zhang ◽

Dong Xu ◽

...

Keyword(s):

Molecular Mechanisms ◽

Cadmium Accumulation ◽

Glutathione Metabolism ◽

Transport Pathway ◽

Cd Accumulation ◽

Metal Transporter ◽

Salix Matsudana ◽

Yellow Stripe ◽

Iron Regulated Transporter ◽

Cd Translocation

Abstract Salix matsudana Koidz is a low cadmium (Cd)-accumulating willow, whereas its cultivated variety, Salix matsudana var. matsudana f. umbraculifera Rehd., is a high Cd-accumulating and tolerant willow (HCW). The physiological and molecular mechanisms underlying differential Cd accumulation and tolerance in the two Salix species are poorly understood. Here, we confirmed that the differential Cd translocation capacity from roots to the shoots leads to the differential Cd accumulation in their aboveground parts between these two willow genotypes. Cadmium accumulation happens preferentially in the transport pathway, and Cd is mainly located in the vacuolar, cell wall and intercellular space in HCW bark by cadmium location analysis at tissue and subcellular levels. Comparative transcriptome analysis revealed that higher expressions of several metal transporter genes (ATP-binding cassette transporters, K+ transporters/channels, yellow stripe-like proteins, zinc-regulated transporter/iron-regulated transporter-like proteins, etc.) are involved in root uptake and translocation capacity in HCW; meanwhile, ascorbate–glutathione metabolic pathways play essential roles in Cd detoxification and higher tolerance of the Cd-accumulator HCW. These results lay the foundation for further understanding the molecular mechanisms of Cd accumulation in woody plants and provide new insights into molecular-assisted-screening woody plant varieties for phytoremediation.

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Comprehensive analysis of variation of cadmium accumulation in rice and detection of a new weak allele of OsHMA3

Journal of Experimental Botany ◽

10.1093/jxb/erz400 ◽

2019 ◽

Vol 70 (21) ◽

pp. 6389-6400 ◽

Cited By ~ 8

Author(s):

Cuiju Sun ◽

Meng Yang ◽

Yuan Li ◽

Jingjing Tian ◽

Yuanyuan Zhang ◽

...

Keyword(s):

Cadmium Accumulation ◽

Rice Cultivars ◽

Cultivated Rice ◽

Potential Threat ◽

Rice Varieties ◽

Cd Accumulation ◽

Transfer Rates ◽

Protein Levels ◽

Analysis Of Variation ◽

Cd Translocation

AbstractExcessive cadmium (Cd) accumulation in rice poses a potential threat to human health. Rice varieties vary in their Cd content, which depends mainly on root-to-shoot translocation of Cd. However, cultivars accumulating high Cd in the natural population have not been completely investigated. In this study, we analyzed the variation in Cd accumulation in a diverse panel of 529 rice cultivars. Only a small proportion (11 of 529) showed extremely high root-to-shoot Cd transfer rates, and in seven of these cultivars this was caused by two known OsHMA3 alleles. Using quantitative trait loci mapping, we identified a new OsHMA3 allele that was associated with high Cd accumulation in three of the remaining cultivars. Using heterologous expression in yeast and comparative analysis among different rice cultivars, we observed that this new allele was weak at both the transcriptional and protein levels compared with the functional OsHMA3 genotypes. The weak Cd transport activity was further demonstrated to be caused by a Gly to Arg substitution at position 512. Our study comprehensively analyzed the variation in root-to-shoot Cd translocation rates in cultivated rice and identified a new OsHMA3 allele that caused high Cd accumulation in a few rice cultivars.

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Iron and copper micronutrients influences cadmium accumulation in rice grains by altering its transport and allocation

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.146118 ◽

2021 ◽

pp. 146118

Author(s):

Ying Han ◽

Qin Ling ◽

Faqin Dong ◽

Víctor Resco de Dios ◽

Zhi Li ◽

...

Keyword(s):

Cadmium Accumulation ◽

Rice Grains

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Effects of aqueous Moringa oleifera leaf extract on growth performance and accumulation of cadmium in a Thai jasmine rice-Khao Dawk Mali 105 variety

10.21203/rs.3.rs-604626/v1 ◽

2021 ◽

Author(s):

Choowong Auesukaree ◽

Jutamas Bussarakum ◽

Sirin Sirirakphaisarn ◽

Patompong Saengwilai

Keyword(s):

Leaf Extract ◽

Moringa Oleifera ◽

Rice Variety ◽

Germination Percentage ◽

Cd Accumulation ◽

Hydroponic System ◽

Rice Grains ◽

System A ◽

Petri Dishes ◽

Jasmine Rice

Abstract The contamination of paddy fields and rice grains by cadmium (Cd) adversely affects human health. Thus, many approaches have been proposed to reduce the accumulation of Cd in rice. Here, we investigate the potential of aqueous Moringa oleifera leaf extract (AMOLE) in decreasing uptake and toxicity of Cd in a popular Thai jasmine rice variety, Khao Dawk Mali 105 (KDML105). Plants were grown in Petri dishes, a hydroponic system, and a pot system under different concentrations of Cd, in the presence and absence of AMOLE. In Petri dishes, Cd reduced the percentage of germination by 79%, but the treatment with 0.5 mg mL -1 AMOLE significantly increased the germination percentage. Moreover, AMOLE significantly decreased Cd accumulation in rice seedlings by 97%. In the hydroponics system, 0.5 mg mL -1 AMOLE decreased Cd content in shoots by 48%. Although no significant physiological changes in response to Cd treatments were observed in the pot system, a large amount of Cd was accumulated in rice roots. The AMOLE treatments significantly reduced Cd accumulation in rice shoots and decreased Cd content in milled grain by half compared to those without AMOLE treatment. We conclude that AMOLE reduced Cd toxicity, enhanced seedling growth, and reduced Cd accumulation in rice grains.

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Microstructural and physiological responses to cadmium stress under different nitrogen levels in Populus cathayana females and males

Tree Physiology ◽

10.1093/treephys/tpz115 ◽

2020 ◽

Vol 40 (1) ◽

pp. 30-45 ◽

Cited By ~ 7

Author(s):

Miao Liu ◽

Jingwen Bi ◽

Xiucheng Liu ◽

Jieyu Kang ◽

Helena Korpelainen ◽

...

Keyword(s):

Nitrogen Deficiency ◽

Ion Homeostasis ◽

N Availability ◽

Cd Stress ◽

Cd Accumulation ◽

N Supply ◽

Populus Cathayana ◽

N Deficiency ◽

Cellular Compartments ◽

Cd Translocation

Abstract Although increasing attention has been paid to the relationships between heavy metal and nitrogen (N) availability, the mechanism underlying adaptation to cadmium (Cd) stress in dioecious plants has been largely overlooked. This study examined Cd accumulation, translocation and allocation among tissues and cellular compartments in Populus cathayana Rehder females and males. Both leaf Cd accumulation and root-to-shoot Cd translocation were significantly greater in females than in males under a normal N supply, but they were reduced in females and enhanced in males under N deficiency. The genes related to Cd uptake and translocation, HMA2, YSL2 and ZIP2, were strongly induced by Cd stress in female roots and in males under a normal N supply. Cadmium largely accumulated in the leaf blades of females and in the leaf veins of males under a normal N supply, while the contrary was true under N deficiency. Furthermore, Cd was mainly distributed in the leaf epidermis and spongy tissues of males, and in the leaf palisade tissues of females. Nitrogen deficiency increased Cd allocation to the spongy tissues of female leaves and to the palisade tissues of males. In roots, Cd was preferentially distributed to the epidermis and cortices in both sexes, and also to the vascular tissues of females under a normal N supply but not under N deficiency. These results suggested that males possess better Cd tolerance compared with females, even under N deficiency, which is associated with their reduced root-to-shoot Cd translocation, specific Cd distribution in organic and/or cellular compartments, and enhanced antioxidation and ion homeostasis. Our study also provides new insights into engineering woody plants for phytoremediation.

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Influence of elevated content of cadmium and arsenic in diet containing feeding yeast on organisms of rats

Czech Journal of Animal Science ◽

10.17221/1739-cjas ◽

2009 ◽

Vol 54 (No. 1) ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

J. Száková ◽

V. Zídek ◽

D. Miholová

Keyword(s):

Sodium Arsenite ◽

Cadmium Accumulation ◽

Yeast Cells ◽

Male Rats ◽

Arsenic Content ◽

Cadmium Content ◽

Cd Accumulation ◽

Experimental Animals ◽

Natural Level ◽

Liver And Kidney

The influence of elevated cadmium content in diet on the content of this element in liver, kidney and testes of 68 male rats was studied in dependence on the chemical form of applied cadmium (as inorganic salt – CdCl2 and organically bound in yeast cells); the influence of elevated arsenic content (as NaAsO2) in diet on its content in the same organs was also investigated. The interactions between arsenic and cadmium in the above-mentioned organs were studied. The addition of cadmium to the diet of rats significantly (P < 0.05) increased cadmium content in several organs. The addition of yeast containing the natural level of Cd increased the content of cadmium in liver and kidney of experimental animals significantly (P < 0.05). A significantly (P < 0.05) increased cadmium accumulation in organs was observed after the addition of Cd as CdCl2, compared with the addition of Cd as organically bound Cd in yeast cells. At the same time, the addition of yeasts containing the natural level of Cd decreased the Cd accumulation applied as CdCl2 in the examined organs. The addition of sodium arsenite to the diet of rats led to a significantly (P < 0.05) increased arsenic content in all the analyzed organs. The addition of yeasts to the diet increased arsenic content in liver and at the same time suppressed its content in kidneys of experimental animals. The interaction between arsenic and cadmium applied simultaneously was evident. The addition of As to the diet decreased the accumulation of Cd in kidney and increased its accumulation in testes. The addition of Cd to the diet increased arsenic content in liver and kidney and decreased its content in testes.

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Selenium Enhances Cadmium Accumulation Capability in Two Mustard Family Species—Brassica napus and B. juncea

Plants ◽

10.3390/plants9070904 ◽

2020 ◽

Vol 9 (7) ◽

pp. 904 ◽

Cited By ~ 1

Author(s):

Zhong-Wei Zhang ◽

Yi-Ying Dong ◽

Ling-Yang Feng ◽

Zong-Lin Deng ◽

Qiang Xu ◽

...

Keyword(s):

Brassica Napus ◽

Brassica Juncea ◽

Brassica Species ◽

Dry Weight ◽

Cadmium Accumulation ◽

Cd Accumulation ◽

Cd Toxicity ◽

Valence States ◽

Early Seedling ◽

High Level

Oilseed rape (Brassica napus) is a Cadmium (Cd) hyperaccumulator. However, high-level Cd at the early seedling stage seriously arrests the growth of rape, which limits its applications. Brassica juncea had higher Cd accumulation capacity, but its biomass was lower, also limiting its applications. Previous studies have confirmed that Selenium (Se) can alleviate Cd toxicity. However, the regulatory mechanism of Se in different valence states of Cd accumulation was unclear. In this study, we investigated the ameliorating effects of three Se valence states, Na2SeO4 [Se(VI)], Na2SeO3 [Se(IV)] and Se-Met [Se(II)], to Cd toxicity by physiological and biochemical approaches in hydroponically-cultured Brassica juncea and Brassica napus seedlings. Although Se treatments slightly inhibited seedling Cd concentration, it tripled or quadrupled the Cd accumulation level per plant, because dry weight increased about four times more with Se and Cd application than with Cd treatment alone. Among the different valence states of Se, Se(II) had the most marked effect on reducing Cd toxicity as evidenced by decreased growth inhibition and Cd content. The application of Se(II) was effective in reducing Cd-induced reactive oxygen species accumulation, and promoted the antioxidant enzyme activity and photosynthesis of both Brassica species. In addition, Se(II) treatment increased the concentrations of Cd in the cell wall and soluble fractions, but the Cd concentration in the organelle part was reduced.

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Reducing Cadmium Accumulation in Plants: Structure–Function Relations and Tissue-Specific Operation of Transporters in the Spotlight

Plants ◽

10.3390/plants9020223 ◽

2020 ◽

Vol 9 (2) ◽

pp. 223 ◽

Cited By ~ 5

Author(s):

Xin Huang ◽

Songpo Duan ◽

Qi Wu ◽

Min Yu ◽

Sergey Shabala

Keyword(s):

Structure Function ◽

Current Knowledge ◽

Cadmium Accumulation ◽

Major Focus ◽

Phloem Tissue ◽

Cd Uptake ◽

Major Health ◽

Cd Accumulation ◽

Tissue Specific

Cadmium (Cd) is present in many soils and, when entering the food chain, represents a major health threat to humans. Reducing Cd accumulation in plants is complicated by the fact that most known Cd transporters also operate in the transport of essential nutrients such as Zn, Fe, Mn, or Cu. This work summarizes the current knowledge of mechanisms mediating Cd uptake, radial transport, and translocation within the plant. It is concluded that real progress in the field may be only achieved if the transport of Cd and the above beneficial micronutrients is uncoupled, and we discuss the possible ways of achieving this goal. Accordingly, we suggest that the major focus of research in the field should be on the structure–function relations of various transporter isoforms and the functional assessment of their tissue-specific operation. Of specific importance are two tissues. The first one is a xylem parenchyma in plant roots; a major “controller” of Cd loading into the xylem and its transport to the shoot. The second one is a phloem tissue that operates in the last step of a metal transport. Another promising and currently underexplored avenue is to understand the role of non-selective cation channels in Cd uptake and reveal mechanisms of their regulation.

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