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

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.

Download Full-text

Aspects of cultivar variation in physiological traits related to Cd distribution in rice plants with a short-term stress

10.21203/rs.3.rs-34413/v2 ◽

2020 ◽

Author(s):

Wan-Ting Chiao ◽

Bo-Ching Chen ◽

Chien-Hui Syu ◽

Kai-Wei Juang

Keyword(s):

Shoot Growth ◽

Rice Grain ◽

Rice Cultivars ◽

Cd Accumulation ◽

Physiological Regulation ◽

Rice Plants ◽

Cd Contamination ◽

Cultivar Variation ◽

Cd Distribution ◽

Cd Translocation

Abstract Background Genotypic variations are seen in cadmium (Cd) tolerance and accumulation in rice plants. Cultivars that show low Cd translocation from the root into shoot can be selected to reduce Cd contamination in rice grains. This study aims to clarify the physiological regulation related to Cd absorption by rice plants for screening out the cultivars, which have relatively low Cd accumulation in grains. Eight Taiwan mega cultivars of paddy rice: japonica (TY3, TK9, TNG71, and KH145 cultivars), indica (TCS10 and TCS17 cultivars), and glutinous (TKW1 and TKW3 cultivars), which are qualified with the criteria for rice grain quality by the Council of Agriculture, Taiwan, were used for illustration. An experiment in hydroponics was conducted for the rice seedlings with a treatment of 50 μM CdCl 2 for 7 days. Results and discussion After the Cd treatment, the reductions in shoot growth were more significant than those in root growth; however, Cd absorbed in the rice plant was sequestered much more in the root. The malondialdehyde (MDA) was preferentially accumulated in rice root but the hydrogen peroxide (H 2 O 2 ) was increased more significantly in the shoot; the antioxidative enzymes, superoxide dismutase (SOD) and ascorbate peroxidase (APX), were pronounced more in rice shoot. Conclusions The rice cultivars preferentially accumulated Cd in the root rather than the shoot with the Cd treatment, which resulted in significant enhancements of MDA and growth reductions in the root. However, H 2 O 2 accumulation was toward the shoot to retard shoot growth suddenly and then the root could keep a gradual growth. Also, the rice cultivars, which preferentially accumulate Cd in the root, would have the regulation tendency of SOD toward the shoot. Due to that SOD is responsible for H 2 O 2 production, H 2 O 2 accumulation would be thus toward the shoot. Moreover, the cultivars, which have a less regulation tendency of APX toward the shoot, would present higher translocation of Cd into the shoot.

Download Full-text

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

Rice ◽

10.1186/s12284-021-00530-8 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Li Tang ◽

Jiayu Dong ◽

Longtao Tan ◽

Zhongying Ji ◽

Yaokui Li ◽

...

Keyword(s):

Genetic Resource ◽

Xylem Sap ◽

Cadmium Accumulation ◽

Cd Accumulation ◽

Rice Grains ◽

Hydroponic Experiment ◽

Zn Uptake ◽

Transporter Family ◽

Molecular Regulatory Mechanisms ◽

Cd Translocation

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.

Download Full-text

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.

Download Full-text

A large-scale analysis of seed natural aging revealed stronger aging resistance in weedy rice than coexisting cultivated rice for continuous 4 years across China

10.21203/rs.2.17773/v1 ◽

2019 ◽

Author(s):

weimin dai ◽

Yuan Wang ◽

Yu-Jie Zhang ◽

Xi-Xi Sun ◽

Jin-Ling Yang ◽

...

Keyword(s):

Oryza Sativa ◽

Large Scale ◽

Oryza Sativa L ◽

Germination Rate ◽

Weedy Rice ◽

Japonica Rice ◽

Rice Cultivars ◽

Cultivated Rice ◽

Rice Varieties ◽

Aging Resistance

Abstract Increasing resistance to aging is conducive to seed storage and germination rate of crop. Meanwhile, the resistance to aging is one of the important adaptive mechanisms of weed to thrive in farmland. Weedy rice (Oryza sativa f. spontanea) and cultivated rice (Oryza sativa L.) provide a unique pair demonstrating a weed and conspecific model crop that can be used to study the aging resistance of plants across a diverse geographical range. Chinese weedy rice derived from de-domestication of cultivated rice has rapidly risen to malignant weeds, though the hazard has only been reported for about 20 years. Whether weedy rice rapidly evolves higher seed aging resistance than cultivated rice during the process of dedomestication, which is conducive to its persistence in rice fields, is still unclear. In this experiment, the seeds of weed rice populations and their co-existing rice varieties were collected from 61 regions of China and germinated under normal and high temperatures for consecutive four years (2013–2016). Our study found that the aging resistance of weedy rice was higher than that of the co-existing rice cultivars, and weedy rice may have evolved a different aging resistance mechanism than rice cultivars and could be used as a germplasm resource to cultivate aging-resistant rice. The indica-type has strong aging resistance and no dormancy, while the japonica type has weak aging resistance and a little weak dormancy. Thus, by introducing indica-type aging-resistant alleles into japonica rice, cultivation of aging-resistant japonica rice could be possible.

Download Full-text

Aspects of cultivar variation in physiological traits related to Cd distribution in rice plants with a short-term stress

10.21203/rs.3.rs-34413/v1 ◽

2020 ◽

Author(s):

Wan-Ting Chiao ◽

Bo-Ching Chen ◽

Chien-Hui Syu ◽

Kai-Wei Juang

Keyword(s):

Shoot Growth ◽

Rice Grain ◽

Rice Cultivars ◽

Cd Accumulation ◽

Physiological Regulation ◽

Rice Plants ◽

Cd Contamination ◽

Cultivar Variation ◽

Cd Distribution ◽

Cd Translocation

Abstract Background Genotypic variations are seen in Cd tolerance and accumulation in rice plants. Cultivars that show low Cd translocation from the root into shoot can be selected to reduce Cd contamination in rice grains. This study aims to clarify the physiological regulation related to cadmium (Cd) absorption by rice plants for screening out the cultivars, which have relatively low Cd accumulation in grains. Eight Taiwan mega cultivars of paddy rice: japonica (TY3, TK9, TNG71, and KH145 cultivars), indica (TCS10 and TCS17 cultivars), and glutinous (TKW1 and TKW3 cultivars), which are qualified with the criteria for rice grain quality by the Council of Agriculture, Taiwan, were used for illustration. An experiment in hydroponics was conducted for the rice seedlings with a treatment of 50 µM CdCl2 for 7 days. Results and discussion After the Cd treatment, the reductions in shoot growth were more significant than those in root growth; however, Cd absorbed in the rice plant was sequestered much more in the root. The malondialdehyde (MDA) was preferentially accumulated in rice root but the hydrogen peroxide (H2O2) was increased more significantly in the shoot; the antioxidative enzymes, superoxide dismutase (SOD) and ascorbate peroxidase (APX), were pronounced more in rice shoot. Conclusions The rice cultivars preferentially accumulated Cd in the root rather than the shoot with the Cd treatment, which resulted in significant enhancements of MDA and growth reductions in the root. However, H2O2 accumulation was toward the shoot to retard shoot growth suddenly and then the root could keep a gradual growth. Also, the rice cultivars, which preferentially accumulate Cd in the root, would have the regulation tendency of SOD toward the shoot. Due to that SOD is responsible for H2O2 production, H2O2 accumulation would be thus toward the shoot. Also, the cultivars, which have a less regulation tendency of APX toward the shoot, would present higher translocation of Cd into the shoot.

Download Full-text

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.

Download Full-text

Aspects of cultivar variation in physiological traits related to Cd distribution in rice plants with a short-term stress

Botanical Studies ◽

10.1186/s40529-020-00304-3 ◽

2020 ◽

Vol 61 (1) ◽

Author(s):

Wan-Ting Chiao ◽

Bo-Ching Chen ◽

Chien-Hui Syu ◽

Kai-Wei Juang

Keyword(s):

Shoot Growth ◽

Rice Grain ◽

Rice Cultivars ◽

Cd Accumulation ◽

Physiological Regulation ◽

Rice Plants ◽

Cd Contamination ◽

Cultivar Variation ◽

Cd Distribution ◽

Cd Translocation

Abstract Background Genotypic variations are seen in cadmium (Cd) tolerance and accumulation in rice plants. Cultivars that show low Cd translocation from the root into shoot can be selected to reduce Cd contamination in rice grains. This study aims to clarify the physiological regulation related to Cd absorption by rice plants for screening out the cultivars, which have relatively low Cd accumulation in grains. Eight Taiwan mega cultivars of paddy rice: japonica (TY3, TK9, TNG71, and KH145 cultivars), indica (TCS10 and TCS17 cultivars), and glutinous (TKW1 and TKW3 cultivars), which are qualified with the criteria for rice grain quality by the Council of Agriculture, Taiwan, were used for illustration. An experiment in hydroponics was conducted for the rice seedlings with a treatment of 50 μM CdCl2 for 7 days. Results and discussion After the Cd treatment, the reductions in shoot growth were more significant than those in root growth; however, Cd absorbed in the rice plant was sequestered much more in the root. The malondialdehyde (MDA) was preferentially accumulated in rice root but the hydrogen peroxide (H2O2) was increased more significantly in the shoot; the antioxidative enzymes, superoxide dismutase (SOD) and ascorbate peroxidase (APX), were pronounced more in rice shoot. Conclusions The rice cultivars preferentially accumulated Cd in the root rather than the shoot with the Cd treatment, which resulted in significant enhancements of MDA and growth reductions in the root. However, H2O2 accumulation was toward the shoot to retard shoot growth suddenly and then the root could keep a gradual growth. Also, the rice cultivars, which preferentially accumulate Cd in the root, would have the regulation tendency of SOD toward the shoot. Due to that SOD is responsible for H2O2 production, H2O2 accumulation would be thus toward the shoot. Moreover, the cultivars, which have a less regulation tendency of APX toward the shoot, would present higher translocation of Cd into the shoot.

Download Full-text

Aspects of cultivar variation in physiological traits related to Cd distribution in rice plants with a short-term stress

10.21203/rs.3.rs-34413/v3 ◽

2020 ◽

Author(s):

Wan-Ting Chiao ◽

Bo-Ching Chen ◽

Chien-Hui Syu ◽

Kai-Wei Juang

Keyword(s):

Shoot Growth ◽

Rice Grain ◽

Rice Cultivars ◽

Cd Accumulation ◽

Physiological Regulation ◽

Rice Plants ◽

Cd Contamination ◽

Cultivar Variation ◽

Cd Distribution ◽

Cd Translocation

Abstract Background: Genotypic variations are seen in cadmium (Cd) tolerance and accumulation in rice plants. Cultivars that show low Cd translocation from the root into shoot can be selected to reduce Cd contamination in rice grains. This study aims to clarify the physiological regulation related to Cd absorption by rice plants for screening out the cultivars, which have relatively low Cd accumulation in grains. Eight Taiwan mega cultivars of paddy rice: japonica (TY3, TK9, TNG71, and KH145 cultivars), indica (TCS10 and TCS17 cultivars), and glutinous (TKW1 and TKW3 cultivars), which are qualified with the criteria for rice grain quality by the Council of Agriculture, Taiwan, were used for illustration. An experiment in hydroponics was conducted for the rice seedlings with a treatment of 50 μM CdCl2 for 7 days. Results and discussion: After the Cd treatment, the reductions in shoot growth were more significant than those in root growth; however, Cd absorbed in the rice plant was sequestered much more in the root. The malondialdehyde (MDA) was preferentially accumulated in rice root but the hydrogen peroxide (H2O2) was increased more significantly in the shoot; the antioxidative enzymes, superoxide dismutase (SOD) and ascorbate peroxidase (APX), were pronounced more in rice shoot. Conclusions: The rice cultivars preferentially accumulated Cd in the root rather than the shoot with the Cd treatment, which resulted in significant enhancements of MDA and growth reductions in the root. However, H2O2 accumulation was toward the shoot to retard shoot growth suddenly and then the root could keep a gradual growth. Also, the rice cultivars, which preferentially accumulate Cd in the root, would have the regulation tendency of SOD toward the shoot. Due to that SOD is responsible for H2O2 production, H2O2 accumulation would be thus toward the shoot. Moreover, the cultivars, which have a less regulation tendency of APX toward the shoot, would present higher translocation of Cd into the shoot.

Download Full-text

Comparison of phytolith-occluded carbon in 51 main cultivated rice (Oryzasativa) cultivars of China

RSC Advances ◽

10.1039/c7ra10685h ◽

2017 ◽

Vol 7 (86) ◽

pp. 54726-54733 ◽

Cited By ~ 4

Author(s):

Xing Sun ◽

Qin Liu ◽

Gengmao Zhao ◽

Xiang Chen ◽

Tongtong Tang ◽

...

Keyword(s):

Carbon Sequestration ◽

High Efficiency ◽

Rice Cultivars ◽

Cultivated Rice ◽

High Productivity ◽

Occluded Carbon

In this study, the carbon (i.e., C) bio-sequestration within phytoliths (PhytOC) in 51 rice cultivars was evaluated to breed cultivars with a high efficiency of carbon sequestration in phytoliths and high productivity.

Download Full-text