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Zhang C.,Nanjing Agricultural University | Zhang C.,CAS Nanjing Institute of Soil Science | Yin X.,Nanjing Agricultural University | Gao K.,Nanjing Agricultural University | And 3 more authors.
Journal of Plant Nutrition and Soil Science | Year: 2013

A hydroponic experiment was conducted to investigate the dynamic variations of cadmium (Cd) uptake and transport, non-protein thiols (NPT) and glutathione (GSH) concentrations, glutathione S-transferase (GST) activity and lipid peroxidation under Cd stress in order to clarify the role of NPT and GST in reducing Cd toxicity and translocation in rice (Oryza sativa L.). Cadmium accumulation was initially fast and then slowed down with increasing time of Cd exposure. However, the rice growth inhibition and lipid peroxidation were not intense until 5d after Cd treatment, even though Cd kept accumulating in root and shoot, suggesting that Cd may be effectively detoxified. The concentrations of NPT in root increased gradually until 5d after Cd stress, whereas those in shoot showed no significant changes. The concentration of shoot GSH was progressively enhanced upon Cd treatment, while it gradually declined in root after an initial increase. The GST activity varied similarly in root and shoot, reaching the maximum level on 3rd day, followed by a significant decrease 5 d after Cd application. Significant increases of lipid peroxidation and root-to-shoot translocation on 7th day indicate that the equilibrium in Cd-thiol interaction in rice might be disturbed upon the prolonged Cd exposure. In summary, our results suggest that Cd may be retained and detoxified in rice root through chelation with thiol compounds and subsequent sequestration. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cai Y.,Zhejiang University | Lin L.,Zhejiang University | Cheng W.,Jiaxing Academy of Agricultural science | Zhang G.,Zhejiang University | Wu F.,Zhejiang University
Plant, Soil and Environment | Year: 2010

A hydroponic experiment was performed using Cd-sensitive (cv. Xiushui63) and tolerant (cv. Bing97252) rice cultivars to evaluate the difference in their response to Cd toxicity in the presence of exogenous glutathione (GSH). The results showed that Cd stress (5 and 50 μmol/l Cd) decreased plant fresh weight, contents of chlorophyll a, b and carotenoids, with Cd-sensitive genotype being more severely affected. Cd significantly decreased concentration and accumulation of Mn in roots/shoots, and Zn in shoots, but increased Cu concentration in roots/shoots. There was a significantly negative correlation between shoot Zn concentrations and shoot/root Cd concentrations, and between root Cd and Mn concentrations. Exogenous GSH significantly alleviated Cd-induced growth inhibition and markedly reduced Cd uptake in both genotypes. In addition, GSH induced a Cd-dose- and genotype-dependent effects on Cd-induced changes in mineral concentration/accumulation and chlorophyll content in rice seedlings. GSH alleviated Cd-induced decrease in root/shoot Zn and Ca concentrations and accumulation of Xiushui 63, while increased root Ca and Mn concentrations in Bing 97252 under 5 μmol/l Cd stress. In addition, GSH also significantly enhanced chlorophyll a and b contents of Bing 97252 in both 5 and 50 μmol/l Cd, and Xiushui 63 in 50 μmol Cd.

Cai Y.,Zhejiang University | Cao F.,Zhejiang University | Cheng W.,Jiaxing Academy of Agricultural science | Zhang G.,Zhejiang University | Wu F.,Zhejiang University
Biological Trace Element Research | Year: 2011

Greenhouse hydroponic experiments were conducted using Cd-sensitive (Xiushui63) and tolerant (Bing97252) rice genotypes to evaluate genotypic differences in response of photosynthesis and phytochelatins to Cd toxicity in the presence of exogenous glutathione (GSH). Plant height, chlorophyll content, net photosynthetic rate (Pn), and biomass decreased in 5 and 50 μM Cd treatments, and Cd-sensitive genotype showed more severe reduction than the tolerant one. Cadmium stress caused decrease in maximal photochemical efficiency of PSII (Fv/Fm) and effective PSII quantum yield [Y(II)] and increase in quantum yield of regulated energy dissipation [Y(NPQ)], with changes in Cd-sensitive genotype being more evident. Cadmium-induced phytochelatins (PCs), GSH, and cysteine accumulation was observed in roots of both genotypes, with markedly higher level in PCs and GSH on day 5 in Bing97252 compared with that measured in Xiushui63. Exogenous GSH significantly alleviated growth inhibition in Xiushui63 under 5 μM Cd and in both genotypes in 50 μM Cd. External GSH significantly increased chlorophyll content, Pn, Fv/Fm, and Y(II) of plants exposed to Cd, but decreased Y(NPQ) and the coefficient of non-photochemical quenching (qN). GSH addition significantly increased root GSH content in plants under Cd exposure (except day 5 of 50 μM Cd) and induced up-regulation in PCs of 5 μM-Cd-treated Bing97252 throughout the 15-day and Xiushui63 of 5-day exposure. The results suggest that genotypic difference in the tolerance to Cd stress was positively linked to the capacity in elevation of GSH and PCs, and that alleviation of Cd toxicity by GSH is related to significant improvement in chlorophyll content, photosynthetic performance, and root GSH levels. © 2010 Springer Science+Business Media, LLC.

Qiao M.,CAS Research Center for Eco Environmental Sciences | Chen W.,Jiaxing Academy of Agricultural science | Su J.,Chinese Institute of Urban Environment | Zhang B.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Journal of Environmental Sciences (China) | Year: 2012

Veterinary antibiotics can enter the environment due to the common practice of land application of manure from treated animals. The environmental fate of tetracyclines in swine manure after composting and field application remains largely unknown. This study analyzed the concentrations of tetracyclines in manure, manure-based compost and compost amended soil in selected swine farms from Beijing, Jiaxing and Putian, China to determine the dilution effects of antibiotics when released into the soil environment. The results demonstrate that residues of antibiotics were detected in all samples and chlortetracycline as well as its degradation products should be regarded critically concerning their potential ecotoxicity. Application of manure-based compost to soil could reduce the possible risk posed by antibiotic contamination, but the trigger value of 100 μg/kg was still exceeded in soil samples (776.1 μg/kg dw) from Putian City after application of compost. Field studies such as the present one can help to improve the routine administration of antibiotic-containing composted manure. © 2012 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Wang S.,CAS Institute of Genetics and Developmental Biology | Wang S.,South China Agricultural University | Li S.,CAS Institute of Genetics and Developmental Biology | Liu Q.,CAS Institute of Genetics and Developmental Biology | And 9 more authors.
Nature Genetics | Year: 2015

The deployment of heterosis in the form of hybrid rice varieties has boosted grain yield, but grain quality improvement still remains a challenge. Here we show that a quantitative trait locus for rice grain quality, qGW7, reflects allelic variation of GW7, a gene encoding a TONNEAU1-recruiting motif protein with similarity to C-terminal motifs of the human centrosomal protein CAP350. Upregulation of GW7 expression was correlated with the production of more slender grains, as a result of increased cell division in the longitudinal direction and decreased cell division in the transverse direction. OsSPL16 (GW8), an SBP-domain transcription factor that regulates grain width, bound directly to the GW7 promoter and repressed its expression. The presence of a semidominant GW7 TFA allele from tropical japonica rice was associated with higher grain quality without the yield penalty imposed by the Basmati gw8 allele. Manipulation of the OsSPL16-GW7 module thus represents a new strategy to simultaneously improve rice yield and grain quality. © 2015 Nature America, Inc.

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