Phytochelatin Synthase has Contrasting Effects on Cadmium and Arsenic Accumulation in Rice Grains.
Phytochelatin Synthase has Contrasting Effects on Cadmium and Arsenic Accumulation in Rice Grains.
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DOI：
10.1093/pcp/pcx114
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发表时间：
2017-10-01
影响因子：
4.9
通讯作者：
Clemens S
中科院分区：
文献类型：
--
作者：
Uraguchi S;Tanaka N;Hofmann C;Abiko K;Ohkama-Ohtsu N;Weber M;Kamiya T;Sone Y;Nakamura R;Takanezawa Y;Kiyono M;Fujiwara T;Clemens S
植物螯合素（Phytochelatin，PC）的合成是拟南芥耐重金属的主要机制，但其在元素远距离运输中的作用，特别是在单子叶植物中的作用尚不清楚。以水稻为模型，研究了水稻植物螯合素合成酶1（OsPCS 1）在砷（As）和镉（Cd）分布和解毒中的生理作用。首先，我们分离了OsPCS 1的四种不同的转录变体以及OsPCS 2的一种。实时荧光定量RT-PCR分析表明，OsPCS 1的最长变异体OsPCS 1full在水稻幼苗中表达量最高，其次是OsPCS 2。OsPCS变体在粟酒裂殖酵母和A.表明OsPCS 1对As（III）和Cd具有PCS活性，而其它PCS变体的活性很低。为了研究OsPCS 1在水稻中的毒性耐受和积累生理功能，鉴定了两个独立的OsPCS 1突变体水稻品系（T-DNA和Tos 17插入系）。OsPCS 1突变体在水培实验中表现出对As（III）和Cd的敏感性增加，表明OsPCS 1依赖的PC合成对水稻As（III）和Cd耐受性的重要性。环境相关的As和Cd浓度的土壤中生长的水稻植株的元素分析表明，增加As积累和减少Cd积累的T-DNA线的颗粒。Tos 17突变体也表现出镉积累减少的表型。这些对比效果的As和Cd分配到谷物表明存在至少部分不同的PC依赖途径As和Cd。
Phytochelatin (PC) synthesis has been well demonstrated as a major metal tolerance mechanism in Arabidopsis thaliana, whereas its contribution to long-distance element transport especially in monocots remains elusive. Using rice as a cereal model, we examined physiological roles of Oryza sativa phytochelatin synthase 1 (OsPCS1) in the distribution and detoxification of arsenic (As) and cadmium (Cd), two toxic elements associated with major food safety concerns. First, we isolated four different transcript variants of OsPCS1 as well as one from OsPCS2. Quantitative real-time reverse transcription–PCR (RT-PCR) of each OsPCS transcript in rice seedlings suggested that expression of OsPCS1full, the longest OsPCS1 variant, was most abundant, followed by OsPCS2. Heterologous expression of OsPCS variants in PCS-deficient mutants of Schizosaccharomyces pombe and A. thaliana suggested that OsPCS1full possessed PCS activity in response to As(III) and Cd while the activity of other PCS variants was very low. To address physiological functions in toxic element tolerance and accumulation, two independent OsPCS1 mutant rice lines (a T-DNA and a Tos17 insertion line) were identified. The OsPCS1 mutants exhibited increased sensitivity to As(III) and Cd in hydroponic experiments, showing the importance of OsPCS1-dependent PC synthesis for rice As(III) and Cd tolerance. Elemental analyses of rice plants grown in soil with environmentally relevant As and Cd concentrations showed increased As accumulation and decreased Cd accumulation in grains of the T-DNA line. The Tos17 mutant also exhibited the reduced Cd accumulation phenotype. These contrasting effects on As and Cd distribution to grains suggest the existence of at least partially distinct PC-dependent pathways for As and Cd.
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DOI：
10.1186/1939-8433-6-3
发表时间：
2013-01-11
期刊：
Rice (New York, N.Y.)
影响因子：
--
作者：
Kuramata M;Abe T;Kawasaki A;Ebana K;Shibaya T;Yano M;Ishikawa S
通讯作者：
Ishikawa S
影响因子：
6.9
作者：
Batista BL;Nigar M;Mestrot A;Rocha BA;Barbosa Júnior F;Price AH;Raab A;Feldmann J
通讯作者：
Feldmann J
影响因子：
11.4
作者：
Honma, Toshimitsu;Ohba, Hirotomo;Katou, Hidetaka
通讯作者：
Katou, Hidetaka
影响因子：
7.2
作者：
Clough, SJ;Bent, AF
通讯作者：
Bent, AF
影响因子：
7.4
作者：
HOWDEN, R;GOLDSBROUGH, PB;COBBETT, CS
通讯作者：
COBBETT, CS