Cd-K双重处理对水稻幼苗生长和Cd吸收转运的影响及相关转运通道分析

发布时间：2018-03-03 16:02

本文选题：水稻　切入点：Cd-K双重处理　出处：《植物资源与环境学报》2016年04期 　论文类型：期刊论文

【摘要】：以水稻(Oryza sativa Linn.)高Cd积累品种‘T优705’(‘T You 705’)和低Cd积累品种‘湘早籼24’(‘Xiangzaoxian 24’)为实验材料,采用水培法对不同浓度Cd(0.0和2.7μmol·L~(- 1)Cd)和K(0、30和60 mmol·L~(- 1)K)处理条件下2个品种幼苗的相对生长量、根系和地上部的Cd含量及其亚细胞分布特征进行了比较,并分析了添加离子通道活性抑制剂TEA和La Cl3后幼苗根系和地上部的Cd和K含量;在此基础上,比较了NSCCs(非选择性阳离子通道)和K专性通道对2个品种幼苗根系和地上部Cd和K吸收贡献率的影响。结果表明:与Cd单一处理组(2.7μmol·L~(- 1)Cd)相比,Cd-K双重处理组(2.7μmol·L~(- 1)Cd-30 mmol·L~(- 1)K和2.7μmol·L~(- 1)Cd-60 mmol·L~(- 1)K)2个品种幼苗的相对生长量显著提高,而幼苗根系和地上部的Cd含量显著下降;随K浓度的提高,2个品种幼苗根系细胞壁和细胞液中的Cd含量显著下降,但细胞壁中Cd含量的分配比例增大而细胞液中Cd含量的分配比例则减小。在含2.7μmol·L~(- 1)Cd和30 mmol·L~(- 1)K的培养液中分别添加5 mmol·L~(- 1)TEA或0.2 mmol·L~(- 1)La Cl3后,2个品种幼苗根系和地上部的Cd和K含量均显著下降,其中,La Cl3处理组的根系Cd含量降幅高于TEA处理组,但La Cl3处理组的根系K含量降幅则低于TEA组。NSCCs对品种‘T优705’幼苗根系和地上部Cd吸收的贡献率显著低于品种‘湘早籼24’幼苗,而K专性通道对品种‘T优705’幼苗根系K吸收和地上部Cd吸收的贡献率则显著低于品种‘湘早籼24’幼苗。研究结果显示:添加外源K可缓解Cd对水稻幼苗生长的抑制作用,并通过提高细胞壁与Cd的结合能力来降低细胞液中Cd的积累,以此减弱幼苗对Cd的吸收和转运能力;幼苗体内的K和Cd均可通过K专性通道和NSCCs转运,其中,K吸收和转运主要通过K专性通道完成,而Cd吸收和转运主要通过NSCCs完成。此外,品种‘T优705’可能具有多种离子通道参与Cd的吸收和转运,而品种‘湘早籼24’主要依赖NSCCs参与Cd的吸收和转运,且后者对K的吸收和积累强于前者。
[Abstract]:In this paper, the relative growth amount of seedlings of rice Oryza sativa Linn.) and low CD accumulation cultivar 'Xiangzaoxian' was studied under different concentrations of Cd(0.0 and 2.7 渭 mol 路L ~ (-1) CD and K030 and 60 mmol 路L ~ (-1) K ~ (-1), respectively, and the low CD accumulation variety 'Xiangzaoxian' ('Xiangzaoxian 24') was used as the experimental material, and the relative growth amount of the two cultivars was studied under different concentrations of Cd(0.0 and Cd(0.0 (2.7 渭 mol 路L ~ (-1) CD) and K030 and 60 mmol 路L ~ (-1) K). The CD content and its subcellular distribution in roots and shoots were compared, and the CD and K contents in roots and shoots were analyzed after adding ion channel active inhibitors TEA and La Cl3. The effects of NSCCs (non-selective cationic channel) and K specific channel on CD and K uptake contribution rates in roots and shoots of two cultivars were compared. The results showed that compared with single CD treatment group (2.7 渭 mol 路L ~ (-1) mol 路L ~ (-1) CD), Cd-K double treatment group was 2.7 渭 mol 路L ~ (-1) ~ (-1) Cd-30 mmol 路L ~ (-1) mmol 路L ~ (-1). The relative growth of seedlings of two cultivars, 1K and 2.7 渭 mol 路L ~ (-1) Cd-60 mmol 路L ~ (-1), increased significantly. However, CD content in root and shoot decreased significantly, and CD content in root cell wall and cell fluid decreased significantly with the increase of K concentration. However, the distribution ratio of CD content in cell wall increased and that in cell fluid decreased. After adding 5 mmol 路L ~ (-1) tea or 0.2 mmol 路L ~ (-1) La Cl3 to the culture medium containing 2.7 渭 mol 路L ~ (-1) ~ (-1) and 30 mmol 路L ~ (-1) K, respectively, the roots and shoot of the two cultivars were obtained. The contents of CD and K decreased significantly. The decrease of CD content in roots of La Cl3 treatment group was higher than that of TEA treatment group, but that of La Cl3 treatment group was lower than that of TEA group. NSCCs contribution rate to root and shoot CD uptake of the seedling was significantly lower than that of 'Xiangzao indica rice 24' seedling. The contribution of K specific pathway to root K uptake and shoot CD uptake was significantly lower than that of 'Xiangzao Indica 24' seedling. The results showed that exogenous K could alleviate the inhibition of CD on rice seedling growth. CD accumulation in the cell fluid was reduced by increasing the binding ability of the cell wall to CD, thus the CD uptake and transport ability of the seedlings were weakened, and both K and CD were transported through K specific channels and NSCCs. The absorption and transport of K and CD are mainly through K specific channels, and CD uptake and transport are mainly through NSCCs. In addition, the variety TY705'may have a variety of ion channels involved in CD absorption and transport. The variety 'Xiangzao indica' mainly depends on NSCCs to participate in CD absorption and transport, and the latter's absorption and accumulation of K is stronger than that of the former.
【作者单位】：农业部环境保护科研监测所生态毒理与环境修复研究中心;天津师范大学生命科学学院天津市动植物抗性重点实验室;河南农业大学农学院;
【基金】：2015年中国农业科学院科技创新工程项目(2015-cxgc-lzq) 国家农业部公益性行业(农业)科研专项(201403015)
【分类号】：S511.21;X503.231

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