缺Fe/Zn及盐胁迫下苋菜对Cd及矿质元素的吸收与IRT1表达的关系

Cadmium and mineral element accumulation and IRT1 gene expression of Amaranth hybidus L. under iron/zinc deficiencies or salt stress

选用Cd低累积品种白梗尖叶苋菜(B)和高累积品种花红苋菜(H)2个苋菜品种,采用水培法分别研究了在缺Fe、缺Zn和盐胁迫3种处理条件下2个苋菜品种对矿质元素以及cd的累积特征,并通过测定2个品种不同处理根部IRT1(铁离子转运蛋白)的表达量,建立了缺Fe/Zn及盐胁迫下苋菜对Cd及矿质元素的吸收与IRT1表达的关系。结果表明,3个处理组中2个苋菜品种生物量均显著低于对照组,缺Fe以及缺Zn处理显著促进了2个苋菜品种对Cd以及矿质元素的累积,而盐胁迫显著抑制了苋菜对Cd的累积,同时促进了其对矿质元素的累积(P<0.05)。不同处理下,Zn、Fe相关转运基因IRT1的表达差异显著,IRT1表达量的增加可以促进植物对Cd、Fe、Zn、Mn、Mg等元素的吸收(P<0.05)。

Previous research has showed that iron-regulated transporter 1（IRT1） gene plays an important role in the accumulation and transfer of metals in plants. Here a low Cd-accumulating cultivar Baigenjianye（B） and a high Cd-accumulating cultivar Huahong（H） were used to investigate the characteristics of mineral element and Cd accumulation by and IRT1 expression level in roots of Amaranth hybidus L. under iron（Fe） or zinc（Zn） deficiencies or salt stress. Quantitative PCR was used to determine the expression level of IRT1. Biomass of two cultivars obviously decreased in the treatments, with the greatest reduction observed in Fe deficiency. The accumulation of Cd and mineral elements significantly（P〈0.05） increased under Fe and Zn deficiency treatments. However, salt stress showed a significant（P〈0.05） inhibiting effect on Cd accumulation but a significant（P〈0.05） promotion on the accumulation of mineral elements. The concentrations of Cd, Fe, Zn and Mg, and the expression of gene IRT1 in root protoplasts were obviously higher in high Cd-accumulating cultivar Huahong（H）than those in low Cd-accumulating cultivar Baigenjianye（B）. Furthermore, elevated expression levels of IRT1 promoted the concentrations of Cd, Fe, Zn and Mg in stems and leaves. Therefore, while Cd concentration in crops is concerned, the content of minerals in the soil should be paid attention to at the same time.