缺磷抑制拟南芥对镉的吸收

以野生型拟南芥Col-0和铁转运蛋白缺失突变体irt1为试验材料,设置缺磷无镉处理(-P-Cd)、缺磷加镉处理(-P+Cd)、正常供磷无镉处理(+P-Cd)和正常供磷加镉处理(+P+Cd),研究缺磷对拟南芥镉吸收的影响。结果表明:40 μmol·L^-1 镉处理条件下,与正常供磷相比,缺磷处理显著提高了Col-0拟南芥叶片的叶绿素相对含量和植株干质量,缓解了镉对拟南芥Col-0的毒害;缺磷处理降低了Col-0植株体内的镉含量,并抑制了根中铁转运蛋白基因IRT1的表达;在irt1突变体中,缺磷处理虽然也降低了植株体内的镉含量,但降低幅度显著低于Col-0植株。因此,推测IRT1基因在缺磷抑制拟南芥对镉的吸收、缓解镉毒害中起作用。

Inhibition of phosphorus deficiency on cadmium accumulation in Arabidopsis thaliana

Wild-type Arabidopsis thaliana Col-0 and iron transporter deletion mutant irt1 were used as experimental materials to study the mechanism of phosphorus deficiency. The following tests were applied: phosphorus-free plus cadmium-free treatment (-P-Cd), phosphorus-free plus cadmium treatment (-P+Cd), normal phosphorus supply without cadmium treatment (+P-Cd) and normal phosphorus supply plus cadmium treatment (+P+Cd). The results showed that under the condition of 40 μmol·L^-1 cadmium treatment, phosphorus deficiency treatment significantly raised relative leaf chlorophyll content and dry weight of wild-type Arabidopsis thaliana Col-0, and attenuated the toxicity of cadmium to wild-type Arabidopsis thaliana Col-0 compared with normal phosphorus supply. At the same time, phosphorus deficiency treatment reduced the cadmium content in Col-0 plants and inhibited the expression of iron transporter 1 (IRT1) in roots. Phosphorus deficiency treatment in the irt1 mutant also reduced cadmium content in plants, but the reduction was significantly lower than the results obtained for Col-0. Therefore, IRT1 gene played a role in inhibiting cadmium uptake and relieving cadmium toxicity.