Cd, Pb Accumulations In Edible Amaranth Cultivars And Their Relationships With Expression Of Metal Key Transporter Genes And Growth Seasons

The research is supposed to study the mechanism of Amaranth heavy metals accumulation through the relationship of heavy metals and nutrient elements accumulation and the expression of two key transporter genes, HMA4 and IRT1. The research also studys the heavy metals accumulation differences between summer Amaranth and autumn Amaranth. Nine cultivars of Amaranth were cultivated with garden soil polluted with heavy metals. The results are as below: 1. No. 8 Amaranth with the most biomass and the high concentration of Cd and Pb in shoot issupposed to be the high-heavy-metals-accumulation cultivar. Besides, No.1 Amaranth withthe large biomass and low concentration of Cd and Pb in shoot is supposed to be thelow-heavy-metals-accumulation cultivar and it’s quite well for human to eat. 2. No.8 and No.1 Amaranth were selected and expression of gene IRT1, HMA4 in root wereinvestigated to determine whether Cd and Pb uptake was affected by transport protein. RootCd accumulation was positively correlated with Fe, Mn and Mg(p<0.01). Concentraitons ofCd and Fe in root and expression of gene IRT1 with high-heavy-metals-accumulationcultivar of No.8 Amaranth were significantly higher than those withlow-heavy-metals-accumulation cultivar of NO.1 Amaranth. This implies the higherexpression of gene IRT1 in root of Amaranth may contribute to Fe uptake in root from thesoil and promoted heavy metals accumulation in shoot. Cd accumulation in shoot wassignificantly positively correlated with Pb, Mn and Ca. Concentrations of Cd, Pb, Ca andMn in shoot and expression of gene HMA4 with high-heavy-metals-accumulation cultivarof No.8 Amaranth were significantly higher than those with low-heavy-metals-accumulationcultivar of No.1 Amarath. This implies the higher expression of gene HMA4 in root ofAmaranth may contribute to heavy metals transport from root to shoot. 3. The growth season had enormous implications on biomass, the heavy metals and nutrientelements accumulation in Amaranth. Genrally, autumn Amaranth’s biomass was less thansummer Amaranth’s. What’s more, the Amaranth cultivated in autumn accumulated morenutrient elements and less heavy metals than the Amaranth cultivated in summer. This implies that autumn Amarath is more healthy and safe for human.