摘要：Heavy metals in farmland soil have negative effects on rice production and pose a great threat to human health. The effects of different concentrations of 28-homobrassinolide (Br28: 0, 0.02, 0.06, 0.18, 0.54, 1.62, 4.86, 14.58 μM) on the accumulation and uptake of cadmium (Cd), lead (Pb), and zinc (Zn) in two genotypes (Donglian5 and Teyou009) of rice seedlings, grown in Cd-Pb-Zn contaminated soil, were investigated using pot experiments. The results showed that Br28 can increase the iron (Fe) content in the iron plaque formed on the rice seedlings of Donglian5, but not on Teyou009. The Fe content in the roots and shoots of Teyou009 can be increased by Br28, but not in Donglian5. The contents of Cd in iron plaque were barely affected by Br28 in both the genotypes of rice seedlings. Br28 significantly decreased the Cd content in the shoots and roots of Teyou009, but not in Donglian5. The highest proportion (60%) of Cd observed was concentrated in the shoots of Teyou009, and reduced by 24% when 0.02 μM of Br28 was used. However, Br28 did not significantly affect the accumulation and uptake of Pb and Zn in the shoots, roots, and iron plaque for both genotypes of rice plants. Our results indicate that Br28 can effectively reduce Cd uptake in rice seedlings, but these results are genotype-dependent.
