Comparation of Se accumulation and distribution of two rice (Oryza sativa L.) cultivars with high- and low- Se efficiency as affected by exogenous application of selenite

Abstract

BackgroundIn production, increasing Selenium (Se) level of rice grain could be achieved by adding exogenous Se and selecting Se efficient rice cultivars. However, the accumulation and distribution of Se in rice cultivars with high- and low-efficiency after Se application is not well documented. A pot experiment with two Se levels was carried out on two rice cultivars. ResultsSe concentration in grain, shoot and root of Se efficient rice was significantly higher than that of Se inefficient rice with Se application (p < 0.05). Besides, Se application significantly increased the expression of NRT1.1B gene in stem nodes of Se efficient rice in comparison to Se inefficient rice. The proportion of Se accumulation in shoot and spike of Se efficient rice was 18.3% and 9.5% higher than that in Se inefficient rice when Se was applied. Moreover, the contents of various mineral elements in leaf showed that Se enhanced the concentration of most elements in Se efficient rice, indicating that it seems to be a better cooperative transport relationship between Se and other mineral elements in Se efficient rice. The spatial distribution of Se, Fe, Mn, Cu and Zn in Se efficient rice grains was tended to be distributed distal to the embryo, while such elements in Se inefficient rice grains was more concentrated proximal to the embryo, which indicated that Se efficient rice could make better use of the storage capacity of grain. ConclusionsHigher Se accumulation in Se efficient rice primarily attributed to the increase of Se transport capability and Se source as well as better synergistic effects between Se and other mineral elements. The findings will provide theoretical support for breeding new rice varieties and developing Se-enriched rice industry.