Variation in arsenic accumulation and translocation among 74 main rice cultivars in Jiangsu Province, China

摘要

Arsenic (As) is a ubiquitous carcinogen and environmental toxin. In China, rice consumption is a major dietary source of inorganic As. Thus, the development of strategies to decrease As accumulation in rice is of considerable importance. In this study, we investigated variation in As accumulation and translocation among 74 hydroponically grown rice cultivars in Jiangsu Province, China. We also examined the relationships between As accumulation and translocation, and the uptake of elements such as silicon (Si), phosphorus (P), iron (Fe), and manganese (Mn). Our results showed 3.43-, 2.7-, and 6.34-fold variations in shoot As concentration, root As concentration, and root-to-shoot As translocation factors (TFs), respectively, among 74 cultivars, indicating that cultivar genotype significantly affected As accumulation and translocation. Redundancy analysis revealed that As uptake and transport were more closely related to P and Mn uptake than to Si and Fe uptake, for all 74 rice genotypes. In addition, the 20 cultivars that accumulated the least shoot As (low-As), and those that accumulated the most shoot As (high-As), exhibited different strategies in response to As exposure. The As TFs were key factors influencing shoot As concentrations in high-As cultivars, but this was not the case in low-As cultivars. In the latter, more accumulated As were sequestered in roots, which restricted As translocation to shoots, thus leading to lower shoot As concentrations. In addition, the shoot As concentrations of various rice cultivars and their parents differed. The low-As rice cultivar YJ2 exhibited a significantly lower shoot As concentration than its parents, suggesting that it is possible to breed low-As rice cultivars from parents that also exhibit low-As characteristics.