Abstract
SummaryCadmium (Cd) is a widespread soil contaminant threatening human health. As an ideal energy plant, sweet sorghum (Sorghum bicolor (L.) Moench) has great potential in phytoremediation of Cd‐polluted soils, although the molecular mechanisms are largely unknown. In this study, key factors responsible for differential Cd accumulation between two contrasting sweet sorghum genotypes (high‐Cd accumulation one H18, and low‐Cd accumulation one L69) were investigated. H18 exhibited a much higher ability of Cd uptake and translocation than L69. Furthermore, Cd uptake through symplasmic pathway and Cd concentrations in xylem sap were both higher in H18 than those in L69. Root anatomy observation found the endodermal apoplasmic barriers were much stronger in L69, which may restrict the Cd loading into xylem. The molecular mechanisms underlying these morpho‐physiological traits were further dissected by comparative transcriptome analysis. Many genes involved in cell wall modification and heavy metal transport were found to be Cd‐responsive DEGs and/or DEGs between these two genotypes. KEGG pathway analysis found phenylpropanoid biosynthesis pathway was over‐represented, indicating this pathway may play important roles in differential Cd accumulation between two genotypes. Based on these results, a schematic representation of main processes involved in differential Cd uptake and translocation in H18 and L69 is proposed, which suggests that higher Cd accumulation in H18 depends on a multilevel coordination of efficient Cd uptake and transport, including efficient root uptake and xylem loading, less root cell wall binding, and weaker endodermal apoplasmic barriers.
Highlights
As global industrialization proceeds, cadmium (Cd) has become one of the most harmful and widespread pollutants in environment (He et al, 2013; Xue et al, 2014)
Sweet sorghum genotypes H18 and L69 exhibited a great difference in the capacity of Cd uptake and translocation
We identified two sweet sorghum genotypes with contrasting Cd translocation factor (TF) from ninety-six germplasm obtained from USDA (United States Department of Agriculture), that is UMM EL TEIMAN
Summary
Cadmium (Cd) has become one of the most harmful and widespread pollutants in environment (He et al, 2013; Xue et al, 2014). Various strategies have been developed to remove Cd from polluted soils, among which phytoremediation is regarded as an environmentally friendly, cost-effective and in situ remediation technology (Kr€amer, 2005). Sweet sorghum is widely cultivated in tropical, subtropical and temperate regions (Marchiol et al, 2007; Zhuang et al, 2009) It has high biomass yield and high sugar content in its stalk, making it an ideal feedstock for ethanol production (Bennett and Anex, 2009; Calvino and Messing, 2012; Gnansounou et al, 2005). Phytoremediation with sweet sorghum can combine soil remediation with bioenergy production, and transfer heavy metals from the food chain into the energy chain, avoiding the harm to human beings (Jia et al, 2016; Li, 2013; Woods, 2001).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
