A novel wheat β-amylase gene TaBMY1 reduces Cd accumulation in common wheat grains

Abstract

Cadmium (Cd) is one of the most environmentally hazardous heavy metals, posing a significant threat to food safety. In the present study, we identified a novel cytoplasmic amylase gene, TaBMY1 , involved in Cd transport in wheat ( Triticum aestivum ) plants. Cysteine residues in the core domain of BMY1 formed disulfide bridges. Yeast expressing TaBMY1 exhibited poor Cd tolerance. These findings suggested that BMY1 might participate in metal tolerance and translocation. Subsequently, RNA interference (RNAi) and overexpression (OE) transgenic wheat were obtained. Compared to wild-type (WT), RNAi lines exhibited shoot or root elongation and increased dry mass and chlorophyll content, whereas TaBMY1 overexpression showed a sensitive growth phenotype. RNAi lines accumulated less Cd and reduced Cd translocation from root to shoot by approximately 38%, as well as Cd accumulation in grains by 71–74%, whereas the OE lines had increased Cd accumulation. Our results suggest that silencing the TaBMY1 gene may affect Cd allocation and distribution. This work provides a novel approach to decreasing Cd accumulation in wheat crops and reducing environmental risks to human health through food chains. • A novel wheat β-amylase gene, TaBMY1 , was investigated. • TaBMY1 was first reported to reside in the cytoplasm. • Heterologous expression of TaBMY1 gene in yeast showed no transport activities for Cd. • Silencing of TaBMY1 decreased root-to-shoot Cd translocation and Cd accumulation in wheat grains. • This study offers a highly effective solution for breeding lower Cd-accumulating wheat crop.