TaHSP17.8 regulates TaJUB1D in the management of low cadmium accumulation in wheat

Abstract In this work, the function of a wheat small heat shock protein TaHSP17.8 to respond to Cd stress was characterized. TaHSP17.8 is mainly expressed in root tissues and was found to be most highly expressed 4 h after Cd stress. The function of TaHSP17.8 in Cd stress response was investigated using transgenic wheat lines. Damage to both the root and shoot tissues of transgenic lines was reduced compared with the wild type (WT) plants. In addition, wheat lines overexpressing TaHSP17.8 showed higher Cd concentrations in root tissues than WT. However, Cd concentration in the shoots of transgenic lines was significantly lower than WT. Physiological and biochemical parameters indicated that proline, malonyldialdehyde (MDA), and H2O2 contents were all substantially decreased in the transgenic lines after Cd treatment, while chlorophyll content was significantly higher. We therefore screened for transcription factors that interacted with TaHSP17.8, and identified TaJUB1D as a putative hit. Further analyses indicated that TaHSP17.8 binds directly to a region 1850–1900 bp upstream of the TaJUB1D open reading frame (ORF). This work confirms the function of TaHSP17.8 in response to Cd stress and identifies a novel pathway to regulate Cd stress in wheat.