SpHsfA4c from Sedum plumbizincicola Enhances Cd Tolerance by the AsA–GSH Pathway in Transgenic Populus × canescens

The ascorbate (AsA)–glutathione (GSH) metabolism pathway is an important antioxidant system in cadmium (Cd) detoxification; the AsA–GSHpathway generally regulated by a specific set of functional genes. However, transcription factors involved AsA–GSH have yet to be identified. Herein, we transformed heat shock factor SpHsfA4c from Sedum plumbizincicola into Populus. × canescens. Under 100 μM CdCl2 stress for 30 d, leaf chlorosis wild-type poplars (WT) more serious than that transgenic poplars. root biomass, shoot biomass and tolerance index (TIs) were higher those WT. In addition, Cd2+ uptake Cd content. Compared with WT, contents hydrogen peroxide (H2O2) superoxide anion (O2•−) significantly reduced leaves under treatment. expression levels five enzymes (ascorbate peroxidase (APX), catalases (CAT), dismutase (SOD), (POD) glutathione S-transferase (GST)) Transgenic contained concentrations intermediate metabolites, including GSH, AsA phytochelatins (PCs), GSH/GSSG ratio pathway. Fourier transform infrared (FTIR) spectra, characteristic peaks indicated cysteine, GSH exceeded compared These results suggested can activate reduce Cd-associated oxidative stress. Therefore, overexpressing P. canescens give rise superior tolerance. Our provide theoretical significance breeding potential new germplasm resources high remediation soil heavy metal pollution.