Abstract
Brassinosteroids are widely used to combat several environmental factors, including heavy metal stress in plants, however the effects on alleviating cadmium (Cd) phytotoxicity in grape seedlings are unknown. This study was designed to investigate the effect of 24-epibrassinolide (EBR) on chlorophyll fluorescence, antioxidant system and gene expression in grape (vitis vinifera L.) plants under Cd stress. The grape seedlings were treated with half-strength Hoaglands nutrient solution, 1 mM Cd2+ (CdCl2) and Cd2+ combination with EBR (0.05 mg/L, 0.1 mg/L, 0.2 mg/L). Oxidative stress caused by higher biosynthesis of reactive oxygen species (ROS) and malondialdehyde (MDA) damaged the morphological features and photosynthesis of grape seedlings under Cd toxicity. However, EBR treatment alleviated the Cd stress injury symptoms, increased the maximal photochemical efficiency of PS II (Fv/Fm), photochemical quenching coefficient (qP) and actual PS II photochemical efficiency (ΦPSII), reduced the levels of superoxide anions (O2·−), hydrogen peroxide (H2O2), and MDA, increased the contents of antioxidants and osmolytes and enhanced the activities of guaiacol peroxidase (POD), superoxide dismutase (SOD), and antioxidases involved in the ascorbate-glutathione (AsA-GSH) cycle. Furthermore, the expression levels of VvSOD, VvPOD, VvAPX, VvGR, VvDHAR and VvMDHAR genes were upregulated in EBR treated grape seedlings under Cd stress. Here, principal component analysis showed that amelioration of Cd-induced oxidative stress by EBR treatment in grapevine seedlings is mainly by regulating AsA-GSH cycle, and the Cd stress alleviation effect of EBR was more prominent at 0.05 mg/L than at 0.1 mg/L and 0.2 mg/L. Taken together, our results suggest that applying EBR can mitigate Cd toxicity in grape seedlings via ASA-GSH cycle and advocate a positive role for EBR in strengthening phytoremediation.
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.
