Differential expression of proteins in the leaves and roots of cadmium-stressed Microsorum pteropus, a novel potential aquatic cadmium hyperaccumulator

摘要

Microsorum pteropusis a fully or partially submerged Polypodiaceae fern that has been proven to be a potential Cd aquatic hyperaccumulator. Proteomic analysis was used in this study to investigate the resistance mechanisms ofM. pteropusroot and leaf tissues under Cd stress.M. pteropusplants were exposed to up to 500 μM Cd in hydroponics for 7 days. The plant can accumulate >4,000 mg/kg Cd in both root and leaf dry mass. Meanwhile, the proteins in roots and leaves in the 500 μM Cd treatment were separated and analyzed by proteomics. Eight proteins with altered expression in roots and twenty proteins with altered expression in leaves were identified using MALDI-TOF/TOF-MS (matrix-assisted laser desorption/ionization time of flight mass spectrometry) in this study. The proteins were involved in energy metabolism, antioxidant activity, cellular metabolism and protein metabolism. However, just three proteins were significantly differentially expressed in both tissues, and they were all involved in basal metabolism, indicating different resistance mechanisms between roots and leaves. Root tissues ofM. pteropusmainly resist Cd damage by antioxidants and the enhancement of energy metabolism, while leaf tissues ofM. pteropusmainly protect themselves by maintaining photosynthetic functions and the regulation of cellular metabolism.