Abstract: The purpose of this paper is to explore the effects of hydrogen sulfide(H₂S) on root injury of Malus hupehensis Rehd. under Cd stress.The nutrient solution culture was used to study the effects of exogenous Ca²⁺,EGTA(Ca²⁺ chelator),La³⁺(blocker of Ca²⁺ channel in plasma membrane) and CPZ(antagoniston of calmodulin) on the growth of seedling,root cell death,reactive oxygen species metabolism and mitochondrial properties. The results showed that adding exogenous Ca²⁺ or H₂S donor NaSH could obviously alleviate the inhibition to the growth of seedlings,reduced the number of cell death in roots induced by Cd stress;and compared with Cd stress alone,the enzymes(SOD,POD,CAT) activities were significantly increased,the rate of superoxide anion production(O₂^·),contents of hydrogen peroxide(H₂O₂) and malondialdehyde(MDA) were significantly decreased,the mitochondrial membrane permeability(MPT) of root was decreased,the mitochondrial membrane potential(Δψm) of root was increased,the content of cytochrome c(Cyt c) was increased. The alleviative effects of H₂S on cadmium injury were inhibited by addition of Ca²⁺-chelate EGTA,Ca²⁺ channel blocker LaCl₃ or calmodulin inhibitor CPZ. Those indicate that Ca²⁺ or H₂S can stabilize mitochondrial function,enhance the ROS scavenging activity,alleviate the injury of Cd to Malus hupehensis Rehd.,and the effect of H₂S on cadmium stress may be dependent on Ca²⁺ in this process.

Key words: Malus hupehensis Rehd., Cadmium, Hydrogen sulfide, Reactive oxygen species, Mitochondria

CLC Number: 

• S571.01