Abstract: The effects of exogenous H₂S and H₂O₂ physiological regulation on the processing tomato seedlings under NaCl stress were investigated,KT-32 with weak salt tolerance and KT-7 with strong salt tolerance as the materia. Research of 50 μmol/L H₂S and H₂O₂ were determined by pot culture under the conditions of 0.5,1.5,3.0 mmol/L. Effects of cotreatment on the growth,osmoregulation,material accumulation and reactive oxygen metabolism of seedlings of processed tomato under 250 mmol/L NaCl stress.The results showed that the cotreatment of exogenous H₂S and H₂O₂ alleviated the inhibitory effect of NaCl stress on the growth of seedlings of processed tomato seedlings,and maintained a strong photosynthetic pigment content,relatived water content and root activity in processed tomato seedlings.And decreased the electrolyte leakage rate,the content of MDA,the content of H₂O₂ and the production rate of O₂^· free radical and enhanced the activities of antioxidant enzymes SOD,POD and CAT activity. Among the two strains,soluble sugar increased 24.0% and 29.4% by compared with 50 μmol/L H₂S treatment alone at 50 μmol/L H₂S and 1.5 mmol/L H₂O₂ ,proline content increased by 25.8% and 21.3%,respectively,and the effect of salt stress alleviation was the most significant.In summary,there were a certain degree of synergy between exogenous H₂S and H₂O₂,which could enhance the osmotic regulatory capacity of plants under enhanced NaCl stress in tomato seedling plants to enhance the removal of reactive oxygen species H₂S and H₂O₂ in the tomato seedlings,and then weakened the injury of reactive oxygen species on the plasma membrane in processed tomato cells and then increased the adaptability of tomato seedlings to salt stress. The synergistic effect of the two signaling molecules will provide the theoretical basis for alleviating the physiological mechanism of salt stress in tomato seedlings.

Key words: H₂O₂, H₂S, NaCl stress, Processing tomato seedlings

CLC Number: 

• S641.01