Inhibition Action of Bionics Signal Molecule to Nitrate and Nitrite Contents in Tobacco

Nitrate and nitrite are the precursors of TSNAs.The bionics signal molecule(BSM) matter sourced from oral secretion of oligophagous tobacco pests was applied to the topped caulis of flue-cured and burley tobacco at different concentrations. The contents of NO₃^- and NO₂^- in treated tobacco leaves and the control were analyzed with colorimetry,and the effects of BSM on NO₃^- and NO₂^- contents were analyzed.The results indicated that:BSM inhibited NO₃^- and NO₂^- accumulation in flue-cured and burley tobacco leaves after topping to different extents;BSM's effects on middle leaves was stronger than on upper leaves,stronger on NO₃^- content than on NO₂^- content.For burley tobacco,the effects of BSM on NO₃^- and NO₂^- correlated with the dose,the higher the concentration of BSM,the lower the contents of NO₃^- and NO₂^- would be.