Sulfur Dioxide And Hydrogen Sulfide Play Roles In Promoting Germination And Regulating Hydrolase Activities In Wheat Seeds

In this experiment, Na2SO3 and NaHSO3 were uesd as sulfur dioxide (SO2) dornor and wheat seeds were cultured with it, we found that the radicle and plumule growth as well as germination rate were increased by low concentration of SO2 solution; the promoting effect would become most obviously when the concentration of SO2 solution at 1.0 mmol/L. Otherwise, wheat seeds which were cultured with SO2 solution can also increase the liquefaction speed of endosperm, shows that SO2 treatment could assist the transformation of stored material in germinated seeds. Further study using polyacrylamide gel electrophoresis (PAGE) and spectrophotometry method were uesd to detecting the amylase and esterase isozyme activity during early seeds germination, the result shows that SO2 can increase the activity of amylase and esterase during early seeds germination, and is dose-dependent:if the SO2 concentration was and below 1.0 mmol/L, the amylase and esterase would enhanced as the increase of SO2 concentration; but if the SO2 concentration beyond 1.0 mmol/L, the amylase and esterase activity would be declined. Wheat seeds were cultured with 1.0 mmol/L SO2 for 3,6,9,12 h, and the distilled water was used as the control, we found that the amylase activity up to maximum at 9th hour of seed germination, while the esterase activity up to maximum at 6th hour. By researching a-andβ-amylase activity individually, the result shows that the expression amylase which induced by SO2 isβ-amylase rather than a-amylase. Further research shows that, SO2 can enhance the activity of latent stateβ-amylase, while free state ofβ-amylase was riot affected. Wheat seeds which were cultured with SO2 dornor (Na2SO3 and NaHSO3), while Na+ and different sulfide-containning were used as the control, we found that SO2 dornor (Na2SO3 and NaHSO3) could activate amylase more effectively, indicated that the effector substance which activate amylase by SO2 dornor (Na2SO3 and NaHSO3) is SO2. It is interesting that, SO2 treatment could enhance the content of endogenous H2S of wheat seeds, and is dose-dependent.Moreover, in this article NaHS was used as hydrogen sulfide (H2S) dornor and wheat seeds were cultured with it, like SO2, signal molecule H2S can also enhance the amylase activity of wheat seeds, and the best concentration is 0.4 mmol/L. Seeds which were cultured with 0.4 mmol/L H2S for 3,6,9,12 h, we found that the amylase activity up to maximum at the 6th hour of seeds germination. But unlike SO2, H2S can both increase free and latent state of P-amylase.Germination inhibitory might be occurred while in adversity situations, wheat seeds germination rate would be declined after treated with Hg2+. While pretreated with SO2 solution for 12 h, germination rate could improved effectively against Hg2+ stress, and the amylase and esterase activity has also been enhanced significantly, indicated that SO2 signal might be mediated the internal mechanism of wheat seeds germination.