The Expression And The Effects Of TrxS Gene On Hydrolytic Enzymes And Degradation Of Storage Substances During Malting Barley Seed Germination

The expression and the effects of TrxS gene on hydrolytic enzymes and degradation of storage substances during malting barley seed germination were studied with transgenic homozygous seeds of malting barley variety Jinyin 6(JY6) plants and non-transgenic seeds.The results showed as follows:1 The expression of TrxS gene in malting barley germinating seedsThe total RNA of transgenic and non-transgenic seeds after 3 days germination were respectively extracted by Trizol reagent and the expression of TrxS gene was analyzed by RT-PCR.The assay of thioredoxin h activity showed that thioredoxin h activities of transgenic seeds were higher than that of non-transgenic seeds and both had the same trend after 1 to 5 days germination. Thioredoxin h activities of transgenic seeds after 2 to 4 days germination were higher than that of the maximum of non-transgenic seeds by 17.61%, 16.21% and 6.35% respectively and reached the maximum earlier than non-transgenic seeds after germination.The above results indicated the expression of TrxS gene enhanced thioredoxin h activity.2 The effects of TrxS gene on starch hydrolytic enzymes and starch degradation of germinating seedsThe paper carried out the effects of TrxS gene on α-amylase activity, α-amylase inhibitor content,free β-amylase activity,bound β-amylase activity,limit dextrinase and starch content.The results showed as follows:The α-amylase activity of transgenic seeds was higher and the α-amylase isoenzyme was 1 day earlier detected than those of non-transgenic seeds.The mobility ratio of isoenzyme bands of transgenic seeds was increased after 4 days germination.Comparing to non-transgenic seeds,the degradation of α-amylase inhibitor was faster and vanished 1 day earlier.The results indicated that the expression of TrxS gene facilitated inactivating the α-amylase inhibitor and accelerating the degradation of α-amylase inhibitor of germinating seeds by reducing disulfide bonds(S-S) to the sulfhydryl(-SH) and corresponsively increased the α-amylase activity.Both the free β-amylase activity and its isoenzyme activity of transgenic seeds were higher than non-transgenic seeds after germination.The whole release of bound β-amylase...