| Soybean[Glycine max (L.) Merr.] can support not only much high-quailty protein and lipid,but also much biological activity isoflavones. This research utilize Methyl Jasmonate as an inducerto spray on the leaf of soybean, in order to investigate the effect of MeJA on the pathway ofisoflavone metabolism, dynamic trend of primary metabolites, secondary metabolites and relatedenzyme in the period of reproductive growth in soybean, and analyse the correlation between eachother as well. Constructing the platform of the research on the secondary metabolites in soybean.The result of the research shows that exogenous Methyl Jasmonate can promote PAL activityboth in leaf and seed, the PAL mRNA level, the soluble protein level, the tryptophan level, thedaidzein level, the genistein level, and total isoflavones level. And this effect can happen in thetranscriptional level. In the sprayed concentration scope of 0～450μmol/L, the level of thesubstances rasied as the sprayed concentration rasied, but as the concentration increased to600μmol/L, the substance level are not raised obviously higher, and some of them get a little lower.So the best optimum concentration is 450μmol/L.MeJA can promote the synthesis of the daidzein, genistein and total isoflavones, and promotethe daidzein level, genistein level, total isoflavones level in grown seed. This effect could gethigher if the sprayed seed is the higher isoflavone level cultivar. Analyzed and compared resultshows that, in the sprayed concentration scope of 0～600μmol/L, the treatment which get thehighest yield is 450μmol/L sprayed concentration, except for dongnong 42 sprayed 600μmol/Lconcentration get the highest genistein level. Compared to the control, the highest daidzein level bywhich increased is respectively that dongnong 42: 4.5μg/g, dongnong 47: 5.1μg/g, dongnong48:5.5μg/g. The highest genistein level by which increased is respectively that: dongnong 42: 4.26μg/g, dongnong 47: 5.1μg/g, dongnong 48: 5.8μg/g. The highest total isoflavones level by whichincreased respectively is that dongnong 42: 970μg/g, dongnong47: 960μg/g, dongnong 48:1150μg/g. Dong nong 47 sprayed by 450μmol/L MeJA get the highest genistein level, which is21.5μg/g. Dongnong 48 sprayed by 450μmol/L MeJA get the highest daidzein level, totalisoflavones level which is respectively: 28μg/g and 4140μg/g.In the period of reproductive growth, PAL activity in leaf and seed present low-high-low.single peak trend, and the PALmRNA level presente this trend as well. Daidzein and genistein present low-high-low-getting higher trend. Soluble protein, tryptophan and total isoflavones presentlow-high-low trend.By analyzing the correlation between the physiologic index each other, it can be concludedthat from the initial to the middle period of the reproductive growth (Aug 12th-Sep 11th), PALactivity in leaf doesn't correlate with the synthesis of daidzein and genistein. The correlationbetween PAL activity in leaf and total isoflavones is negative, but not remarkable. From the initialto the mid-and-late period of the productive growth, PAL activity and PAL mRNA level in seedcorrelate with daidzein and genistein positive remarkablely, but not with the synthesis of totalisoflavones. It proved that PAL is the rate-limiting enzyme of the synthesis of daidzein andgenistein, but isn't the rate-limiting enzyme of the synthesis of total isoflavones. PAL can regulatethe synthesis of daidzein and genistein both in the transcription level and the translational level inthis period. The correlation between the synthesis of tryptophan and total isoflavones, the synthesisof soluble protein and total isoflavones are remarkable positive. But the synthesis of tryptophandoesn't correlated with the synthesis of daidzein and genistein, so does soluble protein. It showsthat the accumulation of total isoflavones raised as the dry matter raised. Daidzein and genistein asthe precursor continue to synthesize other compound. Finally they deposited as other form or othercompound.
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