A pot culture experiment of nitrogen forms (NO3-:NH4+) with four ratios (100:0, 75:25, 50:50, and 25:75) in nutrient solutions was conducted to examine the effect of nitrogen forms on the growth and polyamines contents of developing seeds of vegetable soybean [Glycine max (L.) Merr. cv. Li-xiang 95-1]. Results showed that the best plant growth vigor was observed in NO3- (75%), and then in NH4+ (50%). However, the fresh and dry weight of biomass decreased when a high concentration of either NO3- (100%) or NH4+ (75%) was the primary nitrogen source in the nutrient solution. The numbers of flowers and pods in NH4+ (75%) were significantly decreased compared with other ammonium-nitrate ratios in which the numbers of flowers and pods were not influenced by nitrogen forms. During the development of seeds, levels of free Put and Spd decreased, and the decrease extents were more marked in 100:0 and 25:75 (NO3-:NH4+), but the change of free Spm was opposite. Levels of conjugated and bound polyamines in all nitrogen forms increased, but the increases in 75:25 and 50:50 (NO3-:NH4+) were not so obvious as in 100:0 and 25:75 (NO3-:NH4+) treatments. The possible roles of polyamines in the adaptive mechanism of vegetable soybean seeds to different nitrogen forms were discussed.

The effect of 80 mmol•L-1 stress by excess of calcium nitrate [Ca(NO3)2] on biomass production, oxidative damage, antioxidant enzymes activities and polyamine contents in leaves of grafted and non-grafted eggplant (Solanum melongena L.) seedlings were studied, in which grafted plants were grafted on a salinity tolerant rootstock (Solanum torvum Swartz). The results showed that on the 15th day of treatment, the biomass production reduction of non-grafted seedlings was significantly higher than that of grafted seedlings. Under stress by excess of Ca(NO3)2, superoxide anion radical (O2•¯) producing rate, electrolyte leakage percentage, contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) of non-grafted seedlings were significantly higher than those of grafted seedlings, but activities of superoxide dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) of grafted seedlings were significantly higher than those of non-grafted seedlings, moreover, contents of free, soluble conjugated and insoluble bound polyamines of grafted seedlings were significantly higher than those of non-grafted seedlings, and activities of diamine oxidase (DAO, EC 1.4.3.6) and polyamine oxidase (PAO, EC 1.5.3.3) of grafted seedlings were significantly lower than those of non-grafted seedlings. The possible roles of antioxidant enzymes and polyamines in protective mechanism of grafted eggplant seedlings to stress by excess of Ca(NO3)2 were discussed.

The soybean allergenic protein, Glym Bd 30K[Ogawa et al., J. Nutr. Sci. Vitaminol., 37, 555-565 (1991)]which is most strongly and frequently recognized by the IgE antibodies in sera of soybean-sensitive patients with atopic dermatitis, has been characterized, The allergen was isolated from the crude 7S-globulin fraction as an oligomerie form with a molecular weight of more than 3000,000 by gel-filtration chromatography. On two-dimensional gel electrophoresis, the native oligomeric allergen had an isoelectricpoint of about pH 4.5 and was dissociated into a monomeric form with a molecular weight of about 32,000 by the treatment with sodium dodeeyl sulfate and 2-mercaptoethanol. The monomeric allergen had an N-terminal amino acid sequence and amino acid composition identical with those of the soyhean seed 34-kDa oil-body-associated protein or the soybean vacuolar protein P34 with close homology to papain-like thiol proteinases[Kalinski et al., J. Biol. Chem., 267, 12068 (1992)]. The identity was further confirmed by the 34-kDa oil-body-associated protein. By this observation, Gly m Bd 30K was shown to have about 30% sequence homology with Der pI, a house dust mite allergen that is a thiol proteinase from Dermatophagoides pteronyssius.