Effect of germination on the protein content and on the level of specific activity of lipoxygenase-1 in seedlings of three soybean cultivars.
The effect of germination on the protein content and in the level of specific activity of lipoxygenase-1 on seedlings of Santa Rosa, FT-2 and Davis soybean cultivars were studied. Soybean seeds of the three cultivars were germinated from 0 to 72 hours in a seed germinator at 30 degrees C temperature, 100% relative humidity, and absence of light. The seeds were then frozen in liquid nitrogen, freeze-dried and milled. The lipoxygenase-1 was extracted with 0.02M thris-HCI buffer at pH = 8.2 and 13% saccharose for 30 minutes at 4 degrees C without shaking. The highest levels of specific activity of lipoxygenase-1 per milligram of flour (dry basis) in the Santa Rosa, FT-2 and Davis cultivars were observed between 18 and 36, 18 and 24, and 0 and 12 hours, respectively. The polinomial quadratic model best fits the regression analysis of the variable levels of specific lipoxygenase activity for cultivar Davis (R2 = 0.9197). Although for cultivars Santa Rosa (R2 = 0.9041)., and FT-2 (R2 = 0.7486) the 4th degree polynomial model has shown the best fit. The protein content in the three cultivars studied reached the maximum values at 48h germination. The germination induced a relative increase of the protein content but caused a reduction of the level of specific lipoxygenase-1 activity.
Bordingnon
J R
JR
EMBRAPA-CNPSo, Londrina, PR, Brazil.
Ida
E L
EL
Oliveira
M C
MC
Mandarino
J M
JM
D018525:Germination; D008084:Lipoxygenase / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry*; D012639:Seeds; D013025:Glycine max / Q000737:chemistry* / Q000201:enzymology
D010940:Plant Proteins; D008084:Lipoxygenase