Department of Plant Sciences

We found that application of available Fe to the soil brought about an increase in the pod yield of soybean (Glycine max) plants that did not show Fe-deficiency symptoms. To make clear the effect of Fe to increase in the pod, we examined the effect of injecting the stems of soybean plants with citrate-Fe solution. The Fe-injected plants flowered earlier, but the total number of flowers remains unchanged. To investigate whether Fe enhanced the differentiation of floral primordial or whether it facilitated flowering, we analyzed the expression patterns of LFY gene and AP1 gene. The expression patterns of both these genes were not altered on injecting the plants with Fe. We concluded that Fe supply facilitated the flowering of soybean, and that early flowering increased the seed-setting rates.