Abstract: Experiments were performed with two soybean cultivars (Zhuchun No.3 and Liaoxian No.3) under aeroponic culture. The objective was to investigate (1) The production and development of border cells in soybean; (2) The effect of Al3+ on the release and viability of border cells. Under aeroponic culture, border cells shape of both soybean cultivars at the initial stage was spherical and small. As cells developed, they became ellipsoidal or spectacular and long in shape. The number of border cells reached the maximum value (Zhuchun No.3 3000 and Lianxian No.3 3800 ) when soybean was 15-25 mm in length. The number and viability of border cells released from roots treated with 100, 200, 300, 400?mol·L-1 Al3+ were less than that from roots without Al3+ treatment, and Al3+ seriously inhibited the production and viability with high concentration Al3+ treatment. The PME activity increased with 200?mol·L-1 Al3+and 300?mol·L-1 Al3+ for 4h, whereas remarkably decreased with 400?mol·L-1 Al3+. These results suggested that high concentration Al3+ inhibited the production and release of soybean, decreased PME activity. Response of border cells to Al3+ in Liaoxian No.3 was more sensible than in Zhechun No.3.

Key words: Soybean, Root border cells, Development, Al3+ toxicity