EFFECT OF SINGLE-WALL CARBON NANOTUBE ON SOYBEAN (GLYCINE MAX) REGENERATION FROM MATURE COTYLEDONARY NODE EXPLANTS

One of the major limitations in producing transgenic soybeans using the agrobacterium-mediated cotyledonary-node method is low regeneration frequency. An improved highly efficient regeneration system of soybean was established herein. Cotyledonary node explants were placed in shoot initiation medium with single-wall carbon nanotube (SWNT) for adventitious shoots regeneration, and adventitious shoots were subcultured in shoot elongation medium with SWNT for shoot elongation and rooting. 40 mg/L SWNT supplemented in shoot initiation medium was found to be the optimal concentration with shoots regeneration frequency significantly increased by 21.5% compared with the control treatment, while for 4 mg/L and 400 mg/L, the increase was 4.6% and 6.5%, respectively. Faster elongation and rooting of adventitious shoots was observed in shoot elongation medium with 40 mg/L SWNT. Soybean plantlet formation frequency within the limited four weeks supplemented with 40 mg/L SWNT reached 48.4% while in the other three treatments: 4 mg/L, 400 mg/L and control, 0% were observed. These results indicate that supplement of SWNT in the soybean medium can efficiently promote adventitious shoots formation frequency, increase plantlet formation frequency and shorten the regeneration period.