| In this experiment, the stem nodes, leaf and GTT(Green tumor-shaped tissue ) were used as explants for the studies on the establishment of plant regeneration of high-effeciency and the comparison of the physiological and biochemical differences between the GTT and the normal plantlets in Acacia crassicarpa. and then the introduction of antisense ACS gene and PEAS gene to GTT mediated by Agrobacterium was carried out. The main results were described as follows:1．The effect of different pre-treatments on the germination of the Acacia seeds. The in vitro germination rate reached 48．9% under the pre-treatment of the thick vitriol combined with the solution of 25mg/L IAA for 8 hours on Acacia crassicarpa seeds.2．A system of plant regeneration of high effeciency was established in the experiment using the explants of the stem nodes, the leaves and GTT. The rapid multiplication of explants used by stem nodes reached 4．125 on the MS medium adding 2．0mg/L KT and O.6GA。The more the increasing in 2,4-D level, the easier to induce the callus derived from the leaf. Otherwise the plenty of adventitious roots formed from the media without 2,4-D. The results showed that the combination of hormones of 1．5 mg.L-1 2,4-D and 3．0 mg.L-1 BA was facilitated to induce the callus derived from the leaf and the best media for plant regeneration of the callus derived from the leaf was the MS medium with 3．0mg.L-1 ZT. The GTT multiplied rapidly by cutting itself in the optimized process and the MS medium with 2．0mg/L BA, 3．0mg/L IAA was the best for induction of GTT. Shoot growth and rooting were good on the 1/4MS medium with 0．05 mg·L-1 NAA, and the rooting rate reached 100%. NAA was not tightly related to rooting but shoot growth. The survival rate was up to 66．7% after the plantlets transfer into peat soil.3．Comparative analysis of physiology and biochemistry between normal plantlets and GTT was conducted. The result showed that the activities of peroxidase, catalase and content of proteins in normal plantlets were higher than those in GTT, but the DNA contents were similar between them. The SDS-PAGE analysis also implied that the GTT added a belt at the 13．8kD molecular weight. All of the results was related to the stage of GTT development.4．The antibiotic sensitivity experiment of GTT was done. The results indicated that the concentration of 400 mg/L for kanamycin remarkably restrained the growth of GTT as the effective concentration for resistant selection. Even GTT was sensitive to hygromycin B and the concentration of 10 mg/L for hygromycin B was proved to be suitable for transgenic selection through further experiments. Carbenicillin and cephamycin had no effect on growth of GTT.5．The preliminary study on the transformation of GTT mediated by Agrobacterium was carried out, GGT introduced antisence ACS gene was obtained, from which some small buds had grown. The results were as follows:It was difficult to obtain resistant GTT successfully because the majority of GTT were inclined to turning brown during direct transgenic resistant selection when PEAS gene was introduced to GTT mediated by Argrobacterium tumefaciens, which suggested that GTT be not sensitive to the Strains EHA105．It was also difficult to obtain resistant GTT successfully during indirect transgenic resistant selection when GTTs were cultured on the medium without hygromycin B for one month , and then selected on medium with hygromycin B for one month.In the process of introducing antisense ACS gene mediated by Argrobacterium tumefaciens, the best transient system was obtained under the conditions as follows: the Agrobacterium suspension was with OD value of 1．0～1．5, the samples were infected for 10～15 min and the pH value of the co-culturing medium was 5．8．The indirect method of selecting resistant GTT was that after co-culture, the GTTs were cultured on the MS medium adding 2．0mg/LBA, 3．0mg/LAA, 100 mg/LCef. for one month then selected on the MS medium with2．0mg/LBA, 3．0mg/LAA and 200-400mg kanamycin for one month, transferred on the MS medium supplemented with 2．0mg/LBA, 3．0mg/LAA, 400mg/L kanamycin and 100mg/L Cef for two months. Finally, 10 lines of resistant GTTs were obtained, from which some small buds had grown, and the GUS histochemical assay proved that the report gus gene had been introduced into the genome of GTT in Acacia crassicarpa.
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