| With the development of horticulture, secondry salinization of soil becomes the main factor greatly a fleet the productivity of vegetables. Breed and use the salt-tolerant cultivars will alleviate the productivity loss in salinized soil. Tomato is.medium salt-tolerant plants, and is one of main vegetable in horticulture. It will be of great importance to improve its salt-tolerant through genetic engineering.HALI gene, which is releted to the selected absorption and transport of K+. was first isolated from yeast (Sacchammyces cerevisiae). The results of HAL1 transform and test of salt tolerant show that salt tolerant of transgenic plant is improved than the contrast. But the precise founction of HAL1 has not been ascertained.We transfer MALI gene by Agrobacterium mediation into tomato variety Zhaofen 8, with leaf disk method, and the transgenic plants were obtained after Southern hybridization. Hereditary feature of HALI gene, and salt-tolerant of T, transgenic plants were studied. The main results were summaried as the following:1 According to the effects of different ratio of hormone on the callus induction, bud differentiation and plant re-generation, the reception system of transform for Zhaofen 8 are: use cotyledon as explant, BA 2.0 mg/L+IAA 0.2mg/L+MS as the optional medium.2 Using the growth of explant, multiplication of Agrobacterium, bud differentiation and plant re-generation as the index, optional transfer system of Agrobacterium mediation was constructed. In this system, explant was soaked in Agrobacterium that deluted 10 times for 5 mins, then co-cultured for 2 days.3 HALI! gene was transferred by Agrobacterium mediation into tomato variety Zhaofen 8. with leaf disk method. In PCR and Southern Blot detection, positive transgenic plants were gained. The transfom rate is 4.5%. Seeds of T, generation were also harvested.4 A single copy was detected in transfected tomato in Southern Blot. Kana resistance test of T, generation seeds show that the ratio of kana resistance to un-resistance is 3.29:1, this is nearly the same to Mendelian ratio, means that the MALI gene has inserted in tomato genome with one copy.5 Seeds of T1 generation and the wild type (control) were germinated under different concentration of NaCl. The germination percentage of transgenic seeds and the contrast is 87-89% when exposed to 0 mM NaCl. When the concentration of NaCl is up to 150 mM, there are still 43% of transgenic tomato in Tl generation germinated, and 6% seeds did to 200 mM NaCl. On the contrary, tomato of wild type (control) had only 11% and 0 seeds germinated respectively on mediums containing 100 and 150 mM NaCl. Furthermore, germination index of transgenic seeds is also improved. From this we can see that the salt tolerant of transgenicseeds was increased greatly.6 The electrolytic leakage of the transgenic plants was lower than that of the control while ratio of root/shoot and chlorophyll content of transgenic plants higher than that of control, demonstrating that HAL I transgene significantly had elevated the level of salt tolerance of tomato plants.7 H-ATPase activitis of vacuole memberance and cytomemberance of transgenic tomato greatly improved after 3 days of salt strees. This is useful for roots to selective absorption and transpotation of K', and finally improved the ratio of KYNa*.8 Under high salt strees, the ratio of KVNa' in roots, stem and leaves of transgenic plant was increased while the ratio of Naf net accumulation was decreased, so transgenic plant can keep more Na in roots, more 1C in stem and leaves. At the same time, S Kf/Nat in roots of transgenic plant is higher, while lower in leaves. So the mechanism of salt tolerant of transgenic plant lies in selective absorption and transportation to KYNa*, and their regional distribution in in roots, stem and leaves.9 Not only the growth and productivity, but also the phonotype, such as leaves form, color, budding spot, have no difference between transformant and non-transformant. This means the foreign gene tra...
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