TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: Specifically, the method comprises: (a) establishing primary culture-seedlings of Thlaspi caerulescens, taking mature seeds of Thlaspi caerulescens, using alcohol to perform the surface sterilization, and then placing in mercury bichloride and taking out after dipping, washing by sterile water, sterilizing, absorbing the water on the surface by filter paper; placing on a seed germination culture medium to culture for 7-15 days, obtaining the primary cultures-seedlings of Thlaspi caerulescens; the culture condition thereof as follows: illumination intensity 3000-5000 Lux, illumination time 16 hours/day, temperature 20-25 degrees C; the seed germination culture medium is Murashige-Skoog (MS) culture medium; (b) culture of cespitose buds of Thlaspi caerulescens, placing the seedlings of Thlaspi caerulescens to a differentiation culture medium to perform the differentiation culture of the cespitose buds for 10-14 days, differentiating the cespitose seedling namely the cespitose buds at the eustipes; ; the culture condition as follows: illumination intensity 3000-5000 Lux, illumination time 16 hours/day, temperature of 20-25 degrees C; the constituents and proportion of the differentiation culture medium as follows: differentiation culture medium of each liter comprises 300 milligrams of Lactalbumin Hydrolysate, 0-8 milligrams of vitamin B, 50-300 milligrams of phaseomannite, 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, and 0.1-8 milligrams of two growth hormones 6-benzyl adenine, rhodofix, pH of 5.8; the differentiation culture medium is MS culture medium; (c) pre-culture of cespitose buds of Thlaspi caerulescens, flatly putting the cespitose buds of Thlaspi caerulescens on a culture medium of the pre-culture to pre-culture for 2-3 days; the pre-culture condition as follows: illumination intensity 3000-5000 Lux, illumination time 16 hours/day, temperature 20-25 degrees C; the constituents and proportion of the culture medium of the pre-culture as follows: the culture medium of the pre-culture of each liter contains 300 milligrams of Lactalbumin Hydrolysate, 0-8 milligrams of vitamin B, 50-300 milligrams of phaseomannite, 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, 100 milligrams of acetosyringone, and 0.1-8 milligrams of three growth hormones kinetin, 6-benzyl adenine, rhodofix; pH of 5.2, the differentiation culture medium is MS culture medium; (d) activation of Agrobacterium tumfaciens, respectively picking monocolony of Agrobacterium tumfaciens of an expression carrier of a dicotyledon having an object gene Bjcat5, inoculating to 5 milliliters of LB Agrobacterium tumfaciens liquid culture medium to culture for 8 hours; the culture condition is 28 degrees C, 200 revolutions/minute; picking the LB Agrobacterium tumfaciens culture liquid which has been cultured overnight, diluting into 20 milliliters of LB Agrobacterium tumfaciens liquid culture medium based on the proportion 1:40, continuing to culture for 5-6 hours to OD600 to be 0.6; centrifuging for 5 minutes via 5000 revolutions/minute; collecting thalli, using an inflection liquid culture medium to suspense and deposit, diluting to OD600 to be 0.15 inflection liquid culture medium; standing by; the constitutes and proportion of the LB Agrobacterium tumfaciens liquid culture medium as follows: LB Agrobacterium tumfaciens liquid culture medium of each liter contains 10 grams of tryptone, 5 grams of yeast extract, 10 grams of sodium chloride, 50 grams of rifampicin and 50 milligrams of kanamycin; pH 7.0; the n inflection liquid culture medium is MS culture medium, pH of 5.2; (e) Agrobacterium tumfaciens infection and co-culture of the pre-cultured cespitose buds of Thlaspi caerulescens, placing the cespitose buds of Agrobacterium tumfaciens pre-cultured for 2-3 days to the inflection liquid culture medium having OD600 of Thlaspi caerulescens 0.15, dipping for 5-15 minutes and picking out; using filter paper to absorb the inocula adhered on the surface thereof, flatly putting on a culture medium of the co-culture, under the temperature 25 degrees C, darkly culturing for 2 days; the constitutes and proportion of the culture medium of the co-culture as follows: the culture medium of the co-culture of each liter contains 300 milligrams of Lactalbumin Hydrolysate, 0-8 milligrams of vitamin B, 50-300 milligrams of phaseomannite, 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, 100 milligrams of Acetosyringone, and 0.1-8 milligrams of three growth hormones kinetin, 6-benzyl adenine, rhodofix; pH of 5.2, the culture medium of the co-culture is MS culture medium; (f) front culture, picking out the cespitose buds of Thlaspi caerulescens after the culture in (e), respectively placing in triangular flasks; using sterile water to wash 3-5 times, and using sterile water having 500 milligrams /liter of carbenicillin for 3 times, 10 minutes each time; using sterile water having 500 milligrams /liter of carbenicillin for 1-2 days; picking out the cespitose buds, using filter paper to absorb water, drying at a super-clean workbench; flatly putting on a front culture medium to culture for 3-15 days; the culture condition as follows: illumination intensity 3000-5000 Lux, illumination time 16 hours/day, temperature 20-25 degrees C; the seed germination culture medium is MS culture medium; the constitutes and proportion of the culture medium of the front culture as follows: the culture medium of the front culture of each liter contains 300 milligrams of Lactalbumin Hydrolysate, 0-8 milligrams of vitamin B, 50-300 milligrams of phaseomannite, 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, 100 milligrams of Acetosyringone, and 0.1-8 milligrams of three growth hormones kinetin, 6-benzyl adenine, rhodofix; pH of 5.8; the culture medium of the front culture is MS culture medium; (g) screening culture, picking out the cespitose buds of Thlaspi caerulescens after the front-culture for 3 to 15 days, transferring to a screening culture medium; the culture condition as follows: illumination intensity 3000-5000 Lux, illumination time 16 hours/day, temperature 20-25 degrees C; sub-culturing one time per 18 days, obtaining the cespitose buds in the test tubes; the constitutes and proportion of the screening culture medium as follows: the screening culture medium of each liter contains 300 milligrams of Lactalbumin Hydrolysate, 0-8 milligrams of vitamin B, 50-300 milligrams of phaseomannite, 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, 100 milligrams of Acetosyringone, and 0.1-8 milligrams of three growth hormones kinetin, 6-benzyl adenine, rhodofix; pH=5.8; the screening culture medium is MS culture medium; (h) seedling culture, shearing the cespitose buds in the test tubes not less than 3 centimeters after the screening culture into stem sections having 2 to 3 nodes, inoculating to a seedling culture medium for 18 to 35 days, containing the seedlings in the test tubes; the constitutes and proportion of the seedling culture medium as follows; the seedling basic culture medium of each liter contains 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, 50-300 milligrams of phaseomannite, 250 milligrams of carbenicillin, 5-50 milligrams of kanamycin, pH of 5.8; the seedling basic culture medium is MS culture medium; (i) rooting culture, inoculating the 3.5-8 centimeters of seedlings in the test tubes after the seedling culture to a rooting culture medium to culture for 18-25 days, obtaining the rooted seedlings; picking out from the culture medium, washing the adhered culture medium, transferring to Granda nutrient fluid to water-culture to continue the rooting culture; the culture condition thereof as follows: taking foam panels as seedling supports whose sizes must be consistent with the sizes of the notches of aquiculture, trying to avoid the roots from illumination to cause the breeding of chlorella; altering Granda nutrient fluid culture medium per five days; the temperature 22-25 degrees C, illumination time 16 hours/day, 80-85 degrees C of humidity; the constitutes and proportion of the rooting culture medium as follows: the rooting basic culture medium of each liter contains 10-40 milligrams of sucrose, 5-10 milligrams of agar-agar, 50-300 milligrams of phaseomannite, 250 milligrams of carbenicillin, 5-50 milligrams of kanamycin, pH of 5.8; the rooting basic culture medium is 1/2 culture medium; and (j) permanent planting of transplant, picking out the aquicultured roots not less than 5 centimeters after the aquiculture culture, transplanting to nursery substrates, performing the permanent planting of transplant; the nursery substrates are composed of soils and vermiculites by the weight proportion 1:1; before transplanting the seedlings, deeply pouring the nursery substrates by Granda nutrient fluid culture medium; after the transplantation, using polyvinyl chloride film to cover, keeping 90-95% of humidity, taking caring of the ventilation; spraying water one time per 5 days, spraying Granda nutrient fluid culture medium one time per 14 days; removing the film after the permanent planting of the transplanted seedlings for 10 days; and keeping 80% of the room humidity, temperature 20-30 degrees C, spraying water three times each day, spraying Granda nutrient fluid culture medium one time per 14 days; spraying urea one time per 21 days, fast culturing, accomplishing the culture of the transgenic seedlings of Thlaspi caerulescens. The culture time in the seed germination culture in (a) is from 5 to 9 days. Additionally, the culture medium of the pre-culture, culture medium of the front medium, culture medium of the co-culture and screening culture medium in (c) and (e)-(g) contains 3-7 milligrams/liter of vitamin B, 25-40 milligrams/liter of sucrose, 0.1-8 milligrams/liter of kinetin, 1-4 milligrams/liter of 6-benzyl adenine, and 0.1-8 milligrams/liter of rhodofix. The culture time in (f) is from 5 to 10 days.