| Aloe is a new resource of food with medicinal value, beauty efficacy and food nutritional value. As drought-resistant, but not cold-resistant, Aloe is not conducive to large-scale cultivation. The bitter tastes and poor flavor also constrain the development of Aloe food industry. To enhance the cold tolerance of Aloe vera.L and improve the food taste, The OsDREB and TaDREB gene from rice and wheat separately were transfered into Aloe vera.L mediated by Agrobacterium, and some researches in improve the Aloe vera.L resistance, trehalose, polysaccharide content and Aloe gel filtration techniques and its cosmetic applications for the two transgenic aloe, and preliminary laboratory Aloe vera.L with transfered trehalose-6-phosphate synthase gene otsA.(1) The expression vector PBT containing the rice OsDREB gene were transferred into Agrobacterium EHA105 strain by three pro-hybridization, the aimed gene were transferred into Aloe vera. L young leaf explants mediated by Agrobacterium,98 resistant OsDREB gene plants were obtained by a series of screening protocol, and PCR, cold process treatment and conductivity detection results indicated that the OsDREB gene improved Aloe vera. L cold resistance.(2) In this experiment, the wheat genes TaDREB in plasmid pBIR1 were transferred into Aloe vera. L young leaf explants through Agrobacterium-mediated, A total of 58 selected resistant plants that grown well were obtained by a by a series of screening protocol. The transformation rate is about 0.22% by PCR detecting. The results that the transgenic plants were growing well while the control got serious damaged after two weeks of cold treatment at 4℃,-20℃freezing treatment for 30min indicated that the TaDREB significantly increased Aloe vera. L resistance to low temperature. The isoenzyme of SOD, POD in transgenic plants which were treated by low temperature stress during 14days were analysised and the results showed that SOD, POD activity both expressed a trend of rising after an initial drop, and its indicated the transgenic aloe increased its protective activity in vivo. The average conductivity of the transgenic plants was 0.462 which is significantly lower than the 0.685 in control and it showed that Aloe vera. L with transferred of wheat TaDREB gene had improved cold resistance obviously.(3) Polyamine(PA)content, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci)and maximum photochemical efficiency of PSII(Fv/Fm) of transgenic and control Aloe vera.L were studied separately and the results indicated that the tolerance to the salt treatment(200mmol/L NaCl) of the transgenic Aloe are better than the control. PA maybe play an important role during the response to the salt treatment。Under salt stress, Pn, Gs and Fv/Fm all decreased with the salt treating time in both the wild type Aloe and the transgenic Aloe. However, the level of Fv/Fm decreased less in the transgenic Aloe compared with that in the wild type Aloe. And the result indicated that the injury of PS II is less in transgenic Aloe.(4) In this experiment, D-glucose, lactose, sucrose and trehalose was separately derivated the by 1-methylimidazole, hydroxylamine chloride, acetic anhydride continuously, the retention time of characteristic peak of each of them is within 3 s by using gas chromatography as a means of quantitative analysis, this indicated that this method could differentiate D-glucose, lactose, sucrose and trehalose distinctly. The correlation coefficient of Trehalose is 0.9986 within the detection volume of 3.697～10-9～28.661～10-9 g. The content of trehalose in the Aloe.vera L of 3 years,5 years old and the transgenic of trehalose synthase gene(otsA)Aloe.vera L of 6 months old was 6.905～10-7,1.103～10-6 and 1.614～10-6 (g/g) respectively. The results indicated that Aloe of six months transgenic of otsA gene Aloe.vera L., had significantly increased the contents of trehalose. Further studies on the leaf from transgenic Aloe.vera L showed that the transgenic aloe showed superior moisturizing and anti-aging effect on skin.(5) Using the transgenic of otsA gene Aloe.vera L., of 3 years old as experimental materials, polysaccharide were extracted by cold processing method of alcohol precipitation and it was a mixture containing acetylatedβ-D-pyran mannan identified by IR and molecular weight range was between 12900D and 13100D detected by mass spectrometry. The preliminary purified polysaccharide chromatographic fractionation was carried out by DEAE Sephadex A-25, and neutral sugars and acidic sugars were fractioned, then neutral sugar chromatographic fractionation was carried out by Sepharose CL-6B, and A1 and A2 were fractioned. The results of identification and characterization analysis of these polysaccharides by IR, MS, GC showed that neutral sugars were the type of mannose polysaccharide.(6) In order to make better and large use of Aloe.vera L., the juice of its gel filtration process and the gel from Aloe.vera L application in cleansers, lotions and eye glue were studied, and efficacy and safety of the developed several cosmetics were evaluated. And the more optimizing and stable gel filtration process and cosmetics with Aloe vera L., as the main effectiveness ingredient were developed respectively.
|
PDF Full Text Request