Plant expression cassette for TaDREB from wheat was constructed into plasmid pBIR1.Aloe stems were used as explants for the transformation mediated by Agrobaterium.Infected tissues were selected using G418 to generate transformants.In total,58 resistant plantlets to the antibiotics were obtained from the infected explants.The designed primers according to the selective gene npt II and the target gene TaDREB were used to analyze all of the G418 resistant plantlets.PCR results demonstrated that TaDREB were successful transferred into aloe genomic with the transformation efficiency of 0.5%.The transgenic aloe plants were treated under 4℃ for two weeks and then at-20℃ for 30min.The treatment showed that the leaves of negative plants appeared severe evidence of freeze injury with brown,withered and translucent,while the positive plants appeared good growing condition.The activities of enzymes such as peroxidase(POD)and superoxide dismutase(SOD)of transgenic plants which were stressed for 14 days under low temperature were analyzed.The results indicated that the trend of SOD and POD activities in transgenic plants was down-up-up-up,and that in non-transgenic plants was down-up-down-down.The average value of relative electrical conductivity in the positive plants was 0.456 which was lower than 0.685 in the negative plants.It is supposed that transformation of the kind of gene could improve the resistant ability of aloe to low temperature.

This article was aimed to rapidly analyze chemical composition in A loe Barbadensis Mill, and to compare the chemical composition of commercial aloe vera medicinal materials with that of fresh aloe yellow exudate. An opti-mized liquid chromatography-mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF) method was applied for the analysis of commercial aloe vera medicinal materials and fresh aloe yellow exudates. The Agilent TC-C18 column (4.6 í 250 mm, 5 m) was used. The gradient elution was a solvent system of water(A)-methanol(B). ESI source was operated in both positive and negative ion modes. The results showed that chromones, pyrones, naphthalene deriva-tive, anthrones and anthraquinones were separated successfully, 30 compounds were characterized by the comparison of characteristic MS/MS fragment ions data with the literature. The diagnostic fragmentation patterns of different chemical compositions were also discussed on the basis of EST-IT-TOF MS data. It was concluded that the chemical composition of commercial aloe vera medicinal materials were significantly different from that of fresh aloe yellow ex-udate in terms of types and contents: the former one mainly contains isoaloeresin D and aloin, and few aloesin; but the latter is mainly composed of aloesin and aloin, and the content of aloesin is the highest. The LCMS-IT-TOF analysis can be used to rapidly obtain rich structural information of different chemical compositions, which improves the efficiency of qualitative analysis of chemical composition, and is of great significance to the quality control, eval-uation and the utilization of A loe Barbadensis Mill.

Recent studies have shown that changes in the gut and skin microbiome can directly affect the occurrence of acne. Regulating the skin and gut microbiome has brought new directions for the treatment of acne, and the most direct way to achieve this goal is to restore the balance of the microbiome through the use of probiotics. This review summarizes the relationship between acne and microbiome, and research progress in probiotics for the treatment of acne.