In order to reveal the function of UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) in regulating anthocyanin biosynthesis in spine grape (Vitis davidii Foëx.) callus at the cellular level, the gene encoding VdUFGT was isolated from spine grape callus by using RT-PCR with RACE technology. Its sequence was analyzed by bioinformatics and the expression profiles were investigated by real-time quantitative PCR (RT-qPCR). The results showed that the open reading frame (ORF) of cDNA and DNA of VdUFGT are 1 371 bp and 1 448 bp in length, respectively. It contains two exons and one intron, encoding 456 amino acid residues. The VdUFGT protein, an unstable and hydrophilic protein with negative charges, is a member of the UDPGT superfamily, including a UDPGT domain and a UDP: flavonoid glycosyltransferase YjiC feature regions. Six Vitis plants are clustered into the same group according to the phylogenetic tree, which constructed by proteins encoded from UFGT homologous genes. RT-qPCR analysis showed that the VdUFGT transcription level of red callus of spine grape was significantly higher than that of white callus, which was above 79 times when they were cultured for 25 days. During the continuous culture of spine grape callus, the VdUFGT expression level changed greatly in red callus, two peaks occurred at the middle stage of rapid-growth and the beginning of senescence, respectively. While the expression level of VdUFGT in white callus of spine grape changed not as wells as in red callus, it always maintained at a very low level. These results suggested that VdUFGT is the major gene involved in the regulation of anthocyanin biosynthesis in cell cultures of spine grape callus, and its regulatory role was mainly worked at the middle stage of rapid-growth and the beginning of senescence. This result would lay a foundation for further studying of the regulatory mechanism of anthocyanin biosynthesis in spine grape cells.
In order to explore the physiological response of Brassica napus at seedling stage under aluminum stress, in this study, two oilseed rape varieties with significant difference in aluminum toxicity tolerance of R178 (Al-resistant) and S169 (Al-sensitive) as experimental materials were cultured in the nutrient solution to measure morphological and physiological indexes after 4 weeks with treatments of 0, 50, 100, 150, 200 and 300 μmol·L-1 aluminum (pH 4.5). The results showed that the main root length, total root length, total root surface area, root average diameter and total root volume of R178 had no significant difference in 50 μmol·L-1 aluminum , while compared with the control group, the root-related morphological indexes of S169 had significant difference. In addition, the total number of root tips increased first and then decreased with the increase of aluminum treatment concentration, and other morphology parameters decreased continually with the increase of aluminumconcentration; Under the treatment of 300 μmol·L-1 aluminum , the relative elongation of the main root decreased 65.7% and 79.7%, respectively, in the two varieties than the control group. The content of soluble protein and proline in the seedlings roots of the two varieties increased first and then decreased with the increase of aluminum concentration, with the content of soluble protein decreased and proline increased in leaves with the increase of aluminum concentration, respectively. Under aluminum stress, the plasma membrane permeability of decrease both roots and leaves at seedling stage of two varieties increased significantly, under the treatment of 300 μmol·L-1 aluminum concentration, the relative electrolyte exosmosis rate in roots of R178 and S169 increased by 54% and 59%, and in leaves increased by 82% and 90%, respectively. Under the same treatment, the electrolyte exosmosis rate of R178 roots and leaves was lower than that of S169. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in the roots of two varieties first increased and then decreased with the increase of aluminum concentration. SOD activity in R178 leaves increased with the increase of aluminum concentration, SOD activity in leaves of S169 first increased and then decreased and when the aluminum concentration is 200 μmol·L-1, it reached the maximum value. The activities of POD, CAT and APX in the leaves of two varieties showed the same trend that increased first and then decreased with the increase of aluminum concentration. The results showed that aluminum stress inhibited root growth significantly and damaged the integrity of cytoplasmic membrane of rapeseed. Rape seedlings resist aluminum stress by accumulating the protein and proline content and increasing protective enzyme activity. These results provide a theoretical basis for the selection of resources and breeding of new cultivars of aluminum-tolerant rapeseed.