Cloning and functional validation of DsWRKY6 gene from Desmodium styracifolium.

The purpose of this study was to analyze the role of transcription factor in Desmodium styracifolium, proving that the DsWRKY6 transcription factor was related to the plant phenotypes of Desmodium styracifolium - cv. 'GuangYaoDa1' and it could be used in molecular-assisted breeding. 'GuangYaoDa1' was used as the material and its DNA was the template to clone DsWRKY6, the transgenic Arabidopsis thaliana line was constructed by agrobacterium tumefaciens­mediated transformation. Transgenic Arabidopsis thaliana was cultivated to study phenotype and physiological and biochemical indexes. Phenotypic observation showed that DsWRKY6 transgenic Arabidopsis thaliana had a faster growth rate while compared with the control group, they had longer lengths of main stem, lateral branches of cauline leaves, and root, but a lower number of cauline leaves and lateral branches of cauline leaves. And it also showed that their flowering and fruiting periods were advanced. The results of physiological and biochemical indexes showed that the relative expressions of DsWRKY6 increased and the abscisic acid content significantly increased in DsWRKY6 transgenic Arabidopsis thaliana compared with the control group. According to the above results, DsWRKY6 could regulate the advancing of flowering and fruiting periods caused by the improvement of abscisic acid content, and expression of the DsWRKY6 transcription factor might be the cause of the upright growth of 'GuangYaoDa1'.

Design and Evaluation of Hydrophilic Matrix System for pH-Independent Sustained Release of Weakly Acidic Poorly Soluble Drug.

The aim of this research was to design and evaluate a hydrophilic matrix system for sustained release of glipizide, a weakly acidic poor soluble drug. A combination of inclusion complexation and microenvironmental pH modification techniques was utilized to improve the dissolution and pH-independent release of glipizide. Hydroxypropyl-ß-cyclodextrin (HP-ß-CD) was used as the complexation agent while sodium citrate and magnesium oxide (MgO) were used as model pH modifiers. The hydrophilic matrix tablets were prepared by powder direct compression and evaluated by in vitro dissolution study respectively in pH 6.8 and pH 1.2 dissolution media. The formulations containing MgO exhibited increased cumulative drug release from less than 40% in the reference formulation to 90% within 24 h in acidic media (pH 1.2). The release profile in acidic media was similar to the alkaline media (pH 6.8) with a similarity factor (f2) of 55.0, suggesting the weakening of the effect of pH on the dissolution efficiency of glipizide. The release profile fitted well into the Higuchi model and the dominant mechanism of drug release was Fickian diffusion while case II transport/polymer relaxation occurred. In conclusion, combining inclusion complexation agents and pH modifiers had improved the dissolution of glipizide as well as achieved the pH-independent release profile.