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 tumefaciens‑mediated 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'.
Keywords: Arabidopsis thaliana; Desmodium styracifolium; New variety breeding; transcription factor.