[Cloning of AhWRKY33 from Asarum heterotropoides and its genetic transformation in Arabidopsis].

The WRKY family genes, which play an important role in plant morphogenesis and stress response, were selected based on the data of the full-length transcriptome of Asarum heterotropoides. Using AtWRKY33, which regulates the synthesis of the camalexin in the model plant Arabidopsis to compare homologous genes in A. heterotropoides, primers were designed to amplify the open reading frame(ORF) fragment of AhWRKY33 gene by RT-PCR using total RNA of A. heterotropoides leaves as template. Real-time PCR results showed that there was a significant difference between the aerial part and the underground part of A. heterotropoides, the toxic aristolochic acid content is highly expressed in the leaves higher than the root. After verification, the WRKY33 gene of A. heterotropoides is ORF long 1 686 bp, encoding 561 amino acids.AhWRKY33 had two conserved WRKYGQK domains. According to the classical classification, it belongs to group Ⅰ WRKY transcription factor. A. heterotropoides WRKY33 had some homology with amino acids of other species. The study successfully constructed the plant eukaryotic expression vector PHG-AhWRKY33 and transformed Arabidopsis thaliana, the transgenic Arabidopsis was obtained by PCR detection and hygromycin resistant plate screening. It found that the germination of transgenic Arabidopsis seeds was accelerated and the stress resistance was increased. It laid a foundation for further analysis of WRKY transcription factor in the growth and development of A. heterotropoides and the synthesis of secondary metabolites.

Biological formation of 5-aminolevulinic acid by photosynthetic bacteria.

In this study, 7 stains of Rhodopseudomonas sp. were selected from 36 photosynthetic bacteria stains storied in our laboratory. Rhodopseudomonas sp. strain 99-28 has the highest 5-aminolevulinic acid(ALA) production ability in these 7 strains. Rhodopseudomonas sp. 99-28 strain was mutated using ultraviolet radiation and a mutant strain L-1, which ALA production is higher than wild strain 99-28 about one times, was obtained. The elements affecting ALA formation of strain 99-28 and L-1 were studied. Under the optimal condition( pH 7.5, supplement of ALA dehydratase(ALAD) inhibitor, levulinic acid(LA) and precursors of ALA synthesis, glycine and succinat, 3000 Ix of light density), ALA formation of mutant L-1 was up to 22.15 mg/L. Strain L-1 was used to treat wastewater to remove COD(Cr) and produce ALA. ALA production was 2.819 mg/L, 1.531 mg/L, 2.166 mg/L, and 2.424 mg/L in monosodium glutamate wastewater(MGW), succotash wastewater(SW), brewage wastewater(BW), and citric acid wastewater(CAW) respectively. More than 90% of COD(Cr) was removed in four kinds of wastewater. When LA, glycin and succinate were supplied, ALA production was dramatically increased, however, COD(Cr) could hardly be removed.