ABSTRACT
Base on the transcriptome analysis and RT-PCR techniques,a pathogenesis-related protein 10 gene was isolated from Panax notoginseng root and named as PnPR10-2. Bioinformatics and phylogenetic trees analysis revealed that open reading frame (ORF) of PnPR10-2 was 465 bp in length,encoding 154 amino acids,containing one typical conserved domain of pathogenesis related protein Bet v I family, and showed high similarity with that from P. ginseng. The recombinant expressed plasmid pET32a(+)-PnPR10-2 was expressed in Escherichia coli BL21. The expression conditions were optimized and it could be expressed well in soluble and inclusion body protein. Purified PnPR10-2 recombinant protein from the supernatant of cells was used to analysis the pathogen resistance activity by paper method. The purified recombinant protein could inhibit typical root rot disease pathogen (Fusarium solani and Cylindrocarpon destructans）growth evidently, we conjecture that PnPR10-2 may participated in defense response of P. notoginseng resistance to root rot disease pathogen.
ABSTRACT
ABSTRACT Large amount of agriculturl wastewater containing high level nitrate-nitrogen (NO3 --N) is produced from modern intensive agricultural production management due to the excessive use of chemical fertilizers and livestock scale farming. The hydroponic experiment of water hyacinth was conducted for analyzing the content of NO3 --N, soluble sugar content, N-transported the amino acid content and growth change in water hyacinth to explore its purification ability to remove NO3 --N from agriculture eutrophic wastewater and physiological and biochemical mechanism of this plant to remove NO3 --N. The results showed that the water hyacinth could effectively utilize the NO3 --N from agriculture eutrophic wastewater. Compared with the control, the contents of NO3 -change to NO3 --N in the root, leaf petiole and leaf blade of water hyacinth after treatment in the wastewater for a week was significantly higher than that in the control plants treated with tap water, and also the biomass of water hyacinth increased significantly, indicating that the accumulation of biomass due to the rapid growth of water hyacinth could transfer some amount of NO3 --N.13C-NMR analysis confirmed that water hyacinth would convert the part nitrogen absorbed from agriculture eutrophic wastewater to ammonia nitrogen, which increased the content of aspartic acid and glutamic acid, decreased the content of soluble sugar, sucrose and fructose and the content of N-storaged asparagine and glutamine, lead to enhance the synthesis of plant amino acids and promote the growth of plants. These results indicate that the nitrate in agriculture eutrophic wastewater can be utilized by water hyacinth as nitrogen nutrition, and can promote plant growth by using soluble sugar and amide to synthesis amino acids and protein.
ABSTRACT
With development of wide-host-range vector systems,Tn5 transposon and its derivative vectors have been widely applied to genetic research of gram-negative bacteria.The applications of Tn5 transposon mutagenesis technology to genetic researches of bacteria were briefly discussed,including researches on biological control mechanisms of biocontrol bacteria,identification of bacterial essential genes,discovering virulence genes of bacterial pathogens,characterization of metabolism regulatory genes and genetic improvements of bacteria.
ABSTRACT
Plant insect-resistantgenetic engineering hasopened a new way to prevent and cure against the insect pest incrop and wood productions. With the progresses instudies, many insect-resistantgeneswere cloned and characterized. The classification of most insect-resistantgenes from plant, the functionalmechanism and the applications of theplantinsect-resistantgenes, the problems and prospectsforusing the plant insect-resistant genes in genetic engineering was described.