转基因红花中角质细胞生长因子KGF-1的表达

通过构建重组表达质粒载体p139035S-KGF1和根癌农杆菌介导在红花(Carthamus tinctorius)中表达角质细胞生长因子(KGF-1)。从侵染到诱导生根共需要14周, 转化率达0.1%。红花子叶在潮霉素筛选培养基上培养4–5周后便可获得丛生芽, 再生芽移入含潮霉素的伸长生根培养基, 培养4–8周可诱导生根。通过PCR、Southern blot、RT-PCR及Western blot检测证明目的基因KGF-1已经整合到红花细胞的染色体中, 实现了KGF-1外源蛋白在红花中的成功表达, 为开发KGF-1蛋白新的生产途径奠定了基础。     

Growth rates and biomass production of micropropagated apple plants of M26 and Gravenstein on their own roots and in different micrografted combinations under non-limiting and limiting nutrient conditions

Micropropagated apple plants of semi-dwarf rootstock M26 (M26) and vigorous cultivar Gravenstein (GR) on their own roots and different micrograft combinations were used in the experiment. The combinations included GR scion on GR root (GR/GR), M26 on M26 (M26/M26), GR on M26 (GR/M26), and M26 on GR (M26/GR). The plants were grown under non-limiting and limiting relative addition rates of nutrients. Under non-limiting nutrient conditions, M26 and GR showed a similar relative growth rate (RGR). Grafting reduced RGR significantly in the combination of M26/M26 compared to M26. The relative growth rate for the combination of GR/M26 was similar to the GR/GR plants, but it increased greatly compared to the M26/M26 plants. For the reverse combination of M26/GR, the RGR value decreased significantly compared to either the M26/M26 or the GR/GR plants. The RGR value and specific root length were lower for M26/GR than for GR/M26. No clear relationship between carbohydrate allocation and growth parameters of different plants was found under non-limiting nutrient conditions. Nutrient limitation resulted in increased dry weights and soluble sugars in the roots for all plants except for M26/GR. A reduced leaf area ratio and a lower RGR than the set relative addition rate of nitrogen were found for M26 and GR/M26 under limiting conditions. These results suggest that the dwarfing effect is not directly related to RGR of rootstocks or scions, but rather associated with root morphology of grafted plants and the ability of roots to absorb nutrients.     

A Soybean C2H2-Type Zinc Finger Gene GmZF1 Enhanced Cold Tolerance in Transgenic Arabidopsis

Zinc finger proteins were involved in response to different environmental stresses in plant species. A typical Cys2/His2-type (C2H2-type) zinc finger gene GmZF1 from soybean was isolated and was composed of 172 amino acids containing two conserved C2H2-type zinc finger domains. Phylogenetic analysis showed that GmZF1 was clustered on the same branch with six C2H2-type ZFPs from dicotyledonous plants excepting for GsZFP1, and distinguished those from monocotyledon species. The GmZF1 protein was localized at the nucleus, and has specific binding activity with EP1S core sequence, and nucleotide mutation in the core sequence of EPSPS promoter changed the binding ability between GmZF1 protein and core DNA element, implying that two amino acid residues, G and C boxed in core sequence TGACAGTGTCA possibly play positive regulation role in recognizing DNA-binding sites in GmZF1 proteins. High accumulation of GmZF1 mRNA induced by exogenous ABA suggested that GmZF1 was involved in an ABA-dependent signal transduction pathway. Over-expression of GmZF1 significantly improved the contents of proline and soluble sugar and decreased the MDA contents in the transgenic lines exposed to cold stress, indicating that transgenic Arabidopsis carrying GmZF1 gene have adaptive mechanisms to cold stress. Over-expression of GmZF1 also increased the expression of cold-regulated cor6.6 gene by probably recognizing protein-DNA binding sites, suggesting that GmZF1 from soybean could enhance the tolerance of Arabidopsis to cold stress by regulating expression of cold-regulation gene in the transgenic Arabidopsis.     

Efficient Inhibition of wear debris-induced inflammation by locally delivered siRNA

Aseptic loosening is the most common long-term complication of total joint replacement, which is associated with the generation of wear debris. The purpose of this study was to investigate the inhibitory effect of small interfering RNA (siRNA) targeting tumor necrosis factor-α (TNF-α) on wear debris-induced inflammation. A local delivery of lentivirus-mediated TNF-α siRNA into the modified murine air pouch, which was stimulated by polymethylmethacrylate (PMMA) particles, resulted in significant blockage of TNF-α both in mRNA and protein levels for up to 4 weeks. In addition, significant down-regulation of interleukin-1 (IL-1) and interleukin-6 (IL-6) was observed in TNF-α siRNA-treated pouches. The safety profile of gene therapy was proven by Bioluminescent assay and quantitative fluorescent flux. Histological analysis revealed less inflammatory responses (thinner pouch membrane and decreased cellular infiltration) in TNF-α siRNA-treated pouches. These findings suggest that local delivery of TNF-α siRNA might be an excellent therapeutic candidate to inhibit particle-induced inflammation.     

Studies on Some Properties of the Apoplastic β-N-Acetyl-D-Hexosaminidase from Tomato Leaves

Some properties of the β-N-acetyl-D-hexosaminidase purified from intercellular fluid of tomato leaves after the plant was systematically infected by TMV (tobacco mosaic virus) were studied. When pNP β-D-GlcNAc (p nitrophenyl-N-aeetyl β-D-glucosaminide) or pNP β-D- GalNAc (p-nitrophenyl-N-acetyl-β-D galactosaminide) was used as the substrate, it showed the optical pH between 4. 8--5.0 and optical temperature between 44— 47℃. Studies of thermostabillty indicated that the enzyme had a biphasic denaturation curve. Using pNP-β-D-GIcNAc or pNP-β-D GalNAc as the substrate, the Km value of the enzyme was 0. 36 and 0. 67 mmol/L respectively. N acetyi-D glucosamine and N acetyl-D-galactosamine were competitive inhibitors of the enzyme activities. Ag+ and Hg2+ were sensitive inhibitors and Fe2+ . Fe3+ and Cu2+ were also inhibitors enzyme activities.     

Lanthanum relieves salinity-induced oxidative stress in <Emphasis Type="Italic">Saussurea involucrata</Emphasis>

Changes in growth, physiological and biochemical characteristics under salt stress with or without La³⁺ treatment in Saussurea involucrata Kar. et Kir. were investigated. The results showed that La³⁺ relieved the plant growth inhibition, improved the leaf water potential and water content, increased the soluble protein and the proline contents and decreased malondialdehyde content under salt stress. Further, addition of La³⁺ significantly increased the activities of superoxide dismutase, ascorbate peroxidase, catalase, and glutathione reductase, decreased the photosynthetic pigment decomposition and increased the ratio of total chlorophyll to carotenoids under salt stress.     

EP300 contributes to high-altitude adaptation in Tibetans by regulating nitric oxide production

The genetic adaptation of Tibetans to high altitude hypoxia likely involves a group of genes in the hypoxic pathway,as suggested by earlier studies.To test the adaptive role of the previously reported candidate gene EP300 (histone acetyltransferase p300),we conducted resequencing of a 108.9 kb gene region of EP300 in 80 unrelated Tibetans.The allele-frequency and haplotype-based neutrality tests detected signals of positive Darwinian selection on EP300 in Tibetans,with a group of variants showing allelic divergence between Tibetans and lowland reference populations,including Han Chinese,Europeans,and Africans.Functional prediction suggested the involvement of multiple EP300 variants in gene expression regulation.More importantly,genetic association tests in 226 Tibetans indicated significant correlation of the adaptive EP300 variants with blood nitric oxide (NO) concentration.Collectively,we propose that EP300 harbors adaptive variants in Tibetans,which might contribute to high-altitude adaptation through regulating NO production.     

A novel 62‐bp indel mutation in the promoter region of transforming growth factor‐beta 2 (TGFB2) gene is associated with body weight in chickens

Transforming growth factor‐beta 2 (encoded by TGFB2) is a growth factor that regulates a plethora of cellular functions. In this study, we sequenced the promoter and full‐length exon region of the chicken TGFB2 and found two mutations (g.‐640C>T and g.‐851_‐790del) within the promoter. The two polymorphisms were genotyped in 1030 pedigreed hens recorded for body weight at 7 (BW7), 9 (BW9), 11 (BW11), 13 (BW13), 17 (BW17) weeks old, egg weight at 36 weeks of age (EW36) and egg numbers from the age at first egg (AFE) to 40 weeks of age (EN40). Despite the fact that no mutations were found to have statistically significant genetic effects on egg production, the association results of growth traits showed that both g.‐640C>T and g.‐851_‐790del had significant effects on body weights and that both genotype g.‐640TT and g.‐851_‐790wt/wt were positive for body weight performance. Therefore, the polymorphisms of TGFB2, especially the g.‐851_‐790del mutation associated with body weight at almost all periods, could be potential useful genetic markers to improve the growth of Beijing You chickens.