Vegetables are important constituents of the human diet. Heavy metals and nitrate are among the major contaminants of vegetables. Consumption of vegetables and fruits with accumulated heavy metals and nitrate has the potential to damage different body organs leading to unwanted effects. Breeding vegetables with low heavy metal and nitrate contaminants is a cost-effective approach. We investigated 38 water spinach genotypes for low Cd and nitrate co-accumulation. Four genotypes, i.e. JXDY, GZQL, XGDB, and B888, were found to have low co-accumulation of Cd (<0.71 mg/kg dry weight) and nitrate (<3100 mg/kg fresh weight) in the edible parts when grown in soils with moderate contamination of both Cd (1.10 mg/kg) and nitrate (235.2 mg/kg). These genotypes should be appropriate with minimized risk to humans who consume them. The Cd levels in the edible parts of water spinach were positively correlated with the concentration of Pb or Zn, but Cd, Pb, or Zn was negatively correlated with P concentration. These results indicate that these three heavy metals may be absorbed into the plant in similar proportions or in combination, minimizing the influx to aerial parts. Increasing P fertilizer application rates appears to prevent heavy metal and nitrate translocation to shoot tissues and the edible parts of water spinach on co-contaminated soils.
Biomass ; Cadmium/metabolism* ; Chlorophyll/analysis* ; Genotype ; Humans ; Ipomoea/genetics* ; Nitrates/metabolism*

We have recombined genes VvSUC11, VvSUC12 from Vitis vinifera L., and root-specific promoters of sweet potato storage protein gene from Ipomoea batatas L. Lam., named as SP1 and SP2. We have constructed a vector pCAMBIA2301-SP1- VvSUC11-SP2-VvSUC12 using pCAMBIA2301 as an original vector. VvSUC11 and VvSUC12 were under the control of root-specific promoters of sweet potato storage protein gene. We transformed the vector into KWS-9103 breeding line of Beta vulgaris L. with Agrobacterium-mediated transformation. We have established the optimal genetic transformation protocol of sugar beet as following: the explants pre-cultured for 4 days were immersed in Agrobacterium suspension of OD(600)=0.5, supplemented with 0.005% Silwet L-77, and followed by a 4-day culture on medium containing cefotaxime, then the buds were selected on medium containing kanamycin and cefotaxime. The percentage of kanamycin-resistant buds was as high as 42%. Results of PCR and RT-PCR proved that the target genes had integrated into sugar beet genome and expressed. It will lay a foundation for further studying their function in Beta vulgaris.
Agrobacterium ; genetics ; metabolism ; Beta vulgaris ; genetics ; Genetic Vectors ; Ipomoea batatas ; genetics ; Membrane Transport Proteins ; biosynthesis ; genetics ; physiology ; Plant Proteins ; biosynthesis ; genetics ; physiology ; Promoter Regions, Genetic ; Recombination, Genetic ; Transformation, Genetic ; Vitis ; genetics

A cDNA, named Dd-ace-2, encoding an acetylcholinesterase (AChE, EC3.1.1.7), was isolated from sweet-potato-stem nematode, Ditylenchus destructor. The nucleotide and amino acid sequences among different nematode species were compared and analyzed with DNAMAN5.0, MEGA3.0 softwares. The results showed that the complete nucleotide sequence of Dd-ace-2 gene of Ditylenchus destructor contains 2425 base pairs from which deduced 734 amino acids (GenBank accession No. EF583058). The homology rates of amino acid sequences of Dd-ace-2 gene between Ditylenchus destructor and Meloidogyne incognita, Caenorhabditis elegans, Dictyocaulus viviparous were 48.0%, 42.7%, 42.1% respectively. The mature acetylcholinesterase sequences of Ditylenchus destructor may encode by the first 701 residues of deduced 734 amino acids.The conserved motifs involved in the catalytic triad, the choline binding site and 10 aromatic residues lining the catalytic gorge were present in the Dd-ace-2 deduced protein. Phylogenetic analysis based on AChEs of other nematodes and species showed that the deduced AChE formed the same cluster with ACE-2s.
Acetylcholinesterase ; genetics ; Amino Acid Sequence ; Animals ; Cloning, Molecular ; DNA, Complementary ; genetics ; Genes, Helminth ; genetics ; Ipomoea batatas ; parasitology ; Molecular Sequence Data ; Nematoda ; enzymology ; genetics ; Plant Stems ; parasitology ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, Protein

Sweet potato is an important food crop that can also be used as an industrial raw material. Sucrose is the main form of long-distance carbohydrate transport in plants, and sucrose transporter (SUT) regulates the transmembrane transport and distribution of sucrose during plant growth and metabolism. Moreover, SUT plays a key role in phloem mediated source-to-sink sucrose transport and physiological activities, supplying sucrose for the sink tissues. In this study, the full-length cDNA sequences of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were obtained by rapid amplification of cDNA ends (RACE) cloning according to the transcripts of the two SUT coding genes which were differentially expressed in sweet potato storage roots with different starch properties. Phylogenetic analysis was performed to clarify the classification of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆. The subcellular localization of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ was determined by transient expression in Nicotiana benthamiana. The function of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sucrose and hexose absorption and transport was identified using yeast functional complementarity system. The expression pattern of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sweet potato organs were analyzed by real-time fluorescence quantitative PCR (RT-qPCR). Arabidopsis plants heterologous expressing IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ genes were obtained using floral dip method. The differences in starch and sugar contents between transgenic and wild-type Arabidopsis were compared. The results showed IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ encoded SUT proteins with a length of 505 and 521 amino acids, respectively, and both proteins belonged to the SUT1 subfamily. IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were located in the cell membrane and were able to transport sucrose, glucose and fructose in the yeast system. In addition, IbSUT₆₂₇₈₈ was also able to transport mannose. The expression of IbSUT₆₂₇₈₈ was higher in leaves, lateral branches and main stems, and the expression of IbSUT₈₁₆₁₆ was higher in lateral branches, stems and storage roots. After IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were heterologously expressed in Arabidopsis, the plants grew normally, but the biomass increased. The heterologous expression of IbSUT₆₂₇₈₈ increased the soluble sugar content, leaf size and 1 000-seed weight of Arabidopsis plants. Heterologous expression of IbSUT₈₁₆₁₆ increased starch accumulation in leaves and root tips and 1 000-seed weight of seeds, but decreased soluble sugar content. The results obtained in this study showed that IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ might be important genes regulating sucrose and sugar content traits in sweet potato. They might carry out physiological functions on cell membrane, such as transmembrane transport of sucrose, sucrose into and out of sink tissue, as well as transport and unloading of sucrose into phloem. The changes in traits result from their heterologous expression in Arabidopsis indicates their potential in improving the yield of other plants or crops. The results obtained in this study provide important information for revealing the functions of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in starch and glucose metabolism and formation mechanism of important quality traits in sweet potato.
Ipomoea batatas/metabolism* ; Arabidopsis/metabolism* ; Sucrose/metabolism* ; Saccharomyces cerevisiae/metabolism* ; DNA, Complementary ; Phylogeny ; Plants, Genetically Modified/genetics* ; Membrane Transport Proteins/metabolism* ; Starch/metabolism* ; Plant Proteins/metabolism* ; Gene Expression Regulation, Plant

OBJECTIVETo observe the effect of alcohol extracts from Pharbitidis Semen on the proliferation and metastasis of Lewis lung cancer, and study its anti-tumor mechanism.

METHODIn vitro, MTT assay and scratch assay were adopted to detect the effect of alcohol extracts from Pharbitidis Semen on the proliferation and metastasis of Lewis lung cancer cells. The cell autophagy was detected by the acridine orange staining. The gap-junction intercellular communication (GJIC) was investigated by the fluorescent yellow transfer. The expression of aquaporin 1 (AQP1) was analyzed by the Western blotting. In vivo, the subcutaneous implant model and the experimental pulmonary metastasis model of Lewis lung cancer in mice were established to evaluate the anti-tumor and anti-metastasis effects of alcohol extract from Pharbitidis Semen. The serum carcinoembryonic antigen (CEA) and beta2 microglobulin (beta2-MG) of mice bearing Lewis lung cancer were detected by the electrochemiluminesence immunoassay. The expressions of lung AQP1 and Connexin 43 (Cx43) were examined by the immunohistochemical method.

RESULTIn vitro, alcohol extracts from Pharbitidis Semen inhibited the cell proliferation in a dose-dependent matter, significantly prevented the cell migration, down-regulated AQP1 proteins of cells, promoted GJIC, and decreased the serum-free autophagy of tumor cells. In vivo, compared with untreated model mice, alcohol extracts from Pharbitidis Semen inhibited the tumor growth in a dose-dependent matter, prevented the tumor metastasis and prolonged the life span of mice bearing Lewis lung cancer, while decreasing serum CEA and beta2-MG of mice bearing Lewis lung cancer, enhancing the immumohistochemical staining intensity of Cx43 and weakening aquaporins AQP1 positive intensity.

CONCLUSIONAlcohol extracts from Pharbitidis Semen could prevent the proliferation and metastasis in Lewis lung cancer cells. Its mechanism may be related to the promotion of GJIC and the down-regulation of AQP1.

Animals ; Antineoplastic Agents ; administration & dosage ; Aquaporin 1 ; genetics ; metabolism ; Carcinoma, Lewis Lung ; drug therapy ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Connexin 43 ; genetics ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Ipomoea ; chemistry ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Neoplasm Metastasis ; Seeds ; chemistry