SCFP,a novel fiber-specific promoter in cotton

To investigate the expression pattern of GhSCFP which was isolated from cotton fiber cDNA library, a 1006 bp upstream fragment of the gene was cloned by chromosome walking and fused to GUSand GFP respectively. Histochemical GUS and GFP fluorescence analysis revealed that the expression of the report genes driven by the promoter sequence was detectable only in outer layer cells during the seed development in the transgentic tobaccos. In transgenic cotton, strong GUS activity was observed in spherical protrusions on 0 dpa （days post anthesis） ovule surface, and in the 2-36 dpa fiber cells, while no GUS signals were detected in the root, leaves, stem, corolla, anther and stigma. Our data demonstrated that GhSCFP upstream sequence is a cotton fiber-specific promoter and this promoter will be useful in the molecular research on fiber cell development and in cotton fiber improvements by genetic modification.     

Development of <Emphasis Type="Italic">Gossypium barbadense</Emphasis> chromosome segment substitution lines in the genetic standard line TM-1 of <Emphasis Type="Italic">Gossypium hirsutum</Emphasis>

Chromosome segment substitution lines （CSSL） consist of a battery of near-isogenic lines that have been developed and cover the entire genome of some crops. With the exception of one homozygous chromosome segment transferred from a donor parent, the remaining genome of each CSSL line is the same as the recipient parent. It is an ideal material for genome research and particularly QTL mapping. In the present study, we first developed one set of CSSL lines using G hirsutum acc. TM-1 （the genetic standard）, as the recipient parent and G barbadense cv. Hai7124 as the donor parent using molecular assistedlselection in BC5S1-3 generations. The CSSL consisted of 330 different lines, in which 1-4 different lines had the same or overlapping substituted segments. The genetic length of the substituted segments covered 5271.9 cM with an average segment distance of 10.9 cM, 1.5 times the total genetic length of Upland cotton （3514.6 cM）. The substituted segments of each line varied in length, ranging from 3.5 cM for the shortest segment to 23.2 cM in the longest segment. Our CSSL have not yet to cover the entire tetraploid cotton genome, due to the absence of some donor parent interval segments.     

Transgenic tobacco plants expressing synthetic Cry1Ac and Cry1Ie genes are more toxic to cotton bollworm than those containing one gene

Transgenic tobacco plants carrying CrylAc, Crylle or both genes were obtained. In the leaves of transgenic plants carrying both genes, the contents of CrylAc and Crylle proteins were 0.173% and 0.131% of the total proteins, respectively. CrylAc protein content was 0.182 % and Cry1 le protein content was 0.124% of the total proteins in the leaves of transgenic plants containing only one Bt gene. Fresh leaves of transgenic tobacco and wild-type plants were used for the insect bioassay against wild-type and Cry1Ac-resistant cotton bollworm （Helicoverpa armigera）. The bioassay results showed that transgenic plants carrying both genes were significantly more toxic to wild-type and CrylAc-resistant cotton bollworm than those carrying CrylAc or Crylle alone. This study indicates that the higher toxicity of transgenic tobacco plants carrying both genes is caused by the cooperative function of both Bt proteins, thus providing a potential way to delay the development of insect resistance to transgenic crops.     

Functional characterization and mapping of two MADS box genes from peach （Prunus persica）

Previously an AGAMOUS gene homologue PpMADS4 and a FRUITFULL gene homologue PpMADS6 were isolated from peach （Prunus persica）, and both genes were shown to express in the developing floral and fruits. To gain insight into their function, the two genes were constitutively expressed in Arabidopsis thaliana and their effects on plant growth and floral organ development were studied in this work. The transgenic plants all displayed early flowering and conversion of inflorescence to floral meristem. However, the two genes had different effects on the floral organ structures in A. thaliana. The transgenic plants overexpressing PpMADS4 displayed homeotic conversion of floral organs, and particularly the perianth abscission was inhibited. The plants overexpressing PpMADS6 showed early flowering, produced higher number of carpels, petals, and stamens than nontransgenic plants, and pod shatter was prevented; significantly, the transgenic plants yielded more than one siliques from a single flower. A SSR molecular marker was developed for PpMADS4, and it was then assigned into the G5 linkage group of Prunus sp. Both PpMADS4 and PpMADS6 genes were located at the same region in the G5 linkage group. Our results showed the potential application of these two MADS box genes for crop and fruit tree improvement.     

Fine mapping of the red plant gene R1 in upland cotton(Gossypium hirsutum)

Sub 16 is a substitution line with G. hirsutum cv. TM-1 genetic background except that the 16th chromosome (Chr. 16) is replaced by the corresponding homozygous chromosome of G. barbadense cv. 3-79, and T586 is a G. hirsutum multiple gene marker line with 8 dominant mutation genes. The R ₁ gene for anthocyanin pigmentation was tagged in Chr. 16 in T586. The objective of this research was to screen SSR markers tightly linked with R ₁ by using the F₂ segregating population containing 1259 plants derived from the cross of Sub 16 and T586 and the backbone genetic linkage map from G. hirsutum×G. barbadense BC₁ newly updated by our laboratory. Genetic analysis suggested that the segregation ratio of red plants in the F₂ population fit Mendelian 1:2:1 inheritance, confirming that the red plant trait was controlled by an incomplete dominance gene. Preliminary mapping of R ₁ was conducted using 237 randomLy selected F₂ individuals and JoinMap v3.0 software. Then, a fine map of R1 was constructed using the F₂ segregating population containing 1259 plants, and R ₁ was located between NAU4956 and NAU6752, with only 0.49 cM to the nearest maker loci (NAU6752). These results provided a foundation for map-based cloning of R ₁ and further development of cotton cultivars with red fibers by transgenic technology. Supported by National Natural Science Foundation of China (Grant No. 30730067) and Programme of Introducing Talents of Discipline to Universities (Grant No. B08025)     

Overexpression of phospholipase <Emphasis Type="Italic">D</Emphasis>α gene enhances drought and salt tolerance of <Emphasis Type="Italic">Populus tomentosa</Emphasis>

The cDNA of AtPLDa （Arabidopsis thaliana Phospholipase Da） gene was introduced into P. tomentosa （Populus tomentosa） under the control of the Cauliflower mosaic virus 35S promoter. Southern and Northern blot analyses suggested that the AtPLDa gene has been transferred into the P. tomentosa genome. No obvious morphological or developmental difference was observed between the transgenic and wild-type （WT） plants. Drought and salt tolerance and gene expression of seedlings of several transgenic lines and WT plants （control） were studied. The results showed that the rhizogenesis rate and the average root-length of transgenic lines were significantly higher than WT plants after mannitol and NaCI treatment under the same growth conditions. Northern blot analysis indicated that the higher the PLDa expression in the transgenic plants, the more tolerant the transgenic plants are to drought and salt treatment. Meanwhile, another group of these transgenic lines and WT plants （control） were treated with PEG6000 and NaCI separately. The contents of chlorophylls and the activities of some anti- oxidant enzymes （superoxide dismutase, guaiacol peroxidase and catalase） as well as malondialdehyde and relative electrical conductivity were analyzed. Altogether, our results demonstrated that overexpression of the PLDa gene can enhance the drought and salt tolerance in transgenic P. tomentosa plants.     

The short C-terminal hydrophilic domain of NhaH Na^＋/H^＋ antiporter from Halobacillus dabanensis with roles in resistance to salt and in pH sensing

The Na^＋/H^＋ antiporter plays key roles in maintaining low cytoplasmic NaNa^＋ level and pH homeostasis, while little is known about the Carboxyl-terminal hydrophilic tails of prokaryotic antiporters. In our previous study, the first Na^＋/H^＋ antiporter gene nhaH from moderate halophiles was cloned from Halobacillus dabanensis D-8 by functional complementation. A topological model suggested that only nine amino acid residues （^395PLIKKLGMI403） existed in the hydrophilic C-terminal domain of NhaH. The C-terminal truncated mutant of NhaH was constructed by PCR strategy and designated as nhaH△C. Salt tolerance experiment demonstrated that the deletion of hydrophilic C-terminal nine amino acid residues significantly inhibited the complementation ability of E. coil KNabc, in which three main Na^＋/H^＋ antiporters nhaA, nhaB and chaA were deleted. Everted membrane vesicles prepared from E. coil KNabc/nhaHAC decreased both Na^＋/H^＋ and Li^＋/H^＋ exchange activities of NhaH, and also resulted in an acidic shift of its pH profile for Na^＋, indicating a critical role of the short C-terminal domain of NhaH antiporter in alkali cation binding/translocation and pH sensing.     

Ubi1 intron-mediated enhancement of the expression of Bt cry1Ah gene in transgenic maize （Zea mays L.）

The cry1Ah gene was one of novel insecticidal genes cloned from Bacillus thuringiensis isolate BT8. Two plant expression vectors containing cry1Ah gene were constructed. The first intron of maize ubiqutinl gene was inserted between the maize Ubiquitin promoter and cry1Ah gene in one of the plant expressing vectors （pUUOAH）. The two vectors were introduced into maize immature embryonic calli by microprojectile bombardment, and the reproductively plants were acquired. PCR and Southern blot analysis showed that foreign genes had been integrated into maize genome and inherited to the next generation stably. The ELISA assay to T1 and T2 generation plants showed that the expression of CrylAh protein in the construct containing the ubil intron （pUUOAH） was 20% higher than that of the intronless construct （pUOAH）. Bioassay results showed that the transgenic maize harboring cry1Ah gene had high resistance to the Asian corn borers and the insecticidal activity of the transgenic maize containing the ubil intron was higher than that of the intronless construct. These results indicated that the maize ubil intron can enhance the expression of the Bt cry1Ah gene in transgenic maize efficiently     

Preparation of nano-compounded polyolefin materials through in situ polymerization technique: status quo and future prospects

Nano-compounding of polyolefins, an economical yet very effective route to high-performance polyolefin materials, has received considerable attention in recent years. Unlike most of the other polymers, polyolefins are chemically inert, which dictates that nano-compounding of polyolefins has to be conducted via in situ polymerization. In this review, a technological progress of the nano-compounding of polyolefins via in situ polymerization technique was summarized thoroughly, with emphasis laid on the current research status of polyolefin/montmorillonite (MMT) nanocomposites. A clear perspective for future researches on this specific family of materials was envisaged. Supported by National Natural Science Foundation of China (Grant No. 50373048) and State Key Development Program of Basic Research Program of Ministry of Science and Technology of China (Grant No. G2003CB615600)     

Cloning of fiber-specific cDNAs and their structural variations in 4 fiber mutants

A mRNA preferentially expressed in cotton fiber was cloned from fiber total RNA of normal upland cotton TM-1 (wild-type) by using RT-PCR and corresponding cDNA (signed as TM-E6) was sequenced. TM-E6 gene had no intron and contained an open reading frame of 771 bp long, and might encode a peptide of 246 amino acids. Other 4 genes, Fl-E6, Li-E6, N-E6 and Bl-E6, which were homologous to TM-E6 gene, were also isolated from 4 fiber mutants of Fiberless Xu-zhou 142, Ligon lintless, Naked seed and Brown lint, respectively. Sequence analysis of each of these mutant genes revealed many variations in structure and nucleotide composition of gene when compared with the sequence of TM-E6 gene. (ⅰ) There was a changeable repetitive segment in which GGCTCA (Gly-Ser) was repeated 3—5 times between the 82nd and the 93rd codons in different mutant genes. Since the change of Gly-Ser repetitive segment occurred not only in the mutants but also in the wild-type cotton, the repeat frequency might not be associated with the mutation of fiber characteristics. (ⅱ) Among the 4 mutant genes, the percentage of changed codons was 7.05% in Fl-E6, 4.98% in Li-E6, and 4.15% in N-E6 and Bl-E6. It seems that the percentage of changed codons in E6 sequence was positively correlated to the degree of fiber morphological variation. (ⅲ) E6 polypeptides of two long-fiberless mutants (Fiberless Xuzhou 142 and Ligon lintless) contained high similar (99.4%) variation in the region of 1—174 amino acids from N-terminus, and those of short-fiberless mutants (Fiberless Xuzhou and naked seed) revealed identical variation in the region of 116th—220th amino acids. It also seems that there was a parallel relation between E6 protein variation and fiber phenotype mutation. (ⅳ) Li-E6 and Bl-E6 genes also expressed at low level in seed coat besides at high level in fiber.     

Genetic analysis and gene mapping of a narrow leaf mutant in rice ( Oryza sativa L.)

A narrow leaf mutant was obtained after T-DNA transformation conducted on a rice variety Zhonghua 11. Several abnormal morphological characteristics, including semi-dwarf, delayed flowering time, narrow and inward rolling leaves, and lower seed-setting, were observed. The rate of net photosynthesis (under saturate light) of flag leaves in the mutant was significantly lower than that of the wild type. Moreover, the leaf transpiration rate and stomatal conductance in the mutant flag leaf were lower than those of the wild type at the grain filling stage. It was found that the mutant phenotype was not caused by the T-DNA insertion. Genetic analysis showed that the mutant was controlled by a single recessive gene, designated as nal3(t). A genetic linkage map was constructed using a large F₂ mapping population derived from a cross between nal3(t) and an indica variety Longtefu B with 6 polymorphic markers on chromosome 12 identified from 366 SSR markers by the BAS method. Gene nal3(t) was mapped between the markers RM7018 and RM3331. Fine mapping of nal3(t) locus was conducted with 22 newly developed STS markers based on the sequence diversity around the region harboring nal3(t) between Nipponbare and 93–11, and nal3(t) was finally mapped to a 136-kb region between the STS markers NS10 and RH12-8. Supported by National High Technology Research and Development Program of China (863 Program) (Grant No. 2006AA10A102), National Natural Science Foundation of China (Grant No. 30600349) and Natural Science Foundation of Zhejiang Province (Grant No. Y306149)     

Phylogenetic relationships and divergence times of the family Araucariaceae based on the DNA sequences of eight genes

Araucariaceae is one of the most primitive families of the living conifers, and its phylogenetic relationships and divergence times are critically important issues. The DNA sequences of 8 genes, i.e., nuclear ribosomal 18S and 26S rRNA, chloroplast 16S rRNA, rbcL, matK and rps4, and mitochondrial coxl and atpl, obtained from this study and GenBank were used for constructing the molecular phylogenetic trees of Araucariaceae, indicating that the phyiogenetic relationships among the three genera of this family should be （（Wollemia, Agathis）, Araucaria）. On the basis of the fossil calibrations of Wollemia and the two tribes Araucaria and Eutacta of the genus Araucaria, the divergence time of Araucariaceae was estimated to be （308± 53） million years ago, that is, the origin of the family was in the Late Carboniferous rather than Triassic as a traditional view. With the same gene combination, the diver- gence times of the genera Araucaria and Agathis were （246 ± 47） and （61 ±15） Ma, respectively. Statis- tical analyses on the phylogenetic trees generated by using different genes and comparisons of the divergence times estimated by using those genes suggested that the chloroplast matK and rps4 genes are most suitable for investigating the phylogenetic relationships and divergence times of the family Araucariaceae.     

TiO2-based building materials: Above and beyond traditional applications

In the 1910s, TiO₂ began to be used in building materials as pigments and opacifier due to its excellent optical property. Since the photocatalytic property of TiO₂ was observed in 1972, its application field was expanded to air cleaning and sterilization. Thereafter, people added TiO₂ into building materials to develop novel and facile building materials. These materials were widely used for air cleaning, sterilization, self-cleaning, anti-fogging, decoration, and building cooling. The combination of building and other functions can serve simultaneously. Although TiO₂-based building materials have bright prospects, some aspects such as improving the stability and enhancing photoactive performance of the materials are of importance for future research. Supported by the National High Technology Research and Development Program (“863” Program) of China (Grant No. 2007AA061402), Chinese Key Technology Research and Development Program of the Eleventh Five-year Plan (Grant No. 2006BAJ02A08), Hangzhou Science & Technology Development Program (Grant No. 20061133B27) and Research Fund for the Doctoral Program of Higher Education (Grant No. 20070335197)     

Photodegradation of <Emphasis Type="Italic">N</Emphasis>-nitrosodiethylamine in water with UV irradiation

The direct photolysis of N-nitrosodiethylamine （NDEA） in water with ultraviolet （UV） irradiation was investigated. Results showed that NDEA could be completely degraded under the direct UV irradiation. The effects of the experimental conditions, including the initial concentration of NDEA, humic acid and solution pH, were studied. The degradation products of NDEA were identified and quantified with gas chromatography-mass spectrometry （GC-MS） and high performance liquid chromatography （HPLC）. It was confirmed that methylamine （MA）, dimethylamine （DMA）, ethylamine （EA）, diethylamine （DEA）, NO2^- and NO3^- were the main degradation products. The photolysis degradation mechanism of NDEA was also discussed. As a result of N-N bond fission, NDEA was degraded by direct UV irradiation.     

DNA methylation status of H19 and Xist genes in lungs of somatic cell nuclear transfer bovines

In somatic cell nuclear transfer （SCNT） technologies, the donor cell＇s nuclei need to be epigenetically reprogrsmmed for embryonic development. The incomplete reprogramming of donor cell nuclei has been Implicated as s primary reason for the low efficiency of SCNT. DNA methylstion is s major epigenetic modification of the genome that regulates crucial aspects of genome function, including establishment of genomic imprinting. In order to make sure whether the DNA methylstion reprogramming is efficient in SCNT animals, we analyzed the DNA methylstion status of two imprinting genes, H19 and Xist, in lungs of deceased SCNT bovines that died within 48 h of birth using bisulfite sequencing analysis. Our findings demonstrated that cloned bovines showed significantly lower DNA methylstion of H19 than controls （P〈0.05）, and three tested CpGs sites （1, 2, 3） exhibited unmethylstion in one cloned bovine （9C3）; however, Xist showed similar DNA methylation levels between clones and controis, and both showed hypermethylstion （96.11% and 86.67%）.     

Development of Triticum aestivum-Leymus racemosus ditelosomic substitution line 7Lr#1S（7A） with resistance to wheat scab and its meiotic behavior analysis

Leymus racemosus is highly resistant to wheat scab （Fusarum head bright）. The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the base of wheat resistance. In the present study, the pollen of T. aestivum-L, racemosus monosomic addition line with scab resistance was treated by irradiation with 1200 R ^60Co-γ-rays prior to pollinating to emasculated wheat cv. Mianyang 85-45. Nine plants with a telocentric chromosome 7Lr#1S were observed in M1, and one ditelosomic substitution line 7Lr#1S was selected from selfcrossing progenies and confirmed by chromosome C-banding and GISH. Furthermore, a co-dominant EST-SSR marker CINAU 31 was employed to identify this substitution line. A pair of chromosome 7A of common wheat were found to be replaced by a pair of telocentric chromosome 7Lr#1S, and further investigation showed that chromosome configuration of the substitution line at MI of PMCs after GISH was 17.50Ⅱ^w ＋ 2.19Ⅱ^w ＋ 0.42Ⅱ^7Lr#1S ＋ 1.08 Ⅰ^7Lr#1S ＋ 0.69 Ⅰ^w. Two telocentric chromosomes paired as a bivalent in 59.7% of PMCs. Abnormal chromosome behaviors of telocentric chromosomes were observed in part of PMCs at anaphase I and telophase I, including the moving of two telocentric chromosomes to the same pole, lagging and earlier separation of their sister chromatid. All these abnormal behaviors can be grouped into three distinct types of tetrads according to different numbers of 7Lr#1S in their daughter cells and various micronucleus in some tetrads. However, due to the high transmission frequency of the female and male gametes with a 7Lr#1S, 84% of the selfcrossing progeny plants had ditelosomic substitution. The substitution line showed high resistance to wheat scab in a successive two-year test both in the greenhouse and field; hence, the line will be particularly valuable for alien gene mapping, small fragment translocation induction and telosomic cytological behavior analysis.     

Introduction of antisensewaxy gene into main parent lines ofindica hybrid rice

Amylose content in rice endosperm is one of the key determinants of rice eating and cooking quality, and the poor quality ofindica hybrid rice is closely related to the high amylose level in rice grains. In order to improve the grain quality of theindica hybrid rice by genetic engineering, an antisense fragment of ricewaxy gene, driven by the 5′-franking sequences of the ricewaxy gene, was successfully introduced into three major parent lines ofindica hybrid rice, all contain a high amylose level in the grains, viaAgrobacterium, and more than 100 hygromycinresistant plants were regenerated. The analysis of PCR amplification and Southern blots indicated that the T-DNA containing the antisensewaxy gene had been integrated into the genome of transgenic rice plants. Most of the primary transgenic rice plants grew normally, and the mature seeds from these transgenic plants were performed for analysis of the amylose content. The results showed that the amylose content in the endosperm of some grains was reduced and the lowest reached 7.02% in one homozygous transgenic line, 72.4% lower than that of the wild type. The influence of the altered amylose content on the gelatinization temperature and gel consistency was also observed in several homozygous transgenic rice plants. The two authors contributed equally to this work.     

Magnetoelectric and converse magnetoelectric res ponses in TbxDy1-xFe2-y alloy ＆ Pb（Mg1/3Nb2/3）（1-x）TixO3 crystal laminated composites

Measured results of magnetoelectric （ME） and converse magnetoelectric （CME） effects of TbxDy1-xFe2-y/ Pb（Mg1/3Nb2/3）（1-x）TixO3/TbxDy1-xFe2-y （TD/PMNT/TD） and PMNT/TD/PMNT laminated composites are presented. ME effect was determined by measuring laminate voltage output under a Helmholtz-generated AC field biased by a DC field （0-1 kOe） （1Oe = 79.58 A/m）. The CME effect was measured by recording the voltage induced in a solenoid encompassing the ME sample while exposed to a DC bias field and PMNT layer driven by a 10 V AC source. The ME and CME responses in the two laminated structure are linear. The highest values of ME coefficients in TD/PMNT/TD and PMNT/TD/PMNT composites are 384 mV/Oe and 158 mV/Oe, respectively, while the highest values of CME coefficients in the two composites are 118 mG/V and 162 mG/V （1 G=10^-4 T）, respectively.