Preliminary structure and bioactivities of polysaccharide SMWP-U&E isolated from Salvia miltiorrhiza Bunge Residue.

The fractional polysaccharide SMWP-U&E was isolated from Salvia miltiorrhiza residue. SMWP-U&E consists of 91.40% carbohydrates and has an average molecular weight of 5.07 × 105 Da. The polysaccharides are mainly composed of arabinose (Ara), fructose (Fru), mannose (Man), glucose (Glc), and galactose (Gal), and their mole percentages are 3.72%, 4.11%, 6.18%, 32.08% and 53.91%, respectively. When effected on weaned piglets, 1.5 g/kg SMWP-U&E supplementation significantly increased the villus height to crypt depth ratio in ileum. PCR-denaturing gradient gel electrophoresis and qRT-PCR results indicated that SMWP-U&E supplementation could change the density of intestinal microbiota and the populations of Lactobacillus and Escherichia coli in jejunum, ileum, caecum, and colon. The supplementation also increased contents of IgA, IgG, IgM, IL-2, IFN-γ, and IL-10; promoted T-AOC and SOD activities; and reduced MDA level in the serum. These findings suggest that SMWP-U&E improves digestion and nutrient absorption in weaned piglets, exerts beneficial effects on intestinal morphology and microflora, and enhances the immune and antioxidant capabilities in mode of weaned piglets. Thus, SMWP-U&E exhibits potential as a new type of plant-derived additive and novel prebiotics.

[Heavy metal-transport proteins in plants: a review].

The heavy metals in soil not only damage plant growth, but also threaten the health of human beings and animals through food chain. Heavy metal-transport proteins play crucial roles in the heavy metals uptake and tolerance of plants. Plant heavy metal-transport proteins can be classified as metal-uptake proteins and metal-efflux proteins. The metal-uptake proteins can transport essential heavy metals into cytoplasm, and also, transport toxic heavy metals into cytoplasm due to the absence of essential heavy metals or the competition among ions. The metal-efflux proteins are a group of detoxification proteins, which can efflux excess and toxic heavy metals from cytoplasm, or move these metals into vacuole. In recent years, the associations between elevated steady-state transcript levels of heavy metal-transporter genes and metal accumulation in plants have been revealed, and many heavy metal-transport proteins have been cloned and identified. In this paper, the metal affinity, tissue-specific gene expression, and cellular location of representative heavy metal-transport proteins were reviewed.

[Identification of known microRNAs in root and leaf of maize by deep sequencing].

microRNA (miRNAs) is a newly identified class of 20-24 nt non-protein-coding and endogenous small RNA, which plays an important role in plant growth, development and response to environmental stresses. Combined with bioinformatic method, the types, abundance, and targets of known miRNAs in root and leaf of maize (Zea mays L.) were analyzed by small RNA deep sequencing technology, which was based on Illumina/Solexa principium. The results indicated that 92 known miRNAs were detected in maize root, which were attributed to 18 miRNA families and their abundance ranged from 1 to 105,943 reads. Synchronously, 86 known miRNAs were detected in maize leaf, which were attributed to 17 miRNA families and their abundance ranged from 1 to 85,973 reads. The target gene prediction showed that 54 putative target genes as these known miRNAs were predicted. Some of them were involved in the following processes, such as transcription regulation, substance and energy metabolism, electron transport, stress response, and signal transduction through further function prediction. In conclusion, there were obvious differences in both types and abundance of known miRNAs between root and leaf in maize.

[Identification of QTL associated with tassel branch number and total tassel length in maize].

On the basis of 103 SSR linkage map, QTLs associated with tassel branch number (TBN) and total tassel length (TTL) were studied by composite interval mapping with F3 families, which were developed from the cross N87-1 x 9526 and surveyed for phenotype under normal condition (CK) and drought-stress environment (DS). Four QTLs on chromosomes 2, 5, 7, and 10, respectively, were associated with TBN under DS, two of which were not only repeatedly detected on chromosomes 5 and 7 under the CK but also were linked to some QTLs related to drought tolerance that had already been reported in the same mapping population. The two QTLs controlling TTL were identified on chromosomes 2 and 6 under CK, while three QTLs for TTL were detected on chromosomes 2, 4, and 10 under DS. The QTL on chromosome 2 for TTL was consistent under two environments. Most of QTLs for TBN were partial additive while QTLs for TTL were dominant and over-dominant in terms of gene action.

[Initial identification of quantitative trait loci controlling resistance to banded leaf and sheath blight at elongating and heading date in maize].

The genetic linkage map was constructed with 146 SSR markers based on a maize population consisting of 229 F2 individuals from the cross R15 (resistant) x 478 (susceptible), covering 1666cM on a total of ten chromosomes, with an average interval length of 11.4 cM. The disease index from the population of 229 F24 lines were evaluated for BLSB resistance under artificial inoculation at elongating stage and heading date. With the method of composite interval mapping (CIM) described in QTL cartographer v2.0 procedure, 9 QTLs among of 17 QTLs were identified on 1, 2, 3, 4, 5, 6 and 10 chromosomes at Jointing Stage, accounting for 3.72% to 9.26% of the phenotypic variance. The other 10 QTLs were identified on 2, 3, 4, 5, 6, 8 and 9 chromosomes at elongating stage and heading date, accounting for 4.27% to 9.27% of the phenotypic variance. Among of them, two QTLs were detected at two stages, which were located between bnlgl600-umc1818 and umc1006-umc1723 on chromosome 2 and 6, respectively. The result indicated that the significant difference about QTL Controlling Resistance between the two stages had a close connection with Developing Stages, which was showed on the resistance of banded leaf and sheath blight in maize. So this result provided new information to the resistance breeding of maize.