Micropropagation of Penthorum chinense through axillary buds.

Penthorum chinense Pursh is a traditional medicinal herb in China. Micropropagation protocol of this plant has been established. The shoot induction rate is high by culturing nodal explants on Murashige and Skoog (MS) medium supplemented with 6-benzyladenine (BA) as compared with kinetin (Kn). After 6 wks, the highest shoot formation (5.2) is achieved in 59.2% nodal explants cultured on MS medium combined with 2.0 mg/L BA. After 4 wk of subculture on the fresh MS medium, the highest shoot multiplication rate 6.4 is accomplished. MS medium containing 1.0 mg/L BA is most suitable for shoot propagation. Individual well developed shoots (0.8-to 1.0-cm long) are excised and culture on the MS medium containing with 0.5 mg/L indole-3-acetic acid (IAA), for rooting. Three weeks later, 98.8% of shoots had rooted with an average of ten roots per shoot. Plantlets transferred to soil were successfully acclimatized. This protocol will facilitate the conservation and propagation of this important medicinal plant.

cDNA, genomic sequence cloning and overexpression of ribosomal protein S25 gene (RPS25) from the Giant Panda.

RPS25 is a component of the 40S small ribosomal subunit encoded by RPS25 gene, which is specific to eukaryotes. Studies in reference to RPS25 gene from animals were handful. The Giant Panda (Ailuropoda melanoleuca), known as a "living fossil", are increasingly concerned by the world community. Studies on RPS25 of the Giant Panda could provide scientific data for inquiring into the hereditary traits of the gene and formulating the protective strategy for the Giant Panda. The cDNA of the RPS25 cloned from Giant Panda is 436 bp in size, containing an open reading frame of 378 bp encoding 125 amino acids. The length of the genomic sequence is 1,992 bp, which was found to possess four exons and three introns. Alignment analysis indicated that the nucleotide sequence of the coding sequence shows a high homology to those of Homo sapiens, Bos taurus, Mus musculus and Rattus norvegicus as determined by Blast analysis, 92.6, 94.4, 89.2 and 91.5%, respectively. Primary structure analysis revealed that the molecular weight of the putative RPS25 protein is 13.7421 kDa with a theoretical pI 10.12. Topology prediction showed there is one N-glycosylation site, one cAMP and cGMP-dependent protein kinase phosphorylation site, two Protein kinase C phosphorylation sites and one Tyrosine kinase phosphorylation site in the RPS25 protein of the Giant Panda. The RPS25 gene was overexpressed in E. coli BL21 and Western Blotting of the RPS25 protein was also done. The results indicated that the RPS25 gene can be really expressed in E. coli and the RPS25 protein fusioned with the N-terminally his-tagged form gave rise to the accumulation of an expected 17.4 kDa polypeptide. The cDNA and the genomic sequence of RPS25 were cloned successfully for the first time from the Giant Panda using RT-PCR technology and Touchdown-PCR, respectively, which were both sequenced and analyzed preliminarily; then the cDNA of the RPS25 gene was overexpressed in E. coli BL21 and immunoblotted, which is the first report on the RPS25 gene from the Giant Panda. The data will enrich and supplement the information about RPS25, which will contribute to the protection for gene resources and the discussion of the genetic polymorphism.

Optimizing the shoot proliferation protocol of Penthorum chinense by axillary buds.

Four parameters, three hormones and sucrose, at seven concentrations, were designed for shoot proliferation of Penthorum chinense by uniform design. The obtained data were used for building two quadratic polynomial equations by partial least square to determine optimum concentrations of four factors. Experiments for verification confirmed that no significant difference existed between the predicted and the validated values in shoot number and length based on all inoculated explants.

[Growth and propagation of wild Pinellia ternata in cultivation].

OBJECTIVE: To study the growth and propagation of Pinella ternata in cultivation. METHOD: Forty six populations of P. ternata originated from Sichuan, Shanxi province and chongqing city were collected and cultivated in experimental field under the same cultivation condition. RESULT AND CONCLUSION: Reproduction tubers at the weight of 0.51-2.00 g (diameter 0.9 - 1.5 cm) had higher increments of tubers and general weight. The P. ternata populations originated from Peng-an county, Shehong county, Zhongjiang county, Lezhi county, Lu county grew faster, on the other hand, the populations originated from Lezhi county, Guangyuan county, Peng-an county, Jianyang county had stronger ability of propagation. The sprouting rate of above 0.30 g (diameter 0.7 cm) tubers was about 90%. There was no significant difference in the growth between tubers and bulbils that have the same weight. The two factors that affected the yield increment were weight range and population, and the former was the main one. Significantly positive correlations were found between weight of reproduction tuber and weight of harvested tubers, number of bulbils. However, significantly negative correlations were found between weight of reproduction tuber and weight increments of tubers, increments proportion of tubers and general weight, and a negative correlations was found between weight of reproduction tuber and general weight increments. Curve-estimated models were conjectured about the weight of reproduction tuber and growth or propagation parameters such as the diameter, the sprouting rate, increments of tubers and general weight, increments proportion of tubers and general weight and the number of bulbils. Some proposals to improve the cultivation of P. ternate were suggested.

Genetic mapping of a mutant gene producing three pistils per floret in common wheat.

A common wheat (Triticum aestivum L.) mutation that produces 3 pistils (TP) per floret may result in formation of up to 3 kernels per floret. The TP trait may be important for increasing the number of grains per spike and for improving the yield potential through breeding. This trait is determined by the dominant Pis1 gene. Genetic mapping of Pis1 involved 234 microsatellite markers and bulk segregant analysis of a cross of the TP line with Novosibirskaya 67. The Pis1 gene is located on chromosome 2DL, between markers Xgwm539 and Xgwm349. This result does not agree with a previously published localization of the Pis1 gene on chromosome 5B. The possible importance of TP wheat as an alternative genetic resource is discussed.

Nucleotide sequence of cDNA encoding the mitochondrial precursor protein of the ATPase inhibitor from the giant panda (Ailuropoda melanoleuca).

Mitochondrial ATP synthase (F1Fo-ATPase) is regulated by an intrinsic ATPase inhibitor protein. In the present study, using RT-PCR combined with in silico cloning, we isolated and sequenced the cDNA encoding the inhibitor protein of the giant panda (Ailuropoda melanoleuca). The deduced protein sequence showed that the protein is composed of 106 amino acids and the estimated molecular weight of the ATPIF(1) protein is 12.32 kDa with an isoelectric point (pI) of 10.17. Alignment analysis revealed that the deduced protein sequence shares 66%, 78.3%, 66%, 72.6%, 77.4%, and 78.3% homology with that of Mus musculus, Pan troglodytes, Rattus norvegicus, Bos taurus, Macaca mulatta, and Homo sapiens, respectively. Topology prediction showed that there are three protein kinase C phosphorylation sites, one amidation site, three N-myristoylation sites, one casein kinase II phosphorylation site, and one tyrosine kinase phosphorylation site in the ATPase inhibitor. In particular, amino acids in the region between 39 and 72, which is the minimum sequence showing ATPase inhibitory activity, were highly conserved in the protein.

A complete mitochondrial genome sequence of Asian black bear Sichuan subspecies (Ursus thibetanus mupinensis).

We obtained the complete mitochondrial genome of U.thibetanus mupinensis by DNA sequencing based on the PCR fragments of 18 primers we designed. The results indicate that the mtDNA is 16,868 bp in size, encodes 13 protein genes, 22 tRNA genes, and 2 rRNA genes, with an overall H-strand base composition of 31.2% A, 25.4% C, 15.5% G and 27.9% T. The sequence of the control region (CR) located between tRNA-Pro and tRNA-Phe is 1422 bp in size, consists of 8.43% of the whole genome, GC content is 51.9% and has a 6bp tandem repeat and two 10bp tandem repeats identified by using the Tandem Repeats Finder. U. thibetanus mupinensis mitochondrial genome shares high similarity with those of three other Ursidae: U. americanus (91.46%), U. arctos (89.25%) and U. maritimus (87.66%).

[Epigenetic phenomena of plant polyploids].

Epigenetic phenomena, heritable changes in phenotype, and hence in gene regulation, but not in DNA sequence, occur in the process of polyploidization in many plants. These phenomena include gene silencing, DNA methylation, nucleolar dominance, transposable elements activation and genomic imprinting. Epigenetic phenomena might be caused by gene silencing or alternative gene expression from intergenomic interaction. These could also be induced from the changes of histone coding, without DNA methylation. Furthermore, hypomethylation, chromatin reconstitution or transposable element activation could contribute to epigenetic phenomena. These modifications may give rise to the diversification of gene expressing, to the genetic and cytological diploidization, as well as to intergenomic coordination. This paper reviews epigenetic phenomena in many plants and their influence on evolution of plant genome, thus hint the likely pathway of research in this field.

Characterization of the common wheat (Triticum aestivum L.) mutation line producing three pistils in a floret.

In a normal wheat (Triticum ssp.L.) spike, one floret carries only one pistil that will further develop into one grain after fertilization. The cultivated common wheat (T. aestivum L.) mutation line Three Pistils (TP) carried three pistils in a floret. Although one or two of the pistils died out before seed set in some florets, there were exist many florets that set three seeds. Normally, it was observed that there were one to three seeds in different florets of the same spike. Therefore, this mutation trait could raise considerably the number of grains per spike. The weight of 100 grains in three seeds set florets was lower than that of in one seed set florets. But three seeds set florets were significantly to surpass the one seed set florets in grain(s) weight per floret. Based on these results, the three pistils trait was suggested to be an interesting germplasm resource. Localisation of the gene controlling the three pistils trait was carried out by the method of crossing TP with the Chinese Spring disomic substitutions. F2 population segregation analysis revealed that only the 5B F2 population did not show homogeneity to control population. chi2-test analysis indicated that 5B F2 population, and only this population, was deviated from the Mendelian segregation ratio (3:1). As a conclusion, the gene for three pistils trait was located on chromosome 5B. According to the Recommended rules for gene symbolization in wheat, the name of the dominant gene for three pistils trait in the line TP was suggested as Pis1.

[Progress on research of rapid propagation system of Pinellia ternata].

OBJECTIVE: To improve the rapid propagation system of Pinellia ternata. METHOD: Documentaries at home and abroad were consulted. RESULT: The tissue culture's conditions and research results of P. ternata were summarized. CONCLUSION: Advanced research on the structure of calli and litter tubercle should be made. Traditional rapid propagation system may be improved from the following aspects: the best cooperation of hormones, the most active ex-plant, one time culture and suitable transplant.