The Morphology of Fruits and Starches in Bamboos,and Its Relation to Systematic Position

In this article, 30 speceis of bamboos, including 19 genera in 5 tribes, were collected and the morphology of fruits and starches of them was studied. The results are as follows. I. The morphology of fruits is important in studies of systematic position in bamboos. According to the systems of W. Munro and G. Bentham whether the pericarp is adhesive to or free from the seed coat may be taken as a basis of classification. It is also confirmed in this article. It is found in this work that all taxa with a binding pericarp and seed coat are of caryopsis that also has a ventral suture and hilum, while all others with a separated pericarp and seed coat are of bacca or nut, which has no ventral suture and hilum. The former has a hard and thin pericarp and rich endosperm, while the latter has a fleshy and thick pericarp and no endosperm. These characteristics form a basis of classification of major groups. II. In 1907, Brandis found that no any endosperm in matured fruit of Dinochloa, Melocalamus, Melocanna and Ochlandra. It has been proved by Stapf in at least one genus. We found that the baccae of Qiongzhuea, Melocanna, Ferrocalamus and Chimonobambusa Subg. Oerocalama were empty, with no endosperm. This may be a common character of the bacca. We believe, therefore, that the systematic position of Qiongzhuea, Ferrocalamus and Chimonobambusa Subg. Oreocalama is close to Melocanneae. III. Starch grains of bamboo fruits are complex in structure. They are round or ellipsoidal, consisting of 3-22 polyhedral or apple-like small grains. The morphology of starch grains is not so important as fruit in bamboo classification, but some characteristics are of a high value in the identification of genera and species, when they are combined with other features. In Cephalostachyum, the starch grain is very big, with 20-40 μm in diam, and the starch small grain is polyhedral or apple-like with 7.5-22.5 μm in diam, while in Dendrocalamus, the starch grain is small, with 10-28.9 μm in diam. and the starch small grain is only polyhedral, with 3-11.9 μm in diam. The morphology and size of the starch grain and starch small grain are also different in Melocanna and Chimonobambusa Subg. Oreocalama. IV. W. Munro’s system divided Bambuseae into three major groups according to the morphology of flower and fruit. Because the material was not sufficient at that time, the system wrongly put Cephalostachyum, Dendrocalamus into the group Bacciferea. Now it is found that both Cephalostachyum and Dendrocalamus have a nut. Later G. Bentham found this problem and divided the Bambuseae into four subtribes, treating Dendrocalamus as a separate subtribe, Dendrocalamae, and putting the bacca group into another subtribe, Melocannae. It is better, but it also has some shortcomings. Hackel, Gamble, E. G. Camus, A. Camus and Keng Pojie all accepted the view of Bentham, placing Dendrocalamus and Melocanna into different subtribes or tribes.     

Solvation Energy and Thermal Stability of Hydrophilization-Modified α-Chymotrypsin

As reported in the literature [Mozhaev et al. (1988), Eur. J. Biochem. 173, 147–154], when a series of modifiers, especially the cyclic anhydrides of pyromellitic and mellitic acids, are introduced into each lysine located in the -chymotrypsin (CT) surface, a substantial hydrophilization of the enzyme surface can occur and remarkable stabilization effects of modified enzymes can be obtained. In this paper, four models are applied to calculate the solvation energy of native and the modified CT based on their tertiary structures, which can be built by the CVFF force field. Analyzing the relationship between the solvation energy and the thermal stability in detail, we find that the results of three solvation energy models (Ooi model, WE-1 model, and WE-2 model) can be used to illustrate the relative stability among these enzymes qualitatively. The present study should be of practical value as well as of some theoretical interest.     

Interspecific hybridization of <Emphasis Type="Italic">Prunus persica</Emphasis> with <Emphasis Type="Italic">P. armeniaca</Emphasis> and <Emphasis Type="Italic">P. salicina</Emphasis> using embryo rescue

Embryo rescue technique was used successfully to produce interspecific hybrids by crossing peach (P. persica) as a female parent with apricot (P. armeniaca) and plum (P. salicica). In those crosses that had ‘Yuhualu’ or ‘Zhonghuashoutao’ as female parents, hybrid embryos aborted from the 7th or 8th week after pollination mainly due to post-pollination incompatibility. An embryo rescue protocol was established to rescue such embryos and recover hybrid plants. Modified half-strength MS medium containing 4 mg l⁻¹ 6-BA and 0.5 mg l⁻¹ IBA produced up to 90% germination in the embryos. Modified MS medium with 1.0 mg l⁻¹ 6-BA and 1.0 mg l⁻¹ IBA gave the highest bud induction and multiplication whereas modified MS medium containing 0.5 mg l⁻¹ IAA and 0.2 mg l⁻¹ NAA gave the best rooting percentage. All the hybrids obtained using this embryo rescue technique were verified using simple sequence repeat (SSR) markers. A series of pollen treatments were carried out to partially overcome pre-pollination incompatibility, and it was found accidentally that pollen treatment with electrostatic field not only improved pollen germination but also increased the multiplication coefficient of embryo-induced shoots.     

Changing dendritic field size of mouse retinal ganglion cells in early postnatal development

During early postnatal development, dendrites of retinal ganglion cells (RGCs) extend and branch in the inner plexiform layer to establish the adult level of stratification, pattern of branching, and coverage. Many studies have described the branching patterns, transient features, and regulatory factors of stratification of the RGCs. The rate of RGC dendritic field (DF) expansion relative to the growing retina has not been systematically investigated. In this study, we used two methods to examine the relative expansion of RGC DFs. First, we measured the size of RGC DFs and the diameters of the eyeballs at several postnatal stages. We compared the measurements with the RGC DF sizes calculated from difference of the eyeball sizes based on a linear expansion assumption. Second, we used the number of cholinergic amacrine cells (SACs) circumscribed by the DFs of RGCs at corresponding time points as an internal ruler to assess the size of DFs. We found most RGCs exhibit a phase of faster expansion relative to the retina between postnatal day 8 (P8) and P13, followed by a phase of retraction between P13 and adulthood. The morphological α cells showed the faster growing phase but not the retraction phase, whereas the morphological ON–OFF direction selective ganglion cells expanded in the same pace as the growing retina. These findings indicate different RGCs show different modes of growth, whereas most subtypes exhibit a fast expansion followed by a retraction phase to reach the adult size. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 70: 397–407, 2010     

SAR and molecular mechanism study of novel acylhydrazone compounds targeting HIV-1 CA

We synthesized a series of acylhydrazone compounds bearing naturally occurring amino acids’ side chains as HIV assembly inhibitors. Biological evaluation indicated that the compounds had anti-SIV and capsid assembly inhibitory activities. The structure–activity relationship (SAR) study showed that compounds bearing proper aromatic side chains had potential antiviral activities. The molecular modeling experiments revealed the molecular mechanism that they could bind to CA in the same manner as CAP-1 and occupy two more grooves.     

Microbial Electricity Generation Enhances Decabromodiphenyl Ether (BDE-209) Degradation

Due to environmental persistence and biotoxicity of polybrominated diphenyl ethers (PBDEs), it is urgent to develop potential technologies to remediate PBDEs. Introducing electrodes for microbial electricity generation to stimulate the anaerobic degradation of organic pollutants is highly promising for bioremediation. However, it is still not clear whether the degradation of PBDEs could be promoted by this strategy. In this study, we hypothesized that the degradation of PBDEs (e.g., BDE-209) would be enhanced under microbial electricity generation condition. The functional compositions and structures of microbial communities in closed-circuit microbial fuel cell (c-MFC) and open-circuit microbial fuel cell (o-MFC) systems for BDE-209 degradation were detected by a comprehensive functional gene array, GeoChip 4.0, and linked with PBDE degradations. The results indicated that distinctly different microbial community structures were formed between c-MFCs and o-MFCs, and that lower concentrations of BDE-209 and the resulting lower brominated PBDE products were detected in c-MFCs after 70-day performance. The diversity and abundance of a variety of functional genes in c-MFCs were significantly higher than those in o-MFCs. Most genes involved in chlorinated solvent reductive dechlorination, hydroxylation, methoxylation and aromatic hydrocarbon degradation were highly enriched in c-MFCs and significantly positively correlated with the removal of PBDEs. Various other microbial functional genes for carbon, nitrogen, phosphorus and sulfur cycling, as well as energy transformation process, were also significantly increased in c-MFCs. Together, these results suggest that PBDE degradation could be enhanced by introducing the electrodes for microbial electricity generation and by specifically stimulating microbial functional genes.     

Plant-Plant-Microbe Mechanisms Involved in Soil-Borne Disease Suppression on a Maize and Pepper Intercropping System

Background

Intercropping systems could increase crop diversity and avoid vulnerability to biotic stresses. Most studies have shown that intercropping can provide relief to crops against wind-dispersed pathogens. However, there was limited data on how the practice of intercropping help crops against soil-borne Phytophthora disease.

Principal Findings

Compared to pepper monoculture, a large scale intercropping study of maize grown between pepper rows reduced disease levels of the soil-borne pepper Phytophthora blight. These reduced disease levels of Phytophthora in the intercropping system were correlated with the ability of maize plants to form a “root wall” that restricted the movement of Phytophthora capsici across rows. Experimentally, it was found that maize roots attracted the zoospores of P. capsici and then inhibited their growth. When maize plants were grown in close proximity to each other, the roots produced and secreted larger quantities of 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) and 6-methoxy-2-benzoxazolinone (MBOA). Furthermore, MBOA, benzothiazole (BZO), and 2-(methylthio)-benzothiazole (MBZO) were identified in root exudates of maize and showed antimicrobial activity against P. capsici.

Conclusions

Maize could form a “root wall” to restrict the spread of P. capsici across rows in maize and pepper intercropping systems. Antimicrobe compounds secreted by maize root were one of the factors that resulted in the inhibition of P. capsici. These results provide new insights into plant-plant-microbe mechanisms involved in intercropping systems.     

Peripheral Blood Mitochondrial DNA Copy Number Is Associated with Prostate Cancer Risk and Tumor Burden

Alterations of mitochondrial DNA (mtDNA) have been associated with the risk of a number of human cancers; however, the relationship between mtDNA copy number in peripheral blood leukocytes (PBLs) and the risk of prostate cancer (PCa) has not been investigated. In a case-control study of 196 PCa patients and 196 age-paired healthy controls in a Chinese Han population, the association between mtDNA copy number in PBLs and PCa risk was evaluated. The relative mtDNA copy number was measured using quantitative real-time PCR; samples from three cases and two controls could not be assayed, leaving 193 cases and 194 controls for analysis. PCa patients had significantly higher mtDNA copy numbers than controls (medians 0.91 and 0.82, respectively; P<0.001). Dichotomized at the median value of mtDNA copy number in the controls, high mtDNA copy number was significantly associated with an increased risk of PCa (adjusted odds ratio  = 1.85, 95% confidence interval: 1.21–2.83). A significant dose-response relationship was observed between mtDNA copy number and risk of PCa in quartile analysis (P_trend = 0.011). Clinicopathological analysis showed that high mtDNA copy numbers in PCa patients were significantly associated with high Gleason score and advanced tumor stage, but not serum prostate-specific antigen level (P = 0.002, 0.012 and 0.544, respectively). These findings of the present study indicate that increased mtDNA copy number in PBLs is significantly associated with an increased risk of PCa and may be a reflection of tumor burden.