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To further study the floral organogenesis and discussing the floral origin of Phytolacca, the procedures of floral organogenesis were observed in Phytolacca esculenta and Phytolacca zhejiangensis. The results showed that the floral organogenesis was consistent in Phytolacca. Their sepals were 2/5 helix, and with counter-clockwise and clockwise, usually the first sepal located at non-median of abaxial side. The first sepal of Phytolacca esculenta was initiated at non-median of adaxial side. There was no evident relationship between sepal and stamen initiating position, and the stamens initiated on ring meristem, they initiated approximately at the same time, and when the androecium member was numerous, they initiated centrifugally, the outer stamen initiated irregularly. Carpel initiated alternately with inner stamens. And the carpels connected by septum, if the septum grew more, the carpel was syncarpous at morphology, otherwise the carpel was apocarpous at morphology. So the syncarpous and the apocarpous have no successively relationship on evolution. Ovule initiated inside the carpel and opposite to carpel. Androecium, carpel and ovule initiated at ring meristem.

The ubiquitin/proteasome pathway represents one of the most important proteolytic systems in eukaryotes and has been proposed as being involved in pollen tube growth, but the mechanism of this involvement is still unclear. Here, we report that proteasome inhibitors MG132 and epoxomicin significantly prevented Picea wilsonii pollen tube development and markedly altered tube morphology in a dose- and time-dependent manner, while hardly similar effects were detected when cysteine-protease inhibitor E-64 was used. Fluorogenic kinetic assays using fluorogenic substrate sLLVY-AMC confirmed MG132-induced inhibition of proteasome activity. The inhibitor-induced accumulation of ubiquitinated proteins (UbPs) was also observed using immunoblotting. Transmission electron microscopy revealed that MG132 induces endoplasmic reticulum (ER)-derived cytoplasmic vacuolization. Immunogold-labeling analysis demonstrated a significant accumulation of UbPs in degraded cytosol and dilated ER in MG132-treated pollen tubes. Fluorescence labeling with fluorescein isothiocyanate-phalloidin and β-tubulin antibody revealed that MG132 disrupts the organization of F-actin and microtubules and consequently affects cytoplasmic streaming in pollen tubes. However, tip-focused Ca2+ gradient, albeit reduced, seemingly persists after MG132 treatment. Finally, fluorescence labeling with antipectin antibodies and calcofluor indicated that MG132 treatment induces a sharp decline in pectins and cellulose. This result was confirmed by Fourier transform infrared analysis, thus demonstrating for the first time the inhibitor-induced weakening of tube walls. Taken together, these findings suggest that MG132 treatment promotes the accumulation of UbPs in pollen tubes, which induces ER-derived cytoplasmic vacuolization and depolymerization of cytoskeleton and consequently strongly affects the deposition of cell wall components, providing a mechanistic framework for the functions of proteasome in the tip growth of pollen tubes.

With a pot culture of simulated mercury (Hg) and cadmium (Cd)-polluted wetland, this paper studied the capability of Arundo donax in accumulating these heavy metals, and their distribution in the plant. The results showed that after grown in a 101 mg.kg(-1) Hg-polluted wetland for 8 months, the Hg-concentrating capability of Arundo donax was in order of rootstemleaf, and the Hg concentration in its aboveground parts was 200 +/- 20 mg.kg(-1) (DW); while in the case of 115 mg.kg(-1) Cd-pollution, the Cd-concentrating capability was in order of leafrootstem, and the Cd concentration in leaf was 160 +/- 26 mg.kg(-1) (DW). The heavy metals concentration in Arundo donax organs increased with its growth time, being 30%-50% higher for 8 months than for 4 months. The BCF (Bio-concentration factor) decreased with increasing heavy metals concentration. In polluted wetland, the BCFs of Hg by the leaf and stem were 1.9 and 2.1, and those of Cd were 1.5 and 0.3, respectively; while in unpolluted wetland, the concentration of Hg and Cd was 6.8 and 8.5 mg.kg(-1), the BCFs of Hg by the leaf and stem were 6.8 and 12.2, and those of Cd were 7.0 and 2.7, respectively. It was indicated that Arundo donax not only had the characters of large biomass, exuberant root, and good adaptability, but also exhibited high tolerance and concentrating capability to Cd and Hg.

This paper studied the tolerance of Arundo donax grown in a simulated heavy metals polluted wetland, and determined the biological characters and chlorophyll contents of the plant at its different growth stages as well as the changes of soil heavy metals contents. The results showed that Arundo donax could survive in the wetland when the concentrations of Cu2+, Pb2+, Cd2+, Zn2+, Ni2+ and Hg2+ were 100 mg x kg(-1) and Cr6+ concentration was 50 mg x kg(-1). During 40 days growth period, the chlorophyll content decreased by 20%-56% and the leaf became soft with its tip withered, but the plant still grew. Compared with control, Arundo donax in the polluted wetland was slight and yellow-green, but the impact on plant height was inconspicuous. Arundo donax treated with 100 mg x kg(-1) Cr6+ grew slowly with its root stock rotted, and its leaves withered in a short time, indicating that the plant could not tolerate the pollution of high concentration Cr6+. The concentrations of soil heavy metals declined with the growth of the plant, probably due to the translocation of heavy metals from peripheral soil to rhizosphere and the phytoextraction and phytovolatilization, because the heavy metals contents in rhizosphere were much higher than those in the bulk soil in the test jar. The characters of large biomass, exuberant root and good adaptability of Arundo donax suggested its great potential in remediation of polluted soils. The study on the application of Arundo donax to phytoremediation is of realistic significance.

Aloe plants are the succulents mainly distributed in arid or semi-arid desert in South Africa. TLC analysis indicated that Aole arborescens and Aloe hereroensis contained the high concentration of phenolic derivative metabolites, anthraquinones such as barbaloin, homonataloin, aloeresin and aloenin. In younger leaf, L3 of A. hereroensis, the average content of 4 anthraquinones reached 44.9% of the dry weight of exudates. The similar distribution of the anthraquinones in the two species were found, which showed that the youngest leaves had the highest content, the top part of each leaf had the highest content, and the basal part had the lowest content. Along leaf margin, the content was higher than that of central parts. However, some different distributions were also revealed and compared between the two species. It was inferred that the special distribution of anthraquinones in Aloe was a chemical defense strategy for protection themselves.

SUMMARY An analysis was made of recent observations of solar radiation receipt in upland areas and the longer term data of hours of bright sunshine. Estimates were made of the means and spatial variabilities of these quantities in upland regions of the U.K. It is concluded that: (1) There is a decrease in solar radiation receipt, with increasing altitude, of 2-5-3 MJ m-2 day - km -. This is due to increased cloud cover and is probably more dependent on regional mean altitude than on the altitude of the station. (2) The altitudinal gradient of sunshine duration is 1-3 hour day - km-'. Given the uncertainties in the relationship between sunshine and solar radiation, this value is consistent with the observed gradient of solar radiation. (3) In cloudless conditions, solar radiation increases by approximately 15%. per 1000 m; this is the value which would be expected theoretically from the scattering of solar radiation by aerosol and water vapour. (4) Above 1000 m, the land is frequently above the level of the cloud tops, at least in the summer, so that solar radiation receipt is as much as 35 % greater on the summit of Cairngorm.