Understanding the mechanism of cell cycle control in plants is important for agricultural technology enabling enhancement of growth rate and then crop yield. Progression of the cell cycle requires the cell cycle-dependent appearance of cell cycle regulatory proteins such as cyclin-dependent kinases (CDKs) and cyclins. These regulatory proteins are controlled at several levels, including expression,phosphorylation, and interaction with other regulatory proteins. Recently, it has become clear that the controlled and timed destruction of the proteins plays an essential role in cell cycle regulation and the 26S proteasome is involved in the destruction. For example, Cyc (cyclin) A, CycB, CycD, and B-type CDK are degraded by 26S proteasome in a cell cycle-dependent manner. In this review, recent advances in our understanding of cell cycle regulation through ubiquitin/proteasome-mediated proteolysis in plants are described.

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The authors propose a “rural hydrology" approach for investigating and planning of rural infrastructure build-up in the floodplain zone of Bangladesh. The rural hydrology approach, a form of “alternative engineering", requires the following minimal set of items; a motorcycle or bicycle, feet to walk around, an eye to see the real environmental conditions, an ear to listen to those who are informed of the local conditions, and a flexible mind to share with local people, in order to identify land and water conditions, constraints to development, and the real needs of the locality and local people. Here, a case study is documented. The dynamic hydrological environment of the Tangail district floodplain was analyzed at the level of the union and the results were proposed to be applied to formulate plans for building rural infrastructures. Based on the rural hydrological viewpoint, it is possible to understand a correct dynamic hydrology of the union level. It should be possible to make plans for soil mounded feeder roads, culverts and bridges, which do not disturb the hydrological balance and stability of crop production, using only reasonable labor instead of a great deal of labor and investment. “Rural hydrology" can be a practical proposition for rural development in less developed countries.

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Pericardial cells rapidly cleared recombinant-juvenile hormone esterase (rJHE) expressed within a baculovirus in insects from the hemolymph. To prevent the clearance of rJHE, we used the polymerase chain reaction (PCR) to remove the signal sequence from the JHE gene, thereby converting the enzyme to a non-secreted form (NSJHE). The resulting gene was expressed in a baculovirus (AcNSJHE) using HIGH-FIVE cells and proper cellular enzyme production was monitored. Transcription level of the NSJHE and rJHE were comparable, and purified NSJHE protein from the cytoplasm hydrolyzed JH. However, efficacy of NSJHE production was low. Enzyme-linked immunosorbent assays and enzyme assays demonstrated enzyme production and activity relative to rJHE of 0.5-1.7% and < 0.1%, respectively. Transmission electron microscopy (TEM) revealed that NSJHE was distributed in the nucleus predominantly and some NSJHE aggregated in clumps within the cytoplasm. These results indicate that NSJHE lacks a specific localization site within cells and that the folding of this enzyme is insufficient. Deglycosylation experiments using purified NSJHE showed that NSJHE was much less glycosylated than rJHE as we expected. Although the NSJHE was less glycosylated, enzyme stability of the NSJHE was equivalent to that of rJHE, indicating that the sugar chains are unimportant in the stability of JHE.

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In the central bank of the microorganisms section in the Ministry of Agriculture, Forestry and Fisheries (MAFF) Genebank in Tsukuba, 14,836 strains of fungi, bacteria, yeasts and others are preserved by various methods including cryopreservation and freeze-drying. To evaluate preservation techniques for these microorganisms, the viability of the preserved microorganisms was examined at regular intervals. Almost all tested strains, except for 5 strains out of 2,334 strains, of yeasts, bacteria and Actinomycetes were preserved well in freeze-dried form, indicating that freeze-drying is suitable for their preservation. As for fungi and Oomycetes, 6,578 strains out of 6,681 tested strains (98.5%) and 264 (63.8%) of 414, respectively, survived one-year preservation in the vapor phase of liquid nitrogen. The details on survival of the preserved fungal strains were as follows: 99.0% (1,107 strains/1,118 tested strains) survival in Ascomycota, 96.1% (1,552/1,615) in Basidiomycota, 98.6% (73/74) in Zygomycota, and 99.3% (3,846/3,874) in anamorphic fungi. Thus, cryopreservation is excellent for preservation of most fungus strains, but is not suitable for preservation of many Oomycetous strains.

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Bromide (Br^-) was used to successfully trace the infiltration of rainfall through a sandy soil in northeast Thailand. A method was developed to measure the Br^- concentration in extracted water from soil samples in order to determine the vertical distribution of the Br^- concentration in soil water. Our experimental results revealed that Br^- moved downward with a piston flow and that the increase in the amount of water in the soil above the depth of the peak Br^- concentration equaled the increase in soil moisture caused by the infiltration. Using our method, we found that the largest amount of rainfall infiltration occurred during September. The amount of soil water above the peak Br^- concentration was calculated to be about 0 mm during the period between June 27, 2003 and August 7, 2003; about 100 mm during the period between June 27, 2003 and September 10, 2003; and about 80 mm during the period between June 27, 2003 and February 12, 2004.

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The potential chemopreventive properties of the dietary fiber prepared from sweetpotato (Ipomoea batatas L.) roots were examined to promote the demand of this residue from the starch industry. Dietary fiber was prepared by treating starch granules-removed residue with α-amylase. The dietary fibers at 1% concentration enhanced the growth of Bifidobacterium adolescentis and Bifidobacterium breve in vitro among 5 species of Bifidobacterium, which exist in the human intestinal tract. Analysis of the components of these fibers suggested that their pectin and hemicellulose were concerned with a promotion effect on the growth of bifidobacteria. Water- and oil-holding capacity of the fibers in the varieties with orange-colored flesh was relatively superior to ones from the varieties with yellow- or purple-colored flesh. Furthermore, the dietary fibers adsorbed about 90% of the mutagen, Trp-P-1. Commercial sweetpotato fiber, a byproduct of citric acid production from the residue from the starch industry, had slight effect on the growth of bifidobacteria and was lower in adsorption capacity of Trp-P-1 than the fibers prepared from sweetpotato roots. These results indicate that the residue from the sweetpotato root starch industry is available as a dietary fiber with physiological functions.

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The acoustic characteristics of sound fresh tea leaves were determined nondestructively by ultrasonic transmission analysis. As thickness increases, phase velocity and wavelength increase, and damping ratio and dynamic viscosity decrease, suggesting development of the fibrous tissues, accompanied by frequency convergence. The velocities of all the leaves studied were smaller than that of pure water. Decrease in viscoelasticity corresponds to increase in dynamic modulus. Thus, acoustically, we can regard the leaves as natural quasi-polymers with high viscoelasticity.

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Human T-cell leukemia, CCRF-CEM, produced interleukin (IL)-2 stimulated with phorbol myristate acetate (PMA) and pokeweed mitogen (PWM). In PMA/PWM stimulation, IL-2 production in CCRF-CEM was increased by treatment with kaempferol or quercetin, tea (Camellia sinensis L.) flavonols. In this study, we concluded that (1) flavonols affected the expression of CCRF-CEM surface molecules, (2) CCRF-CEM was activated by flavonols, achieving a state receptive to stimulation, and (3) IL-2 production and mRNA expression were promoted by flavonols.

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The top canopy leaves of mature trees are exposed to high solar radiation, regardless of whether they are climax or pioneer trees. We compared leaf physiology and morphology at the top canopies of a climax Dipterocarpus cornutus tree and a pioneer Macaranga gigantea tree in a rainforest, East Kalimantan. The mass-based maximum net photosynthetic rate (Pn^max) and the nitrogen-based Pn^max for M. gigantea were 2.3-fold and 1.6-fold greater than those for D. cornutus, respectively. However, no significant difference in the area-based Pn^max between the two species was found, because of its thick lamina of D. cornutus. The dependency of net photosynthetic rate and stomatal conductance on leaf-to-air vapor pressure deficit did not differ between the two trees. Under high irradiance, effective quantum yield (∆F/Fm′) of photosystem II (PSII), photochemical quenching (qP), non-photochemical quenchings (qN and NPQ), and electron transport rate in PSII were significantly higher in M. gigantea than in D. cornutus. Under moderate irradiance, a hysteresis in chlorophyll fluorescence parameters between the morning and afternoon was found especially in D. cornutus, i.e., the fraction of qP within the PSII centers decreased and that of excess energy increased in the afternoon. These data indicate low light-use capacity and high susceptibility for excess light energy of PSII in D. cornutus. The leaf properties were different between the mature climax and pioneer trees, even if their leaves grew under similar light environments at the top canopies.

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The Alto Loica experimental site was established to achieve some understanding of the hydrological characteristics and the effects of afforestation on soil and water conservation in semi-arid regions in Chile. Hydrological measurements were taken in the 16.25-ha catchment for seven years. Because of the high variability of annual rainfall, there was a drought year in which streamflow disappeared throughout the year. As the catchment contains intermittent streams, mean annual baseflow is only 5.9% of mean annual rainfall, while mean annual evapotranspiration is 62.6% of that. The seasonal fluctuations of soil moisture storage suggest that moisture conditions during the period of December through March may be the driest ones for the growth of vegetation. While Horton overland flow occurs over grassy and shrub covered hillside during high rainfall intensities, it contributes largely to sharp hydrograph peaks. During large rainstorms, the mean runoff coefficient was more than 50%. Hence, measures to reduce overland flow are required for afforestation as well as soil and water conservation.

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