Yoshinobu Kawamitsu

Molecular cloning and functional characterization of two kinds of betaine-aldehyde dehydrogenase in betaine-accumulating mangrove Avicennia marina (Forsk.) Vierh.

Glycinebetaine is an important osmoprotectant in bacteria, plants, and animals, but only little information is available on the synthesis of glycinebetaine in tree plants. Among four mangrove species, glycinebetaine could be detected only in Avicennia marina. Pinitol was the main osmoprotectant in the other three species. The level of glycinebetaine in A. marina increased under high salinity. Betaine-aldehyde dehydrogenase (BADH) was detected in all four species, but choline monooxygenase could not be detected. A cDNA library was constructed from the leaves of A. marina. Two kinds of BADH cDNAs were isolated, one homologous to the spinach chloroplast BADH, and the other with unique residues SKL at the end of C-terminus. The BADH transcription levels of the former were higher than those of the latter. The levels of the former BADH increased at high salinity whereas those of the latter were independent of salinity. BADHs were expressed in Escherichia coli and purified. Two kinds of A. marina BADHs exhibited similar kinetic and stability properties, but were significantly different from those of spinach BADH. A. marina BADHs efficiently catalyzed the oxidation of betainealdehyde, but not the oxidation of ω-aminoaldehydes and were more stable at high temperature than the spinach BADH.

Water Status of Flower Buds and Leaves as Affected by High Temperature in Heat-Tolerant and Heat-Sensitive Cultivars of Snap Bean (Phaseolus vulgaris L.)

Abstract In snap bean {Phaseolus vulgaris L.), flower and pod abscission causes yield reduction under high-temperature conditions. A high temperature enhances transpiration and thus may induce temporal water deficiency in plants in the daytime. The objective of this study was to clarify the effect of a high temperature on the water status of floral organs at their most heat-sensitive stage. We compared the water potential and its components as well as gas exchange between the heat-tolerant cultivar, Haibushi, and heat-sensitive cultivar, Kentucky Wonder, grown under optimal (control) and high-temperature conditions. Haibushi showed higher pollen fertility under high temperature than Kentucky Wonder. Transpiration was enhanced under a high temperature, causing decrease of water potential in leaves and flower buds. The deterioration of water status in floral organs was larger in Kentucky Wonder than in Haibushi. We conclude that temporal deterioration of the water status in flower buds is one of the factors causing pollen damage.

PRESSURE SHOCKWAVES TO ENHANCE OIL EXTRACTION FROM JATROPHA CURCAS L

ABSTRACT Kinetic data regarding the intensity of maceration and subsequent pretreatment with pressure shockwaves (50 MPa to 60 MPa) are described in detail and evaluated statistically. Mass balances as well as the study on liquid environment are reported, allowing further process optimization according to financial aspects. It was verified on a laboratory scale by Soxhlet apparatus that oil extraction over 94% may be reached. Achieving such a high level of disintegration opens wide options for application of hydrolysis in order to break apart the remaining lignocellulose cell walls and access the last oil remaining in the vacuoles.

Commercial-scale utilization of greenhouse residues

Development of techniques utilizing waste without any additional energy or rare catalysts is a starting point for becoming sustainable. In the present work, the complex utilization of greenhouse residues was studied on a commercial scale. Only the energy produced by the process (8%) was used to run the technology, thanks to multilevel heat recuperation and high methane yields (over 340 m3 volatile solid t−1). Manifestations of labile carbon in relation to available nitrogen, methane yields, and the formation of inhibitors were investigated in detail. The results sweep away many false beliefs about the ratios of carbon to nitrogen and highlight the role of the availability of carbon in phytomass utilization.

The use of underwater high-voltage discharges to improve the efficiency of Jatropha curcas L. biodiesel production.

Underwater high‐voltage discharges (3.5 kV) resulting in 4.9 kJ shock waves (50–60 MPa) were studied at the laboratory scale as a Jatropha curcas L. seed disintegration method. Grinding and macerating in an excess of methanol (3.5:1) was advantageous because methanol acts both as a liquid carrier for the pressure shock waves and as a solvent that increases the efficiency of oil extraction while remaining usable for esterification. The influence of the number of shock waves and the intensity of methanol maceration on the heat values of the pressed cake are stated in detail. Soxhlet extraction demonstrated that a greater than 94% oil extraction was achieved. The increased disintegration of vacuoles rich in oil was documented by surface area analysis, mineralization kinetics analysis, and electron microscopy. The working volumes were small, and the proportion of energy inadequate compared to the yields released; however, much can be improved by upgrading the process.

Effect of NaCl on the Photosynthesis, Water Relations and Free Proline Accumulation in the Wild Oryza Species

Summary The physiological responses of wild Oryza species (Oryza latifolia Desv., a salt-tolerant species and O. rufipogon Griff., a salt-susceptible species) to salinity stress were investigated by comparing with check varieties of cultivated rice (O. sativa L.), SR26B (salt-tolerant) and IR28 (salt-susceptible). As the NaCl concentration of water culture solution was raised to 12 dS m–1 (about 113mM), leaf Na+ content per dry matter in wild Oryza species increased from 4 to 17 times as compared with the control (no NaCl treatment), whereas the accumulation was lower in cultivated rice varieties. The increased concentration of leaf Na+ resulted in the decrease in leaf water potential (Ψw) in all rice species, although the degree of decline in photosynthetic rate was different among the varieties. It was notable that the photosynthetic rate was cdmost constant in O. latifolia though Ψw decreased to – 2.0 MPa with the increased NaCl concentration in the water culture solution. A significant negative correlation between free-proline content and osmotic potential (Ψs) of leaf blade was found in both salt tolerant entries, SR26B and O. latifolia. In spite of higher leaf Na+ storage, the survival rate of O. latifolia was higher than that of SR26B, indicating that the mechanism of salt tolerance in O. latifolia may be different from that in SR26B.

High-susceptibility of photosynthesis to photoinhibition in the tropical plant Ficus microcarpa L. f. cv. Golden Leaves.

BackgroundThe tropical plant Ficus microcarpa L. f. cv. Golden Leaves (GL) is a high-light sensitive tropical fig tree in which sun-leaves are yellow and shade-leaves are green. We compared the response of photosynthetic activities to strong light between GL and its wild-type (WT, Ficus microcarpa L. f.).ResultsField measurements of maximum photosystem II (PSII) efficiency (Fv/Fm) of intact sun-leaves in GL showed that photo synthetic activity was severely photoinhibited during the daytime (Fv/Fm = 0.46) and subsequently recovered in the evening (Fv/Fm = 0.76). In contrast, WT did not show any substantial changes of Fv/Fm values throughout the day (between 0.82 and 0.78). Light dependency of the CO2 assimilation rate in detached shade-leaves of GL showed a response similar to that in WT, suggesting no substantial difference in photosynthetic performance between them. Several indicators of photoinhibition, including declines in PSII reaction center protein (D1) content, Fv/Fm value, and O2 evolution and CO2 assimilation rates, all indicated that GL is much more susceptible to photoinhibition than WT. Kinetics of PAM chlorophyll a fluorescence revealed that nonphotochemical quenching (NPQ) capacity of GL was lower than that of WT.ConclusionWe conclude that the photosynthetic apparatus of GL is more highly susceptible to photoinhibition than that of WT.

Automated Quality Evaluation System for Net and Gross Sugarcane Samples Using near Infrared Spectroscopy

Sugar content is the most important index of sugarcane quality in the payment system. A quality evaluation technique for shredded sugarcane was investigated using an automatic and high-speed near infrared (NIR) spectroscopy system. In this study, net and gross canes were tested in order to assess the potential for labour saving and cost reduction by the NIR measurement. NIR reflectance spectra ranging from 1100 nm to 2498 nm were collected to evaluate the cane quality of the shredded cane. A calibration equation for the pol in cane (PIC) of net cane was developed using a modified partial least squares (MPLS) regression. The accuracy of the PIC calibration for net cane was satisfactory with standard errors of prediction (SEP) of 0.21% and a bias of −0.06% in the range 1100–1848 nm wavelength. To eliminate the trash removal, a PIC calibration for gross cane was also examined. Results of the PIC calibration in the 1100–1848 nm wavelength range showed the highest accuracy (SEP=0.46%, bias=0.01%), although the accuracy for gross cane was lower than that for net cane. The NIR instrument could be used as an evaluation tool for the quality of net and gross sugarcane in a practical payment system.

Field Performance of In vitro-propagated and Sucker-derived Plants of Banana(Musa spp.)

Summary The field performance of in vitro-propagated banana (Musa spp.) plants was compared with that of the sucker-derived plants. In vitro-propagated plants established and grew faster, taller and bigger than the conventional sucker-derived plants. The former produced more leaves resulting in a larger total leaf area (8001.5 cm2 per plant) than the latter (6613.1 cm2 per plant) and could be harvested earlier. The former also produced heavier bunches and fruit (15.2 kg for bunch and 200 g per finger of fruit) than the latter (9.0 kg for bunch and 136.4 g per finger of fruit). In this experiment, the in vitro-propagated plants had many intact roots and a bulk of vermiculite around their roots but the sucker-derived plants had many damaged roots at the time of planting. In addition, in vitro-propagated plants started growth earlier and grew faster enabling them to intercept more light for photosynthesis than the sucker-derived plants. This may explain the higher yield in the in vitro-propagated plants. We conclude that in vitro-propagated Shima banana performs better in terms of growth and yield than the sucker-derived plants under field conditions.

A System for the Measurement of Vertical Gradients of CO2, H2O and Air Temperature within and above the Canopy of Plant

Absract This technical report describes a gradient system for characterizing the vertical gradients of CO2, H2O, and air temperature within and above the canopy of plants. The system is low in cost and easy to use. The instruments were fitted and placed in one box with a total weight of about 10 kg. The box can be carried and moved from one site to another. The features of this apparatus are high frequency sampling cycle as short as 1 min per cycle for all six measurement levels and fast response gas analyzer for measurement as short as 10s per level. Two exhaust pumps, one sampling pump, six 3-way solenoid valves, and flow meter were used to insure simultaneous flow rate of air in all tubes from all measurement levels. This system transfers data from the data-logger directly to the add-in Spreadsheet of Microsoft Excel by using an Ethernet cable to automatically convert digital data to scientific units in less time. This system also allows the use of multiple micro-environmental sensors that can be sampled at the same time. It is useful not only for agricultural ecosystems but is also adequately sensitive and rapidly responds to the gas analyzer with a modifiable flow rate meter for use in forest ecosystems. This system also has potential for use in the measurement of CO2, H2O, associated environmental elements, and CO2 storage flux within the canopy of plant, and other processes including a CO2 sink and source.