Intake of Radionuclides in the Trees of Fukushima Forests 5. Earthquake Could Have Caused an Increase in Xyloglucan in Trees

A megathrust earthquake caused the Fukushima–Daiichi nuclear power plant accident, which dispersed abundant radioiodines, causing them to be bound to xyloglucan into forest trees. Nevertheless, targeted xyloglucan was found in increased quantities in the annual rings of forest trees affected by the earthquake. We propose that trees could acclimate rapidly to shaking stress through an increase in xyloglucan deposition as a plant response under natural phenomena

Intake of Radionuclides in the Trees of Fukushima Forests 3. Removal of Radiocesium from Stem Wood, Cryptomeria Japonica (L.f.) D. Don.

Nuclear power plant accidents have dispersed radiocesium into the atmosphere to contaminate trees with no turnover in heartwood, as occurred in Fukushima, and as has persisted for over 30 years around Chernobyl. Here we employ the ponding method, in which radiocesium can be flushed out from the cross-cut edges of Japanese cedar, Cryptomeria japonica (L.f.) D. Don., stem with water due to xyloglucan degradation in tracheids. Furthermore, lab-scale ponding experiments have shown that a non-detectable level of radiocesium has been observed not only in the pool water used for 575 days but also in the water containing recombinant xyloglucanase. This traditional technology is now a new biotechnology

Intake of Radionuclides in the Trees of Fukushima Forests 4. Binding of Radioiodine to Xyloglucan

The 1, 4-linked glucans such as xyloglucan and amylose are known to form a complex with iodine/iodide ions and to also be precipitated with CaCl2 in the presence of iodine. Here, we show that iodine gas could be specifically incorporated into xyloglucan. Furthermore, we show that [125I]I2 gas is, over time, incorporated at high levels into the entire outer surface of poplar seedlings but that spraying seedlings with abscisic acid to close stomata decreases the incorporation of the gas. There was less incorporation of the gas in a transgenic poplar overexpressing xyloglucanase at the early stages when compared with a wild type. This shows that xyloglucan serves as a key absorber of iodine gas into a plant body. After individual leaves of cultured seedlings were exposed to the gas for 30 min, no radioiodine was emitted from those leaves over the following two weeks, indicating that no turnover occurs in radioiodine once it is bound to the polysaccharides in plant tissues. We conclude that forest trees could serve as one of the largest enormous capture systems for the radioiodine fallout following the nuclear power plant accident in Fukushima

A Method for Producing Bioethanol from the Lignocellulose of Shorea uliginosa Foxw. by Enzymatic Saccharification and Fermentation

Several papers have reported various technical aspects of lignocellulosic bioethanol production. Recalcitrance to saccharification is a major limitation for conversion of lignocellulosic biomass to ethanol. The biological process for converting lignocellulose to fuel ethanol includes delignification in order to liberate cellulose and hemicelluloses, depolymerization of carbohydrate polymers to produce free sugars, and sugar fermentation to produce ethanol. Access of plant cell wall polysaccharides to chemical, enzymatic and microbial digestion is limited by many factors, including the presence of lignin and hemicellulose that cover cellulose microfibrils. An effort to support the fuel ethanol fermentation industry using the Indonesian woody plant species Shorea uliginosa Foxw., was undertaken with regard to the established efficient bioethanol production process. This paper relates to a method for producing bioethanol from the lignocellulose of S. uliginosa Foxw. by saccharification and fermentation of xylem. A literature study of previous research on cellulose hydrolysis as a method for producing bioethanol was necessary. The objective of this study was to gain a deeper understanding of the degradation mechanisms of cellulose by enzymes through a study of previous research, which were then compared to the new method

Analysis on Chemical Components of Woods to Predict Ethanol Production Values

This paper deals with analysis on chemical components of woods to predict ethanol production values. The aim is expected to give a reliable value of ethanol production, eliminating the effort needed to directly measure this ethanol production from each wood species. Since the data of wood chemical components is widely available, this result will be valuable in determining a potential use of a wood species as bio-ethanol feedstock. Saccharification and fermentation processes by enzymatic hydrolysis were applied for xylems derived from49 branch trees of Cibodas, 32 branch trees of Purwodadi, and 19 branch trees of Bali Botanical Gardens in Indonesia. Three major wood components were analysed, i.e. cellulose, hemicellulose, and lignin. The results show varied relationships between ethanol production and chemical components of wood. The content of cellulose in wood was not exactly related to its ethanol production. This trend was also occurred for the relationship between hemicellulose and ethanol production. However, lignin content in woods gave an expected trend where the less lignin content, the higher the ethanol production.Furthermore, the ratios of cellulose-hemicelluloses and cellulose-lignin have been quantified. The result showed that the celullose-lignin ratio can potentially be used to predict the value of ethanol production which is expressed by linear regression y = 0.0616x + 0.8341; where R² = 0.4127, x = ethanol production and y = cellulose-lignin ratio. Gymnostoma sumatranum with cellulose content of 43.8% and lignin content of 24.1% (celullose-lignin ratio of 1.8) has actual ethanol production of 12.1 mg/100mg wood meal, compared to 15.7 mg/100mg wood meal resulted from above equation. Therefore, by using its cellulose-lignin ratio, the woods having high ethanol production can be screened from literatures

Wood Characteristic of Superior Sengon Collection and Prospect of Wood Properties Improvement through Genetic Engineering

Many tree breeding programs ranging from conventional to molecular genetics approach were applied to produce clone or tree genetic industrially desirable wood. This study was aimed to evaluate the wood properties of selected sengon (Paraserianthes falcataria) tree which has high score of  growth parameter and stem form and to evaluate stem properties of transgenic sengon and mangium (Acacia mangium) overexpressing wall hydrolases. Physical and chemical wood properties including basic density, shrinkage and thickness swelling, estimated stand volume, cellulose, lignin and water content were examined for two selected plus tree sengon namely PI and PII, which were grown at Germ Plasm Collection Garden of Research Centre for Biotechnology - LIPI. Both of two sengon tree has high value of  estimated stand volume and basic density (0.43 and 0.49 g/cm3). The PII tree has lower lignin and water content than P I. Cellulase overexpression in sengon and xyloglucanase overexpression in mangium could alter stem cell walls composition. Transgenics mangium stem have higher cellulose content (37.70~53.64%) and lower hemicelluloses content (30~40%) than the wild type.

Activation of β-Glucan Synthases by Wall-Bound Purple Acid Phosphatase in Tobacco Cells1[W][OA]

Wall-bound purple acid phosphatases have been shown to be potentially involved in the regulation of plant cell growth. The aim of this work was to further investigate the function of one of these phosphatases in tobacco (Nicotiana tabacum), NtPAP12, using transgenic cells overexpressing the enzyme. The transgenic cells exhibited a higher level of phosphatase activity in their walls. The corresponding protoplasts regenerating a cell wall exhibited a higher rate of β-glucan synthesis and cellulose deposition was increased in the walls of the transgenic cells. A higher level of plasma membrane glucan synthase activities was also measured in detergent extracts of membrane fractions from the transgenic line, while no activation of Golgi-bound glycan synthases was detected. Enzymatic hydrolysis and methylation analysis were performed on the products synthesized in vitro by the plasma membrane enzymes from the wild-type and transgenic lines extracted with digitonin and incubated with radioactive UDP-glucose. The data showed that the glucans consisted of callose and cellulose and that the amount of each glucan synthesized by the enzyme preparation from the transgenic cells was significantly higher than in the case of the wild-type cells. The demonstration that callose and cellulose synthases are activated in cells overexpressing the wall-bound phosphatase NtPAP12 suggests a regulation of these carbohydrate synthases by a phosphorylation/dephosphorylation process, as well as a role of wall-bound phosphatases in the regulation of cell wall biosynthesis

Overexpression of Poplar Cellulase Accelerates Growth and Disturbs the Closing Movements of Leaves in Sengon1[OA]

In this study, poplar (Populus alba) cellulase (PaPopCel1) was overexpressed in a tropical Leguminosae tree, sengon (Paraserianthes falcataria), by the Agrobacterium tumefaciens method. PaPopCel1 overexpression increased the length and width of stems with larger leaves, which showed a moderately higher density of green color than leaves of the wild type. The pairs of leaves on the transgenic plants closed more slowly during sunset than those on the wild-type plants. When main veins from each genotype were excised and placed on a paper towel, however, the leaves of the transgenic plants closed more rapidly than those of the wild-type plant. Based on carbohydrate analyses of cell walls, the leaves of the transgenic plants contained less wall-bound xyloglucan than those of the wild-type plants. In situ xyloglucan endotransglucosylase activity showed that the incorporation of whole xyloglucan, potentially for wall tightening, occurred in the parenchyma cells (motor cells) of the petiolule pulvinus attached to the main vein, although the transgenic plant incorporated less whole xyloglucan than the wild-type plant. These observations support the hypothesis that the paracrystalline sites of cellulose microfibrils are attacked by poplar cellulase, which loosens xyloglucan intercalation, resulting in an irreversible wall modification. This process could be the reason why the overexpression of poplar cellulase both promotes plant growth and disturbs the biological clock of the plant by altering the closing movements of the leaves of the plant

Intake of Radionuclides in the Trees of Fukushima Forests 1. Field Study

The earthquake and tsunami on 11 March 2011 led to a meltdown followed by a hydrogen explosion at the Fukushima–Daiichi nuclear power plant in Japan, causing the dispersal of abundant radionuclides into the atmosphere and ocean. The radionuclides were deposited onto trees and local residences in aerosol or gaseous forms that were partly absorbed by rain or melting snow. Here, we show that the radionuclides attached to the surfaces of trees, in which some radiocesium was incorporated into the xylem through ray cells and through symplastic pathways. The level of incorporated radiocesium varied based on tree species and age because of the ability of radiocesium to attach to the surface of the outer bark. After four years, the radiocesium level in the forest has been decreasing as it is washed out with rainwater into the sea and as it decays over time due to its half-life, but it can also be continuously recycled through leaf tissue, litter, mulch, and soil. As a result, the level of radiocesium was relatively increased in the heartwood and roots of trees at four years after the event. In private forest fields, most trees were left as afforested trees without being used for timber, although some trees were cut down. We discuss an interdisciplinary field study on the immediate effects of high radiation levels upon afforested trees in private forest fields

Wood Characteristic of Superior Sengon Collection and Prospect of Wood Properties Improvement Through Genetic Engineering

Many tree breeding programs ranging from conventional to molecular genetics approach were applied to produce clone or tree genetic industrially desirable wood. This study was aimed to evaluate the wood properties of selected sengon (Paraserianthes falcataria) tree which has high score of growth parameter and stem form and to evaluate stem properties of transgenic sengon and mangium (Acacia mangium) overexpressing wall hydrolases. Physical and chemical wood properties including basic density, shrinkage and thickness swelling, estimated stand volume, cellulose, lignin and water content were examined for two selected plus tree sengon namely PI and PII, which were grown at Germ Plasm Collection Garden of Research Centre for Biotechnology - LIPI. Both of two sengon tree has high value of estimated stand volume and basic density (0.43 and 0.49 g/cm3). The PII tree has lower lignin and water content than P I. Cellulase overexpression in sengon and xyloglucanase overexpression in mangium could alter stem cell walls composition. Transgenics mangium stem have higher cellulose content (37.70~53.64%) and lower hemicelluloses content (30~40%) than the wild type