Natural capital evaluation in the FutureCity of Shimokawa, Northern Japan, based on forest economics.

We have pragmatically but accurately evaluated the natural capital of a small northern town, Shimokawa, Hokkaido, Japan. The key industries are forestry, wood manufacturing, and agriculture. From an environmental perspective, Shimokawa was nominated as a Japanese FutureCity. Consequently, the total natural capital value (NCV) of the forest and agricultural lands was calculated to be 1.326 billion USD/year (or 24,161 USD/ha/year) and 44 million USD/year (or 19,692 USD/ha/year), respectively, in 2012. The sum of these NCVs was more than 7 times greater than the yearly gross production of the town, although the forest had a higher NCV because of the larger area (54,862 ha for forest area), compared with 2953 ha for agricultural area. This substantial NCV is mainly generated by sustainable forest management. The timber account showed that the annual tree growth was greater than the annual harvest of trees. The CO2 account derived from a one-year calculation showed that the town served as a CO2 sink at 107,249 t-CO2/year due to the large amount of annual tree growth and CO2 storage in the harvested wood products even if CO2 was emitted from industries and households. The forestry and wood manufacturing industries, as well as agriculture, created socioeconomic effects for the townspeople, ranging from job creation, study tours, and social welfare. This NCV accounting for Shimokawa town ensures the sustainable use of valuable environmental assets and will help other communities recognize their own NCV accounts.

Contribution of constitutive characteristics of lipids and phenolics in roots of tree species in Myrtales to aluminum tolerance.

High aluminum (Al) concentration in soil solution is the most important factor restricting plant growth in acidic soils. However, various plant species naturally grow in such soils. Generally, they are highly tolerant to Al, but organic acid exudation, the most common Al tolerance mechanism, cannot explain their tolerance. Lower phospholipid and higher sterol proportions in root plasma membrane enhance Al tolerance. Other cellular components, such as cell walls and phenolics, may also be involved in Al tolerance mechanisms. In this study, the relationships between these cellular components and the Al tolerance mechanisms in Melastoma malabathricum and Melaleuca cajuputi, both highly Al-tolerant species growing in strongly acidic soils, were investigated. Both species contained lower proportions of phospholipids and higher proportions of sterols in roots, respectively. Concentrations of phenolics in roots of both species were higher than that of rice; their phenolics could form chelates with Al. In these species, phenolic concentrations and composition were the same irrespective of the presence or absence of Al in the medium, suggesting that a higher concentration of phenolics is not a physiological response to Al but a constitutive characteristic. These characteristics of cellular components in roots may be cooperatively involved in their high Al tolerance.

Evapotranspiration of tropical peat swamp forests.

In Southeast Asia, peatland is widely distributed and has accumulated a massive amount of soil carbon, coexisting with peat swamp forest (PSF). The peatland, however, has been rapidly degraded by deforestation, fires, and drainage for the last two decades. Such disturbances change hydrological conditions, typically groundwater level (GWL), and accelerate oxidative peat decomposition. Evapotranspiration (ET) is a major determinant of GWL, whereas information on the ET of PSF is limited. Therefore, we measured ET using the eddy covariance technique for 4-6 years between 2002 and 2009, including El Niño and La Niña events, at three sites in Central Kalimantan, Indonesia. The sites were different in disturbance degree: a PSF with little drainage (UF), a heavily drained PSF (DF), and a drained burnt ex-PSF (DB); GWL was significantly lowered at DF, especially in the dry season. The ET showed a clear seasonal variation with a peak in the mid-dry season and a large decrease in the late dry season, mainly following seasonal variation in net radiation (Rn ). The Rn drastically decreased with dense smoke from peat fires in the late dry season. Annual ET forced to close energy balance for 4 years was 1636 ± 53, 1553 ± 117, and 1374 ± 75 mm yr(-1) (mean ± 1 standard deviation), respectively, at UF, DF, and DB. The undrained PSF (UF) had high and rather stable annual ET, independently of El Niño and La Niña events, in comparison with other tropical rainforests. The minimum monthly-mean GWL explained 80% of interannual variation in ET for the forest sites (UF and DF); the positive relationship between ET and GWL indicates that drainage by a canal decreased ET at DF through lowering GWL. In addition, ET was decreased by 16% at DB in comparison with UF chiefly because of vegetation loss through fires.

Arsenic alters uptake and distribution of sulphur in Pteris vittata.

Low-molecular-weight thiol (LMWT) synthesis has been reported to be directly induced by arsenic (As) in Pteris vittata, an As hyperaccumulator. Sulphur (S) is a critical component of LMWTs. Here, the effect of As treatment on the uptake and distribution of S in P. vittata was investigated. In P. vittata grown under low S conditions, the presence of As in the growth medium enhanced the uptake of SO4(2-), which was used for LMWT synthesis in fronds. In contrast, As application did not affect SO4(2-) uptake in Nephrolepis exaltata, an As non-hyperaccumulator. Moreover, the isotope microscope system revealed that S absorbed with As accumulated locally in a vacuole-like organelle in epidermal cells, whereas S absorbed alone was distributed uniformly. These results suggest that S is involved in As transport and/or accumulation in P. vittata. X-ray absorption near-edge structure analysis revealed that the major As species in the fronds and roots of P. vittata were inorganic As(III) and As(V), respectively, and that As-LMWT complexes occurred as a minor species. Consequently, in case of As accumulation in P. vittata, S possibly acts as a temporary ligand for As in the form of LMWTs in intercellular and/or intracellular transport (e.g. vacuolar sequestration).

Carbon dioxide emissions through oxidative peat decomposition on a burnt tropical peatland.

In Southeast Asia, a huge amount of peat has accumulated under swamp forests over millennia. Fires have been widely used for land clearing after timber extraction, thus land conversion and land management with logging and drainage are strongly associated with fire activity. During recent El Niño years, tropical peatlands have been severely fire-affected and peatland fires enlarged. To investigate the impact of peat fires on the regional and global carbon balances, it is crucial to assess not only direct carbon emissions through peat combustion but also oxidative peat decomposition after fires. However, there is little information on the carbon dynamics of tropical peat damaged by fires. Therefore, we continuously measured soil CO2 efflux [peat respiration (RP)] through oxidative peat decomposition using six automated chambers on a burnt peat area, from which about 0.7 m of the upper peat had been lost during two fires, in Central Kalimantan, Indonesia. The RP showed a clear seasonal variation with higher values in the dry season. The RP increased logarithmically as groundwater level (GWL) lowered. Temperature sensitivity or Q10 of RP decreased as GWL lowered, mainly because the vertical distribution of RP would shift downward with the expansion of an unsaturated soil zone. Although soil temperature at the burnt open area was higher than that in a near peat swamp forest, model simulation suggests that the effect of temperature rise on RP is small. Annual gap-filled RP was 382 ± 82 (the mean ± 1 SD of six chambers) and 362 ± 74 gC m(-2)  yr(-1) during 2004-2005 and during 2005-2006 years, respectively. Simulated RP showed a significant negative relationship with GWL on an annual basis, which suggests that every GWL lowering by 0.1 m causes additional RP of 89 gC m(-2)  yr(-1) . The RP accounted for 21-24% of ecosystem respiration on an annual basis.

Biobleaching of Acacia kraft pulp with extracellular enzymes secreted by Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 using low-cost media.

The white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 have been shown in previous studies to have high biobleaching activity in vivo. The aim of this study was to investigate the activities and stabilities of extracellular enzymes, prepared from I. lacteus and L. tigrinus culture grown in three types of economical media of agricultural and forestry wastes, for biobleaching of Acacia oxygen-delignified kraft pulp using kappa number reduction as an indicator of delignification. After 3 days of incubation, the extracellular enzymes preparations from I. lacteus and L. tigrinus cultures in media of Acacia mangium wood powder supplemented with rice bran and addition 1 % glucose (WRBG), resulted in significant decrease of 4.4 and 6.7 %, respectively. A slightly higher kappa number reduction (7.4 %) was achieved with the combine extracellular enzymes from I. lacteus and L. tigrinus. One of the strategies for reducing the cost of enzyme production for treatment processes in the pulp and paper industry is the utilization of agricultural and forestry waste. Thus, WRBG has potential as a culture medium for producing stable lignolytic enzymes simply and economically.

Effect of phosphorus levels on the protein profiles of secreted protein and root surface protein of rice.

Plant roots are complicated organs that absorb water and nutrients from the soil. Roots also play an essential role in protecting plants from attack by soil pathogens and develop a beneficial role with some soil microorganisms. Plant-derived rhizosphere proteins (e.g., root secretory proteins and root surface binding proteins) are considered to play important roles in developing mutual relationships in the rhizosphere. In the rhizosphere, where plant roots meet the surrounding environment, it has been suggested that root secretory protein and root surface binding protein are important factors. Furthermore, it is not known how the physiological status of the plant affects the profile of these proteins. In this study, rice plants were grown aseptically, with or without phosphorus nutrition, and proteins were obtained from root bathing solution (designated as root secretory proteins) and obtained using 0.2 M CaCl2 solution (designated as root surface binding proteins). The total number of identified proteins in the root bathing solution was 458, and the number of root surface binding proteins was 256. More than half of the proteins were observed in both fractions. Most of the proteins were categorized as either having signal peptides or no membrane transport helix sites. The functional categorization suggested that most of the proteins seemed to have secretory pathways and were involved in defense/disease-related functions. These characteristics seem to be unique to rhizosphere proteins, and the latter might be part of the plants strategy to defeat pathogens in the soil. The low phosphorus treatment significantly increased the number of pathogenesis-related proteins in the root secretory proteins, whereas the change was small in the case of the root surface binding proteins. The results suggested that the roots are actively and selectively secreting protein into the rhizosphere.

Peatland groundwater level in the Indonesian maritime continent as an alert for El Niño and moderate positive Indian Ocean dipole events.

In general, it is known that extreme climatic conditions such as El Niño and positive Indian Ocean Dipole (IOD+) cause prolonged drought in Indonesia's tropical peatlands so that groundwater levels (GWL) drop and peat is prone to fire. However, 27 years of GWL measurements in Central Kalimantan peat forests show the opposite condition, where the lowest GWL occurs several weeks before El Niño and after IOD+ reaches its peaks. We show that the dropped sea surface temperature anomaly induced by anomalously easterly winds along the southern Java-Sumatra occurs several weeks before the GWL drop to the lowest value. Local rainfall decreased, and GWL dropped sharply by 1.0 to 1.5 m, during the super El Niño events in 1997/98 and 2015, as well as remarkable events of IOD+ in 2019. It is suggested that the tropical peatland ecohydrological system (represented by the GWL), El Niño Southern Oscillation (ENSO), and IOD+ are teleconnected. Hence, monitoring GWL variability of peatland over the IMC is a possibility an alert for extreme climate events associated with El Niño and/or moderate IOD+.

Changes in saccharide, amino acid and S-methylmethionine content during malting of barley grown with different nitrogen and sulfur status.

BACKGROUND: Changes in saccharide, amino acid and S-methylmethionine (SMM) concentrations and enzyme activities during the malting of barley grown with different nitrogen (N) and sulfur (S) supplementation were investigated in order to clarify their relationship with N and S fertiliser levels. RESULTS: Concentrations of N and S in barley grain were significantly increased by the addition of N to the culture soil. Application of N decreased the starch concentration in grain. On the other hand, higher N fertilisation increased the ß-glucan concentration in grain and malt, thus decreasing the accessibility of ß-glucanase to its substrates. Proteolytic enzyme activity was significantly higher in the absence (-N treatment) than in the presence (+N treatment) of N fertiliser, making the concentration of the majority of amino acids in malt slightly higher in the - N treatment. SMM was synthesised in grain after imbibition, and application of N increased the SMM content in malt. CONCLUSION: Although SMM can be controlled to a certain extent during kilning, a balanced supply of N and S during cultivation can also be helpful for the production of malt with lower SMM concentration. Adequate soil management is desirable to maintain the balance between good agronomic performance and high malt quality.

ATP-dependent but proton gradient-independent polyphosphate-synthesizing activity in extraradical hyphae of an arbuscular mycorrhizal fungus.

Arbuscular mycorrhizal (AM) fungi benefit their host plants by supplying phosphate obtained from the soil. Polyphosphate is thought to act as the key intermediate in this process, but little is currently understood about how polyphosphate is synthesized or translocated within arbuscular mycorrhizas. Glomus sp. strain HR1 was grown with marigold in a mesh bag compartment system, and extraradical hyphae were harvested and fractionated by density gradient centrifugation. Using this approach, three distinct layers were obtained: layers 1 and 2 were composed of amorphous and membranous materials, together with mitochondria, lipid bodies, and electron-opaque bodies, and layer 3 was composed mainly of partially broken hyphae and fragmented cell walls. The polyphosphate kinase/luciferase system, a highly sensitive polyphosphate detection method, enabled the detection of polyphosphate-synthesizing activity in layer 2 in the presence of ATP. This activity was inhibited by vanadate but not by bafilomycin A(1) or a protonophore, suggesting that ATP may not energize the reaction through H(+)-ATPase but may act as a direct substrate in the reaction. This report represents the first demonstration that AM fungi possess polyphosphate-synthesizing activity that is localized in the organelle fraction and not in the cytosol or at the plasma membrane.

Rapid characterization of plant mutants with an altered ion-profile: a case study using Lotus japonicus.

Legumes are second only to cereals in their importance to humans, and study of their functional genomics of nutrition and other trace elements is crucial for agricultural production and food fortification. We describe here an ionomic screening experiment carried out to investigate the accumulation of 15 elements in shoots of mutants of Lotus japonicus, a good genetic tool for legume study.Approximately 2000 mutagenized M2 plants were cultivated in a novel low-cost high-throughput system and their elemental profiles were determined by inductively coupled plasma mass spectroscopy (ICP-MS).After triple-checking the element concentrations in M2 or M3 plant shoots, 31 mutants with altered elemental profiles were identified. Surprisingly, the number of genes regulating essential elements was similar to the number regulating nonessential elements. Magnesium (Mg) and nickel (Ni) were correlated in a number of mutants.Further investigation suggested that phosphorus (P) and cobalt (Co) might be involved in the ion homeostasis network of Mg and Ni.The results suggested that the pathways for element uptake or translocation were highly linked through the ion transport-related genes. Ionomics proved to be a powerful functional genomics tool for determining genes related to ion homeostasisin this study.

A Reduced Phosphorus Application Rate Using a Mycorrhizal Plant as the Preceding Crop Maintains Soybean Seeds' Nutritional Quality.

We tested whether introducing an arbuscular mycorrhizal fungi (AMF)-host plant with a reduced P application rate could maintain soybean seeds' nutrient quality. The dynamic variation of 14 nutrients was analyzed in source and sink organs during the seed-filling stage. The AMF-host and non-AMF-host plants, sunflower and mustard, were grown as preceding crops (PCs). Soybeans, the succeeding crops, were planted with three different phosphorus levels, namely, 0, 50, and 150 kg P2O5 ha-1. The results showed that the AMF-host PC with a reduced P application rate maintained the seed's yield and nutrients quality. During the seed-filling stage, the AMF-host PC with a reduced P application rate increased the uptake of most nutrients compared to the non-AMF-host PC, and improved the remobilization efficiency of all nutrients except Mn, Fe, and Se, compared to the optimal P application rate. These results could help improve the utilization efficiency of P fertilizers and protect soybeans' nutritional value.

Differences in the metabolite profiles of spinach (Spinacia oleracea L.) leaf in different concentrations of nitrate in the culture solution.

The nitrogen (N) status of a plant determines the composition of its major components (amino acids, proteins, carbohydrates and organic acids) and, directly or indirectly, affects the quality of agricultural products in terms of their calorific value and taste. Although these effects are guided by changes in metabolic pathways, no overall metabolic analysis has previously been conducted to demonstrate such effects. Here, metabolite profiling using gas chromatography-mass spectrometry (GC-MS) was used to evaluate the effect of N levels on spinach tissue, comparing two cultivars that differed in their ability to use N. Wide variation in N content was observed without any distinct inhibition of growth in either cultivar. Principal component analysis (PCA) and self-organizing mapping (SOM) were undertaken to describe changes in the metabolites of mature spinach leaves. In PCA, the first component accounted for 44.5% of the total variance, the scores of which was positively correlated with the plant's N content, and a close relationship between metabolite profiles and N status was observed. Both PCA and SOM revealed that metabolites could be broadly divided into two types, correlating either positively or negatively with plant N content. The simple and co-coordinated metabolic stream, containing both general and spinach-specific aspects of plant N content, will be useful in future research on such topics as the detection of environmental effects on spinach through comprehensive metabolic profiling.

Biotransformation of (+)-catechin into taxifolin by a two-step oxidation: primary stage of (+)-catechin metabolism by a novel (+)-catechin-degrading bacteria, Burkholderia sp. KTC-1, isolated from tropical peat.

Peat contains various persistent compounds derived from plant materials. We isolated a novel (+)-catechin-degrading bacterium, Burkholderia sp. KTC-1 (KTC-1), as an example of a bacterium capable of degrading persistent aromatic compounds present in tropical peat. This bacterium was isolated by an enrichment technique and grew on (+)-catechin as the sole carbon source under acidic conditions. The reaction of a crude enzyme extract and a structural study of its products showed that (+)-catechin is biotransformed into taxifolin during the preliminary stages of its metabolism by KTC-1. HPLC analysis showed that this transformation occurs in two oxidation steps: 4-hydroxylation and dehydrogenation. Furthermore, both (+)-catechin 4-hydroxylanase and leucocyanidin 4-dehydrogenase were localized in the cytosol of KTC-1. This is the first report on biotransformation of (+)-catechin into taxifolin via leucocyanidin by an aerobic bacterium. We suggest that tropical peat could become a unique resource for microorganisms that degrade natural aromatic compounds.

Characterization of root mucilage from Melastoma malabathricum, with emphasis on its roles in aluminum accumulation.

Plant roots exude viscous polysaccharides, called mucilage. One of the suggested roles of mucilage is immobilization of toxic metal cations, including aluminum (Al), in the rhizosphere. Mucilage exuded from roots of Melastoma malabathricum (Al accumulator) was characterized in comparison with that of Zea mays (maize; Al nonaccumulator). Removal of mucilage significantly reduced Al accumulation in M. malabathricum. The cation adsorption affinity of M. malabathricum mucilage was higher for Al and lanthanum (La) than for barium (Ba), whereas that of maize mucilage was in the order Ba > La > Al. A (27)Al nuclear magnetic resonance (NMR) spectrum of the Al-adsorbed mucilage and bioassay with alfalfa seedlings indicated that the concentrated Al in the mucilage of M. malabathricum, unlike that of maize, bound very weakly to cation exchange sites of mucilage. The higher charge density in M. malabathricum mucilage, derived from unmethylated uronic acid, is inferred to be related to preferential adsorption of trivalent cation. Not only a higher degree of methylation in the uronic acid (glucuronic acid) but also H(+) release from roots to the mucilage appears to be responsible for the loose binding of Al in M. malabathricum mucilage. These characteristics of mucilage may help Al hyperaccumulation in M. malabathricum.

Sugar signalling mediates cluster root formation and phosphorus starvation-induced gene expression in white lupin.

Cluster root (CR) formation contributes much to the adaptation to phosphorus (P) deficiency. CR formation by white lupin (Lupinus albus L.) is affected by the P-limiting level in shoots, but not in roots. Thus, shoot-derived signals have been expected to transmit the message of P-deficiency to stimulate CR formation. In this study, it is shown that sugars are required for a response to P starvation including CR formation and the expression of P starvation-induced genes. White lupin plants were grown in vitro on P-sufficient or P-deficient media supplemented with sucrose for 4 weeks. Sucrose supply stimulated CR formation in plants on both P-sufficient and P-deficient media, but no CR appeared on the P-sufficient medium without sucrose. Glucose and fructose also stimulated CR formation on the P-sufficient medium. On the medium with sucrose, a high concentration of inorganic phosphate in leaves did not suppress CR formation. Because sorbitol or organic acid in the media did not stimulate CR formation, the sucrose effect was not due to increased osmotic pressure or enriched energy source, that is, sucrose acted as a signal. Gene transcription induced by P starvation, LaPT1 and LaPEPC3, was magnified by the combination of P limitation and sucrose feeding, and that of LaSAP was stimulated by sucrose supply independently of P supply. These results suggest that at least two sugar-signalling mediating systems control P starvation responses in white lupin roots. One system regulates CR formation and LaSAP expression, which acts even when P is sufficient if roots receive sugar as a signal. The other system controls LaPT1 and LaPEPC3 expression, which acts when P is insufficient.

Effects of elevated atmospheric CO2 concentration on the nutrient uptake characteristics of Japanese larch (Larix kaempferi).

We evaluated the response of Japanese larch (Larix kaempferi Sieb. & Zucc.) to elevated atmospheric CO(2) concentration ([CO(2)]) (689 +/- 75 ppm in 2002 and 697 +/- 90 ppm in 2003) over 2 years in a field experiment with open-top chambers. Root activity was assessed as nitrogen, phosphorus and potassium uptake rates estimated from successive measurements of absorbed amounts. Dry matter production of whole plants was unaffected by elevated [CO(2)] in the first year of treatment, but increased significantly in response to elevated [CO(2)] in the second year. In contrast, elevated [CO(2)] increased the root to shoot ratio and fine root dry mass in the first year, but not in the second year. Elevated [CO(2)] had no effect on tissue N, P and K concentrations. Uptake rates of N, P and K correlated with whole-plant relative growth rates, but were unaffected by growth [CO(2)], as was ectomycorrhizal colonization, a factor assumed to be important for nutrient uptake in trees. We conclude that improved growth of Larix kaempferi in response to elevated [CO(2)] is accompanied by increased root biomass, but not by increased root activity.

Contrasting Effects of Cattle Manure Applications and Root-Induced Changes on Heavy Metal Dynamics in the Rhizosphere of Soybean in an Acidic Haplic Fluvisol: A Chronological Pot Experiment.

To characterize the dynamic mobilization of heavy metals (HM) in a crop-soil system affected by cattle manure (CM) application, soybean [Glycine max L. Merr. cv. Toyoharuka] crops were exposed in a chronological pot experiment to three CM application rates and sampled at two vegetative stages and two reproductive stages. A sequential extraction procedure for metal fractionation, soil pH, microbial activity, and plant HM uptake was determined. In non-rhizopshere soil, with CM application a liming effect was detected, and increased microbial activity was detected at the reproductive stage. CM application shifted Cd from available state to oxide-bound pool in non-rhizosphere soil; however, shifts in Cd from an oxide-bound pool to the available state were observed in rhizosphere soil. CM application stabilized the available Zn and Pb to oxide-bound Zn and organic-bound Pb in both non-rhizosphere and rhizosphere soils, and the stabilizing degree increased with higher CM application rates. The promoted Zn immobilization in the rhizosphere was due to the liming effects induced by added CM that counteracted the root-induced acidification. On the basis of a stepwise multiple regression analysis, the shift of Cd and Pb fractionation was mainly related to microbial activity. Adding manure inhibited Zn and Pb uptake but promoted Cd uptake by soybean, and a greater influence was detected at the reproductive stage, at which CM application increased the root Cd-absorbing power but did not significantly affect the Zn- and Pb-absorbing powers. In an agricultural context, long-term CM application, even at the recommended rate of 10.13 Mg ha-1, may cause a soybean Zn deficiency and high Pb accumulation in Haplic Fluvisols, although CM is often considered as an environmentally friendly fertilizer.

3(10)-helices in proteins are parahelices.

The 3(10)-helix is characterized by having at least two consecutive hydrogen bonds between the main-chain carbonyl oxygen of residue i and the main-chain amide hydrogen of residue i + 3. The helical parameters--pitch, residues per turn, radius, and root mean square deviation (rmsd) from the best-fit helix--were determined by using the HELFIT program. All 3(10)-helices were classified as regular or irregular based on rmsd/(N - 1)1/2 where N is the helix length. For both there are systematic, position-specific shifts in the backbone dihedral angles. The average phi, psi shift systematically from approximately -58 degrees, approximately -32 degrees to approximately -90 degrees, approximately -4 degrees for helices 5, 6, and 7 residues long. The same general pattern is seen for helices, N = 8 and 9; however, in N = 9, the trend is repeated with residues 6, 7, and 8 approximately repeating the phi, psi of residues 2, 3, and 4. The residues per turn and radius of regular 3(10)-helices decrease with increasing length of helix, while the helix pitch and rise per residue increase. That is, regular 3(10)-helices become thinner and longer as N increases from 5 to 8. The fraction of regular 3(10)-helices decreases linearly with helix length. All longer helices, N > or = 9 are irregular. Energy minimizations show that regular helices become less stable with increasing helix length. These findings indicate that the definition of 3(10)-helices in terms of average, uniform dihedral angles is not appropriate and that it is inherently unstable for a polypeptide to form an extended, regular 3(10)-helix. The 3(10)-helices observed in proteins are better referred to parahelices.

Differential Responses of Soybean and Sorghum Growth, Nitrogen Uptake, and Microbial Metabolism in the Rhizosphere to Cattle Manure Application: A Rhizobox Study.

In this study, we determined the capacity of soybean (Glycine max L. Merr. cv. Hoyoharuka) and sorghum (Sorghum bicolor L. Moench. cv. Hybrid Sorgo) to utilize different forms of nitrogen (N) in a rhizobox system. Seedlings were grown for 35 days without N or with 130 mg N kg-1 soil as ammonium sulfate or farmyard cattle manure. The soil fractions at different distances from the root were sliced millimeter by millimeter in the rhizobox system. We assessed the distribution of different forms of N and microbial metabolism in different soil fractions in the rhizosphere. There are no treatment-dependent changes in biomass production in the roots and shoots of soybeans, however, the ammonium and manure treatment yielded 1.30 and 1.40 times higher shoot biomass of sorghum than the control. Moreover, the depletion of inorganic N and total amino acids (TAA) in the rhizosphere was largely undetectable at various distances from the soybean roots regardless of the treatments employed. The addition of ammonium sulfate resulted in a decrease in the nitrate concentration gradient as the distance decreased from the sorghum roots. The addition of manure to the soil increased the N content in the sorghum shoots, 1.57 times higher than the control; this increase was negatively correlated with the concentrations of TAA in the soil of the root compartment. In addition, the application of manure simultaneously induced TAA depletion (i.e., the TAA concentration in root compartment was 1.48 times higher than that in bulk soil) and greater microbial activity and diversity in the sorghum rhizosphere, where higher microbial consumption of asparagine, glutamic acid, and phenylalanine were also observed near the roots. Our results are first to present the evidence that sorghum may possess a high capacity for taking up amino acids as a consequence of organic matter application, and microbial metabolism.