Interspecific facilitation of micronutrient uptake between cluster-root-bearing trees and non-cluster rooted-shrubs in a woodland.

Background And Aims: Belowground interspecific plant facilitation is supposed to play a key role in enabling species co-existence in hyperdiverse ecosystems in extremely nutrient-poor, semi-arid habitats, such as woodlands in southwestern-Australia. Manganese (Mn) is readily mobilised by cluster root activity in most soils and accumulates in mature leaves of native Australian plant species without significant remobilisation during leaf senescence. We hypothesised that neighbouring shrubs are facilitated in terms of Mn uptake depending on distance to surrounding cluster root-forming trees.

Phosphorus absorption kinetics and exudation strategies of roots developed by three lupin species to tackle P deficiency.

Different lupin species exhibited varied biomass, P allocation, and physiological responses to P-deprivation. White and yellow lupins had higher carboxylate exudation rates, while blue lupin showed the highest phosphatase activity. White lupin (Lupinus albus) can produce specialized root structures, called cluster roots, which are adapted to low-phosphorus (P) soil.

Effects of Phosphate-solubilizing Bacteria on Soil Phosphorus Fractions and Supply to Maize Seedlings Grown in Lateritic Red Earths and Cinnamon Soils.

Phosphorus (P) is often the limiting factor for plant growth because of its low mobility and availability in soils. Phosphate-solubilizing bacteria (PSB) have been shown to increase the availability of soil P fractions, thereby promoting plant growth. We herein investigated the effects of PSB on P availability in two important Chinese soil types: Lateritic red earths (La) and Cinnamon soils (Ci).

Lipidome Profiling of Phosphorus Deficiency-Tolerant Rice Cultivars Reveals Remodeling of Membrane Lipids as a Mechanism of Low P Tolerance.

Plants have evolved various mechanisms for low P tolerance, one of which is changing their membrane lipid composition by remodeling phospholipids with non-phospholipids. The objective of this study was to investigate the remodeling of membrane lipids among rice cultivars under P deficiency. Rice ( L.

Multiple analysis of root exudates and microbiome in rice (Oryza sativa) under low P conditions.

Plants release various metabolites from roots and root exudates contribute to differences in stress tolerance among plant species. Plant and soil microbes have complex interactions that are affected by biotic and abiotic factors. The purpose of this study was to examine the differences in metabolites in root exudates of rice (Oryza sativa) cultivars and their correlation with bacterial populations in the rhizosphere.

Recent insights into the metabolic adaptations of phosphorus-deprived plants.

Inorganic phosphate (Pi) is an essential macronutrient required for many fundamental processes in plants, including photosynthesis and respiration, as well as nucleic acid, protein, and membrane phospholipid synthesis. The huge use of Pi-containing fertilizers in agriculture demonstrates that the soluble Pi levels of most soils are suboptimal for crop growth. This review explores recent advances concerning the understanding of adaptive metabolic processes that plants have evolved to alleviate the negative impact of nutritional Pi deficiency.

AtALMT3 is Involved in Malate Efflux Induced by Phosphorus Deficiency in Arabidopsis thaliana Root Hairs.

Under phosphorus (P)-deficient conditions, organic acid secretion from roots plays an important role in P mobilization from insoluble P in the soil. In this study, we characterized AtALMT3, a homolog of the Arabidopsis thaliana aluminum-activated malate transporter family gene. Among the 14 AtALMT family genes, only AtALMT3 was significantly up-regulated in P-deficient roots.

Molecular mechanisms underpinning phosphorus-use efficiency in rice.

Orthophosphate (H PO , Pi) is an essential macronutrient integral to energy metabolism as well as a component of membrane lipids, nucleic acids, including ribosomal RNA, and therefore essential for protein synthesis. The Pi concentration in the solution of most soils worldwide is usually far too low for maximum growth of crops, including rice. This has prompted the massive use of inefficient, polluting, and nonrenewable phosphorus (P) fertilizers in agriculture.

Ancient rice cultivar extensively replaces phospholipids with non-phosphorus glycolipid under phosphorus deficiency.

Recycling of phosphorus (P) from P-containing metabolites is an adaptive strategy of plants to overcome soil P deficiency. This study was aimed at demonstrating differences in lipid remodelling between low-P-tolerant and -sensitive rice cultivars using lipidome profiling. The rice cultivars Akamai (low-P-tolerant) and Koshihikari (low-P-sensitive) were grown in a culture solution with [2 mg l (+P)] or without (-P) phosphate for 21 and 28 days after transplantation.

Identification and distribution of cellobiose 2-epimerase genes by a PCR-based metagenomic approach.

Cellobiose 2-epimerase (CE) catalyzes the reversible epimerization of cellobiose to 4-O-β-D-glucopyranosyl-D-mannose. By using a PCR-based metagenomic approach, 71 ce-like gene fragments were obtained from wide-ranging environmental samples such as sheep rumen, soils, sugar beet extracts, and anaerobic sewage sludge. The frequency of isolation of the fragments similar to known sequences varied depending on the nature of the samples used.

The mannobiose-forming exo-mannanase involved in a new mannan catabolic pathway in Bacteroides fragilis.

We have proposed a new mannan catabolic pathway in Bacteroides fragilis NCTC 9343 that involves a putative mannanase ManA in glycoside hydrolase family 26 (BF0771), a mannobiose and/or sugar transporter (BF0773), mannobiose 2-epimerase (BF0774), and mannosylglucose phosphorylase (BF0772). If this hypothesis is correct, ManA has to generate mannobiose from mannans as the major end product. In this study, the BF0771 gene from the B.

Structure of novel enzyme in mannan biodegradation process 4-O-β-D-mannosyl-D-glucose phosphorylase MGP.

The crystal structure of a novel component of the mannan biodegradation system, 4-O-β-D-mannosyl-D-glucose phosphorylase (MGP), was determined to a 1.68-Å resolution. The structure of the enzyme revealed a unique homohexameric structure, which was formed by using two helices attached to the N-terminus and C-terminus as a tab for sticking between subunits.

Phytate degradation by fungi and bacteria that inhabit sawdust and coffee residue composts.

Phytate is the primary source of organic phosphorus, but it cannot be directly utilized by plants and is strongly adsorbed by the soil, reducing bioavailability. Composting is a process used to improve the bioavailability of phytate in organic wastes through degradation by microorganisms. In this study, we aimed to investigate the phytate-degrading ability of fungi and bacteria that inhabit sawdust compost and coffee residue compost, and their contribution to the composting process.

Isolation and characterization of cellulose-decomposing bacteria inhabiting sawdust and coffee residue composts.

Clarifying the identity and enzymatic activities of microorganisms associated with the decomposition of organic materials is expected to contribute to the evaluation and improvement of composting processes. In this study, we examined the cellulolytic and hemicellulolytic abilities of bacteria isolated from sawdust compost (SDC) and coffee residue compost (CRC). Cellulolytic bacteria were isolated using Dubos mineral salt agar containing azurine cross-linked (AZCL) HE-cellulose.

Evaluation of cellulolytic and hemicellulolytic abilities of fungi isolated from coffee residue and sawdust composts.

This study focused on the evaluation of cellulolytic and hemicellulolytic fungi isolated from sawdust compost (SDC) and coffee residue compost (CRC). To identify fungal isolates, the ITS region of fungal rRNA was amplified and sequenced. To evaluate enzyme production, isolates were inoculated onto wheat bran agar plates, and enzymes were extracted and tested for cellulase, xylanase, β-glucanase, mannanase, and protease activities using different azurine cross-linked (AZCL) substrates.

New microbial mannan catabolic pathway that involves a novel mannosylglucose phosphorylase.

The consecutive genes BF0771-BF0774 in the genome of Bacteroides fragilis NCTC 9343 were found to constitute an operon. The functional analysis of BF0772 showed that the gene encoded a novel enzyme, mannosylglucose phosphorylase that catalyzes the reaction, 4-O-β-d-mannopyranosyl-d-glucose+Pi→mannose-1-phosphate+glucose. Here we propose a new mannan catabolic pathway in the anaerobe, which involves 1,4-β-mannanase (BF0771), a mannobiose and/or sugar transporter (BF0773), mannobiose 2-epimerase (BF0774), and mannosylglucose phosphorylase (BF0772), finally progressing to glycolysis.

Influence of arsenic stress on synthesis and localization of low-molecular-weight thiols in Pteris vittata.

The roles of low-molecular-weight thiols (LMWTs), such as glutathione and phytochelatins, in arsenic (As) tolerance and hyperaccumulation in Pteris vittata an As-hyperaccumulator fern remain to be better understood. This study aimed to thoroughly characterize LMWT synthesis in P. vittata to understand the roles played by LMWTs in As tolerance and hyperaccumulation.

Recent progress in plant nutrition research: cross-talk between nutrients, plant physiology and soil microorganisms.

Mineral nutrients taken up from the soil become incorporated into a variety of important compounds with structural and physiological roles in plants. We summarize how plant nutrients are linked to many metabolic pathways, plant hormones and other biological processes. We also focus on nutrient uptake, describing plant-microbe interactions, plant exudates, root architecture, transporters and their applications.

Identification of the cellobiose 2-epimerase gene in the genome of Bacteroides fragilis NCTC 9343.

Cellobiose 2-epimerase (CE, EC 5.1.3.

Effects of epilactose on calcium absorption and serum lipid metabolism in rats.

Epilactose (4-O-beta-galactopyranosyl-D-mannnose) is a rare disaccharide in cow milk that can be synthesized from lactose by the cellobiose 2-epimerase of Ruminococcus albus. In this study, we examined the biological activities of epilactose using male Wistar-ST rats. The apparent rates of calcium and magnesium absorption of rats fed epilactose and fructooligosaccharide diets were greater than those fed control and lactose diets, accompanied by greater weight gain of the cecal wall and higher levels of short-chain fatty acids and other organic acids.

Cloning and sequencing of the gene for cellobiose 2-epimerase from a ruminal strain of Eubacterium cellulosolvens.

Cellobiose 2-epimerase (CE; EC 5.1.3.

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.

Cloning and sequencing of the cellobiose 2-epimerase gene from an obligatory anaerobe, Ruminococcus albus.

Cellobiose 2-epimerase (EC 5.1.3.

Transcriptomic analysis indicates putative metabolic changes caused by manipulation of phosphorus availability in rice leaves.

Plants have developed several strategies for coping with phosphorus (P) deficiency. However, the details of the regulation of gene expression of adaptations to low P are still unclear. Using a cDNA microarray, transcriptomic analyses were carried out of the rice genes regulated by P deficiency and P re-supply to P-deficient plants.