Comparative effects of Glomus mosseae and P fertilizer on foliar mineral composition of Acacia senegal seedlings inoculated with Rhizobium

Summary A factorial experiment with two controlled factors was conducted in the greenhouse with Acacia Senegal seedlings. The substrate was a degraded sandy soil (Dior soil) poor in available P (11 ppm — Olsen). The first controlled factor was soil sterilization, with two levels: (A) sterilized soil; (B) non-sterilized soil. The second factor was fertilization, with six levels: (1) uninoculated control; (2) inoculation with Rhizobium (ORS 1007); (3) inoculation with Glomus mosseae; (4) double inoculation with ORS 1007 and G. mosseae; (5) inoculation with ORS 1007 and 30 ppm phosphorus per plant; (6) inoculation with ORS 1007 and 60 ppm phosphours. The combination of the two factors and their levels led to 12 different plant treatments (A1–A6 and B1–B6). Compared to the control B1, the B5 and B6 treatments containing phosphorus increased: nodule dry weight about 7 times ; leaf dry weight about 4 times ; total N, P and Mg 4–5 times; total K and Ca 3–4 times. The mycorrhizal inoculation had the same positive effect on plant growth and mineral composition but with lower values. Plants inoculated with Rhizobium alone gave the lowest results. The A1 treatment gave lower values than B1. Foliar mineral contents varied within a narrow range (20–30%).     

Relationship between base composition in non-coding DNA of genes and codon composition

The C + G percentage in third position of codons is linearly dependent on the C + G composition of flanking regions and introns. A similar relationship is shown for the first and second position which significantly influence the nature of amino acid sequence. If mutations would be oriented according to the local base composition, this will imply that genes of the same multigenic family would evolve at different rate.     

Role of foliar application of 24-epibrassinolide in response of peanut seedlings to iron deficiency

Limited information is available on the role of brassinosteroids (BRs) in response of plants to nutrient deficiency. To understand the functions of BRs in response to iron deficiency, we investigated the effect of 24-epibrassinolide (EBR) on activities of ferric-chelate reductase (FCR), H⁺-ATPase, Ca²⁺-ATPase, nitrate reductase (NR), antioxidant enzymes, Fe and other minerals content and distribution, chlorophylls, soluble protein, free proline, reactive oxygen species, and malondialdehyde in peanut (Arachis hypogea L.) plants subjected to Fe deficiency (10^?5 M Fe(III)-EDTA) with foliar application of EBR (0, 10^?8, 5.0×10^?8, 10^?7, 5.0×10^?7, and10^?6 M). Results show that EBR increased Fe translocation from roots to shoots and increased Fe content in cell organelles. Activities of antioxidant enzymes increased and so the ability of resistance to oxidative stress was enhanced. As result of enhancement of H⁺-ATPase and Ca²⁺-ATPase activities, the inhibition of Fe, Ca, Mg, and Zn uptake and distribution was ameliorated. Chlorophyll, soluble protein, and free proline content also increased and consequently, chlorosis induced by Fe deficiency was alleviated. The results demonstrate that EBR had a positive role in regulating peanut growth and development under Fe deficiency and an optimal concentration appeared to be 10^?7 M.     

Relationship between bovine serum composition and its capacity to stimulate cell culture growth

A relationship has been studied between the growth-stimulating activity and chemical composition of bovine serum (BS) that is widely used for cell culture growth and virus replication. A direct correlation was shown between the growth-promoting activity of bovine serum, manifested on the model of chick embryo fibroblasts, and the contents of phospholipids, total lipids, proteins, and calcium in this serum. A significant inverse association has also been revealed between the growth-promoting activity of the serum and the amounts of cholesterol and glucose in this.     

Relationship between milk composition and pup's growth in mice

The effect of lactation numbers (first, second, and third) on milk composition and the relationship between milk composition and pup's growth were examined in four strains of mice (SHN, SLN, C3H/He, and GR/A). Although the percentage of milk fat and moisture increased and decreased, respectively, through the first to third lactations in C3H/He mice, no differences in milk composition among lactation numbers were observed in the other mouse strains. In pooled data derived from the four strains of mice, there was no significant correlation between milk composition and body weight or growth rate of pups on Day 12 or 20 of the first lactation. In contrast, the amount of milk fat and moisture was the positively and negatively, respectively, correlated with the pup's growth parameters during the second and third lactations. This was reflected by a lower fat content and a higher moisture content in the milk of GR/A mice, especially evident during the second and third lactations and reduced pup's growth, when compared with the other mouse strains. Milk lactose and ash content was not correlated with pup's growth parameters. The results of our study stress the importance of milk fat for the growth of mouse pups.     

Diagnosis of nitrogen deficiency and toxicity of Eucalyptus globulus seedlings by foliar analysis

The relationship between shoot growth and foliar nitrogen (N) in E. globulus seedlings was studied in the glasshouse to determine standard values for N deficiency and toxicity diagnosis. Seedlings were grown for 9 weeks in yellow sand, at 10 rates of N, applied as ammonium sulphate, calcium nitrate or ammonium nitrate. Shoot dry weight (DW) increased linearly with N rate for all forms of N in the deficiency range. Seedlings continued to respond to higher rates of ammonium and ammonium nitrate than to nitrate. Maximum shoot DW for nitrate fed plants and ammonium nitrate fed plants were 51% and 84% respectively of ammonium fed plants. Total N concentration in the youngest fully expanded leaf (YFEL) ranged from 1.0% to 3.3% in deficient and adequate plants. The critical N concentration for deficiency diagnosis (corresponding to 90% maximum yield) in the YFEL, determined from these growth response curves averaged over all N forms, was 2.6% N. For ammonium nitrate fed plants, total N concentration in the YFEL for the severely deficient, deficient, adequate, and toxic ranges were <1.4%, 1.4–2.5%, 2.6–3.5%, > 4.3%. High total N concentrations were associated with growth depression and toxicity symptoms, which differed with N form. For nitrate fed plants, a total N concentration above 3.3% in the YFEL was associated with severe growth depression, and leaf tip necrosis. The adequate concentration range for ammonium nitrate was similar to values found on a field trial with 7 month old E. globulus trees grown on an exforest site.     

Crop traits and the tolerance of wheat and barley to foliar disease

The relationship between yield loss and disease severity can differ widely between crops. This has given rise to the concept of disease tolerance, with some crops exhibiting a smaller yield loss under a given severity of disease than others. Genetic improvement to minimise yield loss under disease is an attractive goal, as it exerts little or no selection pressure on pathogen populations, and could form a useful component of durable disease management programmes. However, progress towards this end requires a thorough understanding of the phenotypic traits that influence the response of yield to disease, their genetic control and the possible trade-offs involved with other desirable agronomic characteristics. This paper examines the candidate crop traits that may confer tolerance of foliar disease in wheat and barley and reviews evidence of genetic variation in their expression. In wheat grown under the relatively low light conditions of North-West Europe, post-anthesis source (assimilate supply) and grain sink capacity (capacity for dry matter accumulation) appear to be closely balanced. Traits associated with maintaining post-anthesis radiation interception and radiation use efficiency in spite of disease may confer tolerance. The most promising traits include a larger flag leaf and compensatory increases in photosynthetic rate in non-infected parts of leaves. In barley, yield is often more strongly sink limited, and early-season disease management is required to protect the formation of potential grain sites. A wider range of potential traits may influence tolerance including compensatory adjustments in leaf growth and morphology, and differences in the sensitivity of tiller and spikelet mortality to photoassimilate supply. Different methods for quantifying tolerance are suggested depending on the trait of interest.     

Canopy tree species and openness affect foliar endophytic fungal communities of understory seedlings

There is growing evidence demonstrating the diversity of foliar endophytic fungi and their ecological roles in the survival of tree seedlings. However, the factors that shape fungal communities in tree seedlings within natural forest ecosystems remain poorly understood. Here, we evaluated the composition of foliar endophytic fungi growing in current-year seedlings of Cornus controversa and Prunus grayana in a cool temperate deciduous forest through a seed-sowing experiment and fungal isolation. The composition of endophytic fungi was affected by canopy tree species, canopy openness, and time after germination. In total, 27 and 22 fungal taxa were isolated from C. controversa and P. grayana seedlings, respectively. The dominant fungal taxa in both seedling species were Colletotorichum spp., and their isolation frequencies were higher under C. controversa canopies than under P. grayana canopies; the frequencies also increased with time after germination. These results suggest that overstory tree species strongly influences the endophytic fungal communities of understory seedlings.     

Relationship between diet composition and the fecundity of Musca domestica

A study of the relationship between diet compositions of housefly Musca domestica and the fecundity of the insect was carried out. Fecundity was increased more than 30% by adding a protein source and inorganic salts into the larval and adult diets. Also, adding a protein source into the adult diet prolonged the oviposition period of adult houseflies.     

Changes in enzyme activity of corn seedlings after foliar application of triacontanol

Changes in the activity of several enzymes in corn seedlings (Zea mays L.) after 1-triacontanol (TRIA) application have been analyzed. The specific activity of isocitrate dehydrogenase and 6-phosphogluconate dehydrogenase in corn seedlings treated with TRIA increased rapidly. Three days after treatment, the TRIA-treated seedlings showed 89% and 39% more ICDH and 6PGDH activity per mg protein, respectively, than the untreated plants. Malate dehydrogenase activity increased in treated plants at a rate approximately equivalent to the increase in soluble protein. Acid phosphatase, peroxidase, and alkaline phosphatase activity remained relatively constant on a per plant basis and decreased slightly on a per mg protein basis. No qualitative changes were observed in the isozyme patterns of the enzymes analyzed by starch gel electrophoresis, although quantitative changes consistent with the increases using spectrophotometric assays were observed.     

Relationship between hyperuricemia and chronic kidney disease

Because approximately 70% of uric acid is excreted from the kidney, hyperuricemia occurs when renal function deteriorates. Until now, it has not been clear if the hyperuricemia seen in such renal diseases plays a role in the progression of renal disease. However, recent clinical studies show that the serum uric acid value is closely associated with hypertension in hyperuricemic patients (cross-sectional study), and also with the onset of hypertension (longitudinal study). Furthermore, one interesting report shows that treatment of hyperuricemia with allopurinol lowers blood pressure in juvenile essential hypertension patients with hyperuricemia. In addition, it is well known that hyperuricemia is closely associated with chronic kidney disease (CKD), is a risk factor for renal insufficiency in general populations, and is a poor prognostic factor of renal function in patients who also have IgA nephropathy. On the other hand, in intervention studies on hyperuricemia, the treatment of hyperuricemia with allopurinol in CKD has resulted in a fall in blood pressure and inhibition of the progression of renal damage. Conversely, the cessation of allopurinol treatment in CKD was followed by a rise in blood pressure and the development of renal damage. Furthermore, the rise of blood pressure and development of renal damage following cessation of allopurinol treatment are only seen in patients not receiving angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB). This suggests that the renin angiotensin (RA) system plays an important role in the development of hypertension and renal damage from hyperuricemia.     

The activity of dung beetles increases foliar nutrient concentration in tropical seedlings

Dung beetles are extensively used as a focal taxon in tropical forests. Yet, information for most of their ecological functions comes from other systems. We present results from a field experiment in a tropical rain forest showing that dung beetle activity increases foliar phosphorus concentration in seedlings of the tree Brosimum lactescens. Our results open new lines of research to assess the multiple effects that dung beetles may have on rain forest plants.     

Relationship between photosynthetic phosphorus‐use efficiency and foliar phosphorus fractions in tropical tree species

How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P‐use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P‐containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass‐based photosynthetic carbon assimilation rate (A_mass), PPUE, total foliar P concentration, and foliar P fractions in 10 tree species in two tropical montane rain forests with differing soil P availability (five species on sedimentary soils and five species on P‐poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. A_mass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 tree species. Mean A_mass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P‐poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P‐containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P‐poor soils.     

Relationship between whole proteome aminoacid composition and static DNA curvature

To study possible relationships between an organism's genomic DNA curvature and the aminoacid composition of its proteome, every peptidic sequence from fully determined genomes was retrotranslated using the E. coli codon preferences, and the curvature profiles of the resulting DNA sequences were calculated and compared. A clear interdependence between these two variables was observed, as each retrotranslated proteome presented a distinctive, statistically significant DNA curvature profile biased toward its natural DNA curvature profile. In addition, by comparing the profiles arising from real and randomly permuted proteomes, we also found a position-dependent contribution of the peptidic sequence to DNA curvature. The implications of these results support the idea of a possible selection toward a specific global curvature of genomes.