Molecular cloning and characterization of six novel HMW‐GS genes from Aegilops speltoides and Aegilops kotschyi

Six novel high molecular weight glutenin subunits (HMW‐GS) from Aegilops speltoides (SS, 2n = 2x = 14) and Aegilops kotschyi (UUSS, 2n = 4x = 28) were identified by SDS‐PAGE and designated as ASy15*, AKx1*, AKx3*, AKx2.3, AKy20* and AKy8*, respectively. Their complete open reading frames (ORFs) were cloned and sequenced by allele‐specific PCR (AS‐PCR). Sequence comparison demonstrated that these novel genes displayed high single‐nucleotide polymorphisms (SNP) and InDel variations. In particular, AKy8* had an extra cysteine residue at position 140 in the central repetitive domain, while AKx2.3 had an unusually long repetitive domain (816 aa), which might have positive effects on gluten quality. Phylogenetic analysis showed that AKx1* and AKx3* belonged to the 1S genome, AKx2.3 to the 1U genome, and AKy20* and AKy8* most likely to the 1S genome. The divergence between the 6 HMW‐GS genes from the two Aegilops species and those from Triticum species occurred 4.77–23.54 MYA. The authenticity of these isolated endogenous HMW‐GS genes was confirmed through heterologous expression in Escherichia coli and Western blotting.     

Genetic variability,heritability and correlation among agronomic and disease resistance traits in a diversity panel and elite breeding material of spelt wheat

Spelt wheat (Triticum spelta L.) is an old‐world crop that has attracted increased attention since the 1970s accompanied by a constant increase in spelt production. Our objectives were to (i) study the genetic variability and heritability of important agronomic traits and (ii) examine the correlation among these traits for an efficient design of spelt breeding schemes. To this end, we compared a diversity panel of 150 old and new spelt varieties with current elite‐breeding material. Phenotypic data were recorded at multiple locations for yield, plant height, lodging, heading time, number of spikelets, ear snapping and susceptibility to powdery mildew, brown rust and Septoria tritici blotch. We observed highly significant genetic variances for almost all traits in both germplasm sets. Heritability estimates ranged from 0.23 for Septoria tritici blotch to 0.97 for plant height. A significant correlation between yield and plant height of ?0.56 as well as yield and lodging of ?0.39 was determined but no other correlation of yield with any of the examined traits. Thus, pedigree selection with early generation screenings on plant height and lodging can be recommended for further spelt improvement.     

Immunophenotyping and characterization of BNP colostra revealed pathogenic alloantibodies of IgG1 subclass with specifity to platelets, granulocytes and monocytes of all maturation stages

Bovine neonatal pancytopenia (BNP) is mainly characterized by multiple haemorrhages, thrombocytopenia and leukocytopenia as a result of bone marrow depletion. BNP can be induced in healthy calves through application of colostrum from BNP donors, proofing that BNP is mediated to maternal alloantibodies. Alloantibody binding to bovine blood cells is present in sera and colostra of BNP donors and is probably initialized by vaccination with a certain BVD vaccine. To understand etiology and pathomechanisms of BNP, we closely characterized disease inducing antibodies regarding immunoglobulin subclass and binding specificities to peripheral blood derived leukocytes and platelets. By exact phenotyping the targeted blood cell subsets, including platelets for the first time, we investigated that BNP alloantibodies are exclusively of IgG1 subclass. Interestingly, IgG1 of BNP colostra bound to 70% leukocytes and 100% platelets irrespective of different bovine breeds and cellular maturity of all specimens tested. Furthermore, staining pattern on platelets as well as leukocyte subsets by BNP-IgG1 alloantibody exposed 100% reactivity to platelets, granulocytes and monocytes. Interestingly, the main part of T-helper cells was not bound by colostral alloantibodies. Our results point to a crucial role of IgG1 antibodies in BNP and to a target antigen that is expressed by all cells of myeloid lineage, but only partially by the lymphoid lineage.     

Soil‐carbon preservation through habitat constraints and biological limitations on decomposer activity

We review recent experimental results on the role of soil biota in stabilizing or destabilizing soil organic matter (SOM). Specifically, we analyze how the differential substrate utilization of the various decomposer organisms contributes to a decorrelation of chemical stability, residence time, and carbon (C) age of organic substrates. Along soil depth profiles, a mismatch of C allocation and abundance of decomposer organisms is consistently observed, revealing that a relevant proportion of soil C is not subjected to efficient decomposition. Results from recent field and laboratory experiments suggest that (1) bacterial utilization of labile carbon compounds is limited by short‐distance transport processes and, therefore, can take place deep in the soil under conditions of effective local diffusion or convection. In contrast, (2) fungal utilization of phenolic substrates, including lignin, appears to be restricted to the upper soil layer due to the requirement for oxygen of the enzymatic reaction involved. (3) Carbon of any age is utilized by soil microorganisms, and microbial C is recycled in the microbial food web. Due to stoichiometric requirements of their metabolism, (4) soil animals tend to reduce the C concentration of SOM disproportionally, until it reaches a threshold level. The reviewed investigations provide new and quantitative evidence that different soil C pools underlie divergent biological constraints of decomposition. The specialization of decomposers towards different substrates and microhabitats leads to a relatively longer persistence of virtually all kinds of organic substrates in the nonpreferred soil spaces. We therefore propose to direct future research explicitly towards such biologically nonpreferred areas where decomposition rates are slow, or where decomposition is frequently interrupted, in order to assess the potential for long‐term preservation of C in the soil.     

Forstwissenschaftliches centralblatt

Ohne Zusammenfassung     

Cytotoxicity of plants used in traditional medicine in Yemen

Twenty-five extracts obtained from 14 plant species used in the traditional medicine in Yemen have been screened for cytotoxic activity against human ECV-304 cells. Extracts of Dracaena cinnabari, Eucalyptus camaldulensis, Euclea divinorum, Euphorbia cactus, Pulicaria crispa, and Withania somnifera displayed a remarkable activity.     

Ecology of sound communication in fishes

Fishes communicate acoustically under ecological constraints which may modify or hinder signal transmission and detection and may also be risky. This makes it important to know if and to what degree fishes can modify acoustic signalling when key ecological factors—predation pressure, noise and ambient temperature—vary. This paper reviews short‐time effects of the first two factors; the third has been reviewed recently (Ladich, 2018 ). Numerous studies have investigated the effects of predators on fish behaviour, but only a few report changes in calling activity when hearing predator calls as demonstrated when fish responded to played‐back dolphin sounds. Furthermore, swimming sounds of schooling fish may affect predators. Our knowledge on adaptations to natural changes in ambient noise, for example caused by wind or migration between quiet and noisier habitats, is limited. Hearing abilities decrease when ambient noise levels increase (termed masking), in particular in taxa possessing enhanced hearing abilities. High natural and anthropogenic noise regimes, for example vessel noise, alter calling activity in the field and laboratory. Increases in sound pressure levels (Lombard effect) and altered temporal call patterns were also observed, but no switches to higher sound frequencies. In summary, effects of predator calls and noise on sound communication are described in fishes, yet sparsely in contrast to songbirds or whales. Major gaps in our knowledge on potential negative effects of noise on acoustic communication call for more detailed investigation because fishes are keystone species in many aquatic habitats and constitute a major source of protein for humans.     

Use of near infrared spectroscopy to determine biological and chemical characteristics of organic layers under spruce and beech stands

The chemical composition of organic layers of forest soils shows a high spatial variability and fast methods may be required for its study at a landscape level. The objective was to assess the applicability of near infrared spectroscopy (NIRS) to measure several chemical and biological properties of organic layers in spruce, beech, and mixed spruce‐beech stands. Spectra in the VIS‐NIR region (400—2500 nm) were recorded for 406 samples representing Oi, Oe, and Oa layers of forest soils from Solling (Germany), 195 of them were used for calibration and 211 for validation. The calibration equations for each constituent were developed using the whole spectrum (0^th to 3^rd derivative). Humus samples were analyzed for contents of C and N and contents of P, S, Na, K, Ca, Mg, Mn, Fe, and Al after pressure digestion in HNO₃. Additionally, basal respiration and microbial C (C_mic) were measured. NIRS predicted well the contents of C, N, P, S, Ca, Na, K, Fe, and Al and C/N and C/P ratios: the regression coefficients (a) of a linear regression (measured against predicted values) ranged from 0.9 to 1.1, and the correlation coefficients (r) were greater or equal 0.9. C_mic (a = 0.87, r = 0.83) was predicted satisfactorily, whereas the prediction of the basal respiration (a = 0.74, r = 0.87) was less satisfactory. Due to liming of some of the plots NIRS failed to predict contents of Mg (a = 1.27, r = 0.68). For all chemical and biological characteristics the best prediction performances were achieved using the whole sample population. Splitting the samples into smaller groups according to a dominant tree species or an organic layer did not improve the predictions.<?show $6#>