Comparative analysis of storage conditions and homogenization methods for tick and flea species for identification by MALDI‐TOF MS

Ticks and fleas are vectors for numerous human and animal pathogens. Controlling them, which is important in combating such diseases, requires accurate identification, to distinguish between vector and non‐vector species. Recently, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) was applied to the rapid identification of arthropods. The growth of this promising tool, however, requires guidelines to be established. To this end, standardization protocols were applied to species of Rhipicephalus sanguineus (Ixodida: Ixodidae) Latreille and Ctenocephalides felis felis (Siphonaptera: Pulicidae) Bouché, including the automation of sample homogenization using two homogenizer devices, and varied sample preservation modes for a period of 1–6 months. The MS spectra were then compared with those obtained from manual pestle grinding, the standard homogenization method. Both automated methods generated intense, reproducible MS spectra from fresh specimens. Frozen storage methods appeared to represent the best preservation mode, for up to 6 months, while storage in ethanol is also possible, with some caveats for tick specimens. Carnoy's buffer, however, was shown to be less compatible with MS analysis for the purpose of identifying ticks or fleas. These standard protocols for MALDI‐TOF MS arthropod identification should be complemented by additional MS spectrum quality controls, to generalize their use in monitoring arthropods of medical interest.     

Drought Tolerance in Mung Bean is Associated with the Genotypic Divergence,Regulation of Proline,Photosynthetic Pigment and Water Relation

Drought is one of the critical conditions for the growth and productivity of many crops including mung bean (Vigna radiata L. Wilczek). Screening of genotypes for variations is one of the suitable strategies for evaluating crop adaptability and global food security. In this context, the study investigated the physiological and biochemical responses of four drought tolerant (BARI Mung-8, BMX-08010-2, BMX-010015, BMX-08009-7), and four drought sensitive (BARI Mung-1, BARI Mung-3, BU Mung-4, BMX-05001) mung bean genotypes under wellwatered (WW) and water deficit (WD) conditions. The WW treatment maintained sufficient soil moisture (22% ± 0.5%, i.e., 30% deficit of available water) by regularly supplying water. Whereas, the WD treatment was maintained throughout the growing period, and water was applied when the wilting symptom appeared. The drought tolerant (DT) genotypes BARI Mung-8, BMX-08010-2, BMX-010015, BMX-08009-7 showed a high level of proline accumulation (2.52–5.99 mg g⁻¹ FW), photosynthetic pigment (total chlorophyll 2.96–3.27 mg g⁻¹ FW at flowering stage, and 1.62–2.38 mg g⁻¹ FW at pod developing stage), plant water relation attributes including relative water content (RWC) (82%–84%), water retention capacity (WRC) (12–14) as well as lower water saturation deficit (WSD) (19%–23%), and water uptake capacity (WUC) (2.58–2.89) under WD condition, which provided consequently higher relative seed yield. These indicate that the tolerant genotypes gained better physiobiochemical attributes and adaptability in response to drought conditions. Furthermore, the genotype BMX- 08010-2 showed superiority in terms of those physio-biochemical traits, susceptibility index (SSI) and stress tolerance index (STI) to other genotypes. Based on the physiological and biochemical responses, the BMX-08010-2 was found to be a suitable genotype for sustaining yield under drought stress, and subsequently, it could be recommended for crop improvement through hybridization programs. In addition, the identified traits can be used as markers to identify tolerant genotypes for drought-prone areas.     

Molecular cytogenetics studies in Reichardia tingetana: Physical mapping of heterochromatin,telomere repeats,and 5S and 45S rDNA by 4′, 6‐diamidino‐2‐phenylindole and fluorescence in situ hybridization

Abstract Molecular cytogenetics studies of A‐T‐rich regions, telomeres, and 5S and 45S rDNA sites on the chromosomes of Reichardia tingetana Roth (2n= 16; diploid) were done using 4′, 6‐diamidino‐2‐phenylindole (DAPI) and fluorescence in situ hybridization (FISH). The species were collected from three geographically isolated populations at Borg El Arab (salt marsh habitat), and Rashed and Shosha (sandy clay habitats) in Egypt. The three populations showed the chromosome number of all plants are diploid except for two tetraploid samples from Shosha. Plants from both Rashed and Shosha showed similarity in the distribution of six DAPI bands on six chromosomes, whereas those of Borg El Arab showed a distribution of 16 bands on 14 chromosomes. The FISH signals of the telomeres, and 5S and 45S rDNA, were at the telomeres of all chromosomes, two interstitial, and four terminal, respectively. The combination of DAPI and FISH showed colocalization of the DAPI bands with two 5S and two 45S rDNA loci. The increased number of DAPI bands in the cytotypes from the salt marsh habitat could indicate natural genetic adaptation through increasing the heterochromatin of A‐T‐rich regions.     

<Emphasis Type="Italic">Dunaliella salina</Emphasis> exopolysaccharides: a promising biostimulant for salt stress tolerance in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)

Microalgal exopolysaccharides represent a potential sustainable alternative for the enhancement and protection of agricultural crops including management of both biotic and abiotic stress. In the present study, we investigated the potential of Dunaliella salina exopolysaccharides (PS) to attenuate the effect of salt stress on growth of Solanum lycopersicum, which was grown under different salinity levels (3 and 6 g L^?1 NaCl). The effects of PS treatment on plant growth, osmoprotectant molecules, protein content, and antioxidant enzymes activities of tomato plants under salt stress were analyzed. A metabolomics study showed that the exopolysaccharides released by D. salina contained sulfated moiety along with carbohydrates and uronic acids. The application of sulfated exopolysaccharides on tomato plants alleviated the salt stress and mitigated the decrease in length and dry weight of the plant’s shoot and root systems, as well as that of potassium (K⁺), and K⁺/Na⁺ ratio. Furthermore, the increase in proline, phenolic compounds, Na⁺, and antioxidant enzymes (CAT, POD, SOD) activities caused by salt stress were attenuated after the exopolysaccharide treatment. GC-MS metabolomics analysis showed that PS treatment allowed the activation and/or inhibition of various metabolic pathways involved in the plant’s tolerance to stress such as jasmonic acid-dependent pathways. This study shows the potential of microalgal exopolysaccharides for enhancing tomato tolerance to salt stress and highlights the possibility of their use as plant growth biostimulants under harsh environmental conditions.     

Energy and greenhouse gas balance of bioenergy production from poplar and willow: a review

Short‐rotation woody crops (SRWC) such as poplar and willow are an important source of renewable energy. They can be converted into electricity and/or heat using conventional or modern biomass technologies. In recent years many studies have examined the energy and greenhouse gas (GHG) balance of bioenergy production from poplar and willow using various approaches. The outcomes of these studies have, however, generated controversy among scientists, policy makers, and the society. This paper reviews 26 studies on energy and GHG balance of bioenergy production from poplar and willow published between 1990 and 2009. The data published in the reviewed literature gave energy ratios (ER) between 13 and 79 for the cradle‐to‐farm gate and between 3 and 16 for cradle‐to‐plant assessments, whereas the intensity of GHG emissions ranged from 0.6 to 10.6 g CO₂ Eq MJ_biomass^?1 and 39 to 132 g CO₂ Eq kWh^?1. These values vary substantially among the reviewed studies depending on the system boundaries and methodological assumptions. The lack of transparency hampers meaningful comparisons among studies. Although specific numerical results differ, our review revealed a general consensus on two points: SRWC yielded 14.1–85.9 times more energy than coal (ER_coal～0.9) per unit of fossil energy input, and GHG emissions were 9–161 times lower than those of coal (GHG_coal～96.8). To help to reduce the substantial variability in results, this review suggests a standardization of the assumptions about methodological issues. Likewise, the development of a widely accepted framework toward a reliable analysis of energy in bioenergy production systems is most needed.     

Relation among plant growth,carbohydrates and flowering time in the Arabidopsis Landsberg erecta × Kondara recombinant inbred line population

Arabidopsis thaliana natural variation was used to study plant performance viewed as the accumulation of photo‐assimilates, their allocation and storage, in relation to other growth‐related features and flowering‐related traits. Quantitative trait locus (QTL) analysis using recombinant inbred lines derived from the cross between Landsberg erecta (originating from Poland) and Kondara (originating from Tajikistan) grown on hydroponics, revealed QTLs for the different aspects of plant growth‐related traits, sugar and starch contents and flowering‐related traits. Co‐locations of QTLs for these different aspects were detected at different regions, mainly at the ER locus; the top of chromosomes 3, 4 and 5; and the bottom of chromosome 5. Increased plant growth was associated with early flowering and leaf transitory starch, and correlated negatively with the levels of soluble sugar at early phases of development. From the significant correlations and the co‐locations of the QTLs for these aspects, we conclude that there is a complex relationship between plant growth‐related traits, carbohydrate content and flowering‐related traits.     

Iron requirement and siderophore production in Rhizobium ciceri during growth on an iron-deficient medium

Under conditions of iron limitation many rhizospheric bacteria produce siderophores, ferric iron-specific ligands, which may enhance plant growth by increasing the availability of iron near the roots. Thirty-five strains of Rhizobium ciceri, specific to chickpea (Cicer arietinum L.), were screened for their ability to grow on iron-deficient medium and to produce siderophores. Maximal growth of all strains previously depleted in iron was obtained in medium containing 5 to 10 m of ferric iron. When iron limitation was achieved by the addition of 2,2-bipyridyl or EDDHA [ethylene diamine di(o-hydroxyphenyl) acetic acid] to the medium, only two strains were able to scavenge iron and grow. Siderophore production by these two strains was detected by the Chrome Azurol S assay (CAS), a universal test for siderophores. No hydroxamate-type siderophores were detected in the supernatants of Rhizobium ciceri cultures. However, some strains secreted salicylic acid and 2,3-dihydroxybenzoic acid as phenolate-type siderophores. Addition of ferric iron to the culture medium increased growth yield significantly but depressed the production of siderophores. Although these compounds are produced in response to iron deficiency, nutritive components of the culture medium significantly affected their production. It seems that CuII, MoVI and MnII ions bound competitively with iron to siderophores, resulting in a 34 to 100% increase in production.