Egg production and life history of Alona guttata Sars, 1862 (Cladocera, Chydoridae): implications for colonization of temporary ponds

Cladocerans are a diverse group of species that show rapid responses to changes in environmental conditions. This adaptive capacity has important implications for egg production and life cycle, especially in transitory environments such as temporary waterbodies. The present study investigated the life history and egg production of Alona gutatta Sars, 1862 (Crustacea, Cladocera), an abundant and frequent species from a high-altitude temporary pond (Lagoa Seca, Minas Gerais, Brazil). Newly hatched neonates were monitored in relation to time of maturation, number of eggs produced per female and time of survival. Neonates required a mean of 8 days to mature. A. guttata survived for a mean of 30.9 ± 8.1 days and produced 2 eggs per brood, generating a mean of 10.95 ± 6.41 neonates during the entire life cycle. The rapid development, short time to produce eggs and long life cycle are important adaptations to the adverse environmental conditions of temporary aquatic environments, which can contribute to the rapid colonization of Alona guttata in transitory ecosystems.

Biomineralization by Extremely Halophilic and Metal-Tolerant Community Members from a Sulfate-Dominated Metal-Rich Environment

The adaptation to adverse environmental conditions can lead to adapted microbial communities that may be screened for mechanisms involved in halophily and, in this case, metal tolerance. At a former uranium mining and milling site in Seelingstädt, Germany, microbial communities from surface waters and sediment soils were screened for isolates surviving high salt and metal concentrations. The high salt contents consisted mainly of chloride and sulfate, both in soil and riverbed sediment samples, accompanied by high metal loads with presence of cesium and strontium. The community structure was dominated by Chloroflexi, Proteobacteria and Acidobacteriota, while only at the highest contaminations did Firmicutes and Desulfobacterota reach appreciable percentages in the DNA-based community analysis. The extreme conditions providing high stress were mirrored by low numbers of cultivable strains. Thirty-four extremely halotolerant bacteria (23 Bacillus sp. and another 4 Bacillales, 5 Actinobacteria, and 1 Gamma-Proteobacterium) surviving 25 to 100 mM SrCl2, CsCl, and Cs2SO4 were further analyzed. Mineral formation of strontium- or cesium-struvite could be observed, reducing bioavailability and thereby constituting the dominant metal and salt resistance strategy in this environment.

Typical 2-Cys Peroxiredoxins as a Defense Mechanism against Metal-Induced Oxidative Stress in the Solitary Ascidian Ciona robusta

Typical 2-Cys peroxiredoxins (2-Cys Prdxs) are proteins with antioxidant properties belonging to the thioredoxin peroxidase family. With their peroxidase activity, they contribute to the homeostatic control of reactive oxygen species (ROS) and, therefore, participate in various physiological functions, such as cell proliferation, differentiation, and apoptosis. Although Prdxs have been shown to be potential biomarkers for monitoring aquatic environments, minimal scientific attention has been devoted to describing their molecular architecture and function in marine invertebrates. Our study aims to clarify the protective role against stress induced by exposure to metals (Cu, Zn, and Cd) of three Prdxs (Prdx2, Prdx3, and Prdx4) in the solitary ascidian Ciona robusta, an invertebrate chordate. Here, we report a detailed pre- and post-translational regulation of the three Prdx isoforms. Data on intestinal mRNA expression, provided by qRT-PCR analyses, show a generalized increase for Prdx2, -3, and -4, which is correlated to metal accumulation. Furthermore, the increase in tissue enzyme activity observed after Zn exposure is slower than that observed with Cu and Cd. The obtained results increase our knowledge of the evolution of anti-stress proteins in invertebrates and emphasize the importance of the synthesis of Prdxs as an efficient way to face adverse environmental conditions.

To Fight or to Grow: The Balancing Role of Ethylene in Plant Abiotic Stress Responses

Plants often live in adverse environmental conditions and are exposed to various stresses, such as heat, cold, heavy metals, salt, radiation, poor lighting, nutrient deficiency, drought, or flooding. To adapt to unfavorable environments, plants have evolved specialized molecular mechanisms that serve to balance the trade-off between abiotic stress responses and growth. These mechanisms enable plants to continue to develop and reproduce even under adverse conditions. Ethylene, as a key growth regulator, is leveraged by plants to mitigate the negative effects of some of these stresses on plant development and growth. By cooperating with other hormones, such as jasmonic acid (JA), abscisic acid (ABA), brassinosteroids (BR), auxin, gibberellic acid (GA), salicylic acid (SA), and cytokinin (CK), ethylene triggers defense and survival mechanisms thereby coordinating plant growth and development in response to abiotic stresses. This review describes the crosstalk between ethylene and other plant hormones in tipping the balance between plant growth and abiotic stress responses.

Efficiency of in vitro culture techniques applied to soybean (Glycine max (L.) Merr.) accessions from the VIR collection

Using a wide range of modern biotechnologies and genetic techniques to study plant germplasm accessions held by VIR makes it possible to procure valuable results, required for the development of new high-yielding cultivars adapted to adverse environmental conditions and possessing specified technological properties, particularly to identify and mark new genes and alleles useful for plant breeding. This research trend is in line with Presidential Decree No. 680 “Concerning the development of genetic technologies in the Russian Federation”. Soybean is among the key crops in agricultural production, but the use of next-generation breeding tools to obtain new soybean cultivars with desired properties is still limited. Successful application of novel methods also requires new approaches to studying soybean accessions, specifically their ability to regenerate and produce calluses for subsequent inclusion in biotechnological programs.Ten soybean accessions of various origin, contrasting in ripening schedules, were selected to study the possibility of effective introduction into in vitro culture and further assessment of their ability to produce calluses and regenerate in in vitro culture. The work included evaluating the effects of different seed sterilization techniques (one-step sterilization, using a commercial bleach, and two-step one, combining the impacts of a chlorine-containing preparation and hydrogen peroxide), types of explants (epicotyls, hypocotyls, cotyledon nodes, and cotyledon leaf segments), and phytohormone composition of nutrient medium: (1) MS + 1.13 mg/L BAP + 0.5 mg/L HA, and (2) MS +1 mg/L BAP + 0.1 mg/L IAA).The assessment results showed that the option of two-step seed sterilization was the most effective for soybean at the stage of in vitro culture initiation, while hypocotyls, epicotyls, and cotyledon nodes had the highest callus formation ability in both types of nutrient media.

Control Potentials of Three Entomopathogenic Bacterial Isolates for the Carob Moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae) in Pomegranates

Ectomyelois ceratoniae (Lepidoptera: Pyralidae) is the primary pest of pomegranates in Saudi Arabia and is mostly controlled using broad-spectrum pesticides. Providing environmentally sound choices to limit reliance on chemical management is a major challenge in the control of E. ceratoniae and, as a consequence, in the protection of pomegranate crops from its invasion. Entomopathogenic bacteria (EPB) symbiotically associated with entomopathogenic nematodes (EPNs) are well-known biocontrol agents of soil-dwelling or aerial pests. The bacterium symbiont (EPB) is the real insect-killing biocontrol agent, while the nematode (EPN) serves as a vector. We wondered whether the EPB vector, which is extremely vulnerable to adverse environmental conditions, like drought, high temperatures, and repellent soil microorganisms, could be omitted. We intended to evaluate the biocontrol potential of directly applied EPB cells and cell-free culture media (CFCM) on the larval instar E. ceratoniae. Xenorhabdus budapestensis DSM 16342 (EMA), X. szentirmaii DSM 16338 (EMC), and Photorhabdus luminescens ssp. laumondi (TT01) strains were used. After three days of exposure, the cells of EMA, EMC, and TT01 strains resulted in 100%, 88%, and 79.3% larval mortality rates, respectively. The applied EMA CFCM resulted in 53.7% larval mortality, indicating the presences of (at least) one extremely strong component produced by EMA. We concluded that the direct application of either the EPB cells or the CFCM must be a prospective alternative biocontrol of E. ceratoniae, especially to protect the important fruit (pomegranate, Punica granatum) cultivars. Especially, newly identified local EPB isolates could be applied as bio-pesticides for integrated management practices or organic pomegranate production.

Seed Priming: An Interlinking Technology between Seeds, Seed Germination and Seedling Establishment

Biologically seed is a small embryonic plant along with either endosperm or cotyledons, enclosed with in an outer protecting covering called seed coat. During the time of seed development large metabolic conversions take place, including proper partitioning of photo-assimilates and the formation of complex polymeric forms of carbohydrate, protein and fats for storing as seed reserves. In developing phase of seeds, every detail information stored in the embryonic plant are genetically and sometimes epigenetically also predetermined and influenced by various environmental/external factors already faced by the mother plant. In the growth cycle of plants, seed germination and seedling establishment are the two critical phases where survivability of the seedlings in natural habitats is a matter of question until the onset of photosynthesis by the established seedling. The various sequence of complex processes known to occur in both the phases i.e., an array of metabolic activities are initiating which eventually leads to the renewal of embryo growth of the dormant seeds and ultimately seedlings are established. Efficient seed germination is an important factor for agricultural sciences and successful establishment of germinated seedling requires a rapid and uniform emergence and root growth. With these aspects of seed physiology kept in mind the present chapter will be designed in such a way where, a gap filling, inter linking, eco- and farmers\' friendly technology i.e., ‘seed priming’ (a pre-sowing partial hydration of seeds) will be considered to improve the rate and uniformity of germination and seedling establishment. Under optimal and adverse environmental conditions, the primed seeds of diversified species lead to an enhanced germination performance with increased vigor index has been reported by various scientists which indicates a good establishment of seedlings in the field and thereafter enhance the performance of crops as a whole.

Polysaccharide Hydrogels for the Protection of Dairy-Related Microorganisms in Adverse Environmental Conditions

Adverse environmental conditions are severely limiting the use of microorganisms in food systems, such as probiotic delivery, where low pH causes a rapid decrease in the survival of ingested bacteria, and mixed-culture fermentation, where stepwise changes and/or metabolites of individual microbial groups can hinder overall growth and production. In our study, model probiotic lactic acid bacteria (L. plantarum ATCC 8014, L. rhamnosus GG) and yeasts native to dairy mixed cultures (Kluyveromyces marxianus ZIM 1868) were entrapped in an optimized (cell, alginate and hardening solution concentration, electrostatic working parameters) Ca-alginate system. Encapsulated cultures were examined for short-term survival in the absence of nutrients (lactic acid bacteria) and long-term performance in acidified conditions (yeasts). In particular, the use of encapsulated yeasts in these conditions has not been previously examined. Electrostatic manufacturing allowed for the preparation of well-defined alginate microbeads (180–260 µm diameter), high cell-entrapment (95%) and viability (90%), and uniform distribution of the encapsulated cells throughout the hydrogel matrix. The entrapped L. plantarum maintained improved viabilities during 180 min at pH 2.0 (19% higher when compared to the free culture), whereas, L. rhamnosus appeared to be less robust. The encapsulated K. marxianus exhibited double product yields in lactose- and lactic acid-modified MRS growth media (compared to an unfavorable growth environment for freely suspended cells). Even within a conventional encapsulation system, the pH responsive features of alginate provided superior protection and production of encapsulated yeasts, allowing several applications in lacto-fermented or acidified growth environments, further options for process optimization, and novel carrier design strategies based on inhibitor charge expulsion.

Creation of winter wheat source material with increased adaptive potential to adverse environmental conditions

The goal until the last day was to create a new sort with high indicators of productivity, adaptability and quality of grain on the basis of the directed selection process and comprehensive study of hybrid material on field and laboratory estimations. Creation of initial material with high productivity, adaptability and grain quality by directed selection and hybrid material comprehensive study is described. General scientific, special genetic, field, laboratory methods, morphological analysis and statistical methods were used in the research. Given that the weight of grain from 1 ear is a marker in breeding for high yield (r=0.53), the largest (50 %) positive transgressions were in F1 hybrids using new genetic plasma varieties. Among hybrid populations F2, F3 and F4, selection value is represented by hybrid populations 4971 and 4976, which have the lowest stress resistance (–16.1, –18.6) and variation (16.9, 19.9) and the highest genetic stability (50.0, 50.2) and homeostaticity (19.1, 14.3), respectively. Among Control, Preliminary and Competitive tests, lines UK2621/18 and UK9855/18 have high stress resistance (–4.7, –5.8), homeostaticity (1416.0, 1008.0) and low variability (2.6 %, 3.5 %), respectively. They are the most adaptive and malleable to average and adverse environmental conditions. Line UK1182/17, which in 2020 was submitted for consideration to the State variety testing as "Blahovishchenska" (Kiev, Ukraine), was created using the purposeful method of pedigree in each link of selection. It has high adaptability, resistance to lodging, major diseases, high average yield (90.8 c/ha), and grain quality – it is strong wheat (protein amount 13.5–14.0 %, gluten – 30–35 %). Pedigree is the most effective method of continuous individual selection, which allows creating source material with high productivity, resistance to disease and adverse environmental factors