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Plant microbiome (or phytomicrobiome) engineering (PME) is an anticipated untapped alternative strategy that could be exploited for plant growth, health and productivity under different environmental conditions. It has been proven that the phytomicrobiome has crucial contributions to plant health, pathogen control and tolerance under drastic environmental (a)biotic constraints. Consistent with plant health and safety, in this article we address the fundamental role of plant microbiome and its insights in plant health and productivity. We also explore the potential of plant microbiome under environmental restrictions and the proposition of improving microbial functions that can be supportive for better plant growth and production. Understanding the crucial role of plant associated microbial communities, we propose how the associated microbial actions could be enhanced to improve plant growth-promoting mechanisms, with a particular emphasis on plant beneficial fungi. Additionally, we suggest the possible plant strategies to adapt to a harsh environment by manipulating plant microbiomes. However, our current understanding of the microbiome is still in its infancy, and the major perturbations, such as anthropocentric actions, are not fully understood. Therefore, this work highlights the importance of manipulating the beneficial plant microbiome to create more sustainable agriculture, particularly under different environmental stressors.

Abstract Habitat type is a strong determinant of microbial composition. Habitat interfaces, such as the boundary between aquatic and terrestrial systems, present unique combinations of abiotic factors for microorganisms to contend with. Aside from the spillover of certain harmful microorganisms from agricultural soils into water (e.g. fecal coliform bacteria), we know little about the extent of soil-water habitat switching across microbial taxa. In this study, we developed a proof-of-concept system to facilitate the capture of putatively generalist microorganisms that can colonize and persist in both soil and river water. We aimed to examine the phylogenetic breadth of putative habitat switchers and how this varies across different source environments. Microbial composition was primarily driven by recipient environment type, with the strongest phylogenetic signal seen at the order level for river water colonizers. We also identified more microorganisms colonizing river water when soil was collected from a habitat interface (i.e. soil at the side of an intermittently flooded river, compared to soil collected further from water sources), suggesting that environmental interfaces could be important reservoirs of microbial habitat generalists. Continued development of experimental systems that actively capture microorganisms that thrive in divergent habitats could serve as a powerful tool for identifying and assessing the ecological distribution of microbial generalists. A new system using microbiome transfer between aquatic and terrestrial environments to identify putative microbial habitat generalists.

Insects are vital arthropods that significantly impact various ecosystems. Their successful colonization of diverse habitats spanning from cold to warm environments is made possible by numerous adaptations shaped by environmental selection. This comprehensive review delves into the spectrum of physiological adaptations exhibited by insects to thrive in diverse environments, with a particular emphasis on the connection between these adaptations and the challenges posed by cold temperatures. Focusing on both long-term and short-term strategies, the review highlights the key protective mechanisms that insects employ to cope and thrive in cold temperatures. To withstand these constraints, insects have developed four main strategies: freeze tolerance, freeze avoidance, cryoprotective dehydration, and vitrification. These adaptive responses involve crucial physiological and biochemical changes that enable insects to withstand low temperatures. Specifically, insects exhibit cold tolerance through a range of molecular adaptive strategies, which encompass alterations in the expression of specific target genes, the synthesis of ice core formers, and the production of polyol cryoprotectants. Despite these remarkable results, there is still a lack of in-depth knowledge about the major factors contributing to successful overwintering of insects and their ability to withstand extremely low temperatures. To address these gaps, technological advances and genome sequencing of model organisms are critical to uncover the molecular mechanisms in insect responses to low temperatures. The knowledge gained from these advances provides valuable information about insect cold tolerance strategies and paves the way for a better understanding of their ecological importance and potential applications in conservation and ecological management.

1. Atmospheric nitrogen (N) deposition and climate warming are two major components of global change that drive species richness and composition in plant communities. However, their combined effects have been insufficiently investigated across large spatial and temporal scales particularly in high-elevation, nutrient-limited ecosystems. 2. We examine whether and how N deposition and climate warming have altered the plant richness and the composition of subalpine semi-natural, extensively grazed grasslands of the Pyrenees, using two complementary approaches: (i) analysis of 553 relevés to explore vegetation changes across large ecological gradients including temperature and N deposition (spatial approach) and (ii) a re-sampling of a subset of 40 sites among the 553 sites to assess temporal changes over the past decades (temporal approach). 3. Both approaches showed that the vascular plant species richness increased when temperature and cumulative N deposition increase, shifting the species composition towards more thermophilic and eutrophic communities. 4. Synthesis. We hypothesize that the release from abiotic constraints (milder temperature and higher nitrogen availability) due to global changes and long-standing extensive grazing counteracting the negative effects of nitrogen deposition have been responsible for the diversity and compositional changes of plant communities over the last decades in the Pyrenees. Thus, in contrast with other grasslands, high-elevation grazed grasslands may increase in species diversity with nitrogen deposition under climate warming.

BackgroundPulses are cultivated across a range of soil and climatic conditions that often have many abiotic constraints to production. Whilst water stress has been identified as the greatest constraint in Australian pulse cultivation, other limitations include heat, frost, nutrient deficiency, and a variety of soil physiochemical constraints. Several studies on various pulses have examined shoot and root architecture and their ability to mitigate specific abiotic constraints. However, these studies have been conducted independently of each other, and there is a lack of amalgamated information combining both shoot and root responses that can address production constraints.ScopeThis review examines the shoot and root system architecture of key pulses used for human consumption grown in Australia including chickpea, lentil, faba bean, field pea and lupin; and where possible it provides a comparison with relevant research from other crops, especially cereals. It examines research conducted on adaptations to drought, waterlogging, temperature extremes, soil chemical toxicities and high soil strength.ConclusionThe review utilises a physiological framework to identify trait combinations that define theoretical ideotypes of pulse crops that would be better able to mitigate abiotic constraints currently limiting Australian pulse productivity. This framework can be extended directly to other similar environments globally or be used to develop new ideotypes that are better adapted to a wider range of regions within Australia.

Thermal biology of lizards affects their overall physiological performance. Thus, it is crucial to study how abiotic constraints influence thermoregulation. We studied the effect of wind speed on thermoregulation in an endangered mountain lizard ( Iberolacerta aurelioi ). We compared two populations of lizards: one living in a sheltered rocky area and the other living in a mountain ridge, exposed to strong winds. The preferred temperature range of I. aurelioi , which reflects thermal physiology, was similar in both areas, and it was typical of a cold specialist. Although the thermal physiology of lizards and the structure of the habitat were similar, the higher wind speed in the exposed population was correlated with a significant decrease in the effectiveness thermoregulation, dropping from 0.83 to 0.74. Our results suggest that wind reduces body temperatures in two ways: via direct convective cooling of the animal and via convective cooling of the substrate, which causes conductive cooling of the animal. The detrimental effect of wind on thermoregulatory effectiveness is surprising, since lizards are expected to thermoregulate more effectively in more challenging habitats. However, wind speed would affect the costs and benefits of thermoregulation in more complex ways than just the cooling of animals and their habitats. For example, it may reduce the daily activity, increase desiccation, or complicate the hunting of prey. Finally, our results imply that wind should also be considered when developing conservation strategies for threatened ectotherms.

Background Predation is ubiquitous in nature. One form of predation is cannibalism, which is affected by many factors such as size structure and resource density. However, cannibalism may also be influenced by abiotic factors such as seasonal time constraints. Since time constraints are greater at high latitudes, cannibalism could be stronger at such latitudes, but we know next to nothing about latitudinal variation in cannibalism. In this study, we examined cannibalism and activity in larvae of the damselfly Lestes sponsa along a latitudinal gradient across Europe. We did this by raising larvae from the egg stage at different temperatures and photoperiods corresponding to different latitudes. Results We found that the more seasonally time-constrained populations in northern latitudes and individuals subjected to greater seasonal time constraints exhibited a higher level of cannibalism. We also found that activity was higher at north latitude conditions, and thus correlated with cannibalism, suggesting that this behaviour mediates higher levels of cannibalism in time-constrained animals. Conclusions Our results go counter to the classical latitude-predation pattern which predicts higher predation at lower latitudes, since we found that predation was stronger at higher latitudes. The differences in cannibalism might have implications for population dynamics along the latitudinal gradients, but further experiments are needed to explore this.

Despite the agronomical and environmental advantages of the cultivation of legumes, their production is limited by various environmental constraints such as water or nutrient limitation, frost or heat stress and soil salinity, which may be the result of pedoclimatic conditions, intensive use of agricultural lands, decline in soil fertility and environmental degradation. The development of more sustainable agroecosystems that are resilient to environmental constraints will therefore require better understanding of the key mechanisms underlying plant tolerance to abiotic constraints. This review provides highlights of legume tolerance to abiotic constraints with a focus on soil nutrient deficiencies, drought, and salinity. More specifically, recent advances in the physiological and molecular levels of the adaptation of grain and forage legumes to abiotic constraints are discussed. Such adaptation involves complex multigene controlled-traits which also involve multiple sub-traits that are likely regulated under the control of a number of candidate genes. This multi-genetic control of tolerance traits might also be multifunctional, with extended action in response to a number of abiotic constraints. Thus, concrete efforts are required to breed for multifunctional candidate genes in order to boost plant stability under various abiotic constraints.

At a landscape scale, the combined influence of biotic and abiotic factors may determine the distribution patterns of large herbivores in African savanna ecosystems. Herbivores foraging in these ecosystems may become nutritionally stressed during an annual dry season when both forage quality and quantity are reduced. Additionally, the locations of water sources may impose a landscape-scale constraint on dry-season herbivore distributions. We used logistic regression to analyze 13 years of aerial census data collected in the Kruger National Park (KNP), South Africa, and evaluated hypotheses regarding the relative influences that surface water, forage quality, and forage quantity exert on the dryseason, landscape-scale distribution patterns of eight herbivore species. Hypotheses regarding the degree of correlation between species' distributions and distance to water were developed using previous observations of species' relative water dependence. We also developed hypotheses regarding species' responses to the trade-off that may occur between surface-water constraints and nutritional requirements when either forage quality or quantity is reduced. In general, we expect an increase in species' mean distance to water as a result of individuals mitigating limitations in nutritional requirements (i.e., intake quality or quantity) by foraging farther from water. Our analyses suggest that the trade-off between nutritional requirements and surface-water constraints that species face varies according to the species' water dependence, size, and gut morphology. Of the four grazers considered in our analyses, waterbuck distributions appear to be constrained primarily by surfacewater availability. Distributions of buffalo, a large ruminant grazer, suggest that individuals face a trade-off between nutritional requirements and surface-water constraints when forage quantity is reduced. Alternatively, distributions of wildebeest, a smaller ruminant grazer, suggest that individuals face this trade-off when access to high-quality forage is limited. In comparison to buffalo and wildebeest, the strength of this trade-off is moderate for zebra, a nonruminant similar in size to wildebeest, when either forage quality or quantity is reduced. Distribution patterns for browsers are characterized by a weak relationship with distance to water, as expected for these relatively water-independent species. Population densities relative to forage quality confound exploration of this trade-off for mixed feeders.

Drought stress and nitrogen (N) deficiency are the major causes of yield losses in bread wheat (Triticum aestivum) production. Breeding wheat cultivars with combined drought and low N stress tolerance is an economical approach for yield gains. The objective of this study was to evaluate the response of diverse bread wheat genotypes under drought and low N stress conditions to select high-performing genotypes for developing breeding populations and production to mitigate against drought and low N stress. Fifty bread wheat genotypes were evaluated under drought-stressed (DS) and non-stressed (NS) conditions and N application rates of 50, 100 and 200 kg N ha−1. The experiments were conducted in a controlled environment and field conditions during the 2019/20 cropping season. Data on grain yield and yield components were collected and subjected to statistical analysis. The four-way interaction involving genotype, water regime, N treatments and testing environment had a significant (p < 0.05) effect on all assessed agronomic traits, suggesting that genotype response depended on the treatment combinations. Drought stress and 50 kg N ha−1 reduced grain yield by 20% compared to NS and 50 kg N ha−1. The grain yield ranged from 120 to 337 g/m2, with a mean of 228 g/m2 under DS. Under DS and 200 kg N ha−1, the genotype designated as SBO 19 had a higher grain yield of 337 g/m2, followed by SBO 22 (335 g/m2), SBO 16 (335 g/m2), SBO 04 (335 g/m2) and SBO 33 (335 g/m2). Grain yields under DS and 50 kg N ha−1, and NS and 50 kg N ha−1 had a positive and significant correlation (r > 0.5; p < 0.01) with most of the evaluated traits. Highly correlated traits directly contribute to total yield gain and should be incorporated during the selection of high-yielding genotypes. The study identified the 10 best lines that are high-yielding with early flowering and maturity under DS or NS conditions and the three N treatments. The selected lines are recommended as breeding parents to develop drought-adapted and N-use efficient genetic resources. The identified genotypes are important for sustainable wheat production and effective breeding of improved cultivars to mitigate drought stress and soil nutrient deficiencies, to ensure food security in Sub-Saharan Africa.