Plant biodiversity promotes sustainable agriculture directly and via belowground effects

Comparing field and lab quantitative stable isotope probing for nitrogen assimilation in soil microbes

Soil microbial communities play crucial roles in nutrient cycling and can help retain nitrogen in agricultural soils. Quantitative stable isotope probing (qSIP) is a useful method for investigating taxon-specific microbial growth and utilization of specific nutrients, such as nitrogen (N). Typically, qSIP is performed in a highly controlled lab setting, so the field relevance of lab qSIP studies remains unknown. We conducted and compared tandem lab and field qSIP to quantify the assimilation of 15N by maize-associated soil prokaryotic communities at two agricultural sites. Here, we show that field qSIP with 15N can be used to measure taxon-specific microbial N assimilation. Relative 15N assimilation rates were generally lower in the field, and the magnitude of this difference varied by site. Rates differed by method (lab vs field) for 19% of the top N assimilating genera. The field and lab measures were more comparable when relative assimilation rates were weighted by relative abundance to estimate the proportion of N assimilated by each genus with only ~10% of taxa differing by method. Of those that differed, the taxa consistently higher in the lab were inclined to have opportunistic lifestyle strategies, whereas those higher in the field had niches reliant on plant roots or in-tact soil structure (biofilms, mycelia). This study demonstrates that 15N-qSIP can be successfully performed using field-incubated soils to identify microbial allies in N retention and highlights the strengths and limitations of field and lab qSIP approaches.

IMPORTANCE

Soil microbes are responsible for critical biogeochemical processes in natural and agricultural ecosystems. Despite their importance, the functional traits of most soil organisms remain woefully under-characterized, limiting our ability to understand how microbial populations influence the transformation of elements such as nitrogen (N) in soil. Quantitative stable isotope probing (qSIP) is a powerful tool to measure the traits of individual taxa. This method has rarely been applied in the field or with 15N to measure nitrogen assimilation. In this study, we measured genus-specific microbial nitrogen assimilation in two agricultural soils and compared field and lab 15N qSIP methods. Our results identify taxa important for nitrogen assimilation in agricultural soils, shed light on the field relevance of lab qSIP studies, and provide guidance for the future application of qSIP to measure microbial traits in the field.

Plants and soil biota co-regulate stability of ecosystem multifunctionality under multiple environmental changes

The increase in phosphorus (P) and nitrogen (N) inputs, as well as soil acidification resulting from multiple environmental changes, has profound effects on the attributes of plant and soil biota communities, and on ecosystem functions. However, how these community attributes impact ecosystem multifunctionality (EMF) and its stability under multiple environmental changes remains unclear. By integrating datasets over four consecutive years from an experiment with enrichments of soil acidification and N and P in a semiarid grassland on the Mongolian Plateau, we explored the effects of environmental changes on community attributes (species richness, asynchrony, and compositional temporal stability) of plants and soil biota (bacteria, fungi, and nematodes) and their associations with EMF stability. The attributes of plants and soil biota showed opposite responses to nutrient enrichment under soil acidification and non-acidification conditions. Soil acidification had a more significant effect on the community attributes of plants and soil biota, as well as on the components of EMF stability, than nutrient enrichment. Soil acidification decreased both the mean and stability of EMF, while N enrichment increased the mean of EMF. P did not have a significant effect on the components of EMF stability, but N and P showed positive interactive effects on the mean and stability of EMF. We also found that plant and soil biota richness had a positive effect on EMF, while plant asynchrony and soil biota compositional stability determined EMF stability. The community attributes of plants and soil biota co-regulate the components of EMF stability under multiple environmental changes. These findings highlight the urgent need to protect the biodiversity of plants and soil biota to maintain EMF and its stability, especially for ecosystems undergoing multiple environmental changes.

A Comprehensive Review of Antimicrobial Agents Against Clinically Important Bacterial Pathogens: Prospects for Phytochemicals

Antimicrobial resistance (AMR) hinders the effective treatment of a range of bacterial infections, posing a serious threat to public health globally, as it challenges the currently available antimicrobial drugs. Among the various modes of antimicrobial action, antimicrobial agents that act on membranes have the most promising efficacy. However, there are no consolidated reports on the shortcomings of these drugs, existing challenges, or the potential applications of phytochemicals that act on membranes. Therefore, in this review, we have addressed the challenges and focused on various phytochemicals as antimicrobial agents acting on the membranes of clinically important bacterial pathogens. Antibacterial phytochemicals comprise diverse group of agents found in a wide range of plants. These compounds have been found to disrupt cell membranes, inhibit enzymes, interfere with protein synthesis, generate reactive oxygen species, modulate quorum sensing, and inhibit bacterial adhesion, making them promising candidates for the development of novel antibacterial therapies. Recently, polyphenolic compounds have been reported to have proven efficacy against nosocomial multidrug-resistant pathogens. However, more high-quality studies, improved standards, and the adoption of rules and regulations are required to firmly confirm the clinical efficacy of phytochemicals derived from plants. Identifying potential challenges, thrust areas of research, and considering viable approaches is essential for the successful clinical translation of these compounds.

Research on the optimal ratio of improved electrolytic manganese residue substrate about Pennisetum sinese Roxb growth effects

Electrolytic manganese slag (EMR) is a solid waste generated in the manganese hydrometallurgy process. It not only takes up significant land space but also contains Mn2+, which can lead to environmental contamination. There is a need for research on the treatment and utilization of EMR. Improved EMR substrate for Pennisetum sinese Roxb growth was determined in pot planting experiments. The study tested the effects of leaching solution, microorganisms, leaf cell structures, and growth data. Results indicated a substrate of 45% EMR, 40% phosphogypsum, 5% Hericium erinaceus fungi residue, 5% quicklime, and 5% dolomite sand significantly increased the available phosphorus content (135.54 ± 2.88 μg·g-1) by 17.95 times, compared to pure soil, and enhanced the relative abundance of dominant bacteria. After 240 days, the plant height (147.00 ± 0.52 cm), number of tillers (6), and aerial dry weight (144.00 ± 15.99g) of Pennisetum sinese Roxb increased by 5.81%, 200%, and 32.58%, respectively. Analyses of leaves and leaching solution revealed that the highest leaf Mn content (46.84 ± 2.91 μg·g-1) being 3.38 times higher than in pure soil, and the leaching solution Mn content (0.66 ± 0.13 μg·g-1) was lowest. Our study suggested P. sinese Roxb grown in an improved EMR substrate could be a feasible option for solidification treatment and resource utilization of EMR.

Belowground cascading biotic interactions trigger crop diversity benefits

Crop diversification practices offer numerous synergistic benefits. So far, research has traditionally been confined to exploring isolated, unidirectional single-process interactions among plants, soil, and microorganisms. Here, we present a novel and systematic perspective, unveiling the intricate web of plant-soil-microbiome interactions that trigger cascading effects. Applying the principles of cascading interactions can be an alternative way to overcome soil obstacles such as soil compaction and soil pathogen pressure. Finally, we introduce a research framework comprising the design of diversified cropping systems by including commercial varieties and crops with resource-efficient traits, the exploration of cascading effects, and the innovation of field management. We propose that this provides theoretical and methodological insights that can reveal new mechanisms by which crop diversity increases productivity.

Intercropping of tobacco and maize at seedling stage promotes crop growth through manipulating rhizosphere microenvironment

Introduction

Changes in the rhizosphere microbiome and metabolites resulting from crop intercropping can significantly enhance crop growth. While there has been an increasing number of studies on various crop combinations, research on the intercropping of tobacco and maize at seedling stage remains limited.

Methods

This study is the first to explore rhizosphere effects of intercropping between tobacco and maize seedling stages, we analyzed the nitrogen, phosphorus and potassium nutrients in the soil, and revealed the important effects on soil microbial community composition and metabolite profiles, thereby regulating crop growth and improving soil balance.

Results and discussion

Compared with mono-cropping, intercropping increased the biomass of the two crops and promoted the nutrient absorption of nitrogen, phosphorus and potassium. Under intercropping conditions, the activities of sucrase, catalase and nitrate reductase in tobacco rhizosphere soil and the content of available potassium, the activities of nitrate reductase and acid phosphatase in maize rhizosphere soil were significantly increasing. Rhizosphere soil bacterial and fungal communities such as Sphingomonas, Massilia, Humicola and Penicillium respond differently to crop planting patterns, and soil dominant microbial communities are regulated by environmental factors such as pH, Organic Matter, Available Potassium, Nitrate Reductase, and Urease Enzyme. Network analysis showed that soil microbial communities were more complex after intercropping, and the reciprocal relationship between bacteria and fungi was enhanced. The difference of metabolites in soil between intercropping and monocropping system was mainly concentrated in galactose metabolism, starch and sucrose metabolism pathway, and the content of carbohydrate metabolites was significantly higher than that of monocropping soil. Key metabolites such as D-Sucrose, D-Fructose-6-Phosphate, D-Glucose-1-Phosphatel significantly influence the composition of dominant microbial communities such as Sphingomonas and Penicillium. This study explained the effects of intercropping between flue-cured tobacco and maize on the content of soil metabolites and soil microbial composition in rhizosphere soil, and deepened the understanding that intercropping system can improve the growth of flue-cured crops seedlings through rhizosphere effects.

Global hierarchical meta-analysis to identify the factors for controlling effects of antibiotics on soil microbiota

It is widely known that antibiotics can affect the structure and function of soil microbial communities, but the specific degree of impact and controlled factors on different indicators remain inconclusive. We conducted a multiple hierarchical mixed effects meta-analysis on 2564 observations that were extracted from 60 publications, to comprehensively assess the impact of antibiotics on soil microbiota. The results showed that antibiotics had significant negative effects on soil microbial biomass, α-diversity and soil enzyme activity. Under neutral initial soil, when soil was derived from agricultural land or had a fine-textured, the negative impacts of antibiotics on soil microbial community were exacerbated. Both single and mixed additions of antibiotics had significant inhibitory effects on soil microbial enzyme activities. The Random Forest model predicted the following key moderators involved in the effects of antibiotics on the soil microbiome, and antibiotics type, soil texture were key moderators on the severity of soil microbial biomass changes. Soil texture, temperature and single or combined application constitute of antibiotics were the main drivers of effects on soil enzyme activities. The reported results can be helpful to assess the ecological risk of antibiotics in a soil environment and provides a scientific basis for the rational of antibiotics use in the soil environment.

Plant diversity drives positive microbial associations in the rhizosphere enhancing carbon use efficiency in agricultural soils

Expanding and intensifying agriculture has led to a loss of soil carbon. As agroecosystems cover over 40% of Earth's land surface, they must be part of the solution put in action to mitigate climate change. Development of efficient management practices to maximize soil carbon retention is currently limited, in part, by a poor understanding of how plants, which input carbon to soil, and microbes, which determine its fate there, interact. Here we implement a diversity gradient by intercropping undersown species with barley in a large field trial, ranging from one to eight undersown species. We find that increasing plant diversity strengthens positive associations within the rhizosphere soil microbial community in relation to negative associations. These associations, in turn, enhance community carbon use efficiency. Jointly, our results highlight how increasing plant diversity in agriculture can be used as a management strategy to enhance carbon retention potential in agricultural soils.

Underutilized plants increase biodiversity, improve food and nutrition security, reduce malnutrition, and enhance human health and well-being. Let's put them back on the plate!

The global food system depends on a limited number of plant species. Plants with unsatisfactory nutritional value are overproduced, whereas the wide variety of nutrient-rich plant species used in earlier times remains neglected. Basing our diet on a few crops has wide-ranging negative consequences on nutrition and food security. Although still under-researched, underutilized plants are slowly starting to receive increased recognition. These plants have superior nutritional content and immense potential to contribute to food and nutrition security and increased sustainability. This narrative review provides evidence to encourage the promotion, domestication, and commercialization of underutilized plants. The anti-inflammatory, antidiabetic, and anticancer effects of some of underutilized plants are presented in this review. The outstanding ability of forgotten plants to increase food and nutrition security, boost dietary diversity, reduce malnutrition, and enhance human health and well-being is demonstrated. The main barriers and obstacles to reintroducing underutilized foods are reviewed and recommendations for overcoming nutrition and dietary-related challenges for re-establishing underutilized plants into the global food system are presented. The expansion of underutilized plants for human use is of paramount importance. The exceptional nutritional properties, bioactive potential, and proven health benefits of underutilized plants indicate that increased promotion, domestication, and commercialization of these plants should be strongly supported. Besides health benefits, marginalized plants have the potential to enhance human well-being and improve people's lives in many ways, retain biodiversity, and develop local economies. Therefore, underutilized plants should be used in the broader context of well-balanced and healthy diets.

Intercropping enhances maize growth and nutrient uptake by driving the link between rhizosphere metabolites and microbiomes

Intercropping leads to different plant roots directly influencing belowground processes and has gained interest for its promotion of increased crop yields and resource utilization. However, the precise mechanisms through which the interactions between rhizosphere metabolites and the microbiome contribute to plant production remain ambiguous, thus impeding the understanding of the yield-enhancing advantages of intercropping. This study conducted field experiments (initiated in 2013) and pot experiments, coupled with multi-omics analysis, to investigate plant-metabolite-microbiome interactions in the rhizosphere of maize. Field-based data revealed significant differences in metabolite and microbiome profiles between the rhizosphere soils of maize monoculture and intercropping. In particular, intercropping soils exhibited higher microbial diversity and metabolite chemodiversity. The chemodiversity and composition of rhizosphere metabolites were significantly related to the diversity, community composition, and network complexity of soil microbiomes, and this relationship further impacted plant nutrient uptake. Pot-based findings demonstrated that the exogenous application of a metabolic mixture comprising key components enriched by intercropping (soyasapogenol B, 6-hydroxynicotinic acid, lycorine, shikimic acid, and phosphocreatine) significantly enhanced root activity, nutrient content, and biomass of maize in natural soil, but not in sterilized soil. Overall, this study emphasized the significance of rhizosphere metabolite-microbe interactions in enhancing yields in intercropping systems. It can provide new insights into rhizosphere controls within intensive agroecosystems, aiming to enhance crop production and ecosystem services.

Metal ions steer the duality in microbial community recovery from nitrogen enrichment by shaping functional groups

Atmospheric nitrogen (N) deposition has been substantially reduced due to declines in the reactive N emission in major regions of the world. Nevertheless, the impact of reduced N deposition on soil microbial communities and the mechanisms by which they are regulated remain largely unknown. Here, we examined the effects of N addition and cessation of N addition on plant and soil microbial communities through a 17-year field experiment in a temperate grassland. We found that extreme N input did not irreversibly disrupt the ecosystem, but ceasing high levels of N addition led to greater resilience in bacterial and fungal communities. Fungi exhibited diminished resilience compared to bacteria due to their heightened reliance on changes in plant communities. Neither bacterial nor fungal diversity fully recovered to their original states. Their sensitivity and resilience were mainly steered by toxic metal ions and soil pH differentially regulating on functional taxa. Specifically, beneficial symbiotic microbes such as N-fixing bacteria and arbuscular mycorrhizal fungi experienced detrimental effects from toxic metal ions and lower pH, hindering their recovery. The bacterial functional groups involved in carbon decomposition, and ericoid mycorrhizal and saprotrophic fungi were positively influenced by soil metals, and demonstrated gradual recovery. These findings could advance our mechanistic understanding of microbial community dynamics under ongoing global changes, thereby informing management strategies to mitigate the adverse effects of N enrichment on soil function.

Unveiling the resistance of native weed communities: insights for managing invasive weed species in disturbed environments

Weed communities influence the dynamics of ecosystems, particularly in disturbed environments where anthropogenic activities often result in higher pollution. Understanding the dynamics existing between native weed communities and invasive species in disturbed environments is crucial for effective management and normal ecosystem functioning. Recognising the potential resistance of native weed communities to invasion in disturbed environments can help identify suitable native plants for restoration operations. This review aims to investigate the adaptations exhibited by native and non-native weeds that may affect invasions within disturbed environments. Factors such as ecological characteristics, altered soil conditions, and adaptations of native weed communities that potentially confer a competitive advantage relative to non-native or invasive weeds in disturbed environments are analysed. Moreover, the roles of biotic interactions such as competition, mutualistic relationships, and allelopathy in shaping the invasion resistance of native weed communities are described. Emphasis is given to the consideration of the resistance of native weeds as a key factor in invasion dynamics that provides insights for conservation and restoration efforts in disturbed environments. Additionally, this review underscores the need for further research to unravel the underlying mechanisms and to devise targeted management strategies. These strategies aim to promote the resistance of native weed communities and mitigate the negative effects of invasive weed species in disturbed environments. By delving deeper into these insights, we can gain an understanding of the ecological dynamics within disturbed ecosystems and develop valuable insights for the management of invasive species, and to restore long-term ecosystem sustainability.

Intercropping improves maize yield and nitrogen uptake by regulating nitrogen transformation and functional microbial abundance in rhizosphere soil

Intercropping-driven changes in nitrogen (N)-acquiring microbial genomes and functional expression regulate soil N availability and plant N uptake. However, present data seem to be limited to a specific community, obscuring the viewpoint of entire N-acquiring microbiomes and functions. Taking maize intercropped with legumes (peanut and soybean) and non-legumes (gingelly and sweet potato) as models, we studied the effects of intercropping on N transformations and N-acquiring microbiomes in rhizosphere soil across four maize growth stages. Meanwhile, we compiled promising strategies such as random forest analysis and structural equation model for the exploitation of the associations between microbe-driven N dynamics and soil-plant N trade-offs and maize productivity. Compared with monoculture, maize intercropping significantly increased the denitrification rate of rhizosphere soils across four maize growth stages, net N mineralization in the elongation and flowering stages, and the nitrification rate in the seedling and mature stages. The abundance of most N-acquiring microbial populations was influenced significantly by intercropping patterns and maize growth stages. Soil available N components (NH4+-N, NO3--N, and dissolved organic N content) showed a highly direct effect on plant N uptake, which mainly mediated by N transformations (denitrification rate) and N-acquiring populations (amoB, nirK3, and hzsB genes). Overall, the adaptation of N-acquiring microbiomes to changing rhizosphere micro-environments caused by intercropping patterns and maize development could promote soil N transformations and dynamics to meet demand of maize for N nutrient. This would offer another unique perspective to manage the benefits of the highly N-effective and production-effective intercropping ecosystems.

Hexose/pentose ratio in rhizosphere exudates-mediated soil eutrophic/oligotrophic bacteria regulates the growth pattern of host plant in young apple-aromatic plant intercropping systems

Introduction

The positive effect of intercropping on host plant growth through plant-soil feedback has been established. However, the mechanisms through which intercropping induces interspecific competition remain unclear.

Methods

In this study, we selected young apple trees for intercropping with two companion plants: medium growth-potential Mentha haplocalyx Briq. (TM) and high growth-potential Ageratum conyzoides L. (TA) and conducted mixed intercropping treatment with both types (TMA) and a control treatment of monocropping apples (CT).

Results

Our findings revealed that TM increased the under-ground biomass of apple trees and TA and TMA decreased the above-ground biomass of apple trees, with the lowest above-ground biomass of apple trees in TA. The above- and under-ground biomass of intercrops in TA and TMA were higher than those in TM, with the highest in TA, suggesting that the interspecific competition was the most pronounced in TA. TA had a detrimental effect on the photosynthesis ability and antioxidant capacity of apple leaves, resulting in a decrease in above-ground apple biomass. Furthermore, TA led to a reduction in organic acids, alcohols, carbohydrates, and hydrocarbons in the apple rhizosphere soil (FRS) compared to those in both soil bulk (BS) and aromatic plant rhizosphere soil (ARS). Notably, TA caused an increase in pentose content and a decrease in the hexose/pentose (C6/C5) ratio in FRS, while ARS exhibited higher hexose content and a higher C6/C5 ratio. The changes in exudates induced by TA favored an increase in taxon members of Actinobacteria while reducing Proteobacteria in FRS compared to that in ARS. This led to a higher eutrophic/oligotrophic bacteria ratio relative to TM.

Discussion

This novel perspective sheds light on how interspecific competition, mediated by root exudates and microbial community feedback, influences plant growth and development.

Assessing the Human Health Benefits of Climate Mitigation, Pollution Prevention, and Biodiversity Preservation

Background

Since the Industrial Revolution, humanity has amassed great wealth and achieved unprecedented material prosperity. These advances have come, however, at great cost to the planet. They are guided by an economic model that focuses almost exclusively on short-term gain, while ignoring natural capital and human capital. They have relied on the combustion of vast quantities of fossil fuels, massive consumption of the earth's resources, and production and environmental release of enormous quantities of chemicals, pesticides, fertilizers, and plastics. They have caused climate change, pollution, and biodiversity loss, the "Triple Planetary Crisis". They are responsible for more than 9 million premature deaths per year and for widespread disease - impacts that fall disproportionately upon the poor and the vulnerable.

Goals

To map the human health impacts of climate change, pollution, and biodiversity loss. To outline a framework for assessing the health benefits of interventions against these threats.

Findings

Actions taken by national governments and international agencies to mitigate climate change, pollution, and biodiversity loss can improve health, prevent disease, save lives, and enhance human well-being. Yet assessment of health benefits is largely absent from evaluations of environmental remediation programs. This represents a lost opportunity to quantify the full benefits of environmental remediation and to educate policy makers and the public.

Recommendations

We recommend that national governments and international agencies implementing interventions against climate change, pollution, and biodiversity loss develop metrics and strategies for quantifying the health benefits of these interventions. We recommend that they deploy these tools in parallel with assessments of ecologic and economic benefits. Health metrics developed by the Global Burden of Disease (GBD) study may provide a useful starting point.Incorporation of health metrics into assessments of environmental restoration will require building transdisciplinary collaborations. Environmental scientists and engineers will need to work with health scientists to establish evaluation systems that link environmental and economic data with health data. Such systems will assist international agencies as well as national and local governments in prioritizing environmental interventions.

Soil Alveolata diversity in the undisturbed steppe and wheat agrocenoses under different tillage

Microeukaryotes are vital for maintaining soil quality and ecosystem functioning, however, their communities are less studied than bacterial and fungal ones, especially by high throughput sequencing techniques. Alveolates are important members of soil microbial communities, being consumers and/or prey for other microorganisms. We studied alveolate diversity in soil under the undisturbed steppe (US) and cropped for wheat using two tillage practices (conventional, CT, and no-till, NT) by amplifying the ITS2 marker with ITS3_KYO2/ITS4 primers and sequencing amplicons using Illumina MiSeq. A total of 198 Alveolata OTUs were identified, with 158 OTUs attributed to the Ciliophora phylum, containing five classes: Litostomatea, Spirotrichea and Oligohymenophorea, Nassophorea and Phyllopharyngea. Litostomatea and Phyllopharyngea were more abundant in US as compared with CT and NT. The observed OTU richness was higher in US than in CT and NT. The β-biodiversity of soil ciliates also very distinctly differentiated the US field from CT and NT. In the US, Nassophorea and Spirotrichea correlated positively with sand and negatively with clay, silt and SOM contents. This is the first report about soil ciliates diversity in Siberia as assessed by metabarcoding technique. The revealed clear effect of land use on the relative abundance of some taxa and a lack of tillage effect suggest the importance of the quantity and quality of plant material input for shaping the prey for ciliates. The ITS-metabarcoding technique was used for the first time in the research of ciliates diversity; further studies, embracing diverse aspects of soil ciliates by combining -omics methodology with the traditional one, are needed to get a better insight on the ecological roles of the main ciliate taxa in the complex soil system.

Plant disease risk is modified by multiple global change drivers

Plant diseases are strongly influenced by host biodiversity, spatial structure, and abiotic conditions. All of these are undergoing rapid change, as the climate is warming, habitats are being lost, and nitrogen deposition is changing nutrient dynamics of ecosystems with ensuing consequences for biodiversity. Here, I review examples of plant-pathogen associations to demonstrate how our ability to understand, model and predict disease dynamics is becoming increasingly difficult, as both plant and pathogen populations and communities are undergoing extensive change. The extent of this change is influenced via both direct and combined effects of global change drivers, and especially the latter are still poorly understood. Change at one trophic level is expected to drive change also at the other, and hence feedback loops between plants and their pathogens are expected to drive changes in disease risk both through ecological as well as evolutionary mechanisms. Many of the examples discussed here demonstrate an increase in disease risk as a result of ongoing change, suggesting that unless we successfully mitigate global environmental change, plant disease is going to become an increasingly heavy burden on our societies with far-reaching consequences for food security and functioning of ecosystems.

M. Drummond E, Van Tassel DL, Warschefsky EJ. The next era of crop domestication starts now

Current food systems are challenged by relying on a few input-intensive, staple crops. The prioritization of yield and the loss of diversity during the recent history of domestication has created contemporary crops and cropping systems that are ecologically unsustainable, vulnerable to climate change, nutrient poor, and socially inequitable. For decades, scientists have proposed diversity as a solution to address these challenges to global food security. Here, we outline the possibilities for a new era of crop domestication, focused on broadening the palette of crop diversity, that engages and benefits the three elements of domestication: crops, ecosystems, and humans. We explore how the suite of tools and technologies at hand can be applied to renew diversity in existing crops, improve underutilized crops, and domesticate new crops to bolster genetic, agroecosystem, and food system diversity. Implementing the new era of domestication requires that researchers, funders, and policymakers boldly invest in basic and translational research. Humans need more diverse food systems in the Anthropocene-the process of domestication can help build them.

Plant Growth Promoting Rhizobacteria in Plant Health: A Perspective Study of the Underground Interaction

Plants are affected by various environmental stresses such as high or low temperatures, drought, and high salt levels, which can disrupt their normal cellular functioning and impact their growth and productivity. These stressors offer a major constraint to the morphological, physiological, and biochemical parameters; thereby attributing serious complications in the growth of crops such as rice, wheat, and corn. Considering the strategic and intricate association of soil microbiota, known as plant growth-promoting rhizobacteria (PGPR), with the plant roots, PGPR helps plants to adapt and survive under changing environmental conditions and become more resilient to stress. They aid in nutrient acquisition and regulation of water content in the soil and also play a role in regulating osmotic balance and ion homeostasis. Boosting key physiological processes, they contribute significantly to the alleviation of stress and promoting the growth and development of plants. This review examines the use of PGPR in increasing plant tolerance to different stresses, focusing on their impact on water uptake, nutrient acquisition, ion homeostasis, and osmotic balance, as well as their effects on crop yield and food security.

Diversity, detection and exploitation: linking soil fungi and plant disease

Plant-associated fungi are incredibly diverse, comprising over a million species of mycorrhiza, endophytes, saprophytes and pathogens worldwide. This diverse fungal community is highly important for plant health. Many fungi are effective biocontrol agents that can kill or suppress fungal pathogens, with pathogen biocontrol found for both individual microorganisms and plant-associated fungal consortia. Meanwhile, increased plant community diversity aboveground corresponds to an increase in below-ground fungal community diversity, which contributes in turn to improved rhizosphere soil health and pathogen suppression. In this review, we discuss the role of fungal diversity in soil health and plant disease suppression and the various mechanisms by which mycorrhizal and endophytic fungi combat plant pathogenic fungi. We also discuss the array of diagnostic tools, both well-established and newly developed, which are revolutionising fungal pathogen detection and rhizosphere community analysis.

Intercropping with Achyranthes bidentata alleviates Rehmannia glutinosa consecutive monoculture problem by reestablishing rhizosphere microenvironment

BACKGROUND

The consecutive monoculture of Rehmannia glutinosa leads to a serious decrease in its production and quality. Previous studies have demonstrated that intercropping altered species diversity and rhizosphere microbial diversity. However, it remained unknown whether the impaired growth of monocultured plants could be restored by enhanced belowground interspecific interactions.

METHOD

In the present research, a continuous cropping facilitator Achyranthes bidentata was intercropped with R. glutinosa under pot conditions, and three different types of root barrier treatments were set, including that complete belowground interaction (N), partial belowground interaction (S), and no belowground interspecies interaction (M), with the aims to investigate belowground interaction and the underlying mechanism of alleviated replanting disease of R. glutinosa by intercropping with A. bidentata.

RESULTS

The results showed that the land equivalent ratio (LER) of the two years was 1.17, and the system productivity index (SPI) increased by 16.92 % under S treatment, whereas no significant difference was found in N and M regimes. In the rhizosphere soil, intercropping systems had significantly increased the contents of sugars and malic acid in the soil of R. glutinosa, together with the content of organic matter and the invertase and urease activities. Meanwhile, intercropping increased the community diversity of fungi and bacteria, and the relative abundance of potential beneficial bacteria, such as Bacillus, Nitrospira, and Sphingomonas, despite the pathogenic Fusarium oxysporum was still the dominant genus in the rhizospheric soil of R. glutinosa under various treatments. The results of antagonism experiments and exogenous addition of specific bacteria showed that Bacillus spp. isolated from rhizosphere soil had a significant antagonistic effect on the pathogen of R. glutinosa.

CONLUSION

Taken together, our study indicated that the R. glutinosa//A. bidentata intercropping systems alleviate the consecutive monoculture problem of R. glutinosa by recruiting beneficial bacteria. The studies we have conducted have a positive effect on sustainable agricultural development.

Evaluation of grain yield performance and its stability in various spring barley accessions under condition of different agroclimatic zones of Ukraine

Two extremely urgent problems of biological and agronomic research nowadays are ensuring an optimal balance between usage of natural resources to meet rapidly growing needs for food production and preservation of biodiversity. It is also important to extend the genetic diversity of the main crop varieties in agroecosystems. At the same time, modern varieties should be characterized by a combination of high yield and preserving yield stability under variable conditions. Solving the outlined tasks requires comprehensive research and involvement in breeding process of the genetical diversity concentrated in genebanks of the world. Barley (Hordeum vulgare L.) is one of the most important crops that satisfy the various needs of humanity. In respect to this, in 2020–2022, a multi-environment trial was conducted in three agroclimatic zones of Ukraine (Forest-Steppe, Polissia, and Northern Steppe). We studied 44 spring barley collection accessions of different ecological and geographical origin, different subspecies and groups of botanical varieties which were obtained from the National Center for Plant Genetic Resources of Ukraine. Statistical indices (Hom, Sc) and graphical models (GGE biplot, AMMI) were used to interpret the yield performance and its stability. Both individual ecological sites in different years and combinations of different sites and years of trials were characterized for productivity, discriminating power and representativeness. The environments differed quite strongly among themselves in terms of these indicators. It was established that most of the genotypes were characterized by higher adaptability to individual environmental conditions (stability in different years), compared to adaptability for all agroclimatic zones (wide adaptation). A strong cross-over genotype by environment interaction was found for most studied accessions. Nevertheless, both genotypes with very high stability in only one agroclimatic zone (Amil (UKR), Gateway (CAN)) and genotypes with a combination of high adaptability to one or two ecological niches and relatively higher wide adaptability (Stymul (UKR), Ly-1064 (UKR), Rannij (KAZ), Shedevr (UKR), and Arthur (CZE)) were identified. There were also the accessions which did not show maximum performance in the individual sites, but had relatively higher wide adaptability (Ly-1059 (UKR), Ly-1120 (UKR), Diantus (UKR), and Danielle (CZE)). In general, the naked barley genotypes were inferior to the covered ones in terms of yield potential and wide adaptability, but at the same time, some of them (CDC ExPlus (CAN), CDC Gainer (CAN), and Roseland (CAN)), accordingly to the statistical indicators, had increased stability in certain ecological sites. Among naked barley accessions relatively better wide adaptability according to the graphical analysis was found in the accession CDC McGwire (CAN), and by the statistical parameters CDC ExPlus (CAN) was better than standard. The peculiarities of yield manifestation and its variability in different spring barley genotypes in the multi-environment trial revealed in this study will contribute to the complementation and deepening of existing data in terms of the genotype by environment interaction. Our results can be used in further studies for developing spring barley variety models both with specific and wide adaptation under conditions of different agroclimatic zones of Ukraine. The disitnguished accessions of different origin and botanical affiliation are recommended for creating a new breeding material with the aim of simultaneously increasing yield potential and stability, as well as widening the genetic basis of spring barley varieties.

Plant Nutrition for Human Health: A Pictorial Review on Plant Bioactive Compounds for Sustainable Agriculture

Is there any relationship between plant nutrition and human health? The overall response to this question is very positive, and a strong relationship between the nutrition of plants and humans has been reported in the literature. The nutritional status of edible plants consumed by humans can have a negative or positive impact on human health. This review was designed to assess the importance of plant bioactive compounds for human health under the umbrella of sustainable agriculture. With respect to the first research question, it was found that plant bioactives (e.g., alkaloids, carotenoids, flavonoids, phenolics, and terpenoids) have a crucial role in human health due to their therapeutic benefits, and their potentiality depends on several factors, including botanical, environmental, and clinical attributes. Plant bioactives could be produced using plant tissue culture tools (as a kind of agro-biotechnological method), especially in cases of underexploited or endangered plants. Bioactive production of plants depends on many factors, especially climate change (heat stress, drought, UV radiation, ozone, and elevated CO2), environmental pollution, and problematic soils (degraded, saline/alkaline, waterlogged, etc.). Under the previously mentioned stresses, in reviewing the literature, a positive or negative association was found depending on the kinds of stress or bioactives and their attributes. The observed correlation between plant bioactives and stress (or growth factors) might explain the importance of these bioactives for human health. Their accumulation in stressed plants can increase their tolerance to stress and their therapeutic roles. The results of this study are in keeping with previous observational studies, which confirmed that the human nutrition might start from edible plants and their bioactive contents, which are consumed by humans. This review is the first report that analyzes this previously observed relationship using pictorial presentation.