O armário: Fruiting phenology data for 4,462 plant taxa in Portugal (1926-2013).

Species phenology - the timing of key life events - is being altered by ongoing climate changes with yet underappreciated consequences for ecosystem stability. While flowering is generally occurring earlier, we know much less about other key processes such as the time of fruit ripening, largely due to the lack of comprehensive long-term datasets. Here we provide information on the exact date and site where seeds of 4,462 taxa were collected for the Index Seminum (seed exchange catalogue) of the Botanic Garden of the University of Coimbra, between 1926 and 2013. Seeds were collected from spontaneous and cultivated individuals across Portugal, including both native and introduced taxa. The database consists of 127,747 curated records with information on the species, or infraspecific taxa (including authority), and the day and site where seeds were collected. All records are georeferenced and provided with a confidence interval for the collection site. Taxonomy was first curated manually by in-house botanists and then harmonized according to the GBIF backbone taxonomy.

Combined Application of Biochar and Plant Growth-Promoting Rhizobacteria Improves Heavy Metal and Drought Stress Tolerance in Zea mays.

Plants are often exposed to multiple stresses, including heavy metals (HM) and drought, which limit the plant growth and productivity. Though biochar or plant growth-promoting rhizobacteria (PGPR) have been widely used for alleviating HM or drought stress in plants, the study of the effects of combined treatment with biochar and PGPR under simultaneous HM and drought stress is limited. This study investigated individual and combined effects of groundnut shell biochar (GS-BC) and PGPR Bacillus pseudomycoides strain ARN7 on Zea mays growth, physiology, and HM accumulation, along with their impact on soil enzymes under HM (Ni and Zn), drought, or HM+drought stress. It was observed that even under HM+drought stress, Z. mays growth, total chlorophyll, proteins, phenolics, and relative water contents were increased in response to combined GS-BC and ARN7 treatment. Furthermore, the combined treatment positively influenced plant superoxide dismutase, ascorbate peroxidase, and catalase activities, while reducing electrolyte leakage and phenolics, malondialdehyde, and proline under HM, drought, or HM+drought stress. Interestingly, the combined GS-BC and ARN7 treatment decreased HM accumulation and the bioaccumulation factor in Z. mays, highlighting that the combined treatment is suitable for improving HM phytostabilization. Additionally, GS-BC increased soil enzymatic activities and ARN7 colonization irrespective of HM and drought stress. As far as we know, this study is the first to illustrate that combined biochar and PGPR treatment could lessen the adverse effects of both HM and drought, suggesting that such treatment can be used in water-deficient HM-contaminated areas to improve plant growth and reduce HM accumulation in plants.

The effect of COVID-19 confinement on the activity behaviour of red deer.

The COVID-19 pandemic has drastically affected people's social habits, especially those related to outdoor activities. We intended to understand the effects of the two national lockdowns in Portugal on the presence and activity of a wild population of red deer (Cervus elaphus) by analysing data from camera traps installed at Lousã mountain, in the central part of Portugal. The cameras were set between 2019 and 2021, and a total of 2434 individual contacts of red deer and 182 contacts of people were recorded. Results showed a higher human presence in the mountain area during the COVID-19 outbreak, especially during the first lockdown in 2020 (0.05 ± 0.17 individuals/day), compared to the same period of the year before the pandemic (0.02 ± 0.05 individuals/day), which resulted in an increase of people by 150%. The increase in human presence did not have a significant direct effect on the presence of red deer. Despite the low overlap of activity patterns between people and red deer, deer showed avoidance behaviour in the 24 h after the detection of human presence on camera traps, as well as an increase in daily activity during the 2020 lockdown, showing red deer's awareness of human visitation. These results showed that people's increased search for cultural services in wild environments during COVID-19 lockdowns, such as hiking and biking, seemed to influence the population of red deer, albeit momentarily.

Functional Groups Response to Water Deficit in Mediterranean Ecosystems.

Enhanced drought, more frequent rainfall events and increased inter-annual variability of precipitation are the main trends of climate expected for the Mediterranean. Drought is one of the most important stressors for plants and significantly impacts plant communities causing changes in plant composition and species dominance. Through an experiment under controlled conditions, we assessed the response of Mediterranean species from different functional groups (annual grass, annual forb, annual legume, and perennial shrub) to moderate and severe water deficit. Changes in plant traits (leaf dry matter), biomass and physiology (water status, photosynthesis, pigments, and carbohydrate) were evaluated. The studied species differed in their response to water deficit. Ornithopus compressus, the legume, showed the strongest response, particularly under severe conditions, decreasing leaf relative water content (RWC), pigments and carbohydrates. The grass, Agrostis pourreti and the forb, Tolpis barbata, maintained RWC, indicating a higher ability to cope with water deficit. Finally, the shrub, Cistus salviifolius, had the lowest response to stress, showing a higher ability to cope with water deficit. Despite different responses, plant biomass was negatively affected by severe water deficit in all species. These data provide background for predicting plant diversity and species composition of Mediterranean grasslands and Montado under climate change conditions.

Early detection, herbicide resistance screening, and integrated management of invasive plant species: a review.

Invasive plant species (IPS) are often considered weeds that cause high yield losses in crops, negatively affect the environment, and disrupt certain ecosystem services. The negative impact of IPS on biodiversity is increasing and disturbing native vegetation. The management of plant invasions can be divided in two phases (before and after invasion). Prior to introduction it is crucial to develop the knowledge base (biology, ecology, distribution, impact, management) on IPS, prevention measures and risk assessment. After introduction if eradication fails, the monitoring and the integrated management of IPS are imperative to prevent the naturalization and further dispersal. This review uses two major invasive weed species (Amaranthus palmeri S. Wats. and Solanum elaeagnifolium Cav.) as case studies to propose a framework for early detection, rapid herbicide resistance screening, and integrated management. The holistic framework that is presented exploits recent: (i) novel detection tools, (ii) rapid tests and assays for herbicide resistance, and (iii) biology, ecology, distribution traits, and management tools for the IPS. Farmers, advisors, researchers, and policymakers need briefing on IPS growth dynamics, adaptability rates, and response to conventional and novel treatments to prevent new invasions, eradicate isolated stands, and mitigate the impact of invasive weed species in the long term. © 2022 Society of Chemical Industry.

Metal accumulation by Alyssum serpyllifolium subsp. malacitanum Rivas Goday (Brassicaceae) across different petrographic entities in South-Iberian ultramafic massifs: plant-soil relationships and prospects for phytomining.

NOVELTY STATEMENT: To date, studies of hyperaccumulation in plant tissues on ultramafic rocks have not considered the great diversity of petrographic entities in the world's outcrops. One of them is the one that we studied in Spain with more than eight petrographic entities and different soils. Our hypothesis is that the different chemical compositions of the soils in ultramafic rocks significantly affect the hyperaccumulation of metals by specialized plants, which may have consequences for phytomining. For this purpose, individuals, populations, and different soils have been tested and the results have been subjected to the corresponding statistical tests. The obtained knowledge reflects the different behavior of the studied plant not only for the Ni: the obtained results for Sr and for Ba revealed interesting results for the hyperaccumulation in Alyssum of both metals.

Strategies and prospects for biostimulants to alleviate abiotic stress in plants.

Global climate change-induced abiotic stresses (e.g., drought, salinity, extreme temperatures, heavy metals, and UV radiation) have destabilized the fragile agroecosystems and impaired plant performance and thereby reducing crop productivity and quality. Biostimulants, as a promising and eco-friendly approach, are widely used to address environmental concerns and fulfill the need for developing sustainable/modern agriculture. Current knowledge revealed that plant and animal derived stimulants (e.g., seaweeds and phytoextracts, humic substances, and protein hydrolysate) as well as microbial stimulants (e.g., plant beneficial bacteria or fungi) have great potential to elicit plant tolerance to various abiotic stresses and thus enhancing plant growth and performance-related parameters (such as root growth/diameter, flowering, nutrient use efficiency/translocation, soil water holding capacity, and microbial activity). However, to successfully implement biostimulant-based agriculture in the field under changing climate, the understanding of agricultural functions and action mechanism of biostimulants coping with various abiotic stresses at physicochemical, metabolic, and molecular levels is needed. Therefore, this review attempts to unravel the underlying mechanisms of action mediated by diverse biostimulants in relation to abiotic stress alleviation as well as to discuss the current challenges in their commercialization and implementation in agriculture under changing climate conditions.

Encapsulation of Pseudomonas libanensis in alginate beads to sustain bacterial viability and inoculation of Vigna unguiculata under drought stress.

Conventional agricultural practices based on the application of synthetic fertilizers are increasingly considered as unsustainable. Under a forecasted scenario of drought for the next decades, there is a global demand for innovative and sustainable approaches to ameliorate plant performance. Here, encapsulating beneficial microbes (BMs) to promote plant growth is gaining attention. This study evaluates bacterial encapsulation using polymeric beads of alginate, testing the survival of Pseudomonas libanensis TR1 stored up to 90 days. Produced beads were subjected to different treatments (fresh, air-dried and pulverized), which resulted in a variable size range (1200-860 µm). After storage, bacterial viability was maintained, and air-dried beads displayed a higher number of colony-forming units (2 × 107). Then, a glasshouse experiment investigated the drought resistance (plant growth, biomass, and photosynthetic responses) of Vigna unguiculata plants inoculated with these alginate beads. After 10 days of complete water restriction, turgidity and relative water content of V. unguiculata were still high under drought stress (> 80%). Leaf and root growth and biomass did not evidence significant changes after water restriction even after P. libanensis inoculation. Plant photosynthetic parameters (stomatal conductance, net photosynthetic rate, leaf CO2 concentration, or F v'/F m') were slightly affected due to inoculation but the level of stress-induced minimal plant responses. In our experiment, water restriction might have been insufficient to downregulate photosynthetic efficiency and reduce plant growth, limiting our understanding of the role of P. libanensis inoculation in alleviating drought stress in V. unguiculata, but highlighting the important relationship between the stress level and agricultural benefits of using encapsulated BMs.

Bacterial and Archaeal Structural Diversity in Several Biodeterioration Patterns on the Limestone Walls of the Old Cathedral of Coimbra.

The "University of Coimbra-Alta and Sofia" area was awarded the UNESCO World Heritage Site distinction in 2013. The Old Cathedral of Coimbra, a 12th-century limestone monument located in this area, has been significantly impacted during the last 800 years by physical, chemical, and biological processes. This led to the significant deterioration of some of its structures and carvings, with loss of aesthetical, cultural, and historical values. For this work, deteriorated spots of the walls of three semi-open chapels from the cloister of the Cathedral were sampled to ascertain their bacterial and archaeal structural diversity. Based on Next-Generation Sequencing (NGS) result analysis, we report the presence of microbial populations that are well adapted to an ecosystem with harsh conditions and that can establish a diverse biofilm in most cases. While it was possible to determine dominant phylogenetic groups in Archaea and Bacteria domains, there was no clear connection between specific core microbiomes and the different deterioration patterns analyzed. The distribution of these archaeal and bacterial communities within the analyzed biodeterioration spots suggests they are more influenced by abiotic factors (i.e., water availability, salinity, etc.), although they influence (and are influenced by) the algal and fungal population composition in this ecosystem. This work provides valuable information that can assist in establishing future guidelines for the preservation and conservation of this kind of historic stone monuments.

Enhanced phytoextraction of multi-metal contaminated soils under increased atmospheric temperature by bioaugmentation with plant growth promoting Bacillus cereus.

The co-occurrence of environmental stresses such as heavy metals (HM) and increased atmospheric temperature (IAT) pose serious implications on plant growth and productivity. In this work, we evaluated the role of plant growth-promoting bacteria (PGPB) and its effectiveness on Zea mays growth, stress tolerance and phytoremediation potential in multi-metal (MM) contaminated soils under IAT stress conditions. The PGPB strain TCU11 was isolated from metal contaminated soils and identified as Bacillus cereus. TCU11 was able to resist abiotic stresses such as IAT (45 °C), MM (Pb, Zn, Ni, Cu, and Cd), antibiotics and induced in vitro plant growth promotion (PGP) by producing siderophores (catechol and hydroxymate) and indole 3-acetic acid even in the presence of MM under IAT. Inoculation of TCU11 significantly increased the biomass, chlorophyll, carotenoids, and protein content of Z. mays compared to the respective control under MM, IAT, and MM + IAT stress. A decrease of malondialdehyde and over-accumulation of total phenolics, proline along with the increased activity of superoxide dismutase, catalase and ascorbic peroxidase were observed in TCU11 inoculated plants under stress conditions. These results suggested MM and/or IAT significantly reduced the maize growth, whereas TCU11 inoculation mitigated the combined stress effects on maize performance. Moreover, the inoculation of TCU11 under IAT stress increased the MM (Pb, Zn, Ni, Cu, and Cd) accumulation in plant tissues and also increased the translocation of HM from root to shoot except for Ni. The results of soil HM mobilization further indicates that IAT increased the HM mobilizing activity of TCU11, thus increasing the concentrations of bio-available HM in soil. These results suggested that TCU11 not only alleviates MM and IAT stresses but also enhances the biomass production and HM accumulation in plants. Therefore, TCU11 can be exploited as inoculums for improving the phytoremediation efficiency in MM polluted soils under IAT conditions.

Establishment, spread and early impacts of the first biocontrol agent against an invasive plant in continental Europe.

Classical biocontrol is key for the successful management of invasive alien plants; yet, it is still relatively new in Europe. Although post-release monitoring is essential to evaluate the effectiveness of a biocontrol agent, it is often neglected. This study reports the detailed post-release monitoring of the first biocontrol agent intentionally introduced against an invasive plant in continental Europe. The Australian bud-galling wasp Trichilogaster acaciaelongifoliae (Frogatt) is used to control the invasive Acacia longifolia (Andr.) Willd., with a long history of success in South Africa. This biocontrol agent was first released in Europe in 2015 at several sites along the Portuguese coast. We monitored the establishment, spread and early impacts of T. acaciaelongifoliae on target-plants in Portugal, across 61 sites, from 2015 to 2020. Initial release of adults emerging from galls imported from South Africa and the subsequent releases from galls established in Portugal (2018 onwards) was compared, assessing the implications of the hemisphere shift. The impacts on the reproductive output and vegetative growth of A. longifolia were evaluated in more detail at three sites. From 2015 to 2019, 3567 T. acaciaelongifoliae were released at 61 sites, with establishment confirmed at 36 sites by 2020. The transfer of the wasp from the southern hemisphere limited its initial establishment, but increased rates of establishment followed with synchronization of its life cycle with northern hemisphere conditions. Therefore, after an initial moderate establishment, T. acaciaelongifoliae adapted to the northern hemisphere conditions and experienced an exponential growth (from 66 galls by 2016, to 24000 galls by 2018). Galled A. longifolia branches produced significantly fewer pods (-84.1%), seeds (-95.2%) and secondary branches (-33.3%) and had fewer phyllodes but increased growth of the main branch compared to ungalled branches. Trichilogaster acaciaelongifoliae successfully established in the northern hemisphere, despite the initial phenological mismatch and adverse weather conditions. To achieve this, it had to establish and synchronize its life cycle with the phenology of its host-plant, after which it developed exponentially and began to show significant impacts on the reproductive output of A. longifolia.

Drought and Salinity Stress Responses and Microbe-Induced Tolerance in Plants.

Drought and salinity are among the most important environmental factors that hampered agricultural productivity worldwide. Both stresses can induce several morphological, physiological, biochemical, and metabolic alterations through various mechanisms, eventually influencing plant growth, development, and productivity. The responses of plants to these stress conditions are highly complex and depend on other factors, such as the species and genotype, plant age and size, the rate of progression as well as the intensity and duration of the stresses. These factors have a strong effect on plant response and define whether mitigation processes related to acclimation will occur or not. In this review, we summarize how drought and salinity extensively affect plant growth in agriculture ecosystems. In particular, we focus on the morphological, physiological, biochemical, and metabolic responses of plants to these stresses. Moreover, we discuss mechanisms underlying plant-microbe interactions that confer abiotic stress tolerance.

Distribution of arbuscular mycorrhizal fungi (AMF) in Terceira and São Miguel Islands (Azores).

BACKGROUND: The data, presented here, come from samples collected during three research projects which aimed to assess the impact of land-use type on Arbuscular Mycorrhizal Fungi (AMF) diversity and community composition in pastures of Terceira Island (Azores, Macaronesia, Portugal) and also in the native forest of two Azorean Islands (Terceira and São Miguel; Azores, Macaronesia, Portugal). Both projects contributed to improving the knowledge of AMF community structure at both local and regional scales. NEW INFORMATION: Little is known on the AMF communities from Azores islands and this study reports the first survey in two Azorean Islands (Terceira and São Miguel). A total of 18,733 glomeromycotan spores were classified at the species level from 244 field soil samples collected in three different habitat types - native forests (dominated by Juniperus brevifolia and Picconia azorica), semi-natural and intensively-managed pastures. Thirty-seven distinct spore morphotypes, representing ten glomeromycotan families, were detected. Species of the family Acaulosporaceae dominated the samples, with 13 species (38% of the taxa), followed by Glomeraceae (6 spp.), Diversisporaceae (4 spp.), Archaeosporaceae (3 spp.), Claroideoglomeraceae (3 spp.), Gigasporaceae (3 spp.), Ambisporaceae and Paraglomeraceae, both with the same number of AMF species (2 spp.), Sacculosporaceae (1 sp.) and Entrophospora (family insertae sedis). Members of the family Acaulosporaceae occurred almost exclusively in the native forests especially associated with the Picconia azorica rhizosphere, while members of Gigasporaceae family showed a high tendency to occupy the semi-natural pastures and the native forests of Picconia azorica. Members of Glomeraceae family were broadly distributed by all types of habitat which confirm the high ecological plasticity of this AMF family to occupy the more diverse habitats.

The antioxidant system in Olea europaea to enhanced UV-B radiation also depends on flavonoids and secoiridoids.

The Mediterranean crop Olea europaea is often exposed to high UV-B irradiation conditions. To understand how this species modulates its enzymatic and non-enzymatic antioxidant system under high UV-B radiation, young O. europaea plants (cultivar "Galega Vulgar") were exposed, for five days, to UV-B radiation (6.5 kJ m-2 d-1 and 12.4 kJ m-2 d-1). Our data indicate that UV-doses slightly differ in the modulation of the antioxidant protective mechanisms. Particularly, superoxide dismutase (SOD), guaiacol peroxidase (GPox) and catalase (CAT) activities increased contributing to H2O2 homeostasis, being more solicited by higher UV-B doses. Also, glutathione reductase (Gr) activity, ascorbate (AsA) and reduced glutathione (GSH) pools increased particularly under the highest dose, suggesting a higher mobilization of the antioxidant system in this dose. The leaf metabolites' profile of this cultivar was analysed by UHPLC-MS. Interestingly, high levels of verbascoside were found, followed by oleuropein and luteolin-7-O-glucoside. Both UV-B treatments affected mostly less abundant flavonoids (decreasing 4'-methoxy luteolin and 4' or 3'-methoxy luteolin glucoside) and hydroxycinnamic acid derivatives (HCAds, increasing ß-hydroxyverbascoside). These changes show not only different mobilization with the UV-intensity, but also reinforce for the first time the protective roles of these minor compounds against UV-B, as reactive oxygen species (ROS) scavengers and UV-B shields, in complement with other antioxidant systems (e.g. AsA/GSH cycle), particularly for high UV-B doses. Secoiridoids also standout in the response to both UV-B doses, with decreases of oleuropein and increases 2''-methoxyoleuropein. Being oleuropein an abundant compound, data suggest that secoiridoids play a more important role than flavonoids and HCAds, in O. europaea protection against UV-B, possibly by acting as signalling molecules and ROS scavengers. This is the first report on the influence of UV-B radiation on the secoiridoid oleuropein, and provides a novel insight to the role of this compound in the O. europaea antioxidant defence mechanisms.

Amelioration of chromium and heat stresses in Sorghum bicolor by Cr6+ reducing-thermotolerant plant growth promoting bacteria.

Climatic factors particularly increased atmospheric temperature (IAT) greatly alters plant microbe and heavy metal interactions and subsequently reduces plant growth and phytoremediation efficiency. The aim of the study was to assess the effects of inoculation of chromium reducing-thermotolerant plant growth promoting bacteria (CRT-PGPB) on plant growth, physiological responses and chromium (Cr) uptake by Sorghum bicolor under IAT condition. Three potential CRT-PGPB strains were isolated from Cr contaminated sites and identified as Bacillus cereus TCR17, Providencia rettgeri TCR21 and Myroides odoratimimus TCR22 through molecular characterization. These strains displayed the potential to reduce Cr6+ to Cr3+, produce siderophores, indole-3-acetic acid and solubilize phosphate. Inoculation of S. bicolor with CRT-PGPB increased plant growth, antioxidant status (superoxide dismutase, catalase and ascorbate peroxidase) and decreased proline and malondialdehyde contents in plants under Cr, IAT and Cr + IAT stress indicate that PGPB helped plants to reduce stress induced oxidative damage. Irrespective of IAT stress, inoculation of CRT-PGPB decreased the accumulation of Cr in plants compared with un-inoculated control suggest that CRT-PGPB might have the potential to improve phytostabilization process in Cr contaminated soils. Furthermore, gene expression studies confirmed that inoculation of TCR21 down-regulated the expression of proline synthesis gene (p5cs1) and up-regulated the expression of antioxidant related genes (sod, apx1 and cat) and stress tolerance genes (sHsp). Our results showed that CRT-PGPB exhibiting potential to tolerate Cr, temperature, produce plant beneficial metabolites and reduce Cr6+ to Cr3+, can be exploited as potential inoculants for improving plant growth and phytoremediation process in Cr contaminated soil under IAT condition.

Using microbial seed coating for improving cowpea productivity under a low-input agricultural system.

BACKGROUND: Plant-growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal (AM) fungi have the ability to enhance the growth, fitness, and quality of various agricultural crops, including cowpea. However, field trials confirming the benefits of microbes in large-scale applications using economically viable and efficient inoculation methods are still scarce. Microbial seed coating has a great potential for large-scale agriculture through the application of reduced amounts of PGPR and AM fungi inocula. Thus, in this study, the impact of seed coating with PGPR, Pseudomonas libanensis TR1 and AM fungus, Rhizophagus irregularis (single or multiple isolates) on grain yield and nutrient content of cowpea under low-input field conditions was evaluated. RESULTS: Seed coating with P. libanensis + multiple isolates of R. irregularis (coatPMR) resulted in significant increases in shoot dry weight (76%), and in the number of pods and seeds per plant (52% and 56%, respectively) and grain yield (56%), when compared with non-inoculated control plants. However, seed coating with P. libanensis + R. irregularis single-isolate (coatPR) did not influence cowpea grain yield. Grain lipid content was significantly higher (25%) in coatPMR plants in comparison with control. Higher soil organic matter and lower pH were observed in the coatPMR treatment. CONCLUSIONS: Our findings indicate that cowpea field productivity can be improved by seed coating with PGPR and multiple AM fungal isolates under low-input agricultural systems. © 2019 Society of Chemical Industry.

Seed Coating: A Tool for Delivering Beneficial Microbes to Agricultural Crops.

Plant beneficial microbes (PBMs), such as plant growth-promoting bacteria, rhizobia, arbuscular mycorrhizal fungi, and Trichoderma, can reduce the use of agrochemicals and increase plant yield, nutrition, and tolerance to biotic-abiotic stresses. Yet, large-scale applications of PBM have been hampered by the high amounts of inoculum per plant or per cultivation area needed for successful colonization and consequently the economic feasibility. Seed coating, a process that consists in covering seeds with low amounts of exogenous materials, is gaining attention as an efficient delivery system for PBM. Microbial seed coating comprises the use of a binder, in some cases a filler, mixed with inocula, and can be done using simple mixing equipment (e.g., cement mixer) or more specialized/sophisticated apparatus (e.g., fluidized bed). Binders/fillers can be used to extend microbial survival. The most reported types of seed coating are seed dressing, film coating, and pelleting. Tested in more than 50 plant species with seeds of different dimensions, forms, textures, and germination types (e.g., cereals, vegetables, fruits, pulses, and other legumes), seed coating has been studied using various species of plant growth-promoting bacteria, rhizobia, Trichoderma, and to a lesser extent mycorrhizal fungi. Most of the studies regarding PBM applied via seed coating are aimed at promoting crop growth, yield, and crop protection against pathogens. Studies have shown that coating seeds with PBM can assist crops in improving seedling establishment and germination or achieving high yields and food quality, under reduced chemical fertilization. The right combination of biological control agents applied via seed coating can be a powerful tool against a wide number of diseases and pathogens. Less frequently, studies report seed coating being used for adaptation and protection of crops under abiotic stresses. Notwithstanding the promising results, there are still challenges mainly related with the scaling up from the laboratory to the field and proper formulation, including efficient microbial combinations and coating materials that can result in extended shelf-life of both seeds and coated PBM. These limitations need to be addressed and overcome in order to allow a wider use of seed coating as a cost-effective delivery method for PBM in sustainable agricultural systems.

Plant-soil feedback of two legume species in semi-arid Brazil.

Positive feedback between arbuscular mycorrhizal fungal (AMF) and vascular plants can contribute to plant species establishment, but how this feedback affects plant invasion by Prosopis juliflora SW. (DC.), or resistance to invasion by Mimosa tenuiflora (Willd.) Poir in Brazilian semi-arid region is not well known. In this work, we tested how modified and native AMF communities affect the establishment of P. juliflora and M. tenuiflora plants. We examined the effects of inoculation with modified and native AMF communities on number of AMF spores, root colonization, number of N-fixing nodules, plant dry biomass, plant phosphorous concentration, and plant responsiveness to mycorrhizas of P. juliflora and M. tenuiflora. We found that the modified AMF community enhanced the root colonization, plant dry biomass, and plant phosphorous concentration of invasive P. juliflora, whereas native AMF enhanced M. tenuiflora. Our results demonstrate that the invasive P. juliflora alters soil AMF community composition, and this change generates positive feedback to the invasive P. juliflora itself and decreases AMF associations with native M. tenuiflora.