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Plant diseases caused by microbial pathogens pose a severe threat to global food security. Although genetic modifications can improve plant resistance; however, environmentally sustainable strategies are needed to manage plant diseases. Nano-enabled immunomodulation involves using engineered nanomaterials (ENMs) to modulate the innate immune system of plants and enhance their resilience against pathogens. This emerging approach provides unique opportunities through the ability of ENMs to act as nanocarriers for delivering immunomodulatory agents, nanoprobes for monitoring plant immunity, and nanoparticles (NPs) that directly interact with plant cells to trigger immune responses. Recent studies revealed that the application of ENMs as nanoscale agrochemicals can strengthen plant immunity against biotic stress by enhancing systemic resistance pathways, modulating antioxidant defense systems, activating defense-related genetic pathways and reshaping the plantassociated microbiomes. However, key challenges remain in unraveling the complex mechanisms through which ENMs influence plant molecular networks, assessing their long-term environmental impacts, developing biodegradable formulations, and optimizing targeted delivery methods. This review provides a comprehensive investigation of the latest research on nanoenabled immunomodulation strategies, potential mechanisms of action, and highlights future perspectives to overcome existing challenges for sustainable plant disease management. [ABSTRACT FROM AUTHOR]

Climate, land-use, and invasive plants are among the important drivers of ecosystem functions through the changes in functional composition. In this study, we studied the effects of climate (drought), land-use (Biochar application), and the presence of invasive species on the productivity and performance of invaded experimental grasslands. We ran a greenhouse experiment under controlled conditions, in which we grew a combination of the three native species Silene gallica, Brassica nigra and Phalaris minor and the invasive species Avena fatua, being subjected to four different treatments: Biochar+drought, Biochar, drought, and control. We measured the productivity of native and invasive species as total biomass and root to shoot ratio (RSR) and the performance by measuring several plant functional traits (plant height, specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (Nmass), leaf carbon content (Cmass) and total chlorophyll (Chltotal) of all individuals occurring in each plot. The study showed that invasive species were more productive (higher total biomass and lower RSR) and performed better (taller plants, higher SLA, Nmass, Cmass and Chltotal and lower LDMC) than the native species under drought conditions as well as with Biochar application. Accordingly, in contrast to our expectations, the lower productivity and performance of native compared to invasive species under drought were not mitigated by Biochar application. These results provided a deeper understanding of the interplay between climate, land-use, and biological invasion, which is crucial for predicting the consequences of changes in functional composition on ecosystem functions and consequently restoration of grasslands. [ABSTRACT FROM AUTHOR]

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Heavy metal stress, including from chromium, has detrimental effects on crop growth and yields worldwide. Plant growth-promoting rhizobacteria (PGPR) have demonstrated great efficiency in mitigating these adverse effects. The present study investigated the potential of the PGPR strain Azospirillum brasilense EMCC1454 as a useful bio-inoculant for boosting the growth, performance and chromium stress tolerance of chickpea (Cicer arietinum L.) plants exposed to varying levels of chromium stress (0, 130 and 260 µM K2Cr2O7). The results revealed that A. brasilense EMCC1454 could tolerate chromium stress up to 260 µM and exhibited various plant growth-promoting (PGP) activities, including nitrogen fixation, phosphate solubilization, and generation of siderophore, trehalose, exopolysaccharide, ACC deaminase, indole acetic acid, and hydrolytic enzymes. Chromium stress doses induced the formation of PGP substances and antioxidants in A. brasilense EMCC1454. In addition, plant growth experiments showed that chromium stress significantly inhibited the growth, minerals acquisition, leaf relative water content, biosynthesis of photosynthetic pigments, gas exchange traits, and levels of phenolics and flavonoids of chickpea plants. Contrarily, it increased the concentrations of proline, glycine betaine, soluble sugars, proteins, oxidative stress markers, and enzymatic (CAT, APX, SOD, and POD) and non-enzymatic (ascorbic acid and glutathione) antioxidants in plants. On the other hand, A. brasilense EMCC1454 application alleviated oxidative stress markers and significantly boosted the growth traits, gas exchange characteristics, nutrient acquisition, osmolyte formation, and enzymatic and non-enzymatic antioxidants in chromium-stressed plants. Moreover, this bacterial inoculation upregulated the expression of genes related to stress tolerance (CAT, SOD, APX, CHS, DREB2A, CHI, and PAL). Overall, the current study demonstrated the effectiveness of A. brasilense EMCC1454 in enhancing plant growth and mitigating chromium toxicity impacts on chickpea plants grown under chromium stress circumstances by modulating the antioxidant machinery, photosynthesis, osmolyte production, and stress-related gene expression. [ABSTRACT FROM AUTHOR]

Ecosystem functions are heavily dependent on the functional composition of the plant community, i.e., the functional traits of plants forming the community. This, on the one hand, depends on plant occurrence, but on the other hand, depends on the intraspecific variability of functional traits of the species, which are influenced by climate and nutrient availability and affected by plant–plant interactions. To illustrate that, we studied the effects of drought and nitrogen addition (+ N), two important abiotic variables which are changing with ongoing global change, as well as their combined effect on the functional responses of grassland communities in semi‐arid environments of Northern Africa comprising of natural and invasive species. We conducted an experiment where we planted three native species and one invasive plant species in artificial communities of five individuals per species per plot. We exposed these communities to four different treatments: a drought treatment, an N‐addition treatment, the combination between drought and N‐addition, as well as a control. To assess the performance of plants within treatments, we measured selected plant functional traits (plant height, specific leaf area [SLA], leaf dry matter content [LDMC], N content of the leaves [Nmass], specific root length [SRL], and root diameter) for all individuals occurring in our plots, and additionally assessed the above and belowground biomass for each plant individual. We found that the invasive species showed a higher performance (higher biomass accumulation, taller plants, higher SLA, Nmass, SRL, and root diameter as well as lower LDMC) than the native species under drought conditions. The invasive species was especially successful with the combined impact of drought + N, which is a likely scenario in ongoing global change for our research area. Thus, plant functional traits might be a key factor for the invasion success of plant species which will be even more pronounced under ongoing global change. [ABSTRACT FROM AUTHOR]

Land-use changes have huge impacts on natural vegetation, especially megaprojects, as the vegetation layer is destroyed in the course of construction works affecting the plant community composition and functionality. This large-scale disturbance might be a gateway for the establishment of invasive plant species, which can outcompete the natural flora. In contrast, species occurring in the area before the construction are not able to re-establish. In this study, we analyzed the impact of a pipeline construction on a wetland nature reserve located in northern Egypt. Therefore, we analyzed the plant species occurrence and abundance and measured each plant species' traits before the construction in 2017 as well as on multiple occasions up to 2 years after the construction had finished on altogether five sampling events. We found that the construction activity led to the establishment of an invasive species which previously did not occur in the area, namely, Imperata cylindrica, whereas five species (Ipomoea carnea, Pluchea dioscoridis, Polygonum equisetiforme, Tamarix nilotica, and Typha domingensis) could not re-establish after the disturbance. The functionality of ecosystems assessed via the analysis of plant functional traits (plant height, specific leaf area, and leaf dry matter content) changed within species over all sampling events and within the community showing a tendency to approximate pre-construction values. Functional dispersion and Rao's quadratic diversity were higher after the megaproject than before. These findings are important to capture possible re-establishment and recovery of natural vegetation after construction and raise awareness to the impact of megaprojects, especially in areas which are high priority for conservation. [ABSTRACT FROM AUTHOR]

Plant diseases caused by microbial pathogens pose a severe threat to global food security. Although genetic modifications can improve plant resistance; however, environmentally sustainable strategies are needed to manage plant diseases. Nano-enabled immunomodulation involves using engineered nanomaterials (ENMs) to modulate the innate immune system of plants and enhance their resilience against pathogens. This emerging approach provides unique opportunities through the ability of ENMs to act as nanocarriers for delivering immunomodulatory agents, nanoprobes for monitoring plant immunity, and nanoparticles (NPs) that directly interact with plant cells to trigger immune responses. Recent studies revealed that the application of ENMs as nanoscale agrochemicals can strengthen plant immunity against biotic stress by enhancing systemic resistance pathways, modulating antioxidant defense systems, activating defense-related genetic pathways and reshaping the plant-associated microbiomes. However, key challenges remain in unraveling the complex mechanisms through which ENMs influence plant molecular networks, assessing their long-term environmental impacts, developing biodegradable formulations, and optimizing targeted delivery methods. This review provides a comprehensive investigation of the latest research on nano-enabled immunomodulation strategies, potential mechanisms of action, and highlights future perspectives to overcome existing challenges for sustainable plant disease management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Masood, Qi, Zahid, Li, Ahmad, Lv, Shahid, Ali, Ondrasek and Qi.)

Introduction: Invasive species have been identified as a major threat to native biodiversity and ecosystem functioning worldwide due to their superiority in spread and growth. Such superiority is explained by the invasional meltdown phenomena, which suggests that invasive species facilitate the establishment of more invasive species rather than native species by modifying the plant-soil feedback (PSF)., Methods: We conducted a two-phase plant-soil feedback experiment using the native Prosopis cineraria and the invasive Prosopis juliflora in Oman. Firstly, we conditioned the soil by planting seedlings of native species, invasive species, native and invasive species "mixed", and unconditioned soil served as a control. Secondly, we tested the feedback of these four conditioned soil on the two species separately by measuring the productivity (total biomass) and the performance in the form of plant functional traits (plant height, specific leaf area (SLA), leaf nitrogen content (Nmass), leaf carbon content (Cmass) and specific root length (SRL) of native and invasive species as well as the nutrient availability in soil (soil organic carbon (SOC) and soil total nitrogen (STN))., Results and Discussion: We found that the native species produced more biomass, best performance, and higher SOC and STN when grown in soil conditioned by native species, additionally, it gave lower biomass, reduced performance, and lower SOC and STN when grown in the soil conditioned by invasive and mixed species. These results suggest negative PSF for native species and positive PSF for invasive species in the soil conditioned by invasive species, which can be considered as red flag concerning the restoration of P. cineraria as an important native species in Oman, as such positive PSF of the invasive species P. juliflora will inhibit the regeneration of P. cineraria ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ali, Al-Wahaibi and Shahid.)