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Summary: Tomato is one of the most economically important vegetable crops in the world and has been seriously affected by the devastating agricultural pest root‐knot nematodes (RKNs). Current understanding of tomato resistance to RKNs is quite limited. VQ motif‐containing family proteins are plant‐specific regulators; however, whether and how tomato VQs regulate resistance to RKNs is unknown. Here, we found that SlVQ15 recruited SlWRKY30IIc to coordinately control tomato defence against the RKN Meloidogyne incognita without affecting plant growth and productivity. The jasmonate (JA)‐ZIM domain (JAZ) repressors of the phytohormone JAs signalling associated and interfered with the interaction of SlVQ15 and SlWRKY30IIc. In turn, SlWRKY30IIc bound to SlJAZs promoters and cooperated with SlVQ15 to repress their expression, whereas this inhibitory effect was antagonized by SlJAZ5, forming a feedback regulatory mechanism. Moreover, SlWRKY30IIc expression was directly regulated by SlMYC2, a SlJAZ‐interacting negative regulator of resistance to RKNs. In conclusion, our findings revealed that a regulatory circuit of SlVQ15‐SlWRKY30IIc and the JA pathway fine‐tunes tomato defence against the RKN M. incognita, and provided candidate genes and clues with great potential for crop improvement. [ABSTRACT FROM AUTHOR]

Leaf area to sapwood area ratio (AL/AS) influences carbon sequestration, community composition, and ecosystem functioning in terrestrial vegetation and is closely related to leaf economics and hydraulics. However, critical predictors of AL/AS are not well understood. We compiled an AL/AS data set with 1612 species‐site combinations (1137 species from 285 sites worldwide) from our field experiments and published literature. We found the global mean AL/AS to be 0.63 m2 cm−2, with its variation largely driven by growing‐season precipitation (Pgs), which accounted for 18% of the variation in AL/AS. Species in tropical rainforests exhibited the highest AL/AS (0.82 m2 cm−2), whereas desert species showed the lowest AL/AS (0.16 m2 cm−2). Soil factors such as soil nitrogen and soil organic carbon exhibited positive effects on AL/AS, whereas soil pH was negatively correlated with AL/AS. Tree density accounted for 7% of the variation in AL/AS. All biotic and abiotic predictors collectively explained up to 45% of the variation in AL/AS. Additionally, AL/AS was positively correlated to the net primary productivity (NPP) of the ecosystem. Our study provides insights into the driving factors of AL/AS at the global scale and highlights the importance of AL/AS in ecosystem productivity. Given that Pgs is the most critical driver of AL/AS, alterations in global precipitation belts, particularly seasonal precipitation, may induce changes in plant leaf area on the branches. Summary statement: In this study, we assessed global patterns and key predictors of leaf area to sapwood area ratio (AL/AS) and underscored the significance of growing‐season precipitation, soil pH, and tree density in influencing AL/AS variation and its impact on plant primary productivity. [ABSTRACT FROM AUTHOR]

Forest ecosystem nutrient cycling functions are the basis for the survival and development of organisms, and play an important role in maintaining the forest structural and functional stability. However, the response of forest nutrient cycling functions at the ecosystem level to whole-tree harvesting remains unclear. Herein, we calculated the ecosystem nitrogen (N), phosphorus (P), and potassium (K) absorption, utilization, retention, cycle, surplus, accumulation, productivity, turnover and return parameters and constructed N, P, and K cycling function indexes to identify the changes in ecosystem N, P, and K cycling functions in a secondary forest in the Qinling Mountains after 5 years of five different thinning intensities (0% (CK), 15%, 30%, 45%, and 60%). We showed that the ecosystem's N, P, and K cycling parameters varied significantly and responded differently to thinning treatments. As the thinning intensity increased, the N, P, and K cycling function indexes increased by 5%~232%, 32%~195%, and 104%~233% compared with CK. Whole-tree harvesting promoted ecosystem N and P cycling functions through two pathways: (a) directly regulated litter biomass, indirectly affected soil nutrient characteristics, and then regulated ecosystem N and P cycling functions; (b) directly regulated plant productivity, indirectly affected plant and soil nutrient characteristics, and then regulated ecosystem N and P cycling functions. In contrast, whole-tree harvesting mainly indirectly affected the plant and soil nutrient characteristics by directly adjusting the plant productivity, and promoting the ecosystem K cycling function. Furthermore, N and P cycling functions were mainly regulated by understory plant productivity while tree and herb nutrient characteristics were key driving factors for K cycling functions. These findings indicated that whole-tree harvesting significantly improved the ecosystem N, P and K cycling functions, and reveals varied regulatory mechanisms, which may aid in formulating effective measures for sustainable forest ecosystem nutrient management. [ABSTRACT FROM AUTHOR]

Introduction: The sowing date plays a crucial role in influencing the growth and reproduction of plants, with its specific impact on biomass allocation and allometric growth remaining unclear. Understanding these effects is essential for optimizing agricultural practices and enhancing crop productivity. Methods: To investigate the effects of sowing dates on biomass allocation and allometric growth, a field experiment was conducted with sequential sowings of Fagopyrum esculentum from April 12th to August 11th in 2018. Biomass measurements were taken across various plant organs, and corresponding allocation calculations were made. A detailed analysis of the allometric growth relationship involving organ biomass variations was performed. Results: The study revealed that the accumulation and allocation of organ biomass in buckwheat were significantly impacted by the sowing dates. Delayed planting led to reduced vegetative growth and increased biomass allocation towards reproduction. Allometric parameters such as exponent, constant, and individual size of buckwheat were notably affected by delayed planting. Interestingly, the allometric exponents governing the relationships between reproductive vs. vegetative biomass and belowground vs. aboveground biomass exhibited varying trends across different sowing dates. Discussion: Notably, late sowings resulted in significantly higher reproductive biomass compared to early and middle sowings. These findings highlight the nuanced relationship between plant size and reproductive biomass under different sowing dates, emphasizing the critical role of planting timing in shaping mature plant sizes and reproductive outcomes. The study underscores the importance of considering sowing dates in agricultural practices to optimize plant growth and productivity. [ABSTRACT FROM AUTHOR]

Mycorrhizal associations drive plant community diversity and ecosystem functions. Arbuscular mycorrhiza (AM) and ectomycorrhiza (EcM) are two widespread mycorrhizal types and are thought to differentially affect plant diversity and productivity by nutrient acquisition and plant–soil feedback. However, it remains unclear how the mixture of two mycorrhizal types influences tree diversity, forest biomass, and their relationship at large spatial scales. Here, we explored these issues using data from 1247 plots (600 m2 for each) across China's natural forests located mostly in temperate and subtropical regions. Both AM‐dominated and EcM‐dominated forests show relatively lower tree species richness and stand biomass, whereas forests with the mixture of mycorrhizal strategies sustain more tree species and higher biomass. Interestingly, the positive effect of tree diversity on biomass is stronger in forests with low (≤50%) than high AM tree proportion (>50%), reflecting a shift from the complementarity effect to functional redundancy with increasing AM trees. Our findings suggest that mycorrhizal dominance influences tree diversity and richness–biomass relationship in forest ecosystems. [ABSTRACT FROM AUTHOR]

ABSTRACT Mangroves are highly salt‐tolerant species, which live in saline intertidal environments, but rely on alternative, less saline water to maintain hydraulic integrity and plant productivity. Foliar water uptake (FWU) is thought to assist in hydration of mangroves, particularly during periods of acute water deficit. We investigated the dynamics of FWU in Avicennia marina and Aegiceras corniculatum by submerging and spraying excised branches and measuring leaf water potential (Ψ) at different time intervals. Daily changes in xylem sap composition (ionic concentrations, pH and surface tension) were monitored during 2 days characterised by the presence of morning dew and difference in tides. In both species, FWU occurred over relatively short times, with leaf Ψ recovering from −4.5 MPa to about −1.5 MPa in 120–150 min. At predawn, Ψ was higher (−1.5 MPa) than sea water Ψ, indicating that leaves had been partially rehydrated by absorbed dew. Tides did not affect Ψ, but high tides increased the overall ionic content of xylem sap. The results indicated mangroves are extremely efficient in absorbing non‐saline water via the leaves and restoring the water balance to Ψ higher than seawater. Changes in xylem sap composition, which were strongly influenced by tides, were not affected by observed FWU. [ABSTRACT FROM AUTHOR]

Background and aims: The addition of organic fertilizers and sheep slat manure have important effects on soil quality in alpine mining areas, but how they affect soil physicochemical properties and microorganisms is not yet known. Methods: The current study employed field-controlled experiments and high-throughput sequencing technology to investigate differences in soil physicochemical properties, microbial community structures, and diversity under four treatments: no fertilization (CK), 100% sheep manure (SM), a combination of 50% sheep manure and 50% commercial organic fertilizer (MF), and 100% commercial organic fertilizer (OF). Results: Aboveground biomass increased by 191.93, 253.22, and 133.32% under SM, MF and OF treatments, respectively, when compared to CK treatment. The MF treatment resulted in significantly higher soil total nitrogen, total phosphorus, organic matter, and available nitrogen content compared to other treatments. Soil total nitrogen content, total phosphorus content, organic matter, available nitrogen content and available phosphorus content were 211, 120, 380, 557, and 271% higher, respectively, under the MF treatment than the CK treatment. Different nutrient additions significantly influenced soil microbial community composition. The SM and MF treatments notably increased soil bacterial and fungal community Operational Taxonomic Units (OTUs) indices and Chao 1 indices, while nutrient addition had no meaningful effect on the Simpson indices for microbial communities. There was a highly significant positive correlation between aboveground biomass and observed soil nutrient content. Conclusion: The combined application of sheep manure and commercial organic fertilizer is more conducive to improving soil quality and enhancing plant productivity in alpine mining areas. [ABSTRACT FROM AUTHOR]

Anthropogenic land use modifications are causing severe degradation of terrestrial ecosystems, and multiple revegetation strategies are emerging globally to counteract the loss of plant richness and productivity. While soil microorganisms are essential for plant community dynamics, the role of soil microbial biodiversity in regulating changes in plant richness and productivity under different revegetation strategies remains unknown. We used multitrophic co‐occurrence networks to identify soil network modules of strongly co‐occurring phylotypes along a 50‐year revegetation chronosequence of agricultural abandonment and afforestation. Soil biodiversity within these modules was related to soil nutrient cycling functions, plant richness and productivity (understorey layer in afforestation), elucidating how these network modules are associated with changes in plant richness and productivity. Plant richness and productivity increased simultaneously following both agricultural abandonment and afforestation. However, the biodiversity of key soil taxa within distinct network modules was associated with these coupled increases through the regulation of different nutrient cycling functions. Key soil phylotypes within the network modules involved in nitrogen (N) cycling correlated with the simultaneous increase in plant richness and productivity following agricultural abandonment. In contrast, those involved in phosphorus (P) and sulphur (S) cycling were linked to the coupled responses of both plant richness and productivity under afforestation. This reflects the divergent microbial mechanisms associated with the coupled increase in plant richness and productivity along the revegetation chronosequence for both agricultural abandonment and afforestation. Synthesis. Our findings provide correlative evidence that the biodiversity of key phylotypes within soil network modules is closely associated with the simultaneous increase in plant richness and productivity following the cessation of agricultural management. We identify key soil taxa, specific to each revegetation strategy, that could serve as potential targets for genomic and cultivation‐based approaches to counteract plant community degradation. Revegetation efforts to enhance plant richness and productivity should focus on soil phylotypes associated with N cycling after agricultural abandonment and those involved in P and S cycling during afforestation. [ABSTRACT FROM AUTHOR]

Introduction: Composting is one of the effective environmental protection and sustainable measures for improving soil quality and increasing crop yield. However, due to the special physical and chemical properties of saline-sodic soil and the complex rhizosphere microecological environment, the potential mechanism of regulating plant growth after applying compost in saline-sodic soil remains elusive. Methods: Here, we investigated the effects of different compost addition rates (0, 5, 15, 25%) on plant growth traits, soil chemical properties, and rhizosphere bacterial community structure. Results: The results showed that compost promoted the accumulation of plant biomass and root growth, increased soil nutrients, and enhanced the diversity and complexity of the rhizosphere bacterial communities. Moreover, the enriched core bacterial ASVs (Amplicon Sequence Variants) in compost treatment could be reshaped, mainly including dominant genera, such as Pseudomonas , Devosia , Novosphingobium , Flavobacterium , and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium. The functions of these ASVs were energy resources and nitrogen cycle functions, suggesting the roles of these ASVs in improving plant root nutrient resource acquisition for alfalfa growth. The contents of available potassium, available phosphorus, total nitrogen, and organic carbon of the soil surrounding the roots, the root length, root surface area, root volume, and root tips affected the abundance of the core bacterial ASVs, and the soil chemical properties contributed more to the effect of plant biomass. Discussion: Overall, our study strengthens the understanding of the potentially important taxa structure and function of plant rhizosphere bacteria communities, and provides an important reference for developing agricultural microbiome engineering techniques to improve root nutrient uptake and increase plant productivity in saline-sodic soils. [ABSTRACT FROM AUTHOR]

The low availability of phosphorus (P) and nitrogen (N) in the soil is a determining factor in coffee plant productivity. To increase productivity technologies in fertilizers have been developed to improve the use of P and N by plants. Thus, the objective of this work was to evaluate the productivity and nutrition of the conilon coffee tree from the application of phosphate and nitrogen slow-release fertilizers. The experiment was conduced in the field and followed a randomized block design, with three replications, in a 3 × 2 × 3 factorial scheme, with three phosphate fertilizers (conventional monoammonium phosphate – CONV; conventional monoammonium phosphate coated with polymer – POL; and monoammonium phosphate conventional pelletized with filter cake – ORG); two amounts of phosphate fertilizers (Q100 = 100% of the amount of phosphate fertilizer; Q150 = 150% of the amount of phosphate fertilizer); and two nitrogen fertilizers (conventional urea – UC and conventional polymer-coated urea – UP). The experiment was conducted during two coffee harvests (2017/2018 and 2018/2019). Slow-release phosphate fertilizers (POL + ORG), when compared to CONV, showed higher productivity of processed coffee beans, representing an increase in productivity of 6.79% (5067,6 kg ha−1) and 11.62% (6048 kg ha−1) in the 2017/2018 and 2018/2019 harvests, respectively. The application of slow-release phosphate fertilizers (POL + ORG), in relation to CONV, also resulted in higher foliar P contents in some phenological stages of the coffee tree. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA), one of the six major plant hormones, plays an essential and irreplaceable role in numerous physiological and biochemical processes during normal plant growth and in response to abiotic stresses. It is a key factor in balancing endogenous hormones and regulating growth metabolism in plants. The level of ABA is intricately regulated through complex mechanisms involving biosynthesis, catabolism, and transport. The functionality of ABA is mediated through a series of signal transduction pathways, primarily involving core components such as the ABA receptors PYR/PYL/RCAR, PP2C, and SnRK2. Over the past 50 years since its discovery, most of the genes involved in ABA biosynthesis, catabolism, and transport have been characterized, and the network of signaling pathways has gradually become clearer. Extensive research indicates that externally increasing ABA levels and activating the ABA signaling pathway through molecular biology techniques significantly enhance plant tolerance to abiotic stresses and improve plant productivity under adverse environmental conditions. Therefore, elucidating the roles of ABA in various physiological processes of plants and deciphering the signaling regulatory network of ABA can provide a theoretical basis and guidance for addressing key issues such as improving crop quality, yield, and stress resistance. [ABSTRACT FROM AUTHOR]

This study investigates the production and nutritional quality of Panicum maximum cv. Mombasa grass under varying levels of water stress and nitrogen (N) fertilization, aiming to enhance forage production in harsh environments. Four irrigation levels (5760, 6912, 4608, and 3456 m3 ha−1 year−1) and three N fertilizer doses (115, 57.5, and 0 kg ha−1 year−1) were tested. The results indicate that Mombasa grass produced higher fresh and dry weights under higher irrigation levels (I1 and I2) compared to water deficit conditions across all cuts. Interestingly, under moderate water stress (I3), the dry weight was not significantly different from that under higher irrigation for the sixth harvest in the first season. Water deficit conditions led to a significant reduction in protein content across all treatments. However, under lower irrigation levels (I3 and I4), there was a significant increase in phosphorus (P), potassium (K₊), iron (Fe2₊), and zinc (Zn) concentrations. A heatmap analysis of shape descriptors grouped the productivity and nutritional traits into two clusters based on their response to combined fertilization and drought stress. This analysis revealed that the dry weight, number of leaves, and Fe and Zn contents were positively affected under moderate water stress (80% of control; 4608 m3 ha−1 year−1) with recommended N fertilization. The study concludes that Panicum maximum cv. Mombasa is tolerant to moderate water stress and is suitable for forage production in the Qassim region, Saudi Arabia. [ABSTRACT FROM AUTHOR]

Nitrogen (N) transformation inhibitors have been widely recognized as a promising strategy to enhance crop productivity and mitigate N losses. However, the effectiveness of individual or combined inhibitors can vary significantly across different agroecosystems. Using meta‐analysis and cost–benefit analysis (CBA), we synthesized findings from 41 peer‐reviewed studies (285 observations) globally to evaluate the efficacy of urease inhibitors (UIs), nitrification inhibitors (NIs), and combined inhibitors (UINIs). We assessed their influence on soil inorganic N transformations, greenhouse gas emissions, and crop productivity across diverse climates, soil types, cropping systems, and fertilization practices. Our results indicated that combined UINIs were the most efficient, increasing crop yields by 5% and mitigating gaseous emissions by 51% compared to UIs or NIs alone. UINIs achieved these benefits by enhancing crop ammonium (NH4+) availability through regulating urea hydrolysis and prolonging NH4+ retention by suppressing nitrification in the soil. The CBA revealed that the overall economic benefits of UINIs application outweighed the costs, resulting in a net monetary benefit of $23.36 ha−1, equivalent to a 6.4% increase in revenue. Both meta‐regression and random forest analyses suggested that UINIs performance was strongly influenced by factors such as N application rate, organic matter content, and soil pH. Notably, more substantial responses were observed in fine‐textured soils and/or crops exposed to high N fertilization rates. Acidic soils (pH < 6.5) exhibited the largest effect sizes, with increased crop productivity and reduced NH3 volatilization due to specific inhibitory interactions. In conclusion, these findings highlight UINIs beneficial impacts on crop productivity and environmental conservation, achieving a "win‐win" scenario by addressing various N‐loss challenges while enhancing economic outcomes. Further exploration and optimization of the interaction between climate, soil, plant, and management systems and the use of appropriate inhibitors are crucial for maximizing their positive impact on global climate and reaping corresponding economic benefits. [ABSTRACT FROM AUTHOR]

Background/Objective: The midday depression of photosynthesis, a physiological phenomenon driven by environmental stress, impacts plant productivity. This study aims to elucidate the molecular and physiological responses underlying midday depression in two mulberry species, Ewu No. 1 (Ew1) and Husan No. 32 (H32), to better understand their species-specific stress adaptation mechanisms. Methods: RNA-seq analysis was conducted on leaf samples collected at three time points (10:00 a.m., 12:00 p.m., and 4:00 p.m.), identifying 22,630 differentially expressed genes (DEGs). A comparative Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed to reveal the involvement of key metabolic and signaling pathways in stress responses. Results: Ew1 displayed enhanced stress tolerance by upregulating genes involved in energy management, water conservation, and photosynthetic processes, maintaining higher photosynthetic rates under midday stress. In contrast, H32 adopted a more conservative response, downregulating genes related to photosynthesis and metabolism, favoring survival at the expense of productivity. The KEGG analysis highlighted starch and sucrose metabolism and plant hormone signaling as critical pathways contributing to these species-specific responses. Conclusions: Ew1's adaptive molecular strategies make it more suitable for environments with variable light and temperature conditions, while H32's conservative approach may limit its productivity. These findings provide valuable insights for breeding programs aimed at improving stress tolerance and photosynthetic efficiency in mulberry and other crops, particularly under fluctuating environmental conditions. [ABSTRACT FROM AUTHOR]

Here, we examine the effects of ploidy variation in Cannabis sativa L. cell lines on the plant host genotype-associated microbiome. The endophytic microbiome has a protocooperative role in improving plant health and productivity and represents an alternative to synthetic chemical fertilizers and pesticides in sustainable agriculture. This study assessed the effects of seed endophytes on diploid and triploid Haze hemp cultivars. Key phenotypic characteristics were evaluated, revealing significant differences in seed germination in vitro as well as vegetative growth and flowering in phytotron conditions. Endophyte-treated triploid plants exhibited significantly taller heights compared to diploids (p < 0.01). These treated triploid plants also showed longer leaves at nodes 2, 6, and 8, except at node 4, indicating a plant in transition from vegetative growth to the generative developmental stage. Additionally, triploids treated with endophytes displayed the highest number of axillary branches, while endophyte-treated diploids had the fewest (p < 0.05). Both cultivars treated with endophytes exhibited a higher number of inflorescences compared to untreated control plants. This study revealed for the first time a direct correlation between the shifts in diameter of the stem and the biomass in both tested hemp hosts, in association with endophytic microbiomes. [ABSTRACT FROM AUTHOR]

The temporal stability of plant productivity affects species' access to resources, exposure to stressors and strength of interactions with other species in the community, including support to the food web. The magnitude of temporal stability depends on how a species allocates resources among tissues and across phenological stages, such as vegetative growth versus reproduction. Understanding how plant phenological traits correlate with the long‐term stability of plant biomass is particularly important in highly variable ecosystems, such as drylands.We evaluated whether phenological traits predict the temporal stability of plant species productivity by correlating 18 years of monthly phenology observations with biannual estimates of above‐ground plant biomass for 98 plant species from semi‐arid drylands. We then paired these phenological traits with potential climate drivers to identify abiotic contexts that favour specific phenological strategies among plant species.Phenological traits predicted the stability of plant species above‐ground biomass. Plant species with longer vegetative phenophases not only had more stable biomass production over time but also failed to fruit in a greater proportion of years, indicating a growth–reproduction trade‐off. Earlier leaf‐out dates, longer fruiting duration and longer time lags between leaf and fruit production also predicted greater temporal stability.Species with stability‐promoting traits began greening in drier conditions than their unstable counterparts and experienced unexpectedly greater exposure to climate stress, indicated by the wider range of temperatures and precipitation experienced during biologically active periods.Our results suggest that bet‐hedging strategies that spread resource acquisition and reproduction over long time periods help to stabilize plant species productivity in variable environments, such as drylands. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Refractoriness of chrome minerals imposes challenges during chrome ore pelletization process. This study is conducted to find suitable additives to improve chrome ore pelletization and pellet properties. Two types of additives (carbonaceous heating additives and binding fluxes) have been explored to improve pellet induration in pre-heating and elevated temperature zone of a shaft furnace. Ten different types of carbonaceous heating additives (rice husk powder, coke fines, anthracite coal, Indian coal, South African coal, Indonesian coal, graphite powder, carbon soot, pet coke, charcoal) were tested and found that rice husk powder and carbon soot are the most effective additives to improve pellet properties in the shaft furnace pre-heating zone. Rice husk dosing improves pellet strength by 31% (31.76 to 41.90 kgf) in the pre-heating zone which helps pellets to maintain their shape and size, this in terms improve the pellet bed permeability and gas flow during sintering. Seven diverse types of binding fluxes (Dolomite, Magnesium-chromite fines, Magnesium-carbon fines, MgCl2, Na3AlF6, MgO powder, and DRI-additive) were studied in the lab. Cryolite dosing between 0.25% to 2% in pellet mix improved pellet compressive strength by 190% (63 to184 kgf) and reduced pellet swelling by 30%. A pellet mix which contained 95% ore fines, 2% bentonite, 2% rice husk powder, 1% cryolite and 14% moisture has been identified as an optimized pellet mix for producing pellets with 197 kgf/pellet compressive strength. The pellets produced using optimized pellet mix also showed superior metallurgical properties during smelting reduction. It can improve the overall plant productivity economically. [ABSTRACT FROM AUTHOR]

Drought stress, an inevitable global issue due to climate change, hinders plant growth and yield. Nitric oxide (NO), a tiny gaseous signaling compound is now gaining massive attention from the plant science community due to its unparalleled array of mechanisms for ameliorating various abiotic stresses, including drought. Supplementation of NO has shown its astounding effect in improving drought tolerance by prominently influencing its tendency to modulate stomatal movement and reduce oxidative stress; it can enormously affect the various other physio-biochemical processes such as root structure, photosynthesis, osmolyte cumulation, and seed establishment of plants due to its amalgamation with a wide range of molecules during drought conditions. The production and inhibition of root development majorly depend on NO concentration and/or experimental conditions. As a lipophilic free gasotransmitter, NO readily reacts with free metals and oxygen species and has been shown to enhance or reduce the redox homeostasis of plants, depending on whether acting in a chronic or acute mode. NO can easily alter the enzymes, protein activities, and genomic transcriptional and post-translational modifications that assist functional retrieval from water stress. Although progress is ongoing, much work remains to be done to describe the proper target site and mechanistic approach of this vibrant molecule in plant drought tolerance. This detailed review navigates through the comprehensive and clear picture of the mechanistic potential of NO in drought stress following molecular approaches and suggests effective physiological and biochemical strategies to overcome the negative impacts of drought. We explore its potential to increase crop production, thereby ensuring global food security in drought-prone areas. In an era marked by unrelenting climatic conditions, the implications of NO show a promising approach to sustainable farming, providing a beacon of hope for future crop productivity. [Display omitted] • Drought stress severely hampers plant growth and productivity. • Provides deep insights into the potential significance of NO under drought. • Reviews the novel molecular amendments in NO-drought research. [ABSTRACT FROM AUTHOR]

Salinity is a significant environmental stress that adversely impacts plant growth and productivity, posing a significant challenge for sustainable agriculture. While the role of silicon (Si) in enhancing plant resilience against various stresses, including salinity, has been recognized, its specific effects on sea barley (Hordeum marinum) under saline conditions require further exploration. The originality of this study lies in its detailed analysis of ROS detoxification and the enhancement of antioxidant defenses, aspects that have not been extensively studied in Hordeum marinum before. This study provides novel insights into the potential of silicon (0.5 mM Na2SiO3) to mitigate the adverse impacts of salinity (150 mM NaCl) on sea barley. The findings showed that under salt stress, growth parameters, soluble protein levels, and antioxidant enzyme activities such as Superoxide Dismutase (SOD), Catalase (CAT), and Guaiacol Peroxidase (GPX) were significantly reduced. Additionally, the levels of hydrogen peroxide (H2O2) and lipid peroxidation increased under saline conditions. Interestingly, silicon supply effectively counteracted these detrimental effects by improving plant growth, water status, soluble protein content, and antioxidant enzyme activities and reducing H2O2 and malondialdehyde (MDA) contents. Importantly, this study reveals that silicon enhanced salt tolerance in sea barley, in particular through the detoxification of reactive oxygen species and the stimulation of antioxidant defense mechanisms. This study underscores the potential of incorporating silicon in agricultural practices to enhance crop resilience and productivity in salt-affected regions, thus offering significant socioeconomic benefits to the agricultural sector. [ABSTRACT FROM AUTHOR]

Summary: Roots are important in agricultural and natural systems for determining plant productivity and soil carbon inputs. Sometimes, the amount of roots in a sample is too much to fit into a single scanned image, so the sample is divided among several scans, and there is no standard method to aggregate the data.Here, we describe and validate two methods for standardizing measurements across multiple scans: image concatenation and statistical aggregation. We developed a Python script that identifies which images belong to the same sample and returns a single, larger concatenated image. These concatenated images and the original images were processed with RhizoVision Explorer, a free and open‐source software. An R script was developed, which identifies rows of data belonging to the same sample and applies correct statistical methods to return a single data row for each sample. These two methods were compared using example images from switchgrass, poplar, and various tree and ericaceous shrub species from a northern peatland and the Arctic.Most root measurements were nearly identical between the two methods except median diameter, which cannot be accurately computed by statistical aggregation.We believe the availability of these methods will be useful to the root biology community. [ABSTRACT FROM AUTHOR]

The optimal timing of transition from vegetative to floral reproductive phase is critical for plant productivity and agricultural yields. Light plays a decisive role in regulating this transition. The B‐box (BBX) family of transcription factors regulates several light‐mediated developmental processes in plants, including flowering. Here, we identify a previously uncharacterized group II BBX family member, BBX13/COL15, as a negative regulator of flowering under long‐day conditions. BBX13 is primarily expressed in the leaf vasculature, buds, and flowers, showing a similar spatial expression pattern to the major flowering time regulators CO and FT. bbx13 mutants flower early, while BBX13‐overexpressors exhibit delayed flowering under long days. Genetic analyses showed that BBX13 acts upstream to CO and FT and negatively regulates their expression. BBX13 physically interacts with CO and inhibits the CO‐mediated transcriptional activation of FT. In addition, BBX13 directly binds to the CORE2 motif on the FT promoter, where CO also binds. Chromatin immunoprecipitation data indicates that BBX13 reduces the in vivo binding of CO on the FT promoter. Through luciferase assay, we found that BBX13 inhibits the CO‐mediated transcriptional activation of FT. Together, these findings suggest that BBX13/COL15 represses flowering in Arabidopsis by attenuating the binding of CO on the FT promoter. Summary statement: BBX13, a previously uncharacterized protein in the B‐Box family of transcription factors, negatively regulates flowering time in Arabidopsis thaliana. BBX13 physically and genetically interacts with CO and inhibits the CO‐mediated transcriptional activation of FT. [ABSTRACT FROM AUTHOR]

Fluoride is one of the most highly toxic soil and air pollutant prevalent in aquatic as well as terrestrial ecosystems. It seriously affects crop plant quality and productivity worldwide. Although a crop with great nutritional value; oats are susceptible to a variety of abiotic stresses. In the current study, the responses of six oat cultivars (JHO-99-1, JHO-2009, BJ-2012, KANT, JHO-822, and JHO-2000) to fluoride stress on growth measurements, photosynthetic pigments, and photosynthetic parameters have been studied. The fluoride (200 and 400 mg/kg) was added to the soil artificially, seeds were sown and the pots were kept under controlled conditions. Another set of plants without the fluoride treatment (0 mg/kg) were labeled as control. The experiment was conducted in a plant growth chamber and fluoride was artificially added to the soil prior to seeding. All six oat cultivars subjected to fluoride stress exhibited an overall decrease in plant growth when compared to the control. Further under fluoride stress, while the oat cultivars also showed a decrease in chlorophyll content and different photosynthetic parameters but on the contrary the antioxidant activities were increased. While the cultivar JHO-822 was most affected under fluoride stress, JHO-99-1 showed tolerance toward fluoride toxicity in comparison to other cultivars JHO-2009, BJ-2012, KANT, JHO-822, and JHO-2000. It is concluded that the tolerance or susceptibility of a cultivar to fluoride can be well correlated with various parameters studied in the present study. [ABSTRACT FROM AUTHOR]

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The soil microbiome provides essential services in agroecosystems that can increase plant health and productivity, such as disease suppression and growth promotion. A small number of microbial groups have been proposed as main players behind disease suppression, but the complete picture of the underlying mechanisms remains unclear for both functions in many soil systems. Here, we investigated broad and fine‐scale microbial community features for their contributions to disease suppression and growth promotion for potato plants. In a greenhouse study, we grew potato plants in pots sharing a common background soil and inoculated with living soil microbial communities with or without a separate inoculation with Streptomyces scabiei, the causal agent of potato common scab disease. The suppression of common scab and growth promotion abilities of a variety of soil microbial communities were estimated and related to quantitative patterns in microbial community structure. We found that suppression of common scab was mostly driven by fine‐scale microbial community features, especially the diversity within the Actinomycetota phylum. Even though opposing components of microbial community structure might be related to the two functions, disease suppression did not cause a negative trade‐off in growth promotion. This suggests high functional redundancy in growth promotion. It may be possible to improve the multi‐functionality of soil microbial communities by engineering the communities toward optimized disease suppression and growth promotion ability. [ABSTRACT FROM AUTHOR]

Soil microbiomes play key roles in plant productivity and nutrient cycling, and we need to understand whether and how they will withstand the effects of global climate change. We exposed in situ soil microbial communities to multiple rounds of heat, drought, or heat and drought treatments, and profiled microbial communities with 16S rRNA and ITS amplicon sequencing during and after these climatic changes. We then tested how domain and symbiotic lifestyle affected responses. Fungal community composition strongly shifted due to drought and its legacy. In contrast, bacterial community composition resisted change during the experiment, but still was affected by the legacy of drought. We identified fungal and bacterial taxa with differential abundance due to heat and drought and found that taxa affected during climate events are not necessarily the taxa affected in recovery periods, showing the complexity and importance of legacy effects. Additionally, we found evidence that symbiotic groups of microbes important to plant performance respond in diverse ways to climate treatments and their legacy, suggesting plants may be impacted by past climatic events like drought and warming, even if they do not experience the event themselves. [ABSTRACT FROM AUTHOR]

Salinity stress is a significant abiotic factor that limits plant growth and productivity by causing ionic imbalances and oxidative damage. Chelated zinc (Zn) has gained attention as an effective micronutrient to mitigate salinity-induced stress by enhancing antioxidant defense mechanisms, osmotic regulation, and physiological processes. This study aimed to investigate the impact of foliar-sprayed chelated Zn on the alleviation of salinity stress in Calendula officinalis. A pot experiment was conducted with varying salinity levels (0, 1000, 2000, and 3000 ppm NaCl) and Zn concentrations (0, 200, 400, and 600 ppm). The results demonstrated that chelated Zn significantly enhanced the growth parameters, flower yield, and biochemical traits, particularly under high-salinity conditions. Salinity stress was associated with a marked increase in the Na+ and K+ concentrations and a reduction in the Zn levels in the leaves. However, the foliar application of chelated Zn reduced the Na+ and increased the K+ concentrations in the leaves, resulting in an elevated K+/Na+ ratio with higher salinity and Zn application rates. Furthermore, the salinity and chelated Zn treatments stimulated the production of proline, phenols, flavonoids, and antioxidant activity, indicating the plant's adaptive mechanism to enhance its secondary metabolite production under stress. These findings highlight the potential of chelated Zn to improve the salinity tolerance, supporting sustainable agricultural practices in saline-affected areas. Although salinity reduced the overall growth of C. officinalis, farmers are encouraged to cultivate this plant for its valuable inflorescences under saline irrigation conditions (up to 2000 ppm), combined with chelated Zn foliar applications at 400–600 ppm. We also recommend further research on other micronutrients. [ABSTRACT FROM AUTHOR]

Salt marshes exist at the terrestrial-marine interface, providing important ecosystem services such as nutrient cycling and carbon sequestration. Tidal inputs play a dominant role in salt marsh porewater mixing, and terrestrially derived freshwater inputs are increasingly recognized as important sources of water and solutes to intertidal wetlands. However, there remains a critical gap in understanding the role of freshwater inputs on salt marsh hydrology, and how this may impact marsh subsurface salinity and plant productivity. Here, we address this knowledge gap by examining the hydrologic behavior, porewater salinity, and pickleweed (Sarcocornia pacifica also known as Salicornia pacifica) plant productivity along a salt marsh transect in an estuary along the central coast of California. Through the installation of a suite of hydrometric sensors and routine porewater sampling and vegetation surveys, we sought to understand how seasonal changes in terrestrial freshwater inputs impact salt marsh ecohydrologic processes. We found that salt marsh porewater salinity, shallow subsurface saturation, and pickleweed productivity are closely coupled with elevated upland water level during the winter and spring, and more influenced by tidal inputs during the summer and fall. This seasonal response indicates a switch in salt marsh hydrologic connectivity with the terrestrial upland that impacts ecosystem functioning. Through elucidating the interannual impacts of drought on salt marsh hydrology, we found that the severity of drought and historical precipitation can impact contemporary hydrologic behavior and the duration and timing of the upland-marsh hydrologic connectivity. This implies that the sensitivity of salt marshes to climate change involves a complex interaction between sea level rise and freshwater inputs that vary at seasonal to interannual timescales. [ABSTRACT FROM AUTHOR]

Bacteria associated with plants, whether rhizospheric, epiphytic, or endophytic, play a crucial role in plant productivity and health by promoting growth through complex mechanisms known as plant growth promoters. This study aimed to isolate, characterize, identify, and evaluate the potential of endophytic bacteria from the resurrection plant Selaginella lepidophylla in enhancing plant growth, using Arabidopsis thaliana ecotype Col. 0 as a model system. Plant growth-promotion parameters were assessed on the bacterial isolates; this assessment included the quantification of indole-3-acetic acid, phosphate solubilization, and biological nitrogen fixation, a trehalose quantification, and the siderophore production from 163 endophytic bacteria isolated from S. lepidophylla. The bacterial genera identified included Agrobacterium, Burkholderia, Curtobacterium, Enterobacter, Erwinia, Pantoea, Pseudomonas, and Rhizobium. The plant growth promotion in A. thaliana was evaluated both in Murashige Skoog medium, agar-water, and direct seed inoculation. The results showed that the bacterial isolates enhanced primary root elongation and lateral root and root hair development, and increased the fresh and dry biomass. Notably, three isolates promoted early flowering in A. thaliana. Based on these findings, we propose the S. lepidophylla bacterial isolates as ideal candidates for promoting growth in other agriculturally important plants. [ABSTRACT FROM AUTHOR]

Tartary buckwheat is characterized by its numerous inflorescences; however, the uneven distribution of resources can lead to an overload in certain areas, significantly limiting plant productivity. Plant growth regulators effectively modulate plant growth and development. This study investigated the effects of three concentrations of brassinosteroids (EBR) on the Tartary buckwheat cultivar with high seed-setting rates, specifically Chuanqiao No. 1 (CQ1), and low seed-setting rates, namely Xiqiao No. 1 (XQ1), through field experiments. The goal was to investigate how EBR regulates buckwheat grain-filling, enhancing the seed-setting rates, and to understand the physiological mechanisms behind this improvement. The results indicated that EBR treatment followed the typical "S" type growth curve of crops, resulting in an increase in the Tartary buckwheat grain-filling rate. Varieties with high seed-setting rates demonstrated a greater capacity for grain-filling. EBR was observed to regulate hormone content, enhance the photosynthetic capacity of Tartary buckwheat, and increase yield. This was accomplished by enhancing the accumulation of photosynthetic products during the grain-filling period. Specifically, EBR elevated the activity of several key enzymes, including pre-leaf sucrose phosphate synthase (SPS), seed sucrose synthase (SS), late grain-filling acid invertase (AI), grain-filling leaf SPS, and grain SS. These changes led to an increased accumulation of sucrose and starch from photosynthetic products. In summary, the G2 concentration of EBR (0.1 mg/L) demonstrated the most significant impact on the seed-setting rates and yield enhancement of Tartary buckwheat. [ABSTRACT FROM AUTHOR]

Summary The potential for widespread sink‐limited plant growth has received increasing attention in the literature in the past few years. Despite recent evidence for sink limitations to plant growth, there are reasons to be cautious about a sink‐limited world view. First, source‐limited vegetation models do a reasonable job at capturing geographic patterns in plant productivity and responses to resource limitations. Second, from an evolutionary perspective, it is nonadaptive for plants to invest in increasing carbon assimilation if growth is primarily sink‐limited. In this review, we synthesize the potential evidence for and underlying physiology of sink limitation across terrestrial ecosystems and contrast mechanisms of sink limitation with those of source‐limited productivity. We highlight evolutionary restrictions on the magnitude of sink limitation at the organismal level. We also detail where mechanisms regulating sink limitation at the organismal and ecosystem scale (e.g. the terrestrial carbon sink) diverge. Although we find that there is currently no direct evidence for widespread organismal sink limitation, we propose a series of follow‐up growth chamber manipulations, systematized measurements, and modeling experiments targeted at diagnosing nonadaptive buildup of excess nonstructural carbohydrates that will help illuminate the prevalence and magnitude of organismal sink limitation. [ABSTRACT FROM AUTHOR]

In recent years, the role of microbial communities in agricultural systems has received increasing attention, particularly concerning their impact on plant health and productivity. However, the influence of host plant genetic factors on the microbial composition of coffee plants remains largely unexplored. This study provides the first comprehensive investigation into how genotype affects the microbial communities present in the rhizosphere and fruits of Coffea canephora. Conducted on a commercial coffee farm in Brazil, we analyzed six genotypes of C. canephora var. Conilon. Soil and fruit samples were collected from which microbial DNA was extracted and sequenced, targeting the V3-V4 region of the 16 S rDNA and the ITS1 region for fungi. A total of 12,239,769 reads were generated from the 16 S rDNA and ITS1 regions. The PCoA revealed distinct patterns of beta diversity, with genotype 153 exhibiting significant isolation in soil bacterial communities. The dominant bacterial orders included Rhizobiales and Rhodobacterales, while the fungal community comprised diverse taxa from Saccharomycetales and Hypocreales. LEfSe analysis identified key metagenomic biomarkers, highlighting genotype Baiano 4 for its richness in fruit-associated taxa, whereas genotype 153 exhibited lower diversity in both soil and fruit samples. This work enhances our understanding of the microbiomes associated with different coffee genotypes, providing evidence of how host genetic variation influences microbial community composition. Our findings indicate that specific microbial taxa are enriched in the fruits and soil of various genotypes. Future research should focus on identifying these microorganisms and elucidating their specific functions within the rhizosphere and coffee fruits. [ABSTRACT FROM AUTHOR]

Background: Endophytes play an important role in promoting plant growth. To date, although many reports provided insight into the function of endophytes in their hosts, few reports focus on their impact on nearby plants. Intraspecific allelopathy in plant community is common and presents a notable challenge to medicinal plant yield and productivity. Atractylodes lancea is a perennial herb that has relatively low yields due to intraspecific allelopathy. The bacterial endophyte Pseudomonas fluorescens ALEB7B has previously been found to increase essential oil content of A. lancea, but the role of ALEB7B in A. lancea allelopathy is still unknown. Results: Noninoculated A. lancea exhibited growth retardation when it was grown in a community, which was related to ethylene-induced intraspecific allelopathy. Further experiment showed that exposing A. lancea to volatile from noninoculated A. lancea or same concentration of ethylene reduced growth of A. lancea. P. fluorescens-inoculated plants showed reduced ethylene emission and relieved growth retardation on neighboring noninoculated A. lancea. Moreover, P. fluorescens inoculation had little allelopathic effect when receivers were treated with ethylene receptor inhibitor or when emitters were treated with ethylene production inhibitor. Transcriptomic analysis revealed that endophyte ALEB7B altered transcriptional response associated with ethylene response and essential oil production in neighboring A. lancea. Conclusions: Our results demonstrated that the bacterial endophyte ALEB7B provides fitness benefits for both hosts and neighbors. The allelopathic effect on nearby plants can be alleviated by altering airborne signals, such as ethylene, in endophytic bacteria. [ABSTRACT FROM AUTHOR]

Water level fluctuations are among the main factors affecting the development of wetland vegetation communities, carbon sinks, and ecological processes. Hongze Lake is a typical seasonal lake wetland in the Huaihe River Basin. Its water levels have experienced substantial fluctuations because of climate change, as well as gate and dam regulations. In this study, long-term cloud-free remote sensing images of water body area, net plant productivity (NPP), gross primary productivity (GPP), and Fractional vegetation cover (FVC) of the wetlands of Hongze Lake were obtained from multiple satellites by Google Earth Engine (GEE) from 2006 to 2023. The trends in FVC were analyzed using a combined Theil-Sen estimator and Mann-Kendall (MK) test. Linear regression was employed to analyze the correlation between the area of water bodies and that of different degrees of FVC. Additionally, annual frequencies of various water levels were constructed to explore their association with GPP, NPP, and FVC.The results showed that water level fluctuations significantly influence the spatial and temporal patterns of wetland vegetation cover and carbon sinks, with a significant correlation (P<0.05) between water levels and vegetation distribution. Following extensive restoration efforts, the carbon sink capacity of the Hongze Lake wetland has increased. However, it is essential to consider the carbon sink capacity in areas with low vegetation cover, for the lakeshore zone with a higher inundation frequency and low vegetation cover had a lower carbon sink capacity. These findings provide a scientific basis for the establishment of carbon sink enhancement initiatives, restoration programs, and policies to improve the ecological value of wetland ecosystem conservation areas. [ABSTRACT FROM AUTHOR]

In developing world especially Africa, organic fertilizers are mostly used to boost agriculture production. However, less is known about the effectiveness of stored and fresh rabbit urine as an organic fertilizer on the production of vegetables, including Ethiopian mustard (EM) in Tanzania. A split-plot experimental design was used, with rabbit urine status (stored and fresh) serving as the main plots and sub-plots made of rabbit urine concentration (0%, 25%, 50% and 75%). A total of eight experimental treatments with three replications each was used making a total of 24 plots. Plant height, number of leaves, leaf length, and width were recorded every 3 days for 7 weeks. After harvesting, fresh and dry yield was recorded. Rabbit urine was observed to significantly (p < 0.05) increase soil nutrients including nitrogen, potassium and phosphorus across different concentrations where 75% of rabbit urine concentration was found to perform better compared to 50% and 25%. Ethiopian mustard with the 75% concentration of rabbit urine increased plant height by 32.52%, leaf length by 19%, and number of leaves by 20.24% while keeping leaf width constant compared to 0% rabbit urine concentration. Similarly, 75% of fresh urine increased dry biomass by 42%. Fresh rabbit urine performed better in growth and production of the Ethiopian mustard compared to the stored rabbit urine. This result concludes that, the use of fresh rabbit urine can increase productivity of vegetables like Ethiopian mustard especially at 75%. [ABSTRACT FROM AUTHOR]

Background: The early and specific detection of abiotic and biotic stresses, particularly their combinations, is a major challenge for maintaining and increasing plant productivity in sustainable agriculture under changing environmental conditions. Optical imaging techniques enable cost-efficient and non-destructive quantification of plant stress states. Monomodal detection of certain stressors is usually based on non-specific/indirect features and therefore is commonly limited in their cross-specificity to other stressors. The fusion of multi-domain sensor systems can provide more potentially discriminative features for machine learning models and potentially provide synergistic information to increase cross-specificity in plant disease detection when image data are fused at the pixel level. Results: In this study, we demonstrate successful multi-modal image registration of RGB, hyperspectral (HSI) and chlorophyll fluorescence (ChlF) kinetics data at the pixel level for high-throughput phenotyping of A. thaliana grown in Multi-well plates and an assay with detached leaf discs of Rosa × hybrida inoculated with the black spot disease-inducing fungus Diplocarpon rosae. Here, we showcase the effects of (i) selection of reference image selection, (ii) different registrations methods and (iii) frame selection on the performance of image registration via affine transform. In addition, we developed a combined approach for registration methods through NCC-based selection for each file, resulting in a robust and accurate approach that sacrifices computational time. Since image data encompass multiple objects, the initial coarse image registration using a global transformation matrix exhibited heterogeneity across different image regions. By employing an additional fine registration on the object-separated image data, we achieved a high overlap ratio. Specifically, for the A. thaliana test set, the overlap ratios (ORConvex) were 98.0 ± 2.3% for RGB-to-ChlF and 96.6 ± 4.2% for HSI-to-ChlF. For the Rosa × hybrida test set, the values were 98.9 ± 0.5% for RGB-to-ChlF and 98.3 ± 1.3% for HSI-to-ChlF. Conclusion: The presented multi-modal imaging pipeline enables high-throughput, high-dimensional phenotyping of different plant species with respect to various biotic or abiotic stressors. This paves the way for in-depth studies investigating the correlative relationships of the multi-domain data or the performance enhancement of machine learning models via multi modal image fusion. [ABSTRACT FROM AUTHOR]

Coastal marshes vulnerable to sea‐level rise may benefit from sediment amendments to increase elevation. However, nutrient‐loading to estuaries may counter elevation gain through reduced root production and/or increased decomposition. Here, we test if belowground plant productivity, root decomposition, and marsh accretion response to nutrient‐loading differs with sediment addition in three marsh types: a healthy intermediate salinity marsh, a deteriorating brackish marsh, and a created marsh in Barataria Basin, Louisiana, United States. In this region, wetland loss is rapid, and a major restoration project is underway to introduce Mississippi River water, sediment, and nutrients to offset marsh loss. Porewater nutrient concentrations, vegetation structure, belowground productivity and decomposition, and accretion rates were measured over 450 days. Experimental nitrate additions yielded high porewater ammonium‐N concentrations in the Deteriorating marsh but had a smaller effect in Healthy and Created marshes. Belowground productivity in the Deteriorating marsh was neutral to negatively affected by nutrient and sediment treatments, whereas positive effects occurred in Healthy and Created marshes. Despite elevation increase from sediment treatments, and substantial effects of nutrient treatments on porewater nutrient concentrations, belowground decomposition and surface accretion rates were not affected by treatments. Sediment deposition increased species richness in the Healthy marsh and added sediment and added nutrients with sediment increased plant height in the Created and Deteriorating marshes, respectively. Over the timescale measured, experimental sedimentation and pulsed nutrient input had few consistent effects on belowground ingrowth, decomposition, or surface accretion. Our findings highlight that response to nutrient pulses are complex and depend on baseline marsh conditions. [ABSTRACT FROM AUTHOR]

When plants face biotic stress, the induction of defence responses imposes a massive demand for carbon and energy resources, which could decrease the reserves allocated towards growth. These growth–defence trade-offs have important implications for plant fitness and productivity and influence the outcome of plant–pathogen interactions. Biotic stress strongly affects plant cells' primary metabolism, including photosynthesis and respiration, the main source of energy and carbon skeletons for plant growth, development, and defence. Although the nature of photosynthetic limitations imposed by pathogens is variable, infection often increases photorespiratory pressure, generating conditions that promote ribulose-1,5-bisphosphate oxygenation, leading to a metabolic shift from assimilation to photorespiration. Photorespiration, the significant metabolic flux following photosynthesis, protects the photosynthetic apparatus from photoinhibition. However, recent studies reveal that its role is far beyond photoprotection. The intermediates of the photorespiratory cycle regulate photosynthesis, and photorespiration interacts with the metabolic pathways of nitrogen and sulphur, shaping the primary metabolism for stress responses. This work aims to present recent insights into the integration of photorespiration within the network of primary metabolism under biotic stress. It also explores the potential implications of regulating photosynthetic–photorespiratory metabolism for plant defence against bacterial and fungal pathogens. [ABSTRACT FROM AUTHOR]

The co-occurrence of drought and heat significantly hampers plant productivity. Although their impacts are well studied, these studies have been based on the effects of individual stressors rather than their combined influence. Okra is crucial for food and nutritional security and livelihoods in many regions, yet it remains under-researched and unimproved. Okra has been proven to be sensitive to both drought and heat stress. This study employed a cost-effective phenotyping method to assess key traits characterising the diversity of okra morphophysiological responses to independent and interactive heat-drought stresses. This study aimed to understand okra responses to stress, identify stress-resilient traits, and characterise okra genotypes. We also addressed the need to examine interactive stress effects, which mirror real-world scenarios more accurately than single-stress studies. Sixty-three okra genotypes were subjected to heat, drought, or concurrent heat-drought stress at the seedling stage in improvised climate-controlled chambers. The germplasm exhibited significant variations in response to the various stresses. The broad-sense heritability was high (> 0.60) for traits such as chlorophyll content, plant biomass, performance indices, electrolyte leakage, and total leaf area. Drought stress alone had a more pronounced effect than heat stress alone, and the adverse impact was worsened under combined heat and drought stress. The interactive impact of drought and heat was more likely additive than antagonistic or synergistic. A positive and strong relationship was observed between photosynthetic efficiency parameters such as the Fv/Fm ratio, chlorophyll content, relative water index, and biomass parameters such as dry shoot weight. The 63 okra genotypes were classified into three distinct clusters, suggesting potential for future breeding efforts. Okra genotype considered to be tolerant or climate resilient (such as GH170, V1060831, GH174, V1060874, and GH106) to drought and heat, maintained enhanced photosynthetic efficiency and high internal water potential, possibly reducing osmotic and oxidative damage. This study revealed some mechanisms underlying the adaptation of okra genotypes to independent and combined heat and drought stress. The results provide a basis for breeding efforts to develop climate-resilient okra varieties. [ABSTRACT FROM AUTHOR]

Enhancing terrestrial carbon (C) stock through ecological restoration, one of the prominent approaches for natural climate solutions, is conventionally considered to be achieved through an ecological pathway, i.e., increased plant C uptake. By conducting a comprehensive regional survey of 4279 1 × 1 m² plots at 517 sites across China's drylands and a 13-y manipulative experiment in a semiarid grassland within the same region, we show that greater soil and ecosystem C stocks in restored than degraded lands result predominantly from decreased surface soil C loss via suppressed wind erosion. This biophysical pathway is always overlooked in model evaluation of land-based C mitigation strategies. Surprisingly, stimulated plant growth plays a minor role in regulating C stocks under ecological restoration. In addition, the overall enhancement of C stocks in the restored lands increases with both initial degradation intensity and restoration duration. At the national scale, the rate of soil C accumulation (7.87 Tg C y-1) due to reduced wind erosion and surface soil C loss under dryland restoration is equal to 38.8% of afforestation and 56.2% of forest protection in China. Incorporating this unique but largely missed biophysical C-conserving mechanism into land surface models will greatly improve global assessments of the potential of land restoration for mitigating climate change. [ABSTRACT FROM AUTHOR]

Sandy soils are widespread globally and are increasingly utilized to meet the demands of a growing population and urbanization for food, fiber, energy, and other essential services. However, their poor water and nutrient retention makes crop cultivation challenging. This study evaluated the effects of integrating compost and plant growth-promoting rhizobacteria (PGPR; Azospirillum brasilense SWERI 111 and Azotobacter chroococcum OR512393) on wheat (Triticum aestivum L. var. Misr 1) grown in sandy soil under varying levels of recommended NPK (50%, 75%, and 100%) fertilization. Conducted over two growing seasons, the experiment aimed to assess soil health, nutrient uptake, microbial activity, and plant productivity in response to compost and PGPR treatments. The results demonstrated that combining compost and PGPR significantly improved soil chemical properties, such as reducing soil pH, electrical conductivity (ECe), and sodium adsorption ratio (SAR), while enhancing soil organic matter (SOM). Additionally, compost and PGPR improved soil nutrient content (N, P, K) and boosted the total bacterial and fungal counts. The combined treatment also increased urease and phosphatase enzyme activities, contributing to enhanced nutrient availability. Notably, plant productivity was enhanced with compost and PGPR, reflected by increased chlorophyll and reduced proline content, along with improved grain and straw yields. Overall, the results underscore the potential of compost and PGPR as effective, sustainable soil amendments to support wheat growth under varying NPK levels. [ABSTRACT FROM AUTHOR]

Background: Modulating the microbiome with nanomaterials has been proposed to improve plant growth, and reduce reliance on external inputs. Carbon Nanosol (CNS) was attracted for its potential to improve plant productivity. However, the mechanism between CNS and rhizosphere microorganisms remained largely elusive. Results: Here, we tried to systematically explore the effects of CNS (600 and 1200 mg/L by concentration) on tobacco growth, soil physical properties, and root-associated microbiome. The influence of CNS on soil physicochemical properties and plant growth was significant and dose-dependent, leading to a 28.82% increase in biomass accumulation by 600 mg/L CNS. Comparison between the CNS-treated and control plants revealed significant differences in microbiome composition, including 1148 distinct ASVs (923 bacteria and 225 fungi), microbiome interactions, and metabolic function of root-associated microbiomes. Fungal and bacterial communities had different response patterns for CNS treatment, with phased and dose-dependent effects, with the most significant changes in microbial community structure observed at 1200 mg/L after 10 days of treatment. Microbial networks of CNS-treated plants had more nodes and edges, higher connectivity, and more hub microorganisms than those of control plants. Compared with control, CNS significantly elevated abundances of various bacterial biomarkers (such as Sphingomonas and Burkholderia) and fungi biomarkers (including Penicillium, Myceliophthora, and Talaromyces), which were potential plant-beneficial organisms. Functional prediction based on metagenomic data demonstrated pathways related to nutrient cycling being greatly enriched under CNS treatment. Furthermore, 391 culturable bacteria and 44 culturable fungi were isolated from soil and root samples. Among them, six bacteria and two fungi strains enriched upon CNS treatment were validated to have plant growth promotion effect, and two fungi (Cladosporium spp. and Talaromyces spp.) played their roles by mediating volatile organic compounds (VOCs). To some extent, the driving and shaping of the microbiome by CNS contributed to its impact on plant growth and development. Conclusion: Our results revealed the key role of root-associated microbiota in mediating the interaction between CNS and plants, thus providing valuable insights and strategies for harnessing CNS to enhance plant growth. [ABSTRACT FROM AUTHOR]

Purpose: It is a central goal in current ecology to investigate the effects of global changes on ecosystem productivity, which includes above- and below-ground plant productivity as well as soil microbial productivity, but most studies focus on aboveground plant productivity. As plant and microbial communities have different attributes, it is intuitive to hypothesize that belowground plant root productivity will respond to global changes more similarly as aboveground stem/leaf productivity than soil microbial productivity; however, this hypothesis remains largely unexplored. Methods: Here we conducted a long-term nitrogen deposition experiment in the Eurasian steppe, manipulating nine rates (0–50 g N m− 2 yr− 1) at two frequencies under two management strategies (fencing or mowing). Results: Belowground plant productivity was found to respond similarly as soil microbial productivity rather than aboveground plant productivity, contrary to the hypothesis. And this pattern was more obvious under mowing than fencing, because mowing decreased soil water content and caused another pressure beyond the decreased pH induced by N addition. Conclusions: Overall, our results demonstrated the importance of microhabitat (below- or above-ground) relative to community attribute (plants or microorganisms) in determining productivity response to nitrogen deposition, emphasizing the necessity to integratively study the response of both above- and below-ground productivities to global changes. [ABSTRACT FROM AUTHOR]

Sugars, produced through photosynthesis, are at the core of all organic compounds synthesized and used for plant growth and their response to environmental changes. Their production, transport, and utilization are highly regulated and integrated throughout the plant life cycle. The maintenance of sugar partitioning between the different subcellular compartments and between cells is important in adjusting the photosynthesis performance and response to abiotic constraints. We investigated the consequences of the disruption of four genes coding for SWEET sugar transporters in Arabidopsis (SWEET11, SWEET12, SWEET16, and SWEET17) on plant photosynthesis and the response to drought. Our results show that mutations in both SWEET11 and SWEET12 genes lead to an increase of cytosolic sugars in mesophyll cells and phloem parenchyma cells, which impacts several photosynthesis‐related parameters. Further, our results suggest that in the swt11swt12 double mutant, the sucrose‐induced feedback mechanism on stomatal closure is poorly efficient. On the other hand, changes in fructose partitioning in mesophyll and vascular cells, measured in the swt16swt17 double mutant, positively impact gas exchanges, probably through an increased starch synthesis together with higher vacuolar sugar storage. Finally, we propose that the impaired sugar partitioning, rather than the total amount of sugars observed in the quadruple mutant, is responsible for the enhanced sensitivity upon drought. This work highlights the importance of considering SWEET‐mediated sugar partitioning rather than global sugar content in photosynthesis performance and plant response to drought. Such knowledge will pave the way to design new strategies to maintain plant productivity in a challenging environment. [ABSTRACT FROM AUTHOR]

Photosynthesis is the largest flux of carbon between the atmosphere and Earth's surface and is driven by enzymes that require nitrogen, namely, ribulose‐1,5‐bisphosphate (RuBisCO). Thus, photosynthesis is a key link between the terrestrial carbon and nitrogen cycle, and the representation of this link is critical for coupled carbon‐nitrogen land surface models. Models and observations suggest that soil nitrogen availability can limit plant productivity increases under elevated CO2. Plants acclimate to elevated CO2 by downregulating RuBisCO and thus nitrogen in leaves, but this acclimation response is not currently included in land surface models. Acclimation of photosynthesis to CO2 can be simulated by the photosynthetic optimality theory in a way that matches observations. Here, we incorporated this theory into the land surface component of the Energy Exascale Earth System Model (ELM). We simulated land surface carbon and nitrogen processes under future elevated CO2 conditions to 2100 using the RCP8.5 high emission scenario. Our simulations showed that when photosynthetic acclimation is considered, photosynthesis increases under future conditions, but maximum RuBisCO carboxylation and thus photosynthetic nitrogen demand decline. We analyzed two simulations that differed as to whether the saved nitrogen could be used in other parts of the plant. The allocation of saved leaf nitrogen to other parts of the plant led to (1) a direct alleviation of plant nitrogen limitation through reduced leaf nitrogen requirements and (2) an indirect reduction in plant nitrogen limitation through an enhancement of root growth that led to increased plant nitrogen uptake. As a result, reallocation of saved leaf nitrogen increased ecosystem carbon stocks by 50.3% in 2100 as compared to a simulation without reallocation of saved leaf nitrogen. These results suggest that land surface models may overestimate future ecosystem nitrogen limitation if they do not incorporate leaf nitrogen savings resulting from photosynthetic acclimation to elevated CO2. [ABSTRACT FROM AUTHOR]

Drought is one of the major abiotic stresses that affect plant growth and productivity, and plant stress responses are affected by both the intensity of stress and genotype. In Iraqi Kurdistan, tomato plants play a significant role in the country's economy. Due to climate change, which causes soil moisture to diminish, the crop's growth and yield have been dropping in recent years. Accordingly, the effects of simulated drought stress on germination parameters were assessed in 64 tomato accessions gathered from the Iraqi Kurdistan region in order to identify sensitive and tolerant accessions. In this respect, the responses associated with drought stress were observed phenotypically and biochemically. Germination percentage (GP) and morphological characteristics such as root length (RL), shoot length (SL), and shoot fresh weight (SFW) were significantly reduced in both stress treatments with polyethylene glycol (PEG-6000) (7.5% PEG and 15% PEG). On the other hand, significant changes in biochemical profiles such as proline content (PC), soluble sugar content (SSC), total phenolic content (TPC), antioxidant activity (AC), guaiacol peroxidase (GPA), catalase (CAT), and lipid peroxidation (LP) in tomato accessions were detected; all biochemical traits were increased in most tomato accessions under the PEG-induced treatments compared to the control treatment (0.0% PEG). Three tomato accessions (AC61 (Raza Pashayi), AC9 (Wrdi Be Tow), and AC63 (Sandra)) were found to be the most tolerant accessions under all drought conditions, whereas the performances of the other tested accessions (AC13 (Braw), AC30 (Yadgar), and AC8 (Israili)) were inferior. The OMIC analysis identified the biomarker parameters for differentiating the highly, moderately, and low tolerant groups as PC, SSC, and TPC. This study shows that early PEG-6000 screening for drought stress may help in choosing a genotype that is suitable for growth in water-stressed environments. Hence, Raza Pashayi, Wrdi Be Tow, and Sandra accessions, which had great performances under drought conditions, can be candidates for selection in a breeding program to improve the growth of plants and production in the areas that face water limits. [ABSTRACT FROM AUTHOR]

This study investigates the impact of copper (Cu) stress on tomato plants (Solanum pimpinellifolium) and explores the potential of chitosan and nanosilver (nAg) in mitigating its effects. Copper, while essential for plant growth, can be toxic at elevated levels, leading to oxidative stress and reduced plant productivity. This research focuses on determining how chitosan and nAg treatments influence plant growth, fruit yield, and biochemical responses under Cu-induced stress. A greenhouse experiment was conducted, where tomato plants were treated with Cu, chitosan, nAg, and their combinations. The results revealed that chitosan improved root growth, and enhanced antioxidant properties, including increased ascorbic acid and lycopene content. Nanosilver treatments, while reducing shoot growth, significantly increased fruit yield and potassium uptake. The combination of Cu with chitosan or nAg provided synergistic benefits, improving plant resilience and fruit quality. Specifically, copper+chitosan (Cu+Ch) increased dry matter and delayed ripening, while Cu+nAg enhanced potassium uptake and overall fruit yield. Additionally, Cu accelerated the ripening of tomatoes. These findings suggest that chitosan and nanosilver are effective strategies to mitigate copper toxicity in tomato plants, offering a sustainable approach to improve crop productivity and quality under heavy metal stress conditions. [ABSTRACT FROM AUTHOR]