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Reproductive phasiRNAs (phased, small interfering RNAs) are broadly present in angiosperms and play crucial roles in sustaining male fertility. While the premeiotic 21-nt (nucleotides) phasiRNAs and meiotic 24-nt phasiRNA pathways have been extensively studied in maize (Zea mays) and rice (Oryza sativa), a third putative category of reproductive phasiRNAs-named premeiotic 24-nt phasiRNAs-have recently been reported in barley (Hordeum vulgare) and wheat (Triticum aestivum). To determine whether premeiotic 24-nt phasiRNAs are also present in maize and related species and begin to characterize their biogenesis and function, we performed a comparative transcriptome and degradome analysis of premeiotic and meiotic anthers from five maize inbred lines and three teosinte species/subspecies. Our data indicate that a substantial subset of the 24-nt phasiRNA loci in maize and teosinte are already highly expressed at the premeiotic phase. The premeiotic 24-nt phasiRNAs are similar to meiotic 24-nt phasiRNAs in genomic origin and dependence on DCL5 (Dicer-like 5) for biogenesis, however, premeiotic 24-nt phasiRNAs are unique in that they are likely i) not triggered by microRNAs, ii) not loaded by AGO18 proteins, and iii) not capable of mediating PHAS precursor cleavage. In addition, we also observed a group of premeiotic 24-nt phasiRNAs in rice using previously published data. Together, our results indicate that the premeiotic 24-nt phasiRNAs constitute a unique class of reproductive phasiRNAs and are present more broadly in the grass family (Poaceae) than previously known.

Vitamin A deficiency remains prevalent on a global scale, including in regions where maize constitutes a high percentage of human diets. One solution for alleviating this deficiency has been to increase grain concentrations of provitamin A carotenoids in maize (Zea mays ssp. mays L.)-an example of biofortification. The International Maize and Wheat Improvement Center (CIMMYT) developed a Carotenoid Association Mapping panel of 380 inbred lines adapted to tropical and subtropical environments that have varying grain concentrations of provitamin A and other health-beneficial carotenoids. Several major genes have been identified for these traits, 2 of which have particularly been leveraged in marker-assisted selection. This project assesses the predictive ability of several genomic prediction strategies for maize grain carotenoid traits within and between 4 environments in Mexico. Ridge Regression-Best Linear Unbiased Prediction, Elastic Net, and Reproducing Kernel Hilbert Spaces had high predictive abilities for all tested traits (β-carotene, β-cryptoxanthin, provitamin A, lutein, and zeaxanthin) and outperformed Least Absolute Shrinkage and Selection Operator. Furthermore, predictive abilities were higher when using genome-wide markers rather than only the markers proximal to 2 or 13 genes. These findings suggest that genomic prediction models using genome-wide markers (and assuming equal variance of marker effects) are worthwhile for these traits even though key genes have already been identified, especially if breeding for additional grain carotenoid traits alongside β-carotene. Predictive ability was maintained for all traits except lutein in between-environment prediction. The TASSEL (Trait Analysis by aSSociation, Evolution, and Linkage) Genomic Selection plugin performed as well as other more computationally intensive methods for within-environment prediction. The findings observed herein indicate the utility of genomic prediction methods for these traits and could inform their resource-efficient implementation in biofortification breeding programs.

Root-associated microbiomes in the rhizosphere (rhizobiomes) are increasingly known to play an important role in nutrient acquisition, stress tolerance, and disease resistance of plants. However, it remains largely unclear to what extent these rhizobiomes contribute to trait variation for different genotypes and if their inclusion in the genomic selection protocol can enhance prediction accuracy. To address these questions, we developed a microbiome-enabled genomic selection method that incorporated host SNPs and amplicon sequence variants from plant rhizobiomes in a maize diversity panel under high and low nitrogen (N) field conditions. Our cross-validation results showed that the microbiome-enabled genomic selection model significantly outperformed the conventional genomic selection model for nearly all time-series traits related to plant growth and N responses, with an average relative improvement of 3.7%. The improvement was more pronounced under low N conditions (8.4-40.2% of relative improvement), consistent with the view that some beneficial microbes can enhance N nutrient uptake, particularly in low N fields. However, our study could not definitively rule out the possibility that the observed improvement is partially due to the amplicon sequence variants being influenced by microenvironments. Using a high-dimensional mediation analysis method, our study has also identified microbial mediators that establish a link between plant genotype and phenotype. Some of the detected mediator microbes were previously reported to promote plant growth. The enhanced prediction accuracy of the microbiome-enabled genomic selection models, demonstrated in a single environment, serves as a proof-of-concept for the potential application of microbiome-enabled plant breeding for sustainable agriculture.

Local adaptation of populations results from an interplay between their environment and genetics. If functional trait variation influences plant performance, populations can adapt to their local environment. However, populations may also respond plastically to environmental challenges, altering phenotype without shifting allele frequencies. The level of local adaptation in crop landraces and their capacity for plasticity in response to environmental change may predict their continued utility to farmers facing climate change. Yet we understand little about how physiological traits potentially underlying local adaptation of cultivars influence fitness. Farmers in Mexico-the crop center of origin for maize-manage and rely upon a high diversity of landraces. We studied maize grown in Chiapas, Mexico, where strong elevational gradients cover a relatively small geographic area. We reciprocally transplanted 12 populations sourced from three elevational zones (600, 1550 and 2150 m) back into those elevations for two years using a modified split-split plot design to model effects of environment, genetics, and their interaction. We studied physiological and growth traits, including photosynthetic rate, stomatal conductance, stomatal density, relative growth rate (RGR), and seed production. Maize fitness showed indications of local adaptation with highland and midland types performing poorly at warmer lowland locations, though patterns depended on the year. Several physiological traits, including stomatal conductance, were affected by G x E interactions, some of which indicated non-adaptive plastic responses with potential fitness implications. We discerned a significant positive relationship between fitness and relative growth rate. Growth rates in highland landraces were outperformed by midland and lowland landraces grown in high temperature, lowland garden. Lowland landrace stomatal conductance was diminished compared to that of highland landraces in the cooler highland garden. Thus, both adaptive and non-adaptive physiological responses of maize landraces in southern Mexico may have implications for fitness, as well as responses to climate change.

Plants with the C4 photosynthesis pathway typically respond to climate change differently from more common C3-type plants, due to their distinct anatomical and biochemical characteristics. These different responses are expected to drive changes in global C4 and C3 vegetation distributions. However, current C4 vegetation distribution models may not predict this response as they do not capture multiple interacting factors and often lack observational constraints. Here, we used global observations of plant photosynthetic pathways, satellite remote sensing, and photosynthetic optimality theory to produce an observation-constrained global map of C4 vegetation. We find that global C4 vegetation coverage decreased from 17.7% to 17.1% of the land surface during 2001 to 2019. This was the net result of a reduction in C4 natural grass cover due to elevated CO2 favoring C3-type photosynthesis, and an increase in C4 crop cover, mainly from corn (maize) expansion. Using an emergent constraint approach, we estimated that C4 vegetation contributed 19.5% of global photosynthetic carbon assimilation, a value within the range of previous estimates (18-23%) but higher than the ensemble mean of dynamic global vegetation models (14 ± 13%; mean ± one standard deviation). Our study sheds insight on the critical and underappreciated role of C4 plants in the contemporary global carbon cycle.

(1) Background: Clinical results on the effects of excess sugar consumption on insulin sensitivity are conflicting, possibly due to differences in sugar type and the insulin sensitivity index (ISI) assessed. Therefore, we compared the effects of consuming four different sugars on insulin sensitivity indices derived from oral glucose tolerance tests (OGTT). (2) Methods: Young adults consumed fructose-, glucose-, high-fructose corn syrup (HFCS)-, sucrose-, or aspartame-sweetened beverages (SB) for 2 weeks. Participants underwent OGTT before and at the end of the intervention. Fasting glucose and insulin, Homeostatic Model Assessment-Insulin Resistance (HOMA-IR), glucose and insulin area under the curve, Surrogate Hepatic Insulin Resistance Index, Matsuda ISI, Predicted M ISI, and Stumvoll Index were assessed. Outcomes were analyzed to determine: (1) effects of the five SB; (2) effects of the proportions of fructose and glucose in all SB. (3) Results: Fructose-SB and the fructose component in mixed sugars negatively affected outcomes that assess hepatic insulin sensitivity, while glucose did not. The effects of glucose-SB and the glucose component in mixed sugar on muscle insulin sensitivity were more negative than those of fructose. (4) Conclusion: the effects of consuming sugar-SB on insulin sensitivity varied depending on type of sugar and ISI index because outcomes assessing hepatic insulin sensitivity were negatively affected by fructose, and outcomes assessing muscle insulin sensitivity were more negatively affected by glucose.

SUMMARY Sorghum bicolor (sorghum) is a vital C4 monocotyledon crop cultivated in arid regions worldwide, valued for its significance in both human and animal nutrition. Despite its agricultural prominence, sorghum research has been hindered by low transformation frequency. In this study, we examined sorghum transformation using the pVS1‐VIR2 ternary vector system for Agrobacterium, combined with the morphogenic genes BABY BOOM and WUSCHEL2 and selection using G418. We optimized Agrobacterium‐mediated infection, targeting key parameters such as bacterial optical density, co‐cultivation time, and temperature. Additionally, an excision‐based transformation system enabled us to generate transgenic plants free of morphogenic regulators. The method yielded remarkable transformation frequencies, reaching up to 164.8% based on total isolated plantlets. The same combination of ternary vector, morphogenic genes and geneticin‐based selection also resulted in a marked increase in transformation efficiency of the Zea mays (maize) inbred line B104. The potential for genomic editing using this approach positions it as a valuable tool for the development of sorghum and maize varieties that comply with evolving European regulations. Our work marks a significant stride in sorghum biotechnology and holds promise for addressing global food security challenges in a changing climate. [ABSTRACT FROM AUTHOR]

The tropical maize breeding for low-P tolerance and good performance under low-P stress environments can be achieved through selection based on root morphology traits at seedling stage. Here, we assessed the genotypic variation and genetic diversity of a panel of 151 tropical maize inbred lines for root and shoot seedling traits, investigated the relationship among traits and selected a set of promising inbred lines for low-P tolerance and performance. We evaluated the inbred lines at seedling stage in a greenhouse experiment under two conditions: applied P (AP) and non-applied P (NAP). A mixed model approach was used to estimate variance components and predict the genotypic values of each inbred line. The genetic diversity among inbred lines based on root and shoot traits was assessed, and correlations were estimated between tested traits under AP and NAP. Our panel of inbred lines showed huge genetic variability for all traits and presented large genetic diversity under both P conditions. Variance components due to the inbred line × P condition interaction were also highly significant (P < 0.01) for all traits. Root dry weight (RDW) was positively associated with stalk dimeter (SD), shoot dry weight (SDW) and root length, volume, and area under both P conditions. Also, the SD and SDW were associated with most root traits under AP. Based on low-P tolerance and performance indices, we selected a set of top 20 inbred lines to be used in our maize breeding program. We therefore concluded that there is a significant genetic diversity in the tropical maize inbred lines which have the genetic potential to be use in association mapping studies and also to develop improved low-P tolerant and P-efficient hybrids and maize breeding populations for low-P stress environments. [ABSTRACT FROM AUTHOR]

Casparian strip membrane domain proteins like (CASPL), exhibit profound associations with root development, stress responsiveness and mineral element uptake in plants. Nonetheless, a comprehensive bioinformatics analysis of the ZmCASPL gene family in maize remains unreported. In the study, we have identified 47 ZmCASPL members at the whole-genome level, systematically classifying them into six distinct groups. Furthermore, our analysis revealed that the same group of ZmCASPL contains similar gene structures and conserved motifs. Duplication events showed whole genome duplication (WGD) and tandem duplication (TD) contribute to the generation of the ZmCASPL gene family together in maize, but the former plays a more prominent role. Furthermore, we observed that most ZmCASPL genes contain MYB-binding sites (CAACCA), which are associated with the Casparian strip. Utilizing RNA-seq data, we found that ZmCASPL21 and ZmCASPL47 are specifically highly expressed only in the roots. This finding implies that ZmCASPL21 and ZmCASPL47 may be involved in the Casparian strip development. Additionally, RNA-seq analysis illuminated that drought, salt, heat, cold stresses, low nitrogen and phosphorus conditions, as well as pathogen infection, significantly impact the expression patterns of ZmCASPL genes. RT-qPCR revealed that ZmCASPL 5/13/25/44 genes showed different expression patterns under PEG and NaCl treatments. Collectively, these findings provide a robust theoretical foundation for further investigations into the functional roles of the ZmCASPL gene family in maize. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: All US commercial maize (Zea mays) is a single race, "Corn Belt Dent," and its genetic base has been in decline for at least 40 years. Independent genotyping can only be conducted after patent and licensing restrictions have expired, a period of 20 years. These restrictions also impede a molecular based assessment of the standing crop by the United States Department of Agriculture (USDA) as recommended by experts. Data blanks about landscape vulnerability put farmers at risk of crop failure and the public at risk of food insecurity. Understanding maize diversity experts' perspectives and analysis helps describe the contours of these data blanks and inform policy recommendations. Summary: Recommendations by the Maize Crop Germplasm Committee to the United States Department of Agriculture (USDA) for a molecular based vulnerability assessment on the US standing maize (Zea mays) crop have not been acted on because of intellectual property and licensing restrictions. This research explores maize diversity experts' access to data and perceptions and analysis of the standing crop.The data come from semi‐structured interviews conducted with 44 maize diversity experts in the public and private sectors.Experts explain that genetic data blanks restrict non‐industry research, describe public sector concerns that standing diversity is narrow(ing), and find historic sources of pedigree data in Plant Variety Protection and patent records are no longer reliable. Some interviewees perceive that industry monitoring of standing diversity is in their best financial interest. Industry participants describe concentration in US maize allows them to control diversity over time, while public researchers discuss efficiency of scale narrowing genetic diversity and global concentration spreading this trend.Knowledge gaps about genetic diversity in US commercial maize are designed through patents, contracts, non‐disclosure agreements, and confidentiality agreements by patent holders who do not want their inbred lines genotyped by competitors. This restricts research and knowledge flow about genetic information into public networks. The Maize Crop Germplasm Committee is a node for knowledge flow; however, the lack of mechanisms for action suggests it is performative. We recommend all protections used on seed include exemptions for research, breeding, and seed saving; an independent assessment of how industry monitors standing diversity; and a molecular analysis of the standing crop conducted by the USDA. All US commercial maize (Zea mays) is a single race, "Corn Belt Dent," and its genetic base has been in decline for at least 40 years. Independent genotyping can only be conducted after patent and licensing restrictions have expired, a period of 20 years. These restrictions also impede a molecular‐based assessment of the standing crop by the United States Department of Agriculture (USDA) as recommended by experts. Data blanks about landscape vulnerability put farmers at risk of crop failure and the public at risk of food insecurity. Understanding maize diversity experts' perspectives and analysis helps describe the contours of these data blanks and inform policy recommendations. [ABSTRACT FROM AUTHOR]

Mixed cropping with legumes may mitigate negative impacts of maize, Zea mays L. (Poaceae), production on arthropods by providing additional habitat structures and food resources. Still, knowledge about effects of less common legume partner crops for mixed cropping of maize is scarce. Activity density of epigeic predatory arthropods and proxies for ecosystem functions related to biological pest control were assessed on an experimental field. Plots of mixed cropping of maize and sainfoin, Onobrychis viciifolia Scop. (Fabaceae), and respective single plant species (plot size: 6 × 5 m; n = 48) differed in combination of the seed rate of each partner crop and tillage treatment. Using the "rapid ecosystem function assessment" approach in each plot on three occasions, we tested whether the activity density of generalist arthropod predators and their associated ecosystem functions can be promoted by mixed cropping of maize with sainfoin. Our data show that, compared with tilled maize as a pure culture, mixed cropping can increase activity density of generalist arthropod predators and insect predation potential but effects were limited to strip‐tilled cropping systems and partly depended on sampling date. Thus, from an ecological viewpoint, mixed cropping of sainfoin and maize in strip‐till systems offers the possibility to promote predatory insects and their potential for pest regulation. However, this system is inherently more prone to weed occurrence. Competition effects between cropping partners and weeds may reduce yields and hence lead to trade‐offs between enhancement of arthropods and economic viability. [ABSTRACT FROM AUTHOR]

Molybdenum plays an important role as a nutrient for plants. It has an important role in the process of plant growth and fixing nitrogen for the plant. A field experiment conducted in the autumn of 2023 aimed to study how different fertilizer treatments affected the availability of molybdenum in maize (Zea mays L.) rhizosphere and nonrhizosphere soils. The treatments included sheep manure at a rate of 8 tons per hectare, urea at 400 kg per hectare, humic acid at 500 cm³ per liter per dunum, and a control group. The experiment followed a randomized complete block design (RCBD) with three replications, using local maize seeds planted in 3 m by 3 m plots. After applying the treatments, the concentration of available molybdenum was measured in both soil regions at 70 and 100 days after planting. Results indicated that adding fertilizers (sheep manure, humic acid, and nitrogen) increased the concentration of available molybdenum in both soil regions. Specifically, the humic acid treatment had the highest concentration of available molybdenum at both 70 and 100 days, while the nitrogen treatment had the lowest. This highlights the importance of humic acid and organic materials in improving molybdenum availability. Furthermore, molybdenum concentration increased at the 100-day mark for all treatments outside the rhizosphere, except for the control, showing that all treatments enhanced molybdenum content both within and beyond the rhizosphere. [ABSTRACT FROM AUTHOR]

Building models that allow phenotypic evaluation of complex agronomic traits in crops of global economic interest, such as grain yield (GY) in soybean and maize, is essential for improving the efficiency of breeding programs. In this sense, understanding the relationships between agronomic variables and those obtained by high-throughput phenotyping (HTP) is crucial to this goal. Our hypothesis is that vegetation indices (VIs) obtained from HTP can be used to indirectly measure agronomic variables in annual crops. The objectives were to study the association between agronomic variables in maize and soybean genotypes with VIs obtained from remote sensing and to identify computational intelligence for predicting GY of these crops from VIs as input in the models. Comparative trials were carried out with 30 maize genotypes in the 2020/2021, 2021/2022 and 2022/2023 crop seasons, and with 32 soybean genotypes in the 2021/2022 and 2022/2023 seasons. In all trials, an overflight was performed at R1 stage using the UAV Sensefly eBee equipped with a multispectral sensor for acquiring canopy reflectance in the green (550 nm), red (660 nm), near-infrared (735 nm) and infrared (790 nm) wavelengths, which were used to calculate the VIs assessed. Agronomic traits evaluated in maize crop were: leaf nitrogen content, plant height, first ear insertion height, and GY, while agronomic traits evaluated in soybean were: days to maturity, plant height, first pod insertion height, and GY. The association between the variables were expressed by a correlation network, and to identify which indices are best associated with each of the traits evaluated, a path analysis was performed. Lastly, VIs with a cause-and-effect association on each variable in maize and soybean trials were adopted as independent explanatory variables in multiple regression model (MLR) and artificial neural network (ANN), in which the 10 best topologies able to simultaneously predict all the agronomic variables evaluated in each crop were selected. Our findings reveal that VIs can be used to predict agronomic variables in maize and soybean. Soil-adjusted Vegetation Index (SAVI) and Green Normalized Dif-ference Vegetation Index (GNDVI) have a positive and high direct effect on all agronomic variables evaluated in maize, while Normalized Difference Vegetation Index (NDVI) and Normalized Difference Red Edge Index (NDRE) have a positive cause-and-effect association with all soybean variables. ANN outperformed MLR, providing higher accuracy when predicting agronomic variables using the VIs select by path analysis as input. Future studies should evaluate other plant traits, such as physiological or nutritional ones, as well as different spectral variables from those evaluated here, with a view to contributing to an in-depth understanding about cause-and-effect relationships between plant traits and spectral variables. Such studies could contribute to more specific HTP at the level of traits of interest in each crop, helping to develop genetic materials that meet the future demands of population growth and climate change. [ABSTRACT FROM AUTHOR]

SUMMARY The BonnMu resource is a transposon tagged mutant collection designed for functional genomics studies in maize. To expand this resource, we crossed an active Mutator (Mu) stock with dent (B73, Co125) and flint (DK105, EP1, and F7) germplasm, resulting in the generation of 8064 mutagenized BonnMu F2‐families. Sequencing of these Mu‐tagged families revealed 425 924 presumptive heritable Mu insertions affecting 36 612 (83%) of the 44 303 high‐confidence gene models of maize (B73v5). On average, we observed 12 Mu insertions per gene (425 924 total insertions/36 612 affected genes) and 53 insertions per BonnMu F2‐family (425 924 total insertions/8064 families). Mu insertions and photos of seedling phenotypes from segregating BonnMu F2‐families can be accessed through the Maize Genetics and Genomics Database (MaizeGDB). Downstream examination via the automated Mutant‐seq Workflow Utility (MuWU) identified 94% of the presumptive germinal insertion sites in genic regions and only a small fraction of 6% inserting in non‐coding intergenic sequences of the genome. Consistently, Mu insertions aligned with gene‐dense chromosomal arms. In total, 42% of all BonnMu insertions were located in the 5′ untranslated region of genes, corresponding to accessible chromatin. Furthermore, for 38% of the insertions (163 843 of 425 924 total insertions) Mu1, Mu8 and MuDR were confirmed to be the causal Mu elements. Our publicly accessible European BonnMu resource has archived insertions covering two major germplasm groups, thus facilitating both forward and reverse genetics studies. [ABSTRACT FROM AUTHOR]

Background: Microplastics are contaminants in soil ecosystems that alter biophysical processes, affect plant growth, ecosystems and humans in the long run. This study was conducted to investigate the influence of soil microplastic contamination on the growth, development, and microbial dynamics of maize (Zea mays).Composite soil samples were collected from the farm from 0 to 10 cm depth. Physicochemical properties were assessed before maize seed sowing. Three soil weight categories were treated with 30 g, 20 g and 10 g microplastics. Soil physicochemical properties and heavy metal content in maize plants were analyzed. Morphological parameters, microbial counts, and microorganism identification were conducted. FTIR analysis was carried out in selected plant parts. Results: The study revealed a pH range of 5.00–6.70, electrical conductivity of 70–158 µS/cm, organic carbon and organic matter, total nitrogen, average phosphorus content, clay and silt content. The concentrations of heavy metals in plant parts were within WHO standard limits of 425.5 and 500 mg/kg for iron and manganese, but above the limits of 40, 60, and 350 mg/kg for copper, zinc and magnesium. The plant had various leaf sizes and heights, with chlorosis and necrotic activity ranging from 0.33 to 2.67, and a range of 1.33 to 6.33, respectively. Soil samples showed a total bacterial count (TBC) of 2.00 × 103 cfu/g to 7.60 × 104 cfu/g and a total fungal count (TFC) of 4.00 × 103 cfu/g to 2.20 × 104 cfu/g. Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus epidermidis, Proteus mirabilis and Bacillus cereus had percentage occurrences of 44.31, 21.17, 9.12, and 3.26%, respectively. Penicillium notatum was the most prevalent, while Fusarium spp. was the least prevalent. The FTIR analysis of maize seeds from soil samples A, B, and C revealed various organic compounds, with opium powder and streptomycin sulphate being the most abundant. The study revealed that pot B had the highest microplastic concentration at 1 WAS, while pot C had the lowest at 0.10 mg/kg, indicating a differential soil microplastic accumulation. Conclusion: Microplastics impact soil health, plant growth, and nutrient cycling, necessitating sustainable agriculture. Long-term research is needed to understand ecological and physiological impacts and explore remediation techniques. [ABSTRACT FROM AUTHOR]

SUMMARY: Genome‐wide association study (GWAS) with single nucleotide polymorphisms (SNPs) has been widely used to explore genetic controls of phenotypic traits. Alternatively, GWAS can use counts of substrings of length k from longer sequencing reads, k‐mers, as genotyping data. Using maize cob and kernel color traits, we demonstrated that k‐mer GWAS can effectively identify associated k‐mers. Co‐expression analysis of kernel color k‐mers and genes directly found k‐mers from known causal genes. Analyzing complex traits of kernel oil and leaf angle resulted in k‐mers from both known and candidate genes. A gene encoding a MADS transcription factor was functionally validated by showing that ectopic expression of the gene led to less upright leaves. Evolution analysis revealed most k‐mers positively correlated with kernel oil were strongly selected against in maize populations, while most k‐mers for upright leaf angle were positively selected. In addition, genomic prediction of kernel oil, leaf angle, and flowering time using k‐mer data resulted in a similarly high prediction accuracy to the standard SNP‐based method. Collectively, we showed k‐mer GWAS is a powerful approach for identifying trait‐associated genetic elements. Further, our results demonstrated the bridging role of k‐mers for data integration and functional gene discovery. Significance Statement: Through genetically dissecting five maize traits (cob color, kernel color, leaf angle, oil content, and flowering time) and identifying a novel gene responsible for leaf angle, our study illustrates the potent capability of pinpointing genetic elements associated with traits. Our study also demonstrates a bridging role of k‐mers in data integration for facilitating functional gene discovery, as well as the use of k‐mers in phenotypic prediction. [ABSTRACT FROM AUTHOR]

In this study, the effectiveness of an inoculant containing a nitrogen (N)-fixing microorganism (Methylobacterium symbioticum) was evaluated on maize (Zea mays L.) grown both in the field (silage maize) and in pots over two years (2021 and 2022). The field trial included the following two treatments: with (Yes) and without (No) the inoculant. The pot experiment was designed as a factorial arrangement with two factors: the application of the inoculant (Yes and No) and N applied to the soil (0, 0.4, 0.8, and 1.6 g pot−1). In the field, total dry matter yield (DMY) did not differ significantly between treatments, although the average DMY was higher in the inoculant treatment. In pots, the total DMY varied significantly across all N rates but was only significantly affected by the inoculant application in 2022. N fixation estimates in the field were 58.8 and 14.5 kg ha−1 for 2021 and 2022, respectively, representing 23.7% and 9.1% of the N recovered in the aboveground plant parts. In pots, the estimated fixed N values were −49.2 and 199.2 mg pot−1 in 2021 and 2022, respectively, which corresponded to −5.2% and 18.5% of the N found in the aboveground plant parts. Considering the average values obtained across the four cultivation conditions, there was a positive outcome for the treated plants. However, these values cannot be considered significant when compared to nitrogen removal in maize crops. A commercial product should provide an unequivocal and quantitatively relevant contribution to plant nutrition, which did not appear to be the case. Thus, for this inoculant to provide reliable guarantees of positive outcomes for farmers and become a useful tool in promoting more sustainable agriculture, further studies appear necessary. These studies should aim to determine in which crops and under what cultivation conditions the application of the inoculant is truly effective in enhancing N fixation and improving crop productivity. [ABSTRACT FROM AUTHOR]

Biosurfactants are amphiphilic biomolecules with promising tensoative and emulsifying properties that find application in the most varied industrial sectors: environment, food, agriculture, petroleum, cosmetics, and hygiene. In the current work, a 23 full-factorial design was performed to evaluate the effect and interactions of pineapple peel and corncob as substrates for biosurfactant production by Bacillus subtilis LMA-ICF-PC 001. In a previous stage, an alkaline pretreatment was applied to corncob samples to extract the xylose-rich hydrolysate. The results indicated that pineapple peel extract and xylose-rich hydrolysate acted as partial glucose substitutes, minimizing production costs with exogenous substrates. Biosurfactant I (obtained at 8.11% pineapple peel extract, 8.11% xylose-rich hydrolysate from corncob, and 2.8109 g/L glucose) exhibited a significant surface tension reduction (52.37%) and a promising bioremediation potential (87.36%). On the other hand, biosurfactant III (obtained at 8.11% pineapple peel extract, 31.89% xylose-rich hydrolysate from corncob, and 2.8109 g/L glucose) exhibited the maximum emulsification index in engine oil (69.60%), the lowest critical micellar concentration (68 mg/L), and the highest biosurfactant production (5.59 g/L). These findings demonstrated that using pineapple peel extract and xylose-rich hydrolysate from corncob effectively supports biosurfactant synthesis by B. subtilis, reinforcing how agro-industrial wastes can substitute traditional carbon sources, contributing to cost reduction and environmental sustainability. [ABSTRACT FROM AUTHOR]

The PHOSPHATE STARVATION RESPONSE REGULATOR (PHR) plays a crucial regulatory role in plants during the process of responding to phosphate starvation. In this study, we combined reverse genetics and biotechnology to investigate the function of ZmPHR1 and ZmPHR2, including proteins containing the Myb_DNA_banding and Myb_CC-LHEQLE structural domains, in maize seedlings. Phylogenetic analysis revealed that ZmPHR1 and ZmPHR2 have high homology with AtPHR1 and OsPHR2, and share the characteristic features of nuclear localisation and transcriptional self-activation. Real-time quantitative PCR analysis showed that low phosphate (Pi) stress significantly induced the expression of ZmPHR1 and ZmPHR2 in maize seedling stage, and candidate gene association analysis further revealed the close association of these two genes with root traits under Pi stress conditions. Transgenic plants overexpressing ZmPHR1 and ZmPHR2 in Arabidopsis show a significant increase in lateral root number, fresh weight and total phosphorus accumulation under low-Pi stress. Besides, CHIP-PCR experiments identified target genes involved in hormone regulation, metal ion transport and homeostasis, phosphatase encoding, and photosynthesis, providing new insights into the biological functions of ZmPHR1 and ZmPHR2. Furthermore, our study showed that ZmPHR1 interacts with six SPX domain-only proteins (ZmSPXs) in maize, while ZmPHR2 interacts with five of these proteins. ZmPHR1 and ZmPHR2 expression was repressed in low Pi conditions, but was up-regulated in ZmSPX1 knockout material, according to our study of transgenic seedlings overexpressing ZmSPX1 in maize. We identified downstream target genes involved in the phosphorus signaling pathway, which are mainly involved in plant-pathogen interactions, ascorbic acid and arabinose metabolism, and ABC transporter proteins, by RNA-seq analysis of transgenic seedlings grown under low Pi stress for 7 days. Collectively, these results provide important clues to elucidate the role and functional significance of ZmPHR1 and ZmPHR2 under low Pi stress and also provide insights into understand the molecular mechanism of phosphorus homeostasis in maize. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the most widely cultivated grain crops globally. In sub-Saharan Africa (SSA), it plays an important role in ensuring both food and income security for smallholder farmers. This study was conducted to (i) assess the performances of testcross hybrids constituted from maize lethal necrosis (MLN) tolerant doubled haploid (DH) lines under various management conditions; (ii) estimate the combining ability effects and determine the nature of gene action in the DH lines; and (iii) identify DH lines and testcross hybrids for resistance to MLN, high grain yield, and other important traits. Eleven DH lines were crossed with 11 single-cross testers using the line-by-tester mating design, and 115 successful testcross hybrids were generated. These hybrids, along with five commercial check hybrids, were evaluated across four optimum management conditions, two MLN artificial inoculations, and one managed drought environment in Kenya. Under each management condition, the effects of genotypes, environments, and genotype-by-environment interactions were significant for grain yield (GY) and most other traits. Hybrids T1/L3, T10/L3, and T11/L3 exhibited higher grain yields under at least two management conditions. A combining ability analysis revealed that additive gene effects were more important than non-additive effects for GY and most other traits, except for leaf senescence (SEN) and MLN disease severity score. DH line L3 exhibited a desirable general combining ability (GCA) effect for GY, while L5 was the best general combiner for anthesis date (AD) and plant height (PH) across all management conditions. DH lines L2, L6, and L7 showed negative GCA effects for MLN disease severity. Single-cross testers T11 and T10 were good general combiners for GY under all management conditions. Hybrids T2/L11, T9/L10, and T2/L10 demonstrated high specific combining ability (SCA) effects for GY under all conditions. This study identified DH lines and testers with favorable GCA effects for grain yield, MLN resistance, and other agronomic traits that can be used in breeding programs to develop high-yielding and MLN-resistant maize varieties. Better-performing testcross hybrids identified in the current study could be verified through on-farm testing and released for commercial production to replace MLN-susceptible, low-yield hybrids grown in the target ecologies. [ABSTRACT FROM AUTHOR]

Water deficit is a major cause of yield loss for maize (Zea mays), leading to ovary abortion when applied at flowering time. To help understand the mechanisms involved in this phenomenon, the proteome response to water deficit has been analysed in developing ovaries at the silk emergence stage and five days later. Differential analysis, abundance pattern clustering and co-expression networks were performed in order to draw a general picture of the proteome changes all along ovary development and under the effect of water deficit. The results show that even mild water deficit has a major impact on ovary proteome, but this impact is very different from a response to stress. A part of the changes can be related to a slowdown of ovary development, while another part cannot. In particular, ovaries submitted to water deficit show an increase in proteins involved in protein biosynthesis and in vesicle transport together with a decrease in proteins involved in amino acid metabolism and proteolysis. According to the functions of increased proteins, the changes may be linked to auxin, brassinosteroids and jasmonate signalling but not abscisic acid. [ABSTRACT FROM AUTHOR]

The interaction of plant mitochondrial and nuclear genetic systems is exemplified by mitochondria-encoded cytoplasmic male sterility (CMS) under the control of nuclear restorer-of-fertility genes. The S type of CMS in maize is characterized by a pollen collapse phenotype and a unique paradigm for fertility restoration in which numerous nuclear restorer-of-fertility lethal mutations rescue pollen function but condition homozygous-lethal seed phenotypes. Two nonallelic restorer mutations recovered from Mutator transposon-active lines were investigated to determine the mechanisms of pollen fertility restoration and seed lethality. Mu Illumina sequencing of transposon-flanking regions identified insertion alleles of nuclear genes encoding mitochondrial ribosomal proteins RPL6 and RPL14 as candidate restorer-of-fertility lethal mutations. Both candidates were associated with lowered abundance of mitochondria-encoded proteins in developing maize pollen, and the rpl14 mutant candidate was confirmed by independent insertion alleles. While the restored pollen functioned despite reduced accumulation of mitochondrial respiratory proteins, normal-cytoplasm plants heterozygous for the mutant alleles showed a significant pollen transmission bias in favor of the nonmutant Rpl6 and Rpl14 alleles. CMS-S fertility restoration affords a unique forward genetic approach to investigate the mitochondrial requirements for, and contributions to, pollen and seed development. [ABSTRACT FROM AUTHOR]

Drought is considered the main agricultural menace, limiting the successful realization of land potential, and thereby reducing crop productivity worldwide. Therefore, breeding maize hybrids with improved drought tolerance via genetic manipulation is necessary. Herein, the multiple bud clumps of elite inbred maize lines, DH4866, Qi319, Y478 and DH9938, widely used in China, were transformed with the Escherichia coli betA gene encoding choline dehydrogenase (EC 1.1.99.1), a key enzyme in the biosynthesis of glycine betaine from choline, using Agrobacterium to generate betA transgenic lines. After 3–4 consecutive generations of self-pollination in these transgenic plants, progenies with a uniform appearance, excellent drought tolerance, and useful agricultural traits were obtained. We evaluated the drought tolerance of T4 progenies derived from these transgenic plants in the field under reduced irrigation. We found that a few lines exhibited much higher drought tolerance than the non-transformed control plants. Transgenic plants accumulated higher levels of glycine betaine and were relatively more tolerant to drought stress than the controls at both the germination and early seedling stages. The grain yield of the transgenic plants was significantly higher than that of the control plants after drought treatment. Drought-tolerant inbred lines were mated and crossed to create hybrids, and the drought tolerance of these transgenic hybrids was found to be enhanced under field conditions compared with those of the non-transgenic (control) plants and two other commercial hybrids in China. High yield and drought tolerance were achieved concurrently. These transgenic inbred lines and hybrids were useful in marginal and submarginal lands in semiarid and arid regions. The betA transgene can improve the viability of crops grown in soils with sufficient or insufficient water. [ABSTRACT FROM AUTHOR]

In this study a liquid extract from the seaweed Sargassum boveanum (LESb) was prepared using four different methods and solvents. The optimal method, where the extract was prepared using microwave digestion, was selected, and its spray solution was applied to maize (SC704) plants at different concentrations (0.0%, 1.0%, 1.5%, 2.0%, and 2.5% LESb (V/V)) and three irrigation levels: non-stress (80% of field capacity (FC), 60% FC, and 40% FC). Water stress (40% and 60% FC) limited plant growth by disrupting physiological and biochemical functions. However, the concentration of 1.5% LESb demonstrated a significant improvement in various traits compared to the 0.0% LESb. This improvement included an increase in shoot dry weight by 15.46%, 27.55%, and 57.52% under conditions of 80%, 60%, and 40% FC. Additionally, there was an increase in the activity of antioxidant enzymes, such as superoxide dismutase (SOD), by 13.27%, 30.42%, and 32.19% under conditions of 80%, 60%, and 40% FC, respectively, which could effectively reduce malondialdehyde (MDA) levels. At the concentration of 1.5% there was an increase in proline content by 20.07%, 19.50%, and 10.40% under conditions of 80%, 60%, and 40% FC, respectively, as well as an increase in soluble sugar content under conditions of 60% and 40% FC compared to 0.0% LESb. The relative water content (RWC) also improved with the 1.5% LESb under 60% and 40% FC conditions, by 29.23% and 25.97%, respectively, compared to 0.0% LESb. These results indicate that a concentration of 1.5% LESb can effectively alleviate the negative effects of water stress on maize plants. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTThe absorption of cadmium by plants largely depends on cadmium contamination in the soil. The development of phytomining and phytoremediation methods to clean cadmium-contaminated ecosystems is an urgent issue that needs to be solved. Therefore, the role of exogenous O-(2-naphthylsulfonyl)oxime (ANSO) to maize seedlings under cadmium stress was tested. The results showed that when ANSO+cadmium application was compared to cadmium, the cadmium content increased by 7.8 times, while the abscisic acid content decreased. Under cadmium stress, ANSO application did not change the relative water content, but increased the chlorophyll content. While carotenoid content increased with cadmium application, it increased further with ANSO+cadmium application. As a result of the positive effects of ANSO application on the antioxidant system under cadmium stress, hydrogen peroxide content, lipid peroxidation and proline content decreased. ANSO application under cadmium stress increased the phenolic substance content. This study shows that exogenous ANSO makes significant contributions to the protection of maize seedlings despite being under cadmium stress. It also provides important references to the fact that despite stress, the cadmium chelation mechanisms of seedlings continue to work actively to accumulate cadmium in tissues, and it has deep implications for the remediation of cadmium-polluted soils.Exogenous acetone O-(2-naphthylsulfonyl)oxime increased the activity of maize defense systems. Moreover, it supported the continuity of the activity of defense systems by regulating the phenolic content of maize.The fact that acetone O-(2-naphthylsulfonyl)oxime causes 7.8 times more cadmium accumulation and the use of a newly synthesized substance in the phytoremediation of cadmium is one of the most innovative approaches.The acetone O-(2-naphthylsulfonyl)oxime molecule can not only make serious contributions to the industrialization of cadmium in Cd-polluted soils through phytoremediation and phytomining, but also make significant contributions to environmental protection.Exogenous acetone O-(2-naphthylsulfonyl)oxime increased the activity of maize defense systems. Moreover, it supported the continuity of the activity of defense systems by regulating the phenolic content of maize.The fact that acetone O-(2-naphthylsulfonyl)oxime causes 7.8 times more cadmium accumulation and the use of a newly synthesized substance in the phytoremediation of cadmium is one of the most innovative approaches.The acetone O-(2-naphthylsulfonyl)oxime molecule can not only make serious contributions to the industrialization of cadmium in Cd-polluted soils through phytoremediation and phytomining, but also make significant contributions to environmental protection. [ABSTRACT FROM AUTHOR]

Warm night frequency has increased steadily in the last years across maize production regions, but high night temperature (HNT) effects on growth, grain yield and maize dry matter allocation (DMA) to different plant organs remain poorly understood. In this study, we aimed to (i) analyse the DMA among reproductive and vegetative organs, (ii) evaluate the individual kernel weight through its determinants, rate and duration of grain filling and (iii) quantify changes in grain yield per plant and its components due to HNT during the postflowering and early grain‐filling period. Field‐grown maize was subjected to HNT induced by shelters during a 15‐ or 30‐day period after silking, encompassing the postflowering period (HNT15) and extending the heating into early grain filling (HNT30), respectively. The HNT was applied from 1900 to 0700 h while control plots remained at ambient night temperature (ANT). Kernel number per plant was decreased under both temperature regimes (i.e., HNT15 and HNT30); however, significant reductions in grain yield were only observed under HNT30. The DMA during the heating period was differentially affected by the duration of heating. While DMA to the stem was likewise reduced by both heating treatments, the partition to the uppermost ear was only reduced under HNT30. Related to the lack of response to HNT treatments of the rate and duration of grain filling, the individual kernel weight was not reduced. The source‐sink ratio was not affected by HNT, meanwhile, the apparent reserve use was significantly reduced under HNT30. Our results demonstrate that the magnitude of HNT effects is subjected to the duration of the heating period, but also depends on the intensity of heating explored across seasons, especially for kernel number and grain yield. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is highly sensitive to salt stress, which poses a threat to its production, especially with predicted increases in salinity due to climate change. Enhancing salt tolerance in maize is critical to mitigating these adverse effects, sustaining its production, and ensuring global food security. This study aimed to evaluate the effects of exogenously applied lipoic acid or Si, alone or in integration with soil application of vermicomposttea on physio-biochemical components, antioxidant defense systems, growth, and yield of maize plants exposed to salt stress. The application of vermicompost-tea was carried out as a soil treatment incorporated into irrigation water at a concentration of 200 L ha-1, and administered in three equal doses in irrigation water within the last 10 min of drip irrigation. Silicon was applied at a rate of 6 mM using potassium silicate and lipoic acid was applied at 0.1 mM. Silicon and lipoic acid were applied three times at 25, 40, and 55 d after planting. The results indicated that the integrative application of soil-based vermicompost-tea with exogenously applied Si or lipoic acid significantly enhanced all studied parameters. Specifically, the combination of Si with vermicomposttea exhibited the highest improvement percentage compared to untreated control in chlorophyll a (60.3%), chlorophyll b (72.7%), carotenoids (69.9%), net photosynthetic rate (111%), transpiration rate (134%), stomatal conductance (129.5%), relative water content (28.4%), membrane stability index (44.3%), N (33.4%), P (71.9%), K (39.7%), Ca (89.9%), K/Na (81.2%), total soluble sugars (63.7%), proline (60.1%), ascorbate (44.4%), glutathione (83.5%), and α-tocopherol (72.1%). These positive effects were reflected in enhancing yield traits under salt-affected soil conditions by enhancing plant height (25.1%), number of grains per row (43.3%), number of rows per ear (26.7%), 1000-grain weight (25.9%), grain yield (45.4%), and biological yield (42.8%) compared to untreated control. [ABSTRACT FROM AUTHOR]

The systemic coordination of accumulation of plasma membrane aquaporins (PIP) was investigated in this study in relation to mycorrhized maize response to a rapid development of severe drought followed by rewatering. In non-mycorrhizal roots, drought led to a drop in PIP abundance, followed by a transient increase under rewatering, whereas leaves showed an opposite pattern. In contrast, mycorrhiza contributed to maintenance of high and stable levels of PIPs in both plant organs after an initial increase, prolonged over the irrigation period. Isoelectric focusing electrophoresis resolved up to 13 aquaporin complexes with highly reproducible pl positions across leaf and root samples, symbiotic and non-symbiotic, stressed or not. Mass spectrometry recognized in leaves and roots a different ratio of PIP1 and PIP2 subunits within 2D spots that accumulated the most. Regardless of symbiotic status, drought regulation of aquaporins in roots was manifested as the prevalence of complexes that comprise almost exclusively PIP2 monomers. In contrast, the leaf response involved enrichment in PIP1s. PIP1s are thought to enhance water transport, facilitate CO2 diffusion but also affect stomatal movements. These features, together with elevated aquaporin levels, might explain a stress tolerance mechanism observed in mycorrhizal plants, resulting in faster recovery of stomatal water conductance and CO2 assimilation rate after drought. [ABSTRACT FROM AUTHOR]

Summary MicroRNA827 (miR827) is functionally conserved among different plant species and displays species‐specific characteristics, but the mechanisms by which miR827 regulates phosphate (Pi) starvation tolerance and maize development remain elusive. We found that miR827 selectively targets the Pi transporter genes SPX‐MFS1 and SPX‐MFS5. miR827 overexpression improved the Pi starvation tolerance, plant architecture and grain yield and quality, whereas miR827 suppression yielded a contrasting phenotype. In addition, we identified a specific long noncoding RNA (lncRNA767) that serves as a direct target and a facilitator of miR827 and can stabilize the SPX‐MFS1 and SPX‐MFS5 transcripts, leading to their translation inhibition. The orchestrated regulation of SPX‐MFS1 and SPX‐MFS5 modulates PHR1; 1 and PHR1; 2, which are critical transcription factors in Pi signalling, and thereby affects the expression of downstream Pi starvation‐induced genes. Together, these findings demonstrate that miR827, assisted by lncRNA767, enhances SPX‐MFS1 and SPX‐MFS5 suppression and thus exerts a significant impact on Pi homeostasis and several essential agronomic traits of maize. [ABSTRACT FROM AUTHOR]

Summary: Diverse networks of specialized metabolites promote plant fitness by mediating beneficial and antagonistic environmental interactions. In maize (Zea mays), constitutive and dynamically formed cocktails of terpenoids, benzoxazinoids, oxylipins, and phenylpropanoids contribute to plant defense and ecological adaptation. Recent research has highlighted the multifunctional nature of many specialized metabolites, serving not only as elaborate chemical defenses that safeguard against biotic and abiotic stress but also as regulators in adaptive developmental processes and microbiome interactions. Great strides have also been made in identifying the modular pathway networks that drive maize chemical diversity. Translating this knowledge into strategies for enhancing stress resilience traits has the potential to address climate‐driven yield losses in one of the world's major food, feed, and bioenergy crops. [ABSTRACT FROM AUTHOR]

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AbstractSoil cover biomass in integrated systems can improve agronomic characteristics and impact in soybean productivity. Thus, the objective is to evaluate the desiccation efficiency, biomass production, nutrient accumulation, and soybean productivity in Quênia guinea grass (Panicum maximum cv. BRS Quênia) biomass after with an intercropped with maize in different forms of seeding, in compare the conventional soybean. The experimental design was a randomized block with four replicates. The treatments consisted of cover crop biomass: maize monoculture; Quênia guinea grass monoculture; maize intercropped with Quênia guinea grass within rows; maize intercropped with Quênia guinea grass between rows and an additional soybean treatment without cover biomass. The results showed that the Quênia guinea grass in the different cropping systems presented high desiccation efficiency, showing potential as a cover plant in integrated systems. The intercropping system of maize with Quênia guinea grass between rows is more recommended than seeding in the same rows as maize, because it promotes greater biomass production and nutrient cycling, reflecting in higher soybean productivity. The integrated production systems is a promising and efficient technology for production systems compared to the system of monoculture maize and soybeans without soil cover biomass, which ensures greater sustainability of agricultural systems. [ABSTRACT FROM AUTHOR]

Invasive alien insects have the potential to pose a significant threat to global agriculture, with their distinctive traits enabling rapid reproduction, successful adaptation to new environments and high distribution capability. These pests can devastate crops, livestock, biodiversity and ecosystem functioning, resulting in ecological damage and substantial economic losses. Climate change plays a crucial role in driving the invasion of these pests, creating favorable conditions for their development, and negatively impacting global biodiversity. Among invasive alien insects, fall armyworm (FAW) (Spodoptera frugiperda) (JE Smith) (Lepidoptera: Noctuidae) has emerged as a major pest species, causing significant yield losses in maize cropping outside his native range. Initially, reliance on pesticides for control proved ineffective and led to pesticide resistance. Significant progress has been made in implementing integrated pest management (IPM) strategies that integrate agro-ecological and biological approaches. This review article focuses on the compilation of IPM methods, combining agro-ecological practices and biological control agents such as parasitoids and viruses, for the effective management of FAW. Approaches such as intercropping, agronomic practices, and the use of parasitoids and viruses have shown promising results in controlling FAW. This review article provides insights into successful management methods, recommendations and suggestions for the sustainable control of FAW using agro-ecological practices, biological control agents or their combination. [ABSTRACT FROM AUTHOR]

Nanopriming with green-synthesized nanoparticles (NPs) has the potential to optimize crop performance under different conditions. This work investigated the implications of nanopriming of maize seeds with green-synthesized Cu-based NPs (ascorbic acid/starch, ACu, and green tea extract, GTCu) on the nutritional and morphophysiological traits of maize plants. Seeds Zea mays cv. Balu 787 were treated with different concentrations (14.5, 29, 58, and 116 mg Cu L–1) of both NPs, compared to hydropriming (CONT) and unprimed seeds (TEST). In a laboratory, seeds were germinated under different water conditions, while the long-term effects of seed nanopriming were evaluated in a greenhouse experiment with plants under different water conditions. The ionomic profile and morphophysiological traits of the plants were evaluated. In germination with water, both NPs increased the seedling Cu content by 37%, while in germination with PEG-6000, ACu and GTCu increased germination by 53 and 131%, respectively, compared with TEST and CONT. Without water restriction, hydropriming and ACu provided higher concentrations of many elements in seedling tissues. Under water deficit, only ACu stood out compared to the other treatments. GTCu promoted nutritional imbalance in both germination conditions. Although both NPs improved the water use efficiency of plants, ACu stood out for providing a better root/shoot ratio, helping the plants to be more tolerant to water deficit. GTCu provided greater shoot growth combined with lesser induction of root growth, leading to higher susceptibility to water deficit. In both experimental conditions, the dose of 58 mg Cu L–1 was highlighted, due to the induction of the greatest effects on seedling/plant development. The results suggest differences in the adsorption/absorption of NPs, with ACu triggering more positive effects on maize plants than GTCu. Overall, this study highlights the potential contribution of green nanotechnology in inducing plant growth and tolerance to abiotic stress by seed nanopriming. [ABSTRACT FROM AUTHOR]

Introduction: Salinity negatively affects maize productivity. However, calcium lignosulfonate (CLS) could improve soil properties and maize productivity. Methods: In this study, we evaluated the effects of CLS application on soil chemical properties, plant physiology and grain quality of maize under salinity stress. Thus, this experiment was conducted using three CLS application rates, CLS0, CLS5, and CLS10, corresponding to 0%, 5%, and 10% of soil mass, for three irrigation water salinity (WS) levels WS0.5, WS2.5, and WS5.5 corresponding to 0.5 and 2.5 and 5.5 dS/m, respectively. Results and discussion: Results show that the WS0.5 × CLS10 combination increased potassium (K 0.167 g/kg), and calcium (Ca, 0.39 g/kg) values while reducing the sodium (Na, 0.23 g/kg) content in soil. However, the treatment WS5.5 × CLS0 decreased K (0.120 g/kg), and Ca (0.15 g/kg) values while increasing Na (0.75 g/kg) content in soil. The root activity was larger in WS0.5 × CLS10 than in WS5.5 × CLS0, as the former combination enlarged K and Ca contents in the root while the latter decreased their values. The leaf glutamine synthetase (953.9 µmol/(g.h)) and nitrate reductase (40.39 µg/(g.h)) were higher in WS0.5 × CLS10 than in WS5.5 × CLS0 at 573.4 µmol/(g.h) and 20.76 µg/(g.h), leading to the improvement in cell progression cycle, as revealed by lower malonaldehyde level (6.57 µmol/g). The K and Ca contents in the leaf (881, 278 mg/plant), stem (1314, 731 mg/plant), and grains (1330, 1117 mg/plant) were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 at (146, 21 mg/plant), (201, 159 mg/plant) and (206, 157 mg/plant), respectively. Therefore, the maize was more resistance to salt stress under the CLS10 level, as a 7.34% decline in yield was noticed when salinity surpassed the threshold value (5.96 dS/m). The protein (13.6 %) and starch (89.2 %) contents were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 (6.1 %) and (67.0 %), respectively. This study reveals that CLS addition can alleviate the adverse impacts of salinity on soil quality and maize productivity. Thus, CLS application could be used as an effective soil amendment when irrigating with saline water for sustainable maize production. [ABSTRACT FROM AUTHOR]

The combining ability provides insightful information about the genetic mechanisms that govern the inheritance of traits and enables the identification of potential inbred lines; and promising hybrid combinations for crop improvement. However, most studies on quality protein maize (QPM) have focused on nutritional aspects, and very few are focused on their combining ability. In addition, studies on the adaptation, hybrid performance and stability of QPM in temperate areas remain scarce. Therefore, the present study sought to examine the combining ability of eight QPM inbred lines (QPM13, QPM14, QPM20, QPM21, QPM49, QPM50, VQL1, and VQL17). These 8 lines were subjected to half-diallel mating. Consequently, 28 crosses obtained were further evaluated in the temperate region of Kashmir against one check and parents in the RCBD, with three replications in a single row. The results revealed significant variances for general combining ability (GCA) and specific combining ability (SCA) for most of the recorded agronomic, yield, and quality traits. The crosses QPM49 × VQL1, QPM 13 × QPM14, QPM21 × VQL17, QPM13 × QPM50 and QPM50 × VQL17 were found to perform best in terms of earliness in tasselling (-1.842), silking (-1.204), days to mature (-2.654), highest yield (12.875 g)and protein content (1.113%), respectively. These promising crosses can be viable material sources for future QPM variety development programs in temperate regions. [ABSTRACT FROM AUTHOR]

Wheat is often planted directly after maize in fields following the maize harvest, and maize residues decompose in the soil by various biological factors, releasing phenolic compounds that affect the germination and growth of some crops planted with or after it. This research aimed to identify the effect of Zea mays leaf extract on seed germination physiological and anatomical features of Z. mays var. (Drachma, Mahali) and Triticum aestivum var. (Baraka, Abu Ghraib). The results showed Z. mays leaf extract stimulated some traits germination (100%) in Drachama at control, plumule length (7.8cm) in Abu-Graib, radicle length (11.6cm) in Baraka at 2%, fresh weight of plumule and radical (0.0113, 0.0148gm) respectively in Drachama at control. There was highest reduction germination (60%) in Drachama at 6% extract [plumule length (1.0)cm, radicle length (4.2cm), fresh weight of plumule (0.0052cm) in Mahali at 4%], fresh weight of radical (0.00026gm) in Abu-Graib at 6%. There was a difference in response in greenhouse experiments. Anatomical traits of the two corn cultivars differed at 2% and 4% concentrations. The highest increase in germination (96.7%) was in Baraka at 4%, shoot length (22.1cm) in Drachama at 4%, fresh weight of root (0.254gm) in Abu-Graib at 4%, [root length (44cm), fresh weight of root (0.052 gm) in Abu-Graib at 4%], the highest reduction in germination (80%) in Abu-Graib, dry weight of root (23gm) in Abu-Graib at 2%. Using HPLC, compounds tannic acid, gallic acid, benzoic acid, and salicylic acid were identified from Z. mays L. extracts. The study will help to develop sustainable agricultural practices, such as crop rotation, to increase crop productivity and reduce reliance on chemicals. [ABSTRACT FROM AUTHOR]

Considering that maize (Zea mays L.) is a staple food for a large segment of the population worldwide, many attempts have been made to improve the nutritional value of its grain and at the same time to achieve sustainable cropping systems. The present study aimed to characterize the composition and nutritional value of maize grain as influenced by cropping system, genetic background (variety), and growing year using untargeted NMR metabolomics. The composition of both water- (sugars and polyols, organic acids, and amino acids) and liposoluble metabolites (free and esterified fatty acids, sterols, and lipids) extracted from the maize grain was determined. Multivariate statistical analyses (PCA and ANOVA) pointed to the growing year and the variety as the most important random and fixed factors, respectively, influencing the metabolite profile. The samples were separated along PC1 and PC3 according to the growing year and the variety, respectively. A higher content of citric acid and diunsaturated fatty acids and a lower content of tyrosine, trigonelline, and monounsaturated fatty acids was observed in the organic with respect to the conventional variety. The effect of the cropping system was overwhelmed by the random effect of the growing year. The results provide novel knowledge on the influence of agronomic practices on maize micronutrient contents. [ABSTRACT FROM AUTHOR]

Profiled metabolites from 5-donor plants; Mucuna pruriens, L. (Mc), Cymbopogon nardus L. (C), Desmodium uncinatum Jacq. DC. (D), (Zea mays, L. (Mz) and New Rice for Africa 1 (NERICA 1) were Terpenoids and Phenols. NERICA 1 (R) is a cross of Oryza sativa and Oryza glaberrima. C produced 10 terpenoids + 1 ester, R and D each released 6 Terpenoids + 3 Phenols. Mc produced 2 Terpenoids + 4 Phenols and 5 Terpenoids + 4 Phenols were profiled from Mz. We adopted a completely randomised block design with 3 replicates and eight combinations of 3 leaf+ stem+root powders namely; Mc+D+C, Mz+Mc+C, RDC, Mc+D+C, Mz+R+Mc, Mz+D+Mc, R+Mc+C and Mz+R+C, mixed with 1.5 kg soil (15, 30 and 45 %, w/w). Controls had no powders. Mixtures were placed in plastic pots and 20 seeds of Biden pilosa L. were sown in each pot. Every 2 days, 200 ml of water was applied to all treatments for 60 days. Mz+Mc controlled B. pilosa and volunteer weeds relative to R+C and C+D. Weed germination and biomass reduced with increased powder doses. Volunteer monocot weeds were more inhibited than dicots. High potential exists for functional allelopathy using allelochemicals in the donor plants to develop bio-herbicides. [ABSTRACT FROM AUTHOR]

SUMMARY: Pathogen infection induces massive reprogramming of host primary metabolism. Lipid and fatty acid (FA) metabolism is generally disrupted by pathogens and co‐opted for their proliferation. Lipid droplets (LDs) that play important roles in regulating cellular lipid metabolism are utilized by a variety of pathogens in mammalian cells. However, the function of LDs during pathogenic infection in plants remains unknown. We show here that infection by rice black streaked dwarf virus (RBSDV) affects the lipid metabolism of maize, which causes elevated accumulation of C18 polyunsaturated fatty acids (PUFAs) leading to viral proliferation and symptom development. The overexpression of one of the two novel LD‐associated proteins (LDAPs) of maize (ZmLDAP1 and ZmLDAP2) induces LD clustering. The core capsid protein P8 of RBSDV interacts with ZmLDAP2 and prevents its degradation through the ubiquitin–proteasome system mediated by a UBX domain‐containing protein, PUX10. In addition, silencing of ZmLDAP2 downregulates the expression of FA desaturase genes in maize, leading to a decrease in C18 PUFAs levels and suppression of RBSDV accumulation. Our findings reveal that plant virus may recruit LDAP to regulate cellular FA metabolism to promote viral multiplication and infection. These results expand the knowledge of LD functions and viral infection mechanisms in plants. [ABSTRACT FROM AUTHOR]

The evaluation of plant growth-promoting bacteria in order to increase corn productivity is a biotechnology of global interest. This study evaluated the efficiency of the consortium between P. fluorescens CNPSo 2719(=CCTB03) and A. brasilense Ab-V06 in corn. Four experiments were carried out in four different locations, with a randomized block design and four replications, with the treatments: (1) without inoculation and without application of N coverage; (2) without inoculation and application of 100% of the recommended dose of N in coverage (200 kg ha-1 of N); (3) Azospirillum brasilense + application of 75% of the recommended dose of N in coverage (150 kg ha-1 of N); (4) bacterial consortium of Azospirillum brasilense + Pseudomonas fluorescens + application of 75% of the recommended dose of N in coverage (150 kg ha-1 of N). In all locations, with the use of the bacterial consortium (A. brasilense + P. fluorescens) + 75% of the recommended dose of N in coverage, it was possible to reduce the dose of N in coverage by up to 25% without compromising the productivity of the crop. In this way, it is concluded that the use of the consortium of the two bacteria promotes savings of up to 25% of N fertilization in top dressing and the possibility of using two microorganisms with the capacity to stimulation plant growth with a single application. [ABSTRACT FROM AUTHOR]

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In semi-arid southern Kenya, climate change is putting rainfed agriculture at risk with major implications for food security. The zai pit, a Climate-Smart Agriculture (CSA) technique, has proven to enhance yields in arid regions, but its labor demands have limited adoption rates. This study assessed how the zai pit depth and manure application within zai pits influenced maize (Zea mays) success (i.e., growth, development, and productivity). Three zai pit treatments were prepared at the Wildlife Works Research Center in southeastern Kenya: (1) deep (50 cm) with manure; (2) shallow (25 cm) with manure; and (3) deep (50 cm) without manure, and all were compared to a non-zai pit control (surface planting). Maize growth/development (e.g., height, stage, roots) and productivity (e.g., yield) measurements were taken over two growing periods. For most measures, shallow zai pits performed equally as well as deep zai pits, with both performing better than the control. Zai pits without manure performed significantly worse than zai pits with manure, oftentimes not differing from the control. Results suggest that maize success is influenced more by manure than the depth of the pit. Kenyan farmers are encouraged to dig shallower, manure-enriched zai pits to enhance food security in response to climate change. [ABSTRACT FROM AUTHOR]

This study was conducted in Turkey in Samsun conditions to determine some morphological and agronomic traits of different corn varieties planted at different sowing times. In our study, three different hybrid corn varieties (Otello, Golden Frank and Goldenver) and five different sowing times (May 13, June 3, June 21, July 9, July 29) were tested. The trial was established with 3 replications according to Randomized Complete Block Design. In the trial, 9 morphological and agronomic traits (plant height, stem diameter, leaf number, stem weight, root weight, leaf weight, cob length, cob diameter, row number) were examined. Repeated measurement analysis was conducted for plant height, stem diameter, leaf number, stem height, root weight, and leaf weight variables. Factor analysis was used for cob length, cob diameter, and row number variables for completely randomized design. Canonical Discriminant analysis was performed for classification of diversity factor. Pearson correlation coefficients were calculated to determine the correlation between variables. In the study, the highest plant height was determined as 192.16 cm, the highest leaf number as 10.22, the highest stem weight as 51.58 g, the highest root weight as 33.52 g, the highest leaf weight as 30.35 g, the highest cob length as 20.39 cm, and the highest row number in the cob as 23.25. As a result of the study, the best results were obtained from the first and second varieties with the sowing time of May 13. [ABSTRACT FROM AUTHOR]

Societal Impact Statement All US commercial maize (Zea mays) is a single race, “Corn Belt Dent,” and its genetic base has been in decline for at least 40 years. Independent genotyping can only be conducted after patent and licensing restrictions have expired, a period of 20 years. These restrictions also impede a molecular based assessment of the standing crop by the United States Department of Agriculture (USDA) as recommended by experts. Data blanks about landscape vulnerability put farmers at risk of crop failure and the public at risk of food insecurity. Understanding maize diversity experts' perspectives and analysis helps describe the contours of these data blanks and inform policy recommendations. Summary Recommendations by the Maize Crop Germplasm Committee to the United States Department of Agriculture (USDA) for a molecular based vulnerability assessment on the US standing maize (Zea mays) crop have not been acted on because of intellectual property and licensing restrictions. This research explores maize diversity experts' access to data and perceptions and analysis of the standing crop. The data come from semi‐structured interviews conducted with 44 maize diversity experts in the public and private sectors. Experts explain that genetic data blanks restrict non‐industry research, describe public sector concerns that standing diversity is narrow(ing), and find historic sources of pedigree data in Plant Variety Protection and patent records are no longer reliable. Some interviewees perceive that industry monitoring of standing diversity is in their best financial interest. Industry participants describe concentration in US maize allows them to control diversity over time, while public researchers discuss efficiency of scale narrowing genetic diversity and global concentration spreading this trend. Knowledge gaps about genetic diversity in US commercial maize are designed through patents, contracts, non‐disclosure agreements, and confidentiality agreements by patent holders who do not want their inbred lines genotyped by competitors. This restricts research and knowledge flow about genetic information into public networks. The Maize Crop Germplasm Committee is a node for knowledge flow; however, the lack of mechanisms for action suggests it is performative. We recommend all protections used on seed include exemptions for research, breeding, and seed saving; an independent assessment of how industry monitors standing diversity; and a molecular analysis of the standing crop conducted by the USDA.

Abstract Building models that allow phenotypic evaluation of complex agronomic traits in crops of global economic interest, such as grain yield (GY) in soybean and maize, is essential for improving the efficiency of breeding programs. In this sense, understanding the relationships between agronomic variables and those obtained by high-throughput phenotyping (HTP) is crucial to this goal. Our hypothesis is that vegetation indices (VIs) obtained from HTP can be used to indirectly measure agronomic variables in annual crops. The objectives were to study the association between agronomic variables in maize and soybean genotypes with VIs obtained from remote sensing and to identify computational intelligence for predicting GY of these crops from VIs as input in the models. Comparative trials were carried out with 30 maize genotypes in the 2020/2021, 2021/2022 and 2022/2023 crop seasons, and with 32 soybean genotypes in the 2021/2022 and 2022/2023 seasons. In all trials, an overflight was performed at R1 stage using the UAV Sensefly eBee equipped with a multispectral sensor for acquiring canopy reflectance in the green (550 nm), red (660 nm), near-infrared (735 nm) and infrared (790 nm) wavelengths, which were used to calculate the VIs assessed. Agronomic traits evaluated in maize crop were: leaf nitrogen content, plant height, first ear insertion height, and GY, while agronomic traits evaluated in soybean were: days to maturity, plant height, first pod insertion height, and GY. The association between the variables were expressed by a correlation network, and to identify which indices are best associated with each of the traits evaluated, a path analysis was performed. Lastly, VIs with a cause-and-effect association on each variable in maize and soybean trials were adopted as independent explanatory variables in multiple regression model (MLR) and artificial neural network (ANN), in which the 10 best topologies able to simultaneously predict all the agronomic variables evaluated in each crop were selected. Our findings reveal that VIs can be used to predict agronomic variables in maize and soybean. Soil-adjusted Vegetation Index (SAVI) and Green Normalized Dif-ference Vegetation Index (GNDVI) have a positive and high direct effect on all agronomic variables evaluated in maize, while Normalized Difference Vegetation Index (NDVI) and Normalized Difference Red Edge Index (NDRE) have a positive cause-and-effect association with all soybean variables. ANN outperformed MLR, providing higher accuracy when predicting agronomic variables using the VIs select by path analysis as input. Future studies should evaluate other plant traits, such as physiological or nutritional ones, as well as different spectral variables from those evaluated here, with a view to contributing to an in-depth understanding about cause-and-effect relationships between plant traits and spectral variables. Such studies could contribute to more specific HTP at the level of traits of interest in each crop, helping to develop genetic materials that meet the future demands of population growth and climate change.

Abstract Background Microplastics are contaminants in soil ecosystems that alter biophysical processes, affect plant growth, ecosystems and humans in the long run. This study was conducted to investigate the influence of soil microplastic contamination on the growth, development, and microbial dynamics of maize (Zea mays).Composite soil samples were collected from the farm from 0 to 10 cm depth. Physicochemical properties were assessed before maize seed sowing. Three soil weight categories were treated with 30 g, 20 g and 10 g microplastics. Soil physicochemical properties and heavy metal content in maize plants were analyzed. Morphological parameters, microbial counts, and microorganism identification were conducted. FTIR analysis was carried out in selected plant parts. Results The study revealed a pH range of 5.00–6.70, electrical conductivity of 70–158 µS/cm, organic carbon and organic matter, total nitrogen, average phosphorus content, clay and silt content. The concentrations of heavy metals in plant parts were within WHO standard limits of 425.5 and 500 mg/kg for iron and manganese, but above the limits of 40, 60, and 350 mg/kg for copper, zinc and magnesium. The plant had various leaf sizes and heights, with chlorosis and necrotic activity ranging from 0.33 to 2.67, and a range of 1.33 to 6.33, respectively. Soil samples showed a total bacterial count (TBC) of 2.00 × 103 cfu/g to 7.60 × 104 cfu/g and a total fungal count (TFC) of 4.00 × 103 cfu/g to 2.20 × 104 cfu/g. Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus epidermidis, Proteus mirabilis and Bacillus cereus had percentage occurrences of 44.31, 21.17, 9.12, and 3.26%, respectively. Penicillium notatum was the most prevalent, while Fusarium spp. was the least prevalent. The FTIR analysis of maize seeds from soil samples A, B, and C revealed various organic compounds, with opium powder and streptomycin sulphate being the most abundant. The study revealed that pot B had the highest microplastic concentration at 1 WAS, while pot C had the lowest at 0.10 mg/kg, indicating a differential soil microplastic accumulation. Conclusion Microplastics impact soil health, plant growth, and nutrient cycling, necessitating sustainable agriculture. Long-term research is needed to understand ecological and physiological impacts and explore remediation techniques.

In the summer of 2023, a study was conducted in the Hawija district of Kirkuk to evaluate the impact of irrigation water quality and soil fertility on primary metabolites and maize crop productivity. Three distinct sites were selected for this assessment. The irrigation water quality index values, which ranged from 27.5 to 59.13, indicated that the water from all the wells used was unsuitable for irrigation. Concurrently, soil fertility values at all locations were found to be poor, ranging between 0.46 and 0.5.These suboptimal conditions had varying effects on the yield and primary metabolites of the maize crop at the selected sites. Specifically, the carbohydrate content in maize varied from 50.5 to 68.6 ppm across the sites. Protein levels ranged widely, from 4.02 to 57 ppm. Fatty acid content was measured between 68.54 and 84.34 ppm, while total chlorophyll content ranged from 25.84 to 33.71 ppm.The study also measured the weight of 100 maize , with the highest weights recorded at the first and third sites, each at 75, whereas the second site recorded the lowest weight at 65. The harvest index, which measures the efficiency of the crop in converting biomass into grain, showed a notable range across the sites. The highest harvest index was observed at the first location (0.0421%), while the third location recorded the lowest value (0.0283%).The overall biological outcomes of the study indicated a clear disparity in productivity among the sites. The second site was identified as the least productive, likely due to its poor soil fertility and substandard irrigation water quality. In contrast, the first site emerged as the most productive, suggesting relatively better conditions despite the general challenges posed by water and soil quality. This study underscores the critical influence of irrigation water quality and soil fertility on maize productivity.

Abstract Invasive alien insects have the potential to pose a significant threat to global agriculture, with their distinctive traits enabling rapid reproduction, successful adaptation to new environments and high distribution capability. These pests can devastate crops, livestock, biodiversity and ecosystem functioning, resulting in ecological damage and substantial economic losses. Climate change plays a crucial role in driving the invasion of these pests, creating favorable conditions for their development, and negatively impacting global biodiversity. Among invasive alien insects, fall armyworm (FAW) (Spodoptera frugiperda) (JE Smith) (Lepidoptera: Noctuidae) has emerged as a major pest species, causing significant yield losses in maize cropping outside his native range. Initially, reliance on pesticides for control proved ineffective and led to pesticide resistance. Significant progress has been made in implementing integrated pest management (IPM) strategies that integrate agro-ecological and biological approaches. This review article focuses on the compilation of IPM methods, combining agro-ecological practices and biological control agents such as parasitoids and viruses, for the effective management of FAW. Approaches such as intercropping, agronomic practices, and the use of parasitoids and viruses have shown promising results in controlling FAW. This review article provides insights into successful management methods, recommendations and suggestions for the sustainable control of FAW using agro-ecological practices, biological control agents or their combination.