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Switchgrass (Panicum virgatum) is a bioenergy model crop valued for its energy efficiency and drought tolerance. The related monocot species rice (Oryza sativa) and maize (Zea mays) deploy species-specific, specialized metabolites as core stress defenses. By contrast, specialized chemical defenses in switchgrass are largely unknown. To investigate specialized metabolic drought responses in switchgrass, we integrated tissue-specific transcriptome and metabolite analyses of the genotypes Alamo and Cave-in-Rock that feature different drought tolerance. The more drought-susceptible Cave-in-Rock featured an earlier onset of transcriptomic changes and significantly more differentially expressed genes in response to drought compared to Alamo. Specialized pathways showed moderate differential expression compared to pronounced transcriptomic alterations in carbohydrate and amino acid metabolism. However, diterpenoid-biosynthetic genes showed drought-inducible expression in Alamo roots, contrasting largely unaltered triterpenoid and phenylpropanoid pathways. Metabolomic analyses identified common and genotype-specific flavonoids and terpenoids. Consistent with transcriptomic alterations, several root diterpenoids showed significant drought-induced accumulation, whereas triterpenoid abundance remained predominantly unchanged. Structural analysis verified select drought-responsive diterpenoids as oxygenated furanoditerpenoids. Drought-dependent transcriptome and metabolite profiles provide the foundation to understand the molecular mechanisms underlying switchgrass drought responses. Accumulation of specialized root diterpenoids and corresponding pathway transcripts supports a role in drought stress tolerance.

Plant β-amylase (BAM) proteins play an essential role in growth, development, stress response, and hormone regulation. Despite their typical (β/α)8 barrel structure as active catalysts in starch breakdown, catalytically inactive BAMs are implicated in diverse yet elusive functions in plants. The noncatalytic BAM7/8 contain N-terminal BZR1 domains and were shown to be involved in the regulation of brassinosteroid signaling and possibly serve as sensors of yet an uncharacterized metabolic signal. While the structures of several catalytically active BAMs have been reported, structural characterization of the catalytically inactive BZR1-type BAMs remain unknown. Here, we determine the crystal structure of β-amylase domain of Zea mays BAM8/BES1/BZR1-5 and provide comprehensive insights into its noncatalytic adaptation. Using structural-guided comparison combined with biochemical analysis and molecular dynamics simulations, we revealed conformational changes in multiple distinct highly conserved regions resulting in rearrangement of the binding pocket. Altogether, this study adds a new layer of understanding to starch breakdown mechanism and elucidates the acquired adjustments of noncatalytic BZR1-type BAMs as putative regulatory domains and/or metabolic sensors in plants.

Abstract Soil depletion constitutes a major challenge for agriculture and food security in highlands of eastern Democratic Republic of Congo (DRC). This study aimed to assess the effectiveness of the split-application of nitrogen fertilizer on grain yield and profitability of maize on Nitisols in eastern DRC. The urea fertilizer (100 kg ha−1) was applied in single, two, and three split-applications on three maize varieties for two cropping seasons. Results showed that maize growth and yield parameters varied significantly with N splitting strategy, varieties, and cropping season (p

Nutrient deficiency (ND) stands as a prominent environmental factor that significantly impacts global plant growth and productivity. While numerous methods have been employed for detecting nutrient deficiencies in plants, many of them are invasive, time-consuming, and costly. In contrast, chlorophyll fluorescence (ChlF) signals have emerged as a non-destructive tool for the identification of specific nutrient deficiencies, such as nitrogen (N), phosphorus (P), and potassium (K), across various plant species. In this pioneering study, ChlF measurements were employed for the first time to detect a combination of nutrient deficiencies, including deficiencies in nitrogen and phosphorus (–NP), nitrogen and potassium (–NK), potassium and phosphorus (–KP), and a complete NPK deficiency (–NPK). The experiment was conducted using wheat (Triticum aestivum) and maize ( Zea mays) plants, which were grown under controlled laboratory conditions. An optimal hydroponic system was established to facilitate eight experimental conditions, namely: control, –N, –P, –K, –NP, –NK, –KP, and –NPK. Measurements were systematically collected at two-day intervals over a span of 24 days. Our findings demonstrate that chlorophyll fluorescence signals can enable the differentiation of various nutrient deficiencies even prior to the onset of observable symptoms. Furthermore, the examination of chlorophyll fluorescence parameters enables us not only to identify a singular macronutrient deficiency but also to detect multiple macronutrient deficiencies concurrently in a plant.

The efficiency of the assignment of germplasm lines into heterotic groups is a prerequisite for obtaining useful heterotic patterns among germplasm lines. Therefore, this study was conducted to group lines into heterotic group besides assess the effects of both general and specific abilities. Fifteen white maize parental lines were crossed with two testers, i.e. parental line SK-12 and Single cross 120 at Agricultural Research Station in Sakha, Egypt during 2021 summer season. The resultant 30 crosses were evaluated along with four commercial hybrids in three locations during 2022. The parental inbred lines Sk5001/42, Sk5003/48, Sk5003/53, Sk5004/55 and Sk5004/56 recorded positive GCA effect on grain yield while Sk5001/41, Sk5002/46 and Sk5004/56 exhibited desirable GCA effects for earliness. Five single crosses viz. (Sk5003/53 × Sk12), (Sk5001/42 × Sk12), (Sk5004/55 × Sk12), (Sk5003/48 × Sk12) and (Sk5004/56 × Sk12) and two three way crosses (Sk5001/42 × SC.120) and (Sk5003/53 × SC.120) did not differ significantly against their respective check hybrids (SC 10 and TWC 321) though they outyield their respective checks. These hybrids could be subjected to further multi-location evaluation to assess the yield stability for commercial exploitation. Two groups of parental lines were created based on Heterotic Group Specific and General Combining Ability (HSGCA) method for grain yield trait. These groups might be employed in a breeding program to pick the best parents to make crosses in other combinations.

This study was conducted in the fields of Nineveh Research Department (animal wealth) in the fall season to study the effect of different levels of potassium fertilization on the growth of maize plant Zea myas class 106, a completely randomized design was used with three replications. Each of the treatments included three levels of potassium sulfate fertilizer (K0, 0, K1, 20, K2, 30, K3 50) kg/D. The results of adding potassium fertilizer at its levels showed a significant effect on the studied traits (potassium K3 concentration showed a significant effect on the length of (the plant, leaf, ear, number of ears, the weight of ear leaves, number of ear rows, weight of (calcareous, and whole plant), which amounted to 195.5, 78.3, 10.5, 32.7, 2.50, 0.030, 16.8, 0.177, 0.30, compared with other concentrations of fertilizer and comparison treatment, which amounted to 176.6, 70.9, 9.5, 30.0, 1.75, 0.02, 14.7, 0.08, 0.29, gm/kg soil on The addition of potassium K3 level gave the highest value in terms of ash and water absorption of maize grains, which amounted to 0.420 and 61.23, respectively, compared with other concentrations and treatment, which amounted to 0.416 and 60.23 gm/kg soil, as well as an increase in the value of both dissolved and available potassium and phosphorous percentage. Which amounted to 22.0, 422.7, 26.67, gm/kg soil compared with other concentrations of fertilizer and control treatment, which amounted to 332.3, 14.07, and 23.91 gm/kg soil respectively compared to other concentrations of potassium fertilizer, and give significant effect to Both available-made ammonium, Ph. , electric conductivity but no significant nitrate content in the soil.

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.

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.

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.

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.

The cuticle, a hydrophobic layer of cutin and waxes synthesized by plant epidermal cells, is the major barrier to water loss when stomata are closed. Dissecting the genetic architecture of natural variation for maize (Zea mays L.) leaf cuticular conductance (gc) is important for identifying genes relevant to improving crop productivity in drought-prone environments. To this end, we performed an integrated genome- and transcriptome-wide association studies (GWAS and TWAS) to identify candidate genes putatively regulating variation in leaf gc. Of the 22 plausible candidate genes identified, 4 were predicted to be involved in cuticle precursor biosynthesis and export, 2 in cell wall modification, 9 in intracellular membrane trafficking, and 7 in the regulation of cuticle development. A gene encoding an INCREASED SALT TOLERANCE1-LIKE1 (ISTL1) protein putatively involved in intracellular protein and membrane trafficking was identified in GWAS and TWAS as the strongest candidate causal gene. A set of maize nested near-isogenic lines that harbor the ISTL1 genomic region from eight donor parents were evaluated for gc, confirming the association between gc and ISTL1 in a haplotype-based association analysis. The findings of this study provide insights into the role of regulatory variation in the development of the maize leaf cuticle and will ultimately assist breeders to develop drought-tolerant maize for target environments.

Tocochromanols (tocopherols and tocotrienols, collectively vitamin E) are lipid-soluble antioxidants important for both plant fitness and human health. The main dietary sources of vitamin E are seed oils that often accumulate high levels of tocopherol isoforms with lower vitamin E activity. The tocochromanol biosynthetic pathway is conserved across plant species but an integrated view of the genes and mechanisms underlying natural variation of tocochromanol levels in seed of most cereal crops remains limited. To address this issue, we utilized the high mapping resolution of the maize Ames panel of ∼1,500 inbred lines scored with 12.2 million single-nucleotide polymorphisms to generate metabolomic (mature grain tocochromanols) and transcriptomic (developing grain) data sets for genetic mapping. By combining results from genome- and transcriptome-wide association studies, we identified a total of 13 candidate causal gene loci, including 5 that had not been previously associated with maize grain tocochromanols: 4 biosynthetic genes (arodeH2 paralog, dxs1, vte5, and vte7) and a plastid S-adenosyl methionine transporter (samt1). Expression quantitative trait locus (eQTL) mapping of these 13 gene loci revealed that they are predominantly regulated by cis-eQTL. Through a joint statistical analysis, we implicated cis-acting variants as responsible for colocalized eQTL and GWAS association signals. Our multiomics approach provided increased statistical power and mapping resolution to enable a detailed characterization of the genetic and regulatory architecture underlying tocochromanol accumulation in maize grain and provided insights for ongoing biofortification efforts to breed and/or engineer vitamin E and antioxidant levels in maize and other cereals.

Native Americans domesticated maize (Zea mays ssp. mays) from lowland teosinte parviglumis (Zea mays ssp. parviglumis) in the warm Mexican southwest and brought it to the highlands of Mexico and South America where it was exposed to lower temperatures that imposed strong selection on flowering time. Phospholipids are important metabolites in plant responses to low-temperature and phosphorus availability and have been suggested to influence flowering time. Here, we combined linkage mapping with genome scans to identify High PhosphatidylCholine 1 (HPC1), a gene that encodes a phospholipase A1 enzyme, as a major driver of phospholipid variation in highland maize. Common garden experiments demonstrated strong genotype-by-environment interactions associated with variation at HPC1, with the highland HPC1 allele leading to higher fitness in highlands, possibly by hastening flowering. The highland maize HPC1 variant resulted in impaired function of the encoded protein due to a polymorphism in a highly conserved sequence. A meta-analysis across HPC1 orthologs indicated a strong association between the identity of the amino acid at this position and optimal growth in prokaryotes. Mutagenesis of HPC1 via genome editing validated its role in regulating phospholipid metabolism. Finally, we showed that the highland HPC1 allele entered cultivated maize by introgression from the wild highland teosinte Zea mays ssp. mexicana and has been maintained in maize breeding lines from the Northern United States, Canada, and Europe. Thus, HPC1 introgressed from teosinte mexicana underlies a large metabolic QTL that modulates phosphatidylcholine levels and has an adaptive effect at least in part via induction of early flowering time.

Genomic imprinting refers to allele-specific expression of genes depending on parental origin, and it is regulated by epigenetic modifications. Intraspecific allelic variation for imprinting has been detected; however, the intraspecific genome-wide allelic epigenetic variation in maize and its correlation with imprinting variants remain unclear. Here, three reciprocal hybrids were generated by crossing Zea mays inbred lines CAU5, B73, and Mo17 in order to examine the intraspecific conservation of the imprinted genes in the kernel. The majority of imprinted genes exhibited intraspecific conservation, and these genes also exhibited interspecific conservation (rice, sorghum, and Arabidopsis) and were enriched in some specific pathways. By comparing intraspecific allelic DNA methylation in the endosperm, we found that nearly 15% of DNA methylation existed as allelic variants. The intraspecific whole-genome correlation between DNA methylation and imprinted genes indicated that DNA methylation variants play an important role in imprinting variants. Disruption of two conserved imprinted genes using CRISPR/Cas9 editing resulted in a smaller kernel phenotype. Our results shed light on the intraspecific correlation of DNA methylation variants and variation for imprinting in maize, and show that imprinted genes play an important role in kernel development. [ABSTRACT FROM AUTHOR]

Sub-Saharan African smallholder farmers face challenges due to limited access to commercial fertilizers, affecting food security. Exploring the benefits of intercropping is promising, but evaluating crop performance in specific agroecological contexts is crucial. This study in Vilankulo, Mozambique, conducted over two growth seasons (2018 and 2019), aimed to assess the benefits of intercropping maize (Zea mays L.) and cowpea (Vigna unguiculata L., Walp) (M+C) compared to maize (M) and cowpea (C) as sole crops. Key variables for comparison included dry matter yield (DMY), land equivalent ratio (LER), competitive ratio (CR), tissue nutrient concentration, nutrient recovery, and apparent N fixation (ANF). This study also examined the effects on cabbage (Brassica oleracea L.), cultivated as a succeeding crop, and soil properties. In 2018, maize plants were severely affected by drought and did not produce grain. This year, cowpea grain yields were 2.26 and 1.35 t ha−1 when grown as sole crop or intercropped. In 2019, maize grain yield was 6.75 t ha−1 when intercropped, compared to 5.52 t ha−1 as a sole crop. Cowpea grain yield was lower when intercropped (1.51 vs. 2.25 t ha−1). LER values exceeded 1 (1.91 and 1.53 for grain and straw in 2019), indicating improved performance in intercropping compared to sole crops. In 2019, CR was 1.96 for maize grain and 0.58 for cowpea grain, highlighting the higher competitiveness of maize over cowpea. Cowpea exhibited higher average leaf nitrogen (N) concentration (25.4 and 37.6 g kg−1 in 2018 and 2019, respectively) than maize (13.0 and 23.7 g kg−1), attributed to its leguminous nature with access to atmospheric N, benefiting the growth of maize in intercropping and cabbage cultivated as a succeeding crop. Cowpea also appears to have contributed to enhanced phosphorus (P) absorption, possibly due to access to sparingly soluble P forms. In 2019, ANF in M+C was 102.5 kg ha−1, over 4-fold higher than in C (25.0 g kg−1), suggesting maize accessed more N than could cowpea provide, possibly through association with endophytic diazotrophs commonly found in tropical grasses. [ABSTRACT FROM AUTHOR]

Corn plants Zea mays L. are sensitive to many stress factors that cause excessive formation of reactive oxygen species, the elimination mechanism of which includes the monodehydroascorbate reductase (MDHAR; EC 1.6.5.4), which catalyzes the reduction of monodehydroascorbic acid to ascorbate. There are four known genes in the maize genome, ZmMDHAR1–ZmMDHAR4, differing in the intracellular localization of the encoded MDHAR proteins. In this work, a novel gene of the family was identified, ZmMDHAR5 (Zm00001d017786; LOC100193942), encoding a close structural homolog of peroxisomal ZmMDHAR3. It has been assumed that ZmMDHAR5 may function similarly to chloroplast-mitochondrial MDHARs. Differential expression of ZmMDHAR1–ZmMDHAR5 genes in maize seedlings in response to various stress factors also suggested the important role of ZmMDHAR4 and ZmMDHAR5 in response to exogenous abscisic acid, low temperature, and dehydration; ZmMDHAR1 and ZmMDHAR3 to salt stress; and ZmMDHAR2 to salt and water stresses. [ABSTRACT FROM AUTHOR]

Maize striate leaves2 (sr2) is a mutant that causes white stripes on leaves that has been used in mapping studies for decades though the underlying gene has not been identified. The sr2 locus has been previously mapped to small regions of normal chromosome 10 (N10) and a rearranged variant called abnormal chromosome 10 (Ab10). A comparison of assembled genomes carrying N10 and Ab10 revealed only five candidate sr2 genes. Analysis of a stock carrying the sr2 reference allele (sr2‐ref) showed that one of the five genes has a transposon insertion that disrupts its protein sequence and has a severe reduction in mRNA. An independent Mutator transposon insertion in the gene (sr2‐Mu) failed to complement the sr2‐ref mutation, and plants homozygous for sr2‐Mu showed white striped leaf margins. The sr2 gene encodes a DUF3732 protein with strong homology to a rice gene with a similar mutant phenotype called young seedling stripe1 (yss1). These and other published data suggest that sr2 may have a function in plastid gene expression. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the absorption, partitioning, and redistribution of nutrients by phenological stage of the maize crop, under the edaphoclimatic conditions of the municipality of Brejo, Maranh~ao, Brazil. The experiment was carried out in a Yellow Argisol, under a randomized block design, with seven treatments corresponding to the phenological stages V5, V8, VT, R1, R3, R5, and R6, and four replicates. The plant was partitioned into leaves, stalk, reproductive organs (tassel, straw, cob), and grains to determine the concentrations of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn. The accumulation of nutrients in each organ in the different phenological stages was estimated based on the values of dry weight and nutrient concentrations. A slow accumulation of dry weight was observed in the maize plant until the flowering stage (VT), a pattern also observed for the nutrients P, Mg, S, and Cu. Nutrients N, K, Ca, B, Fe, Mn, and Zn showed values close or superior to 50% of the maximum accumulated up to VT. The decreasing order of nutrient accumulation was N>K>P>Mg> S>Ca>Fe>Zn>Mn>Cu>B. The nutrients with the highest harvest rates were P>N>Mg>S>Zn (0.84, 0.74, 0.72, 0.69, and 0.51, respectively). N, K, Ca, B, Zn, Fe, and Mn are the most absorbed nutrients in the initial stage of crop development. The nutrients that are absorbed in greater quantity after flowering are P, S, Mg, and Cu. The degrees day sum showed no effects on the maize crop cycle under the edafoclimatic conditions of this study. [ABSTRACT FROM AUTHOR]

Strigolactones (SLs) represent a recently identified class of plant hormones that are crucial for plant tillering and mycorrhizal symbiosis. The D14 gene, an essential receptor within the SLs signaling pathway, has been well-examined in crops, like rice (Oryza sativa L.) and Arabidopsis (Arabidopsis thaliana L.), yet the research on its influence in maize (Zea mays L.) remains scarce. This study successfully clones and establishes Arabidopsis D14 gene overexpression lines (OE lines). When compared with the wild type (WT), the OE lines exhibited significantly longer primary roots during germination. By seven weeks of age, these lines showed reductions in plant height and tillering, alongside slight decreases in rosette and leaf sizes, coupled with early aging symptoms. Fluorescence-based quantitative assays indicated notable hormonal fluctuations in OE lines versus the WT, implying that D14 overexpression disrupts plant hormonal homeostasis. The OE lines, exposed to cold, drought, and sodium chloride stressors during germination, displayed an especially pronounced resistance to drought. The drought resistance of OE lines, as evident from dehydration–rehydration assays, outmatched that of the WT lines. Additionally, under drought conditions, the OE lines accumulated less reactive oxygen species (ROS) as revealed by the assessment of the related physiological and biochemical parameters. Upon confronting the pathogens Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), post-infection, fluorescence quantitative investigations showed a significant boost in the salicylic acid (SA)-related gene expression in OE lines compared to their WT counterparts. Overall, our findings designate the SL receptor D14 as a key upregulator of drought tolerance and a regulator in the biotic stress response, thereby advancing our understanding of the maize SL signaling pathway by elucidating the function of the pivotal D14 gene. [ABSTRACT FROM AUTHOR]

Selection in the Iowa Stiff Stalk Synthetic (BSSS) maize population for high yield, grain moisture, and root and stalk lodging has indirectly modified plant architecture traits that are important for adaptation to high plant density. In this study, we developed doubled haploid (DH) lines from the BSSS maize population in the earliest cycle of recurrent selection (BSSS), cycle 17 of reciprocal recurrent selection, [BSSS(R)17] and the cross between the two cycles [BSSS/BSSS(R)C17]. We aimed to determine the phenotypic variation and changes in agronomic traits that have occurred through the recurrent selection program in this population and to identify genes or regions in the genome associated with the plant architecture changes observed in the different cycles of selection. We conducted a per se evaluation of DH lines focusing on high heritability traits important for adaptation to high planting density and grain yield. Trends for reducing flowering time, anthesis-silking interval, ear height, and the number of primary tassel branches in BSSS(R)17 DH lines compared to BSSS and BSSS/BSSS(R)C17 DH lines were observed. Additionally, the BSSS(R)C17 DH lines showed more upright flag leaf angles. Using the entire panel of DH lines increased the number of SNP markers identified within candidate genes associated with plant architecture traits. The genomic regions identified for plant architecture traits in this study may help to elucidate the genetic basis of these traits and facilitate future work about marker-assisted selection or map- based cloning in maize breeding programs. [ABSTRACT FROM AUTHOR]

Salinity is known to have a greater impact on shoot growth than root growth. Na+ buildup in plant tissue under salt stress has been proposed as one of the main issues that causes growth inhibition in crops via ionic imbalances, osmotic stress and pH disturbances. However, the evidence for apoplastic Na+ buildup and the role of silicon in Na+ accumulation at the subcellular level is still enigmatic. The current study focuses on the accumulation of Na+ in the apoplast and symplast of younger and older leaves of two maize varieties (Iqbal as salt-tolerant and Jalal as salt-sensitive) using hydroponic culture along with silicon supplementation under short-term salinity stress. Subcellular ion analysis indicated that silicon nutrition decreased Na+ concentration in both apoplastic washing fluid and symplastic fluid of maize under salt stress. The addition of silicon under NaCl treatment resulted in considerable improvement in fresh biomass, relative water content, chlorophyll content, and concentration of important subcellular ions (i.e., Ca2+, Mg2+, and K+). Knowledge of subcellular ion analysis is essential for solving the mechanisms underlying vital cellular functions e.g. in the current study, the soluble Na+ concentration in the apoplast of older leaves was found to be significantly greater (36.1 mM) in the salt-sensitive variety under NaCl treatment, which was 42.4% higher when compared to the Na+ concentration in the salt-tolerant variety under the same treatment which can influence permeability of cell membrane, signal transduction pathways and provides insights into how ion compartmentalization can contributes to salt tolerance. Calcium silicate enrichment can contribute to increased growth and improved ionic homeostasis by minimizing leaf electrolyte leakage, improving mechanical functions of cell wall and reducing water loss, and improved photosynthetic function. In current investigation, increased water content and intracellular ionic homeostasis along with reduced concentration of Na+ in the maize leaf apoplast suggest that calcium silicate can be used to ameliorate the adverse effects of salt stress and obtain yield using marginal saline lands. [ABSTRACT FROM AUTHOR]

The cultivation of corn holds immense importance as a foundational global grain crop, catering to human sustenance and serving as vital animal feed. Moreover, corn plays a substantial role in biofuel production. Additionally, cultivating corn can have a positive effect on crop rotation by improving soil quality and reducing erosion. In a pot trial using six distinct compost variations derived from different organic wastes as fertilizers for GS210 corn, specific indices, such as Fv/Fm (0.80, 0.80, 0.81), Fv/F0 (4.07, 3.99, 4.03), PI (4.62, 4.22, 5.21), and RC/ABS (1.71, 1.68, 2.01), exhibited the highest values. Interestingly, mineral fertilization with NPK displayed significant benefits on various growth parameters like plant height (188.9 cm), cob length (17.50 cm), grains per cob (324.0), and thousand-grain weight (MTZ) (285.2). The difference in the cob grain count between NPK mineral fertilization and the control reached 168.5 grains, which was statistically confirmed. Furthermore, the grain's protein content notably increased with mineral fertilization (9.5) compared to the control (8.5). While organic fertilizers showed lower outcomes (9.1–9.3) than NPK mineral fertilization, they generally outperformed the control (8.5). This prompts the need for future studies to assess the effectiveness of individual organic fertilizers in combination with mineral nitrogen fertilization. [ABSTRACT FROM AUTHOR]

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Maize is a staple food for most South Africans, yet maize meal (corn flour) does not provide enough sustenance, contributing to food insecurity and malnutrition. Improving the nutrient content of maize and maize-based products could benefit communities where maize is the staple food. This study aimed to determine the relationship and frequency of consuming maize products, side dishes and snacks preferred by consumers of different provinces of origin and language speakers. One hundred respondents participated in a survey after tasting nixtamalized maize products in a sensory laboratory. The results showed that Pap in the forms of soft (58%), stiff (73%), phutu [crumbly] (68%), or porridge (55%) was regularly or frequently included in meals. Pap was eaten daily by 11.2% for breakfast, 17.2% for lunch and 23.2% of respondents for supper. Soft (36.1%), stiff (56.6%) and phutu (43.0%) were preferred for supper, while porridge (73.7%) was preferred for breakfast. Braaied meat (40.2%) and meat stew or soup (40.0%) were enjoyed as side dishes. The language that participants spoke influenced the food items or side dishes more than the province of origin. The study showed the maize consumption habits of South African consumers to inform future product development or nutrition intervention programs. [ABSTRACT FROM AUTHOR]

Growth of crops in the semi-arid and arid regions of the world is significantly affected by salinity stress. The present study investigated maize, which is a globally cultivated crop and known for its salt sensitivity. Widespread cultivation and notable characteristics of maize make it an exemplary model for investigating stress response. We analyzed maize plants morphological and biochemical responses under salinity stress at different intervals. Current results showed that under 100 mM NaCl stress, germination rate of maize seeds decreases up to 40% compared to their respective control non-stressed seeds. Additionally, prolonged exposure to salinity stress negatively impacted various physiological and biochemical aspects of maize plants including shoot/root length, leaf width, and chlorophyll contents, especially in plants treated with NaCl for 21 days. Furthermore, our findings showed that the NaCl stress triggered various enzymatic and non-enzymatic activities, including catalase (CAT), polyphenol oxidase (PPO), total polyphenol (TPP), and flavonoid in maize plants. However, maize plants respond differently to NaCl stress regarding protein content in different durations. This research underscores the urgent need for innovative strategies to mitigate salinity stress and food security for local maize varieties in saline regions and provides valuable insights to tackle these challenges. [ABSTRACT FROM AUTHOR]

Nitrogen fertilization is a very complex factor due to the various transformations that occur with nitrogen (N) in the soil, which influence its use by the plant. Another factor that directly influences decision-making is the high cost of acquiring fertilizers and also the difficulty of application. Bearing in mind the importance of N management, the objective was to evaluate the agronomic performance of maize, cultivated in a no-tillage system, as a function of the application of foliar N in coverage. The treatments were divided into completely randomized blocks, four blocks with four treatments each, in the first and second harvest periods. Being a witness (no N in coverage); urea; 1/2 urea and 1/2 foliar N and only with foliar N in coverage. Topdressing N dosages were divided into two applications. The following variables were analyzed: plant height, stem diameter and productivity. Under the edaphoclimatic conditions in which this study was carried out, the application of foliar N should not be used as the only way to supply N to the crop, as it could be an efficient way to complement what is absorbed by the roots. One should be aware of the dosages used to avoid phytotoxic effects on the leaves. [ABSTRACT FROM AUTHOR]

Stress-related NAC (NAM, ATAF1-2 and CUC2) genes, known as SNAC sub-family have been identified in four different species such as Arabidopsis thaliana, Oryza sativa, Sorghum bicolor and Zea mays using the tools of bioinformatics. These genes have been characterized by finding out their introns, exons, cis-regulatory elements, sub-cellular localization, highly conserved motifs, and motif signatures. Phylogenetic tree has been constructed using protein sequences, calculated synonymous to non-synonymous substitution rates (Ka/Ks) of SNAC paralogs and generated 3-dimensional protein models. Predicted SNAC homologs in maize genome have been studied by analysing the synteny of ZmSNAC genes with NAC genes in Arabidopsis thaliana, Oryza sativa and Sorghum bicolor. miRNA binding sites have been predicted and analysis of cis-regulatory elements in the promoter regions of SNAC genes in the four plant species has been performed. Identification of SNAC transcription factor homologues in the four plant species and their comparative analysis may provide a basis for further characterization of SNAC transcription factors in various other plant species. Available data have been mined for gene expression analysis under different abiotic stress conditions which displayed up- and down-regulations indicating apparent involvement of SNAC genes during abiotic stress responses. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is the staple food of many people in developing countries. However, during postharvest storage of the grain, various biotic stresses have been reported. Among these are molds caused by a complex of fungi, including those of the Fusarium genus. To combat these postharvest molds, growers and traders frequently use synthetic pesticides during grain preservation. However, the abusive use of these synthetic pesticides poses a problem of environmental pollution and human health. Faced with this situation, sustainable management strategies are being sought as alternatives to chemical control of these molds. Therefore, this study was initiated with the aim of contributing to food safety through the biological control of Fusarium fungi, one of the agents responsible for postharvest molds. In vitro mycelial radial growth inhibition tests at five concentrations (200, 400, 800, 1000 and 2000 ppm) were performed with five biopesticides (BIOSAKINE 50 EC, NORDINE 50 EC, NOSTAG 50 EC, RHOSO 50 EC and WACHET 50 EC) formulated with aromatic plant extracts. Results showed that the biopesticide RHOSO 50 EC completely inhibited the radial mycelial growth of all Fusarium sp. strains at a concentration of 2000 ppm. The biopesticides RHOSO 50 EC, WACHET 50 EC, and NOSTAG 50 EC were effective in inhibiting the radial mycelial growth of Fusarium strains. The biopesticides NORDINE 50 EC and BIOSAKINE 50 EC were the least effective. The biopesticides RHOSO 50 EC, WACHET 50 EC, and NOSTAG 50 EC can be proposed as part of an integrated pest management program against Fusarium fungi, which are responsible for postharvest mildew in maize. [ABSTRACT FROM AUTHOR]

Maize is part of the traditional diet of Mexico and other Latin American countries. The diverse varieties of maize produced by adaptation to different regions and climates are known as creole or native maize. The characteristics and nutritional contributions of each of these native maize are relatively diverse areas of study. This work specifically analyzes the nutritional aspects of creole maize grown in the Sierra Gorda in Querétaro. For this, a proximal chemical analysis was carried out, with a quantification of polyphenolic compounds and antioxidant capacities using the ABTS (2,20-azinobis (3-ethyl-benzothiazolin,6-sulfonic acid) and DPPH (2,2-difenil-1-picrilhidrazilo) methods to examine four landraces and one commercial hybrid control. The results indicate that, in general, the landraces present similar—and, in some cases, higher—nutritional indices than the commercial hybrid. With regard to polyphenolic compounds, the Elotes Occidentales and Tuxpeño varieties present greater amounts of total phenols and antiradical activity (ARA), as well as a higher concentration of flavonoids and percentage inhibition, respectively. Condensed tannins are identified both in the creole varieties and in the commercial hybrid. Creole maize presents important nutritional characteristics and can be a good source of antioxidant compounds, which can help the population as a source of food and in the prevention of chronic diseases. [ABSTRACT FROM AUTHOR]

Plants perceive environmental stresses as whole organisms via distant signals conveying danger messages through their vasculature. In parallel to vascular transport, airborne plant volatile compounds, including green leaf volatiles (GLVs), can bypass the lack of vascular connection. However, some small volatile compounds move through the vasculature; such vascular transport is little known about GLVs. Here we illustrate GLV alcohols as solutes move within xylem vessels in Zea mays. We describe GLV alcohols, including Z‐3‐hexen‐ol and its isomer E‐3‐hexen‐ol, which is not synthesized in maize, moving through the transpiration stream via xylem vessels. Since transpiration is mediated by the stomatal aperture, closing stomata by two independent methods diminishes the transport of GLV alcohol and its isomer. In addition, the lower transport of GLV alcohols impairs their function in inducing terpenoid biosynthesis, suggesting that xylem transport of GLV alcohols plays a significant role in their systemic function. Our study suggests that GLV alcohols, in addition to airborne signals, are transported through xylem vessels. Our findings can be critical in future studies about the perception and function of these compounds in plants. Summary statement: We report that green leaf volatiles, known as airborne signals, move through xylem vessels in plants. [ABSTRACT FROM AUTHOR]

Climate change presents a challenge for plants to acclimate their water relations under changing environmental conditions, and may increase the risks of hydraulic failure under stress. In this study, maize plants were acclimated to two different CO2 concentrations ([CO2]; 400 ppm and 700 ppm) while under either water stress (WS) or soil salinity (SS) treatments, and their growth and hydraulic traits were examined in detail. Both WS and SS inhibited growth and had significant impacts on hydraulic traits. In particular, the water potential at 50% loss of stem hydraulic conductance (P 50) decreased by 1 MPa in both treatments at 400 ppm. When subjected to elevated [CO2], the plants under both WS and SS showed improved growth by 7–23%. Elevated [CO2] also significantly increased xylem vulnerability (measured as loss of conductivity with decreasing xylem pressure), resulting in smaller hydraulic safety margins. According to the plant desiccation model, the critical desiccation degree (time×vapor pressure deficit) that the plants could tolerate under drought was reduced by 43–64% under elevated [CO2]. In addition, sensitivity analysis showed that P 50 was the most important trait in determining the critical desiccation degree. Thus, our results demonstrated that whilst elevated [CO2] benefited plant growth under WS or SS, it also interfered with hydraulic acclimation, thereby potentially placing the plants at a higher risk of hydraulic failure and increased mortality. [ABSTRACT FROM AUTHOR]

SUMMARY: Gene regulatory networks (GRNs) represent the interactions between transcription factors (TF) and their target genes. Plant GRNs control transcriptional programs involved in growth, development, and stress responses, ultimately affecting diverse agricultural traits. While recent developments in accessible chromatin (AC) profiling technologies make it possible to identify context‐specific regulatory DNA, learning the underlying GRNs remains a major challenge. We developed MINI‐AC (Motif‐Informed Network Inference based on Accessible Chromatin), a method that combines AC data from bulk or single‐cell experiments with TF binding site (TFBS) information to learn GRNs in plants. We benchmarked MINI‐AC using bulk AC datasets from different Arabidopsis thaliana tissues and showed that it outperforms other methods to identify correct TFBS. In maize, a crop with a complex genome and abundant distal AC regions, MINI‐AC successfully inferred leaf GRNs with experimentally confirmed, both proximal and distal, TF–target gene interactions. Furthermore, we showed that both AC regions and footprints are valid alternatives to infer AC‐based GRNs with MINI‐AC. Finally, we combined MINI‐AC predictions from bulk and single‐cell AC datasets to identify general and cell‐type specific maize leaf regulators. Focusing on C4 metabolism, we identified diverse regulatory interactions in specialized cell types for this photosynthetic pathway. MINI‐AC represents a powerful tool for inferring accurate AC‐derived GRNs in plants and identifying known and novel candidate regulators, improving our understanding of gene regulation in plants. Significance Statement: Gene regulatory networks (GRNs) are a crucial component of the information processing machinery of the cell, but their inference in plants remains challenging. MINI‐AC (Motif‐Informed Network Inference based on Accessible Chromatin) is a computational method that infers accessibility‐based GRNs from bulk‐ or single‐cell‐derived data, representing a valuable tool for unraveling regulatory cascades. As an example, a maize GRN reporting cell‐type specific leaf regulatory interactions is provided as a resource to study photosynthesis. [ABSTRACT FROM AUTHOR]

Volunteer corn plants have infested crops sown in succession, causing yield losses. The objective of this study was to evaluate the competitive ability and economic damage level (EDL) of soybean cultivars infested by volunteer corn plants. The experiment was conducted in a randomized block design with one replication. The treatments consisted of six soya cultivars and 12 densities of volunteer corn, hybrid Syngenta 488 Vip 3, established for each cultivar, with a minimum of 0 and a maximum of 130 plants m-2. At 30 days after emergence, the plant density, ground cover, leaf area and dry mass of the aerial part of the volunteer corn plants were quantified. In soybeans, grain yield, control cost, bag price and control efficiency were determined. Dry mass was the variable that best fitted the rectangular hyperbola model. The soybean cultivars Nidera 5909 RG, Syngenta 13561 IPRO and Brasmax Lança IPRO showed greater competitive ability and EDL values of 0.07 to 0.20 plants m-2 in the presence of volunteer corn. The lowest EDL values ranged from 0.02 to 0.12 plants m-2 for the cultivars Dom Mario 5958 RSF IPRO, Nidera 6909 IPRO and Brasmax Lança IPRO, which were the least competitive. [ABSTRACT FROM AUTHOR]

Although nitrogen is the nutrient most required by maize, doses of N lower than those recommended are applied to maize grown in semiarid environments, which limits the achievement of profitable yields. The objective of this study was to evaluate changes in soil fertility, nutritional status and dry matter production of maize plants fertilized with organic and mineral fertilizers in a semiarid region. A factorial experiment was carried out in Sobral, Ceará state, Brazil, in a randomized block design. The factors were two N sources (organic compost and urea), and four N rates: 27.5, 55, 110 and 165 kg ha−1, with three replications. We assessed variables associated with soil fertility, plant nutritional status, chlorophyll content, grain yield and total dry matter production. The highest rates of organic compost resulted in the highest levels of P (17.7 mg dm−3) and K (102.2 mg dm−3) in soil when compared to the control (7.7 and 69.0 mg dm−3, respectively). However, organic compost rates below 110 kg ha−1 of N-equivalent fertilizer were not enough to supply the plants' demand for P and K. Low N rates promoted a decrease in soil inorganic N in the second year of application. Applying urea to maize plants led to greater dry matter production than organic compost in the second consecutive crop season. The use of organic compost at rates lower than 110 kg ha−1 of N-equivalent fertilizer decreases soil fertility and has no impact on maize dry matter production. [ABSTRACT FROM AUTHOR]

Water deficit is one of the most impactful factors that seriously alter plant physiology, ultimately leading to a decline in crop productivity. Therefore, it is essential to understand the morphophysiological behavior of plants with C3 and C4 metabolism in relation to different levels of water deficit so that management strategies can be developed. Therefore, we evaluated the impact of induced water stress on the morphophysiological characteristics of corn (Zea mays L.) and eggplant (Solanum gilo Raddi) plants. The experiment was carried out in a completely randomized design, with treatments consisting of a factorial combination of two plant species, maize (C4) and Jiló (C3), and three soil moisture levels T1 (50%), T2 (65%) and T3 (90%) with four repetitions. Growth variables, allometric relationships and photosynthetic aspects were evaluated. We found that the severe induced water regime significantly affected germination, emergence, growth and phenological stages, in addition to causing a decrease in the photosynthetic rate in the two studied species, however, with a greater impact on the scarlet eggplant. Corn (C4) showed greater photosynthetic efficiency compared to scarlet eggplant (C3), even under conditions of severe water regime. [ABSTRACT FROM AUTHOR]

The use of tank mixtures has long been a practice in the phytosanitary management of agricultural crops. However, when diff erent molecules are mixed in a tank, interactions may occur that reduce the efficiency of the products and cause a loss of selectivity in the crops. The aim of this study was to evaluate selectivity in maize, with a tank mixture of diff erent phytosanitary products recommended for use with the crop. The following products were used: herbicides -- Sanson®, Soberan®, Callisto®, Zapp Pro®; fungicides -- Priori Xtra®, Nativo®, Tebufort®, Aproach Prima®; insecticides -- Connect®, Lorsban® 480 BR, Karate Zeon®; and nutrition -- Kellus Manganese®, Kellus Blindex®. The experimental units consisted of 5-litre pots, containing two plants per pot, with the products applied at phenological stage V6. Assessments were made of phytotoxicity, transient chlorophyll a fluorescence, chlorophyll content and shoot dry weight. The data obtained in the experiment were submitted to ANOVA (p ≤ 0.05), and when significant, to the Scott-Knott test (p ≤ 0.05). The maize crop suff ered phytotoxicity of up to 30%, with the plants recovering from 28 DAA. The phytotoxicity was caused by mixing the diff erent products in the spraying solution, mainly due to the synergism caused by the mixture of the herbicides nicosulfuron and tembotrione with the insecticide chlorpyrifos and the fertiliser Kellus Manganese®, which aggravated the incompatibility of some treatments. The results of this study defined which phytosanitary products recommended for use with maize should not be mixed in the same spraying solution due to the possibility of damaging the crop. [ABSTRACT FROM AUTHOR]

Copyright of Investigación Agraria is the property of Investigacion Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nitrogen is an essential plant nutrient and a major yield-determining factor, required for normal vegetative growth and grain development of maize. Applying nitrogen requires appropriate fertilization management to achieve efficient nutrient utilization. A field experiment was carried out on Fluvisol to evaluate the yield and growth parameters response of maize (Zea mays var. saccharate) to incremental rates of N fertilizer (100, 150, 200 kg N/ha) from two different fertilization sources - ammonium nitrate (NH4NO3) and urea (CH4N2O). Highest yield was measured in plants subjected to N200 (9.76 t/ha) fertilization rate with NH4NO3. A high linear correlation was observed between yield and nitrogen fertilization rate regardless of the nitrogen source. The effect of different nitrogen rates was significant on leaf number and mass, ears mass, internodes number and mass per plant. The results revealed that the nitrogen source significantly affected the number of leaves per plant and the leaves mass. The individual effects of fertilization rate and source on yield were not statistically significant in isolation. However, when considered together, they exhibited a significant effect at the 95% confidence level. [ABSTRACT FROM AUTHOR]

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)