Search Results (174)

Within the framework of organic acid alternatives to chemical herbicides, pre-emergence weed control research is scarce. Citric acid (CA) and lactic acid (LA), considered significantly less effective than pelargonic acid (PA) and acetic acid (AA) from post-emergence (foliar spraying) studies, have largely been disregarded. This in vitro study was aimed at comparing the effects of 5–20% AA, AA + essential oils, PA, CA, and LA on radicle emergence inhibition (direct spraying of seeds) and shoot emergence inhibition (application to peat) on both weeds (perennial ryegrass, green foxtail, common vetch and chicory) and crops (soft wheat, alfalfa and millet). All tested compounds demonstrated concentration-dependent and species-specific effects on shoot emergence inhibition, with CA and LA (IC₅₀ range: 3.4–19.3%) showing a comparable efficacy to PA and AA (IC₅₀ range: 3.1–35.9%). The results also showed that CA and, to a lesser extent, LA were less inhibitory to soft wheat (CA IC₅₀ = 62.5%; LA IC₅₀ = 35.9%) and alfalfa (CA IC₅₀ = 57.8%; LA IC₅₀ = 44.1%) shoot emergence. CA and LA show potential promise for pre-emergence weed control in field testing, either on a stale seedbed in pre-crop sowing or concurrently with soft wheat and alfalfa sowing. Investigating organic compound herbicidal effects on crops of interest warrants attention. Full article

Plant growth is susceptible to abiotic stresses like salt and drought, and Na⁺/H⁺ antiporters (NHXs) play a pivotal role in stress responses. NHX proteins belong to the CPAs (cation/proton antiporters) family with a conserved Na⁺ (K⁺)/H⁺ exchange domain, which is widely involved in plant growth, development, and defense. While NHX genes have been extensively studied in model plants (e.g., Arabidopsis thaliana and Oryza sativa), research in other species remains limited. In this study, we identified nine NHX genes in foxtail millet (Setaria italica) and analyzed their systematic phylogeny, gene structure, protein characteristics, distribution of the chromosome, collinearity relationship, and cis-elements prediction at the promoter region. Phylogenetic analysis revealed that the members of the SiNHX gene family were divided into four subgroups. RT-qPCR analysis of the SiNHX family members showed that most genes were highly expressed in roots of foxtail millet, and their transcriptional levels responded to salt stress treatment. To determine SiNHX7’s function, we constructed overexpression Arabidopsis lines for each of the two transcripts of SiNHX7, and found that the overexpressed plants exhibited salt tolerance. These findings provide valuable insights for further study of the function of SiNHX genes and are of great significance for breeding new varieties of salt-resistant foxtail millet. Full article

To explore the effects of various zinc (Zn) fertilizer application methods and concentrations on foxtail millet quality and flavonoid biosynthesis, we used Zhangzagu 13 as the experimental material. The transcriptome and metabolome were used to examine variations in flavonoid biosynthesis and metabolism in foxtail millet under different Zn application methods. The results showed that different Zn application methods significantly increased the total polyphenol, carotenoid, total flavonoid, and Zn contents in the grains of foxtail millet. Under the basal soil application (S3) and foliar spray (F2) treatments, the total flavonoid content significantly increased by 45.87% and 64.40%, respectively, compared with that of CK. Basal soil Zn fertilization increased the flavonoid content of foxtail millet by up-regulating genes related to flavonoid metabolism and biosynthesis, including flavanone-3-hydroxylase, chalcone isomerase, and leucoanthocyanidin reductase. Foliar Zn application enhanced flavonoid content by up-regulating genes involved in flavonoid metabolic and biosynthetic processes and chalcone isomerase. In conclusion, using Zn fertilizer can improve the synthesis and metabolism of foxtail millet flavonoids, effectively increase the content of functional substances in grains, and realize the biofortification of foxtail millet grains. Full article

Finger millet (Eleusine coracana L.) is a nutrient-dense cereal with high flavonoid content, yet the mechanisms regulating its secondary metabolite biosynthesis remain underexplored. Various exogenous stimuli can readily activate the enzymatic pathways and gene expression associated with flavonoid biosynthesis in plants, which are regulated by developmental cues. Research has established that methyl jasmonate (MeJA) application enhances secondary metabolite production in plant systems. This investigation examined MeJA’s influence on flavonoid accumulation and physiological responses in finger millet sprouts to elucidate the molecular mechanisms underlying MeJA-mediated flavonoid accumulation. The findings revealed that MeJA treatment significantly suppressed sprout elongation while enhancing the biosynthesis of total flavonoids and phenolic compounds. MeJA treatment triggered oxidative stress responses, with hydrogen peroxide and superoxide anion concentrations increasing 1.84-fold and 1.70-fold compared to control levels at 4 days post-germination. Furthermore, the antioxidant defense mechanisms in finger millet were upregulated following treatment, resulting in significant enhancement of catalase and peroxidase enzymatic activities and corresponding transcript abundance. MeJA application augmented the activities of key phenylpropanoid pathway enzymes—phenylalanine ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H)—and upregulated their respective gene expression. At 4 days post-germination, EcPAL and EcC4H transcript levels were elevated 3.67-fold and 2.61-fold, respectively, compared to untreated controls. MeJA treatment significantly induced the expression of downstream structural genes and transcriptional regulators. This study provides a deeper understanding of the mechanism of flavonoid accumulation in foxtail millet induced by MeJA, and lays a foundation for exogenous conditions to promote flavonoid biosynthesis in plants. Full article

The SCARECROW (SCR) transcription factor governs cell-type patterning in plant roots and Kranz anatomy of leaves, serving as a master regulator of root and shoot morphogenesis. Foxtail millet (Setaria italica), characterized by a compact genome, self-pollination, and a short growth cycle, has emerged as a C₄ model plant. Here, we revealed two SCR paralogs in foxtail millet—SiSCR1 and SiSCR2—which exhibit high sequence conservation with ZmSCR1/1h (Zea mays), OsSCR1/2 (Oryza sativa), and AtSCR (Arabidopsis thaliana), particularly within the C-terminal GRAS domain. Both SiSCR genes exhibited nearly identical secondary structures and physicochemical profiles, with promoter analyses revealing five conserved cis-regulatory elements. Robust phylogenetic reconstruction resolved SCR orthologs into monocot- and dicot-specific clades, with SiSCR genes forming a sister branch to SvSCR from its progenitor species Setaria viridis. Spatiotemporal expression profiling demonstrated ubiquitous SiSCR gene transcription across developmental stages, with notable enrichment in germinated seeds, plants at the one-tip-two-leaf stage, leaf 1 (two days after heading), and roots during the seedling stage. Co-expression network analysis revealed that there is a correlation between SiSCR genes and other functional genes. Abscisic acid (ABA) treatment led to a significant downregulation of the expression level of SiSCR genes in Yugu1 roots, and the expression of the SiSCR genes in the roots of An04 is more sensitive to PEG6000 treatment. Drought treatment significantly upregulated SiSCR2 expression in leaves, demonstrating its pivotal role in plant adaptation to abiotic stress. Analysis of heterologous expression under the control of the 35S promoter revealed that SiSCR genes were expressed in root cortical/endodermal initial cells, endodermal cells, cortical cells, and leaf stomatal complexes. Strikingly, ectopic expression of SiSCR genes in Arabidopsis led to hypersensitivity to ABA, and ABA treatment resulted in a significant reduction in the length of the meristematic zone. These data delineate the functional divergence and evolutionary conservation of SiSCR genes, providing critical insights into their roles in root/shoot development and abiotic stress signaling in foxtail millet. Full article

C2H2 zinc finger proteins (C2H2-ZFPs) constitute one of the largest transcription factor families in plants, playing crucial roles in growth, development, and stress responses. Here, we performed a comprehensive genome-wide analysis of C2H2-ZFPs in foxtail millet (Setaria italica v2.0), identifying 67 members that were unevenly distributed across all nine chromosomes. Most SiC2H2 proteins were predicted to be alkaline, stable, and nuclear-localized, with the exception of SiC2H2-11 and SiC2H2-66, which were chloroplast-targeted. Phylogenetic analysis with Arabidopsis thaliana and Oryza sativa (rice) homologs classified these genes into seven distinct subfamilies, each containing the characteristic motif1 domain. Evolutionary studies revealed 14 segmental duplication events and strong syntenic conservation with Triticum aestivum (wheat, 163 orthologous pairs), suggesting conserved functions during evolution. Promoter analysis identified multiple cis-acting elements associated with light responsiveness, hormone signaling, and stress adaptation. Transcriptome profiling and qPCR validation in the YuGu 56 cultivar identified several stress-responsive candidates, including SiC2H2-35 and SiC2H2-58 (salt tolerance), as well as SiC2H2-23 (5.19-fold induction under salt stress) and SiC2H2-32 (5.47-fold induction under drought). This study provides some valuable insights into the C2H2-ZFP family in foxtail millet and highlights potential genetic markers for improving stress resilience through molecular breeding approaches. Full article

Foxtail millet (Setaria italica), a significant C4 model crop known for its exceptional photosynthetic efficiency and robust environmental adaptability, serves as an excellent model for investigating C4 photosynthesis and crop stress resilience. When subjected to abiotic stress, foxtail millet employs a sophisticated signal transduction network to regulate its physiological processes, ensuring sustained high photosynthetic efficiency and normal growth. The mitogen-activated protein kinase (MAPK) family plays a key role in plant growth, development, and stress response. Here, we identified and named a MAPK in S. italica as SiMPK6. Fluorescence quantitative PCR analysis revealed that SiMPK6 is mainly expressed in the leaves during the early shooting stage, with induction under various abiotic stresses such as low temperature, high osmotic pressure, high salt, high temperature, and high light. Overexpressing the SiMPK6 in Arabidopsis thaliana mitigated damage to photosystem II induced by stress, underscoring the gene’s crucial role in foxtail millet’s stress signal transduction and maintenance of high photosynthetic efficiency. Full article

Underutilized starch sources are gaining increasing recognition. However, the inherent functional deficiencies of native starch have limited its application in food industry. To counteract the deficiencies in its native characteristics, starch can be modified by acetylation. Two waxy starches (proso millet and amaranth) and four non-waxy starches (foxtail millet, quinoa, buckwheat, and oat) were modified by acetic anhydride and vinyl acetate, respectively. Degree of substitution of acetylated starches revealed that granule size did not significantly affect acetylation efficiency in starches from different plant origins. Acetylation increased peak and final viscosity of starches, with vinyl acetate exhibiting a more pronounced effect than acetic anhydride. Acetic anhydride decreased K and increased n values of non-waxy starches, showing reduced thickening ability. In contrast, vinyl acetate modification showed opposite trends, suggesting increased viscosity and pseudoplasticity. For non-waxy starches, G′_25°C, G′_0.1Hz, G′_20Hz and gel hardness decreased after acetylation, indicating that acetylation contributed to a less solid and less elastic gel network. The extent of change in vinyl acetate modification was more pronounced than that of acetic anhydride. For waxy starch, vinyl acetate modification decreased tan δ_25°C and increased gel hardness. In summary, acetylation reagent type was the major factor determining the pasting properties of acetylated starch, but the presence or absence of amylose would influence the rheological and gel properties of acetic anhydride and vinyl acetate modified starches. These findings could help unlock the potential applications of acetylated underutilized starches in the food industry. Full article

Soil salinization and alkalization are becoming increasingly severe in recent decades, which poses serious threats to crop production and food security in the world. Foxtail millet (Setaria italica L.) is an important cereal crop in China, and it is important to elucidate its saline-alkali tolerance mechanisms for the breeding of new saline-alkali tolerant varieties. In this study, we used 75% seawater to treat two foxtail millet varieties with different saline-alkali tolerances (JK3, saline-alkali tolerant; B175, saline-alkali sensitive) during the seedling stage, and conducted morphological, cellular ultrastructure, physiological, and transcriptomic analyses on the two varieties. The morphological analysis of the saline-alkali response indicated that JK3 exhibited stronger saline-alkali tolerance than B175. The results of the cellular ultrastructure showed that under saline-alkali stress, JK3 had a more intact leaf cell structure than B175, indicating that saline-alkali stress causes less damage to its cells. The physiological analysis of saline-alkali response indicated that JK3 had consistently higher activities of catalase and polyphenol oxidase, as well as higher contents of soluble sugars and soluble proteins at 48–120 h than B175. Transcriptomic analysis revealed that JK3 enhanced its saline-alkali tolerance by positively regulating pathways such as tryptophan/fatty acid metabolism, the MAPK signaling pathway, and peroxisome pathways. Further, WGCNA combining morphological and physiological indicators identified four key modules and five functional pathways (MAPK signaling, glycerolipid metabolism, phosphate and phosphonate metabolism, galactose metabolism, and endoplasmic reticulum protein processing) in response to saline-alkali stress, and identified a total of 24 core genes. Functional annotation indicated that these genes may be involved in the response to saline-alkali stress. These findings lay a foundation for in-depth studies of the molecular mechanisms for saline-alkali tolerance in foxtail millet. Full article

Foxtail millet (Setaria italica L.), a representative C4 species, is recognized for its efficient nutrient utilization and robust abiotic stress responses. However, the molecular mechanisms mediating its tolerance to biotic stresses are poorly understood. In this study, we investigated the root transcriptomic response of foxtail millet to the damage-associated molecular pattern (DAMP), the plant elicitor peptide 1 (Pep1). Transcriptome analysis of Pep1-treated roots identified 401 differentially expressed genes (DEGs), comprising 144 up-regulated and 257 down-regulated genes. Gene Ontology (GO) enrichment analysis revealed a significant enrichment of ‘peroxidase activity’. This finding was corroborated by DAB staining, which confirmed H₂O₂ accumulation, along with elevated malondialdehyde (MDA) levels, collectively indicating oxidative stress. Notably, Pep1 treatment also resulted in a marked up-regulation of the pathogenesis-related protein 1 (PR1) gene in leaves, suggesting the activation of systemic acquired resistance. Together, these results demonstrate that Pep1 triggers substantial transcriptional reprogramming in roots, induces oxidative stress, and activates systemic defense signaling in foxtail millet. Full article

Foxtail millet attracts much attention for its rich nutrients and health benefits. However, ultra-polishing has greatly reduced its nutrition. Germination can enhance nutrition value. Nevertheless, knowledge of nutrient changes in kernels and sprouted grains under different polishing methods and at different germination stages is limited. Here, comparative metabolomics was used to detect metabolite changes in differently polished millets (Manually Polished Millet, MPM; Ultra-Polished Millet, UPM; Manually Ultra-Polished Millet, MUPM) and in sprouted grains with hot air drying (HAD) and freeze-drying (FD) at different germination times. Compared to whole grains, MPM, UPM, and MUPM had 306 to 720 down-regulated metabolites, reducing most antioxidants, essential amino acids, fatty acids, and vitamins in whole grains. For sprouted grains, metabolic activities were comprehensively activated. The early stages accumulated basic nutrients such as free and functional amino acids, small sugars, and essential fatty acids. The 16 h stage increased secondary antioxidant metabolites like flavonoids, and the 24 h germination generated more functional components such as sulfur-containing metabolites. More basic nutrients were preserved by FD in comparison to the reduced basic nutrients and increased antioxidant accumulation associated with HAD. This work systematically characterizes the metabolite changes in polished millets and sprouted grains, providing a reference for developing functional millet products. Full article

Foxtail millet (Setaria italica), a cereal crop in China, is renowned for its resilience to abiotic stresses, including saline-alkali conditions. This study examined the transcriptomic and metabolomic responses of two contrasting foxtail millet varieties, B103 (tolerant) and B323 (sensitive), under saline-alkali stress. Physiological analysis showed that B103 exhibited higher growth parameters and chlorophyll content than B323, highlighting its enhanced tolerance. Transcriptomic analysis identified differentially expressed genes (DEGs) enriched in stress-response pathways such as phenylpropanoid biosynthesis, flavonoid metabolism and calcium signaling. Metabolomic profiling revealed differentially accumulated metabolites (DMs) involved in energy and secondary metabolism, including citrate, fumarate and flavonoids. Integration of DEGs and DMs revealed key gene-metabolite interactions, particularly those involving the nicotinamide compound and three candidate genes Si9g20070, Si7g22360 and Si5g39810, for future functional validation, which may contribute to stress adaptation. Dynamic clustering of gene expression trends highlighted the importance of rapid stress responses. These findings establish a molecular framework for understanding saline-alkali stress tolerance and provide genetic resources for developing stress-resilient foxtail millet varieties. Full article

Foxtail millet (Setaria italica), a vital cereal crop in China, serves as both a staple food and forage source but is threatened by rust disease caused by Uromyces setariae-italicae (Usi), leading to severe yield and quality losses. The NAM, ATAF1/2, and CUC2 (NAC) transcription factor family represents one of the largest plant-specific regulatory gene families, playing pivotal roles in development and stress responses. However, the functional relevance of NAC genes in foxtail millet’s defense against this pathogen remains unexplored. Here, we systematically analyzed 33 SiNAC genes from the foxtail millet genome. Phylogenetic analysis classified these genes into 11 subgroups, while chromosomal mapping localized them to nine chromosomes unevenly. Promoter analysis identified stress- and plant hormone-related cis-elements, suggesting functional diversity. Expression profiling analysis showed that most SiNAC genes exhibit tissue-specific expression patterns. Quantitative real-time PCR (qRT-PCR) results indicated that 30 genes responded to Usi infection, with 17 showing a strong association with rust resistance. Three resistance-associated genes demonstrated transactivation activity and nuclear localization, indicating their regulatory function in defense responses. This study provides both mechanistic insights into SiNAC-mediated rust resistance and potential targets for molecular breeding in foxtail millet. Full article

Leucine-rich repeat receptor-like kinases (LRR-RLKs) are involved in the regulation of various biological processes, including plant growth, development, and responses to biotic and abiotic stresses. Foxtail millet (Setaria italica), an important cereal crop, has been extensively studied for its stress tolerance mechanisms. In this study, we performed a comprehensive phylogenetic analysis and chromosomal mapping of LRR-RLK genes in Setaria italica. A total of 285 SiLRR-RLK genes were identified and classified into 12 subfamilies based on phylogenetic relationships. Chromosome localization analysis revealed that SiLRR-RLK genes are unevenly distributed across the chromosomes, with certain regions showing gene clusters. Functional analysis of these genes under biotic and abiotic stress conditions suggested that several SiLRR-RLK family members are involved in key stress response pathways. Expression profiling indicated differential expression patterns of SiLRR-RLK genes in response to various stresses, including drought, salinity, and pathogen infection, highlighting their potential roles in stress adaptation. In conclusion, the phylogenetic and functional analysis of the SiLRR-RLK gene family in Setaria italica provides valuable insights into their roles in stress responses and lays the groundwork for future studies aimed at enhancing stress tolerance in foxtail millet. Full article

Biochar has the ability to enhance the solubilization of phosphorus (P) in soil. Nonetheless, the role played by organic acid and microorganism in P solubilization under biochar application conditions remains unclear. In this study, we examined the relationship between soil organic acids and microorganisms, as well as P fractions, following the addition of biochar, utilizing foxtail millet, maize, soybean, and mung bean as materials. The results demonstrated that the addition of biochar increased the availability of P by increasing the content of the resin-P fraction and decreasing the content of the NaOH-Pi, NaOH-Po, and HCl-P fractions in the soil. In addition, resin-P fractions were elevated by 142.78%, 95.27%, 35.99%, and 21.55% in the soils of foxtail millet, maize, soybean, as well as mung bean, respectively. In the microorganisms, the addition of biochar promotes P conversion by increasing the number of labile-P-associated microorganisms and decreasing the number of moderate-labile-P- and non-labile-P-associated microorganisms. In the organic acids, biochar expanded the biological pathways for the solubilization of moderate-labile-P through organic acids. This study illustrates the potential mechanism of biochar to enhance soil P availability. Full article