Search Results (146)

Soil salinization is a major abiotic stress limiting maize (Zea mays L.) growth and productivity worldwide. Recently, many genes involved in salt stress have been identified. However, the molecular mechanisms underlying salt tolerance in maize remain largely elusive. In this study, we identified a member of the ZmPIRIN family genes, ZmPRN1, acting as a negative regulator in response to salt stress. The expression levels of ZmPRN1 were down-regulated under salt and H₂O₂ treatment. Subcellular localization analysis showed that ZmPRN1 is localized to the chloroplast. Under salt stress, the Zmprn1-Mu mutant exhibited higher survival rates and lower reactive oxygen species (ROS) accumulation compared to wild-type plants. Whereas, ZmPRN1 overexpression lines were more sensitive to salt stress, and had higher ROS levels and lower chlorophyll content than wild-type plants. Transcriptome analysis showed that the differentially expressed genes (DEGs) were mainly involved in the oxidation-reduction process. Furthermore, yeast-two hybrid and split-luciferase complementation assays revealed that ZmPRN1 can interact with the chloroplast NDH complex subunit NDF4, the RING-type E3 ubiquitin ligase RING371, and the auxin-responsive protein IAA27. Collectively, our findings demonstrated that ZmPRN1 negatively regulates salt tolerance in maize by modulating ROS homeostasis, providing a valuable genetic resource for breeding salt-tolerant maize varieties. Full article

Amino acids are organic compounds that serve as the fundamental building blocks of proteins and are additionally responsible for a multitude of other biological functions. This review synthesizes recent evidence elucidating that amino acids function as vital players in nitrogen transport, stress defense, and perhaps most intriguingly as signaling molecules. For example, glutamate triggers calcium signals through GLR receptors to guide root growth and pollen tubes. Others, like proline and glutathione, protect cells from drought, salt, and oxidative damage. Aromatic and sulfur-containing amino acids also feed into the production of hormones (auxin, ethylene) and a wide range of defense compounds. Beyond metabolism, we highlighted how plants sense amino acid status via ancient sensors such as PII and the TOR pathway, which fine-tune growth and resource allocation. Understanding this hidden side of amino acids opens new doors for agriculture. We discussed how these insights could lead to smarter biostimulants, gene-edited crops with better nutrient efficiency, and nano-based delivery systems. In short, amino acids are not just food for plants—they are signals, shields, and switches that shape how plants grow and cope with stress. Full article

This study demonstrates that the ericoid mycorrhizal (ERM) fungus RM2 can colonize the non-ericaceous host Malus robusta as a functional endophyte, enhancing drought resilience through an active avoidance strategy. Under drought, inoculation was associated with qualitative changes in root growth patterns, and inoculated seedlings showed a more extensive and branched root appearance compared with non-inoculated controls. This morphological tendency was accompanied by a distinctive physiological state of oxidative priming, characterized by elevated H₂O₂ as a signaling molecule, reduced antioxidant enzyme activity, and a marked shift toward proline-mediated osmotic adjustment. Transcriptomic analysis suggested a molecular basis for these responses: endophytic colonization reprogrammed auxin and brassinosteroid signaling, including the repression of auxin inactivation (GH3) and activation of genes involved in auxin transport (AUX1) and cell wall loosening (TCH4), which is consistent with sustained root growth under drought. Our findings indicate that ERM fungi can transcend traditional host barriers and improve drought performance via integrated oxidative signaling and hormonal regulation, highlighting their potential as cultivable biostimulants for sustainable horticulture. Full article

In the current context of environmental sustainability and reduced agricultural inputs, biostimulants represent one of the most efficient, eco-friendly and innovative strategies to preserve plants from biotic and abiotic stresses and to ensure sustainable agriculture. Ranging from benefic microorganisms, seaweed extracts, and humic acids to complex carbohydrates such as polysaccharides and oligosaccharides, these biostimulants are able to increase plant growth, photosynthetic efficiency, root development and nutrient uptake when they are applied during seed priming as foliar sprays or as liquid and solid soil amendments. The mechanisms underlying their effective action on plants are mainly related to the enhancement of antioxidant defenses and the regulation of hormonal pathways, particularly auxin homeostasis and transport. Several studies reported the relevance of biostimulant application in promoting root growth. In plants, roots play crucial roles, performing a variety of functions such as nutrients and water uptake, mediating stress perception and adaptation, influencing the rhizosphere microbiome, and providing structural support. The effectiveness and perception of polysaccharide-based biostimulants (PBs) are highly dependent on crucial factors, including the degree of depolymerization and the chemical modifications such as acetylation, methylation, sulfation, and oxidation. Furthermore, not all receptors and co-receptors involved in the recognition of PBs have yet been identified. However, there remain many gaps in our understanding regarding the interaction between biostimulants and roots, which is still far from fully elucidated. For these reasons, the present review provides a comprehensive overview of current research on biostimulants–root interactions, with a particular focus on polysaccharide-based biostimulants. It highlights the mechanisms involved in their recognition by plants roots, from perception to response, and the subsequent signaling cascades and the molecular pathways activated, with special emphasis on existing knowledge gaps and future research perspectives. Full article

Nanotechnology holds great promise for alleviating drought stress in crops. This study elucidates and compares the distinct physiological mechanisms by which two nanomaterials, nano-cerium oxide (CeO₂) and nano-titanium dioxide (TiO₂), function as seed-priming agents to enhance drought tolerance in barley. A comprehensive analysis encompassing germination performance, hormonal dynamics, starch metabolism, osmotic adjustment, photosynthetic pigments, and the antioxidant system revealed that each nanomaterial operates through a unique pathway. Specifically, priming with 150 mg·L⁻¹ nano-CeO₂ (CP-150) primarily promoted root development and stress resilience. This effect was achieved by persistently reducing abscisic acid (ABA) levels, elevating gibberellin (GA₃), enhancing amylase activity to mobilize seed reserves, and increasing soluble protein accumulation in roots. In contrast, priming with 500 mg·L⁻¹ nano-TiO₂ (TP-500) was more effective in enhancing shoot physiology and adaptive capacity by rapidly inducing auxin (IAA), robustly stimulating the antioxidant enzyme system, and increasing photosynthetic pigment content. The temporally and spatially complementary actions of these nanomaterials, with nano-CeO₂ fostering root-based resilience and nano-TiO₂ boosting shoot-level functions, synergistically support seed germination and seedling establishment under drought conditions. This study provides a mechanistic foundation for designing targeted nano-priming strategies to improve crop drought resistance. Full article

Cadmium (Cd) pollution poses significant threats to ecosystems and human health, with agricultural soils in China particularly affected. Ilex verticillata, a popular ornamental plant, has not been extensively studied for its response to Cd stress. This study investigated the physiological and molecular mechanisms underlying Cd stress tolerance in I. verticillata, focusing on auxin signaling pathways. Under Cd stress (500 mmol/kg soil), I. verticillata exhibited inhibited stem growth, reduced photosynthetic capacity, and elevated oxidative stress markers such as malondialdehyde, H₂O₂, ·O₂⁻, and antioxidant enzyme activities. Transcriptomic analysis revealed 3750 differentially expressed genes (DEGs) with significant enrichment in auxin signaling pathways. Six nucleus-localized IvIAA genes were identified and shown to interact with the transcription factor IvMYB77, suggesting a regulatory module in Cd stress responses. These findings highlight the role of auxin signaling in mediating Cd stress tolerance and provide insights into the molecular adaptation of I. verticillata to heavy metal pollution. Full article

Background: Maize (Zea mays L.) is a vital global crop, and yield improvement through dwarfing breeding—inspired by the Green Revolution—holds promise for addressing food security challenges. Despite the identification of over 60 dwarf genes in maize, their genetic diversity remains limited. Brassinosteroids (BRs) are key phytohormones that regulate plant height, and mutations in BR-related genes often result in dwarf phenotypes. Methods: The zmbrd1 mutant was generated via EMS mutagenesis in the B73 background. Phenotypic traits (plant height, root length) and histological features (e.g., mesocotyl cell length) were compared between mutant and wild-type plants. Transcriptome sequencing of leaves and root tips identified differentially expressed genes (DEGs), followed by GO and KEGG enrichment analyses. Key hormone-related genes were validated by means of qRT-PCR. Results: The zmbrd1 mutant exhibited severe dwarfism and reduced root length, primarily due to inhibited longitudinal cell elongation in internodes. Transcriptome analysis revealed 1652 DEGs in leaves and 1450 DEGs in roots. Enriched pathways included BR biosynthesis, plant hormone signal transduction, and glutathione metabolism. In leaves, upregulated genes were linked to hormone signaling and chloroplast function, while downregulated genes involved oxidoreductase activity and stress response. In roots, DEGs were enriched in ethylene signaling, MAPK pathways, and plant–pathogen interaction, suggesting impaired defense responses. qRT-PCR confirmed dysregulation of hormone-related genes: GA biosynthesis genes were downregulated, whereas auxin-related genes were upregulated in leaves but downregulated in roots. Conclusions: The dwarf phenotype of zmbrd1 stems from disrupted BR biosynthesis, leading to hormonal imbalance (particularly in GA and auxin pathways), oxidative stress, and suppressed cell elongation. Our results suggest that ZmBRD1 plays a key role in integrating aboveground and underground growth likely through modulating hormone crosstalk. This study elucidates BR-mediated height regulation and provides genetic resources for maize breeding. Full article

A genomic analysis of the hydrocarbon-oxidizing strain R. qingshengii F2-2 was conducted to characterize the genes responsible for plant growth stimulation and phytopathogen biocontrol. Understanding these mechanisms is vital for developing effective phytoremediation approaches. It was shown that the F2-2 genome consists of a 6.3 Mb chromosome and three plasmids, two of which are linear—pLP156 (155 kb) and pLP337 (337 kb)—and one circular—pCP209 (210 kb). The genes responsible for biosynthesis of phytohormones (auxins, gibberellins, cytokinins), phosphate solubilization, and production of siderophores and antibiotic-active compounds (chloramphenicol and pristinamycin IA) were identified in the strain chromosome. Orthologous genes encoding phenazine antibiotics were found in the linear plasmid pLP156. The phytostimulating properties of the strain, associated with auxin production (2–4 μg/mL); the ability to effectively colonize rapeseed, mustard, and tobacco plants; and protective action against Fusarium spp. under artificial phytopathogenic background conditions, were experimentally confirmed. Thus, the discovered properties of the R. qingshengii F2-2 strain indicate its potential for the phytoremediation of oil-contaminated soils. Full article

Salt stress is a major form of abiotic stress that disrupts soybean germination and early seedling establishment. In this study, physiological, biochemical, and transcriptomic analyses—including germination index, antioxidant enzyme activity, and RNA-seq profiling—were conducted during soybean germination to elucidate early responses to salt stress and biostimulant treatment. A preliminary screening of six biostimulants (nanoparticle zinc oxide (NP-ZnO), nanoparticle silicon dioxide (NP-SiO₂), silicon dioxide (SiO₂), glucose, humic acid, and fulvic acid) revealed NP-SiO₂ as the most effective in promoting germination under salt stress. Under 150 mM NaCl, NP-SiO₂ increased the germination rate and length of the radicle compared with the control, also enhancing peroxidase and ascorbate peroxidase activities while reducing malondialdehyde accumulation, suggesting alleviation of oxidative stress. RNA sequencing revealed extensive transcriptional reprogramming under salt stress, identifying 4579 differentially expressed genes (DEGs) compared with non-stress conditions, while NP-SiO₂ treatment reduced this number to 2734, indicating that NP-SiO₂ mitigated the transcriptional disturbance caused by salt stress and stabilized gene expression networks. Cluster analysis showed that growth- and hormone-related genes suppressed by salt stress were restored under NP-SiO₂ treatment, whereas stress-responsive genes that were induced by salt were attenuated. Hormone-related DEG analysis revealed that NP-SiO₂ down-regulated the overactivation in the abscisic acid, jasmonic acid, and salicylic acid pathways while partially restoring gibberellin, auxin, cytokinin, and brassinosteroid signaling. Overall, NP-SiO₂ at 100 mg/L mitigated salt-induced oxidative stress and promoted early soybean growth by fine-tuning physiological and transcriptional responses, representing a promising nano-based biostimulant for enhancing salt tolerance in plants. Full article

MicroRNAs (miRNAs) are key post-transcriptional regulators of plant development and stress responses, with many being conserved across diverse plant lineages. In this study, we investigated the expression profiles of miRNAs and their corresponding target genes in Arachis stenosperma, a wild peanut relative that exhibits robust resistance to root-knot nematodes (RKN). Small RNA sequencing of nematode-infected roots identified 107 miRNA loci, of which 93 corresponded to conserved miRNA families and 14 represented novel candidates, designated as miRNOVO. Among these, 18 miRNAs belonging to 11 conserved families were identified as differentially expressed (DEMs). Notably, miR399 and miR319 showed the highest upregulation (logFC = 4.25 and 4.20), while miR393 and miR477 were the most downregulated (logFC = −0.83 and −0.79). Integrated analysis of miRNA and transcriptome data revealed several regulatory interactions involving key defense-related genes. These included NLR genes targeted by miR393 and miR477, hormone signaling components such as the auxin response factor ARF8 targeted by miR167, and the growth regulator GRF2 targeted by miR396. Additionally, miR408 was predicted to target laccase3, a gene involved in the oxidation of phenolic compounds, lignin biosynthesis, copper homeostasis and defense responses. Remarkably, four immune receptor genes belonging to the nucleotide-binding site leucine-rich repeat (NLR) family displayed inverse expression patterns relative to their regulatory miRNAs, suggesting miRNA-mediated post-transcriptional control during the early stages of nematode infection. These findings reveal both conserved and species-specific miRNA–mRNA modules associated with nematode resistance in A. stenosperma, highlighting promising targets for developing RKN-tolerant peanut cultivars through miRNA-based strategies. Full article

Antimony (Sb), a toxic metalloid, inhibits plant growth and threatens human health. Yellow Stripe-Like (YSL) proteins play crucial roles in metal ion transport and cellular homeostasis. While the OPT gene family has been characterized in some species, its genome-wide organization and functional involvement in Sb stress response remain unexplored in Brassica juncea. Here, we identified 47 high-confidence BjOPT genes and combined transcriptomic approaches to elucidate their regulatory roles under Sb stress. Phylogenetic tree, conserved motifs, and gene structure analyses consistently distinguished the BjOPT and BjYSL subfamilies. Comparative and collinearity analyses indicated that OPT genes in Brassica species (including B. rapa, B. nigra, and B. juncea) expanded independently of whole-genome triplication events. Transcriptomic profiling revealed significant enrichment of differentially expressed genes (DEGs) related to key biological processes (oxidative and toxic stress response, metal ion transport, and auxin efflux) and pathways (glutathione metabolism, MAPK signaling, and phytohormone transduction), highlighting their roles in Sb detoxification and tolerance. Notably, three BjYSL3 (BjA10.YSL3, BjB02.YSL3, and BjB05.YSL3) genes exhibited strong up-regulation under Sb stress. Heterologous expression in yeast demonstrated that both BjA10.YSL3 and BjB02.YSL3 enhance Sb tolerance, suggesting their potential role in transporting Sb–nicotianamine (NA) or phytosiderophore (PS) complexes. These findings advance our understanding of Sb tolerance mechanisms and provide a basis for developing metal-resistant crops and phytoremediation strategies. Full article

Synthetic auxins are used in agriculture as herbicides worldwide, which leads to localized pollution and their potential entry into food crops during early developmental stages. Triticum aestivum L. is a major agricultural crop, and for this reason, understanding the mechanisms by which herbicides affect photosynthetic and lipid metabolic processes in wheat is crucial for assessing yield reduction risks. This study aimed to evaluate the toxic effects of three synthetic auxins, 1-naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), and clopyralid (CLD) on growth parameters, membrane permeability, lipid peroxidation (LPO) product content, fatty acid (FA) profiles, and photosynthetic pigment levels in both etiolated and green spring wheat seedlings. FA content was assessed using gas chromatography-mass spectrometry. The results revealed that NAA and 2,4-D exerted the most pronounced inhibitory effects on seedling growth, whereas 2,4-D and CLD increased membrane permeability. In etiolated seedlings exposed to synthetic auxins, there was an elevation in FA content noted. Conversely, in green seedlings, exposure to all tested synthetic auxins led to a reduction in FA content, particularly affecting polyunsaturated fatty acids (PUFAs), as well as declines in chlorophyll and carotenoid levels. CLD reduced odd-chain fatty acid content (OCFAs) and very long-chain fatty acid content (VLCFAs) to undetectable levels. The increase in LPO products under the action of 2,4-D and CLD indicates oxidative stress as a possible cause of the decrease in PUFA content in green seedlings. These findings suggest that synthetic auxins have detrimental impacts on the photosynthetic apparatus of wheat, which in turn may have negative consequences for its productivity. Full article

Global temperature rise has become a critical challenge to agricultural sustainability, severely affecting crop growth, productivity, and survival. Human-induced climate change and greenhouse gas emissions cause heat stress, disrupting plant metabolism and physiology at all developmental stages from germination to harvest. Elevated temperatures during germination impair water uptake, enzyme activity, and energy metabolism, leading to poor or uneven seedling emergence. At key phases such as flowering and grain filling, heat stress limits photosynthesis and transpiration by inducing stomatal closure, restricting carbon dioxide intake, and reducing photosynthetic efficiency. The reproductive stage is particularly vulnerable to high temperatures, impairing pollen viability, preventing anther dehiscence, and reducing fertilization success. Membrane instability further accelerates chlorophyll degradation and leaf senescence. Heat stress also alters biochemical and hormonal balances by disrupting the synthesis and signaling of auxins, gibberellins, and abscisic acid (ABA). Elevated ABA promotes stomatal closure to enhance stress tolerance, while increased ethylene levels trigger premature leaf senescence and abscission. These hormonal shifts and oxidative stress hinder plant growth and reproduction, threatening global food security. Although plants employ adaptive mechanisms such as heat shock protein expression and stress-responsive gene regulation, current strategies remain inadequate, highlighting the urgent need for innovative approaches to improve crop resilience under rising temperatures. Full article

Drought is a leading constraint on plant productivity and will intensify with climate change. Plant acclimation emerges from a multilayered regulatory system that integrates signaling, transcriptional reprogramming, RNA-based control, and chromatin dynamics. Within this hierarchy, non-coding RNAs (ncRNAs) provide a unifying regulatory layer; microRNAs (miRNAs) modulate abscisic acid and auxin circuits, oxidative stress defenses, and root architecture. This balances growth with survival under water-deficient conditions. Small interfering RNAs (siRNAs) include 24-nucleotide heterochromatic populations that operate through RNA-directed DNA methylation, which positions ncRNA control at the transcription–chromatin interface. Long non-coding RNAs (lncRNAs) act in cis and trans, interact with small RNA pathways, and can serve as chromatin-associated scaffolds. Circular RNAs (circRNAs) are increasingly being detected as responsive to drought. Functional studies in Arabidopsis and maize (e.g., ath-circ032768 and circMED16) underscore their regulatory potential. This review consolidates ncRNA biogenesis and function, catalogs drought-responsive modules across model and crop species, especially cereals, and outlines methodological priorities, such as long-read support for isoforms and back-splice junctions, stringent validation, and integrative multiomics. The evidence suggests that ncRNAs are tractable entry points for enhancing drought resilience while managing growth–stress trade-offs. Full article

This study explored the regulatory effects of exogenous glucose (Glu) and sucrose (Suc) on the growth performance and physiological mechanisms of cucumber seedlings under salt stress. Using two cucumber cultivars as experimental materials, pot experiments demonstrated that salt stress significantly suppressed seedling growth, decreased chlorophyll content, and triggered oxidative damage. However, pretreatment with exogenous sugars effectively mitigated these adverse effects by maintaining photosynthetic efficiency, enhancing the activities of key antioxidant enzymes—superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)—and reducing the accumulation of reactive oxygen species (ROS) and membrane lipid peroxidation. Transcriptomic analysis revealed that the two sugars differentially modulated antioxidant pathways and transcription factor networks to synergistically enhance salt tolerance. Specifically, sucrose preferentially activated POD, whereas glucose specifically induced APX and RbohD. Furthermore, glucose upregulated NAC and ERF family genes, while sucrose suppressed certain WRKY members. Both sugars contributed to the restoration of auxin and abscisic acid (ABA) signaling pathways. This study provides a theoretical foundation for the role of sugar signaling in enhancing crop resistance to abiotic stress. Full article