Search Results (146)

Global warming-triggered heat stress severely restricts plant growth and crop productivity. Peanut (Arachis hypogaea L.), a vital oilseed and cash crop that is susceptible to high temperatures throughout its growth cycle, exhibits inhibited peg and pod development, growth retardation, and premature leaf senescence under heat stress, which ultimately causes substantial yield losses. Heat shock factors (Hsfs) serve as core regulatory modulators of plant abiotic stress tolerance, among which the HsfB subfamily exerts a critical function in thermotolerance modulation. Nevertheless, the biological functions of peanut HsfB genes remain largely uncharacterized. In the present study, a total of 16 HsfB subfamily members were identified from the peanut genome, possessing highly conserved gene structures and protein motifs. Phylogenetic analysis revealed that the peanut AhHsfB genes are classified into four distinct subfamilies. Chromosomal localization analysis indicated that these 16 AhHsfB genes are unevenly distributed across nine peanut chromosomes. Transcriptomic profiling demonstrated that the transcript levels of AhHsfB genes were significantly upregulated by 6- to 120-fold upon heat stress exposure. Subcellular localization and transcriptional activity assays further validated that AhHsfB1-5A is a nucleus-localized protein with intrinsic transcriptional activation activity. Ectopic overexpression of AhHsfB1-5A in Arabidopsis thaliana remarkably enhanced seed germination ability and antioxidant capacity under heat stress conditions, with a maximum 18.84% increase in green seedling rate. This study systematically characterizes the HsfB subfamily in peanut and elucidates the positive regulatory role of AhHsfB1-5A in plant thermotolerance. These findings deepen our understanding of the role of HsfB and provide valuable genetic resources for molecular breeding of heat-resistant peanut varieties. Full article

Peanut (Arachis hypogaea L.) production faces persistent threats from various infectious diseases. Planting healthy varieties with robust botanical defense networks is critical for minimizing future costs. Non-expressor of pathogenesis-related (NPR) regulators are involved in immune activation and act as key targets for deeper stress adaptation, and are thus promising targets for genetic enhancement. In this study, we characterized the peanut NPR4B protein and demonstrated its local subcellular binding to the nucleus. Ectopic overexpression of AhNPR4B in Arabidopsis thaliana significantly enhanced resistance to the necrotrophic pathogen Botrytis cinerea and enhanced cold tolerance, as supported by quantitative and statistical analyses (p < 0.05). As regards underlying molecular events, Y2H (Yeast 2-Hybrid) analysis revealed a binding in vitro physical relation of AhPR2-like to AhNPR4B. This binding was demonstrated in vivo through BiFC (Bimolecular Fluorescence Complementation). These results suggest that the AhNPR4B-AhPR2-like complex may act as a key regulatory module associated with biotic and abiotic stress signaling, potentially contributing to broad-spectrum stress resistance. These findings provide foundational insights into the functional roles of AhNPR4B and its interaction with AhPR2-like in regulating stress resistance and support its potential as a candidate target for future genetic improvements to enhance stress resilience in peanuts. Full article

Modern agriculture must balance productivity with sustainability. In this context, unmanned aerial vehicles (UAVs) offer flexible, cost-effective tools for crop and soil monitoring in precision agriculture. This study aimed to evaluate the potential of UAV-borne RGB imagery, combined with vegetation indices and machine learning, to estimate surface soil properties and crop physiological traits in peanut (Arachis hypogaea) cultivation. A factorial field experiment with four varieties, two planting densities, and two tillage systems was monitored using high-resolution RGB orthomosaics acquired at key phenological stages. From these images, 17 RGB-based indices were computed and related to soil variables and crop traits using Spearman correlation and two regression algorithms: Random Forest (RF) and k-Nearest Neighbors (KNN). RF models outperformed KNN, with the Red Chromatic Coordinate (RCC) index achieving an R² of 0.87 for predicting soil organic matter content. Indices such as visible NDVI and the Green Vegetation Index also provided robust estimates of canopy condition and leaf chlorophyll. Overall, the results demonstrate that UAV RGB imagery, processed through simple vegetation indices and RF models, constitutes an effective, low-cost approach for monitoring key agronomic parameters in peanut farming. Full article

Soil salinization is a significant global challenge that severely impacts agricultural productivity, particularly through its negative effects on crop growth and yield. Peanuts (Arachis hypogaea L.) are an important oil crop. One of the major goals in peanut breeding programs is to develop varieties with both high oil content and salt tolerance. Previously, we obtained a peanut line (HO) with high oil content through mutagenesis, which showed higher salt tolerance than its parental line (HY20). In this study, we employed multiple approaches including anatomical, physiological, and transcriptomic analyses to elucidate salt tolerance mechanisms of the HO peanut line. Under salt stress, the HO line exhibited better-developed vascular structures, with increased root vessel diameter and higher crystal idioblast density in leaves compared to HY20. HO also showed enhanced antioxidant enzyme activities, with POD and SOD activities higher than HY20. Photosynthetic efficiency was substantially improved in HO, with Fv/Fm decreasing under severe salt stress. Additionally, HO maintained a lower Na⁺/K⁺ ratio and higher linolenic acid content under salt stress. Transcriptomic analysis revealed up-regulated lignin biosynthesis genes in HO. This study established potential connections between salt stress tolerance and oil biosynthesis in peanuts, providing insights that could be leveraged for the development of high-yield and salt-resistant varieties. Full article

Seed size-related traits are pivotal determinants of yield and appearance quality in peanut breeding programs. This study aimed to (1) investigate the genetic diversity and population structure of 120 peanut accessions (including landraces, cultivated varieties, and introduced germplasm) through genome-wide resequencing, and (2) identify key genomic regions and candidate genes associated with seed size-related traits using Genome-wide association studies (GWAS) and haplotype analysis. The population relationship and the evolution of peanuts using a large-scale single nucleotide polymorphism (SNP) dataset generated from the genome-wide resequencing of 120 peanut accessions was explored. GWAS and haplotype analysis were employed to identify regions and candidate genes associated with seed size-related traits. GWAS and haplotype analysis identified a novel region associated with HSW and SW on chr14, and a haplotype that was more dominant in HSW and SW. Two candidate genes were screened by combining LD decay distance, SNP variation information and gene function annotations. Full article

Resveratrol is a promising polyphenolic bioactive compound found in peanuts. However, the distribution of cis- and trans-resveratrol and their glycosides varies significantly among cultivars, and their correlations with other quality traits remain unclear. In this study, Ultra-Performance Liquid Chromatography (UPLC) combined with high-throughput spectral analysis was employed to systematically evaluate 42 main cultivated peanut varieties from seven series across China’s three major production regions. The results indicated that trans-piceid (trans-resveratrol glycoside) was the predominant component, accounting for over 85% of the total content. Significant variation was observed in the total content of resveratrol and its glycosides among cultivars (4.61–88.79 mg/kg), with the Weihua series (represented by Weihua 23) exhibiting the strongest resveratrol enrichment ability. Multidimensional correlation analysis systematically revealed, for the first time, distinct association patterns: trans-piceid was positively correlated with sucrose, cis-resveratrol was positively correlated with fatty acids such as oleic acid, and trans-resveratrol showed a specific association with linoleic acid. Based on these findings, seven specialized high-resveratrol cultivars suitable for processing, including Weihua 23 and Kainong 301, were identified. Furthermore, a specific correlation system between “resveratrol and key quality indicators” was established. This study provides important theoretical support for the targeted breeding of novel functional peanut varieties that combine a high resveratrol content with traits such as high oleic acid or sugar content, thereby promoting the high-value industrial utilization of high-quality peanuts. Full article

Biofuels can help reduce dependence on petroleum-based fuels, and peanut oil is a potentially valuable biofuel source. This study estimates the carbon intensity (CI) of peanut oil production in Texas using the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. Both the Argonne National Laboratory (ANL) and California (CA) versions of GREET were employed to calculate CI values across various scenarios. Six pathways were developed considering farming, transportation, oil extraction, and land use change processes. These scenarios varied based on peanut varieties (High Oil and Conventional Oil content), irrigation methods (irrigated or dryland), and locations (Stephenville, Dilley, and Vernon): (1) Stephenville Dryland var. High Oil, (2) Stephenville Fully Irrigated var. High Oil, (3) Vernon Limited Irrigated var. High Oil/Rye cover crop, (4) Vernon Limited Irrigated var. Conventional Oil, (5) Vernon Limited Irrigated var. Conventional Oil/Rye cover crop, (6) Dilley Fully Irrigated var. High Oil. The CI values of these scenarios were compared with those of soybean oil. According to the ANL-GREET model results, the highest CI was observed in the Dryland scenario, though it remains lower than that of soybean oil. The lowest CI was found in the Vernon Span 17 Rye Irrigated scenario. The CA-GREET model results indicated the lowest CI for Dilley and the highest for Stephenville Dryland. The high oil yield in Dilley (1.25 tons/acre) significantly reduced the CI compared to the yield in Stephenville Dryland (0.25 tons/acre). These findings suggest that peanut oil is a promising addition to the currently available biofuel options. Full article

Soil acidification is among the primary abiotic stress factors that constrain plant growth. The adoption of acid-tolerant plant varieties and the inoculation of plant growth-promoting rhizobacteria have the distinct advantages of simultaneously increasing soil fertility and ensuring crop growth in acidic soil. However, how acid-tolerant plant varieties interact with the associated rhizosphere microbiota still needs to be explored. In this study, acid-tolerant peanut varieties were screened and planted in natural and sterile environments. The results revealed significant differences in growth performance among the varieties in acidic soil and between natural and sterile environments, revealing that the rhizosphere microbiota is dependent on acid tolerance. Through high-throughput sequencing analysis, the key taxa Sinomonas and Aspergillus were identified, and subsequent greenhouse verification experiments demonstrated their function in promoting peanut plant growth in acidic soil. In total, our findings suggest that the holobiont of tolerant plants and the rhizosphere microbiota is important for stress resistance. This perspective opens up new avenues for improving crop cultivation in soils with different stresses, in which both plant and associated microbial properties are considered. Full article

Background: Peanut is susceptible to iron (Fe) deficiency, particularly in calcareous soils. However, comparative studies on the adaptive mechanisms of different peanut cultivars to Fe deficiency remain limited. This study aimed to investigate the physiological and molecular responses of two distinct peanut cultivars to Fe deprivation and to identify the key traits contributing to differential Fe efficiency. Methods: Two peanut cultivars, LH11 and YZ9102, were cultivated under Fe-sufficient and Fe-deficient conditions, using both hydroponic and pot-based soil culture systems. Multiple parameters were assessed, including visual symptomology, biomass, tissue Fe concentration, active Fe in leaves, chlorophyll (Chl) content (SPAD value), net photosynthetic rate (Pn), Chl fluorescence (Fv/Fm), rhizosphere pH, root ferric chelate reductase (FCR) activity, and the relative expression of two Fe-acquisition-related genes (AhIRT1 and AhFRO1) via qRT-PCR. Results: Cultivar YZ9102 exhibited more severe Fe deficiency chlorosis symptoms, which also appeared earlier than in LH11, under both cultivation systems. Under Fe deficiency, YZ9102 showed significantly lower Chl content, Pn, and Fv/Fm compared to LH11. In contrast, LH11 demonstrated a greater capacity for rhizosphere acidification and maintained significantly higher root FCR activity under Fe-limited conditions. Gene expression analysis revealed that Fe deficiency induced the up-regulation of AhIRT1 and AhFRO1 in the roots of LH11, while their transcript levels were suppressed or unchanged in YZ9102. Conclusions: The peanut cultivar LH11 possesses superior tolerance to Fe deficiency compared to YZ9102. This enhanced tolerance is attributed to a synergistic combination of traits: the maintenance of photosynthetic performance, efficient rhizosphere acidification, heightened root Fe³⁺ reduction capacity, and the positive transcriptional regulation of key Fe uptake genes. These findings provide crucial insights for the selection and breeding of Fe-efficient peanut varieties for cultivation in Fe-deficient environments. Full article

Aims: The plant and soil microbiome serve as a reservoir of beneficial endophytic bacteria, including plant-growth-promoting (PGP) Bacillus subtilis, which enhances nutrient acquisition and protects plants against environmental stresses. We isolated novel bacteria from cultivated peanut plants selected from agricultural fields that survived a season of water scarcity and high temperatures. Experiments were conducted to determine whether plant survival was partially attributable to the presence of beneficial microbes that could be harnessed for future biotechnology applications. Methods and Results: Seven bacterial isolates of Bacillus spp. were identified through 16S rRNA sequencing, revealing close affiliations to B. subtilis, B. safensis, and B. velezensis. Growth curve analysis and colony morphology characterization revealed distinct growth patterns across different media types, while phytohormone production assays demonstrated variable indole-3-acetic acid (IAA) synthesis among isolates. When applied as seed biopriming agents to two hybrid peanut varieties, bacterial inoculation significantly enhanced root surface area and root tip development, with B. subtilis-TAM84A showing the most pronounced effects on ‘Schubert’ roots. In addition, vegetative growth assessments indicated increased branch numbers and plant height, particularly with treatments with B. velezensis strains TAM6B and TAM61A, and a consortium of all isolates. Under drought conditions, inoculated plants exhibited delayed wilting and improved recovery after rehydration, indicating enhanced drought resilience. Conclusions: Several local Bacillus strains recovered from drought-tolerant peanut plants showed improved growth and drought tolerance in greenhouse-grown peanut plants. Ongoing field studies aim to evaluate the potential of regionally adapted microbial populations as soil amendments during planting. Impact Statement: This study demonstrates that local strains of Bacillus isolated from drought-resistant peanut plants possess significant potential as bioinoculants to improve growth and drought tolerance in potted peanut plants. This work provides a foundation for utilizing regionally adapted microbial populations to address agricultural challenges related to water scarcity. Full article

Sucrose is a key quality trait in peanuts, yet high-sucrose varieties are scarce. Although sucrose transporters (SUT/SUC) play crucial roles in sucrose transport and accumulation during seed development, systematic analyses in peanuts are limited. This study conducted a genome-wide analysis of the SUC gene family in cultivated peanut (Arachis hypogaea L.). Sixteen AhSUC genes were identified and characterized for genomic distribution, phylogeny, and expression across tissues and developmental stages. The genes are unevenly distributed across the genome with clustered chromosomal localization. All AhSUC proteins contain the conserved sucrose/proton co-transporter domain (IPR005989), exhibit the typical 12 transmembrane α-helical structure of the major facilitator superfamily, are hydrophobic, and predicted to localize to the membrane. Promoter analysis revealed cis-regulatory elements associated with growth, development, light, hormone, and stress responses. Expression profiling showed tissue-specific patterns, with eight AhSUC genes being highly expressed in cotyledons and embryos. Comparative analysis between high-sugar and conventional varieties showed higher expression of AhSUC2, AhSUC9, and AhSUC11 in the high-sugar variety, correlating with increased sucrose accumulation. Functional validation using a sucrose transport-deficient yeast mutant confirmed the sucrose transport activity of these genes. These findings provide insight into sucrose accumulation mechanisms and offer genetic targets for breeding high-sugar peanut varieties. Full article

In order to address the problems of high mechanical damage rate (MDR) and poor variety adaptability in mechanical peanut shelling, this paper improves a small, flexible arc-plates drum–circular grid bar concave screen-type peanut-shelling device. Firstly, by combining the Hertz theory and the Weibull distribution model, the shelling and separation models of drums of rigid rods and flexible arc-plates were established. Through comparative analysis, it was verified that the latter has a lower MDR and energy consumption and has excellent shelling performance. Then, through single-factor experiments and an Analysis of Variance (ANOVA), the influence laws of peanut moisture content, drum speed, shelling spacing, and hardness of flexible material (silicone) on the MDR and shelling efficiency (SE) were explored. Subsequently, Box–Behnken’s four-factor three-level regression experiments were carried out, and the optimal shelling operation parameters were obtained by using the response surface multi-objective optimization method (RSM) and verified experiments. The results show that when moisture content is 11%, drum speed is 227 rpm, shelling spacing is 24 mm, and silicone hardness is 40 HA, the kernel’s MDR after shelling is 4.73%, which is reduced by 5.51% and the SE is 95.21%, which is increased by 3%. The R² and the Root Mean Square Error (RMSE) of the actual value versus the predicted value of the model were 0.9921, 0.9624, 7.99 × 10⁻², and 3.1 × 10⁻³, respectively. The relevant research provides references for reducing losses, improving quality, and applying new materials for components in mechanical peanut shelling. Full article

Some special volatile organic compounds (VOCs) that significantly induce female oviposition preferences may be utilized to disrupt oviposition behavior and to enhance trapping strategies; such approaches offer a promising avenue for reducing insect infestations in stored commodities. Based on the significant differences in the oviposition preference of P. interpunctella among six normal-oleic varieties (NOPs), the key VOCs involved were further explored. Seventeen VOCs that may contribute the oviposition preference and that exhibited a high content in the peanut varieties were measured through electroantennogram (EAG) response measurements of female moths. The VOCs that produced significant EAG responses by the females were further assayed for behavioral responses by the Y-tube olfactometer method, wind tunnel tests, and a multiple-choice device for female oviposition. Heptanal, acetophenone, nonanal, hexanal, benzaldehyde, octanal, hexanoic acid, decanal, phenylacetaldehyde, and 1-octen-3-ol from peanuts elicited strong antennal EAG responses. These VOCs (especially heptanal, nonanal, hexanal, octanal, and decanal) attracted more females in both Y-tube olfactometer and wind tunnel assays and increased oviposition rates in oviposition tests. The results indicate that heptanal, decanal, octanal, nonanal, and hexanal may be utilized to develop oviposition attractants for female moths further. Full article

Drought stress severely limits peanut productivity, highlighting the urgent need to understand the molecular mechanisms that underlie drought adaptation. While microRNAs (miRNAs) are known to play essential roles in plant stress responses, their functional contributions in polyploid crops like peanut remain insufficiently explored. This study provides the first integrated transcriptomic analysis of drought-responsive miRNAs in tetraploid peanut (Arachis hypogaea). We performed high-throughput sRNA sequencing on a drought-tolerant cultivar Fenhua 8 under PEG6000-simulated drought stress, identifying 10 conserved drought-responsive miRNAs. Among these, ahy-miR398 and ahy-miR408 were significantly downregulated under drought conditions. Degradome sequencing revealed that ahy-miR398 targets copper chaperones for superoxide dismutase (CCSs), potentially reducing SOD activation and amplifying oxidative stress. In contrast, ahy-miR408 targets laccase 12 (LAC12), P-type ATPase copper transporters (COPAs), and a blue copper protein-like (PCL) gene. These targets are involved in copper homeostasis and the regulation of reactive oxygen species (ROS), suggesting that ahy-miR408 plays a role in oxidative stress management. Functional validation in transgenic Arabidopsis lines overexpressing ahy-miR398 or ahy-miR408 showed significantly reduced drought tolerance, with impaired seed germination, shorter primary roots, and exacerbated growth suppression during water deprivation. Taken together, these findings highlight a novel miRNA-mediated regulatory network in peanut drought adaptation, centered on copper-associated oxidative stress management. This study provides new insights into miRNA-based regulation in polyploid crops and offers potential molecular targets for breeding climate-resilient peanut varieties, especially in arid regions where yield stability is crucial. Full article

Peanut (Arachis hypogaea L.) is an important oil and cash crop, but its growth and productivity are severely constrained by low-temperature stress. Growth-regulating factors (GRFs) are plant-specific transcription factors involved in development and stress responses, yet their roles in peanut remain poorly understood. In this study, we identified AhGRF3b as a direct target of ahy-miR396 using degradome sequencing, which demonstrated precise miRNA-mediated cleavage sites within the AhGRF3b transcript. Expression profiling confirmed that ahy-miR396 suppresses AhGRF3b via post-transcriptional cleavage rather than translational repression. Functional analyses showed that overexpression of AhGRF3b in Arabidopsis thaliana promoted leaf expansion by enhancing cell proliferation. Specifically, leaf length, width, and petiole length increased by 104%, 22%, and 28%, respectively (p < 0.05). Under cold stress (0 °C for 7 days), transgenic lines (OE-2 and OE-6) exhibited significantly better growth than Col-0, with fresh weight increased by 158% and 146%, respectively (p < 0.05). Effect size analysis further confirmed these differences (Cohen’s d = 11.6 for OE-2 vs. Col-0; d = 6.3 for OE-6 vs. Col-0). Protein–protein interaction assays, performed using the yeast two-hybrid (Y2H) system and 3D protein–protein docking models, further supported that AhGRF3b interacts with Catalase 1 (AhCAT1), vacuolar cation/proton exchanger 3 (AhCAX3), probable polyamine oxidase 4 (AhPAO4), and ACT domain-containing protein 11 (AhACR11), which are involved in reactive oxygen species (ROS) scavenging and ion homeostasis. These interactions were associated with enhanced CAT and PAO enzymatic activities, reduced ROS accumulation, and upregulation of stress-related genes under cold stress. These findings suggest that the ahy-miR396/AhGRF3b module plays a potential regulatory role in leaf morphogenesis and cold tolerance, providing valuable genetic resources for breeding cold-tolerant peanut varieties. Full article