Search Results (802)

Salt and low temperature are serious abiotic stresses and important constraints to agricultural productivity across the globe. These abiotic stresses negatively affect plant growth and physiological, biochemical, and molecular processes. Glycine betaine (GB) is an important osmoprotectant that enables plants to resist salinity, low temperature, and drought. GB can be synthesized in many organisms, including animals, plants, and bacteria. In higher plants, GB is synthesized through two-step oxidation of choline. However, rice, an important food crop, cannot synthesize GB. Thus, conferring the ability to synthesize GB to rice through genetic engineering is of great significance for enhancing its tolerance to abiotic stress. Recently, an enzyme, GSDMT (glycine, sarcosine, and dimethylglycine methyltransferase) was found in a diatom, Talassiosira pseudonana, and found able to catalyze the three successive methylation steps of glycine to form GB. This biosynthetic pathway for GB synthesis is also the simplest in living organisms. Here, the optimized codon of the TpGSDMT gene sequence was synthesized and cloned into an overexpression vector, pBWA(V)HS, which contains a CaMV 35S promoter, and then, the constructed vector was transferred into rice (Oryza sativa L. ssp. Japonica). The GB content in transgenic rice showing overexpression of TpGSDMT was significantly increased, and these transformants exhibited markedly enhanced tolerance to salt and low temperature. These results indicate that the TpGSDMT gene can be used for the genetic improvement in crop plants’ resistance to salinity and low temperature. Full article

Soybean (Glycine max) is a vital oilseed and economic crop in China, often constrained by drought, salinity, and biotic stresses. In this study, we identified a soybean bZIP transcription factor, GmbZIP59, whose expression is upregulated by salt, drought, ethylene (ETH), methyl jasmonate (MeJA), and abscisic acid (ABA). Overexpression of GmbZIP59 in Arabidopsis (OE-13 and OE-20, two independent Arabidopsis transgenic lines) exhibited enhanced resistance to Sclerotinia sclerotiorum (S. sclerotiorum), improved tolerance to salt stress, and increased sensitivity to phytohormones. Overexpression of GmbZIP59 in rice (OE-1 and OE-2, two independent rice transgenic lines) improved tolerance to salt and drought stresses. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that elevated expression of stress-related genes occurred in transgenic lines under adverse conditions. Furthermore, chromatin immunoprecipitation-qPCR (ChIP-qPCR) assays confirmed that GmbZIP59 directly binds to the promoters of ETH, MeJA, and ABA, responsive genes associated with stress responses. These findings demonstrate that GmbZIP59 acts as a positive regulator of biotic and abiotic stress tolerance in soybean. Full article

Helper component-proteinase (HC-Pro), encoded by tobacco vein banding mosaic virus (TVBMV), can cause various viral symptoms and even abortion. HC-Pro counteracts host-mediated inhibition by interfering with the accumulation of microRNAs (miRNAs) and small interfering RNAs (siRNAs). However, it is unclear whether the abortion phenotype of transgenic plants expressing HC-Pro is related to the abnormal expression of TEOSINTE BRANCHED 1/CYCLOIDEA/PROLIFERATING cell factors (TCPs), which are involved in regulating fertility. In this study, the molecular mechanisms through which HC-Pro causes various sterile phenotypes in plants were investigated. Reverse transcription–quantitative polymerase chain reaction (RT–qPCR) and Northern blotting revealed that in HC-Pro transgenic plants, the expression levels of TCP4 and TCP24 significantly increased. The increased expression of TCP4 further upregulated LIPOXYGENASE2 (LOX2), a gene encoding a key enzyme in the synthesis of jasmonic acid (JA) precursors. Further studies confirmed that the aberrant expression of TCP3, TCP4 and TCP24 blocks the elongation of petals and anthers and that the aberrant expression of TCP4 and TCP24 blocks the release of pollen. This study demonstrated that HC-Pro affects the expression levels of the miR319-targeted genes TCP2, TCP3, TCP4, TCP10 and TCP24, thereby affecting the normal development of floral organs and resulting in plant abortion. Both tobacco and Arabidopsis thaliana were used as model systems in this study on virus-mediated fertility, which provides important information for understanding how viral pathogenicity affects the regulation of fertility in crops. Full article

Rubisco activase (RCA) is an ATP-dependent enzyme that plays a crucial role in plant stress responses by regulating the catalytic activity of Rubisco. However, the alternative splicing and functional characteristics of the RCA gene exhibit notable species-specific diversity. The variable splice forms and functions of the RCA gene in mangrove plants remain poorly understood. Herein, we cloned the RCA cDNA in the leaves of mangrove plant Kandelia candel (L.) in response to combined flooding and salinity stress, and performed systematic expression analysis and functional validation. Our results demonstrated that the RCA gene undergoes alternative splicing to produce two isoforms, designated as KcRCA_l (GenBank accession: MG492021) and KcRCA_s (GenBank accession: MG492022), respectively. The KcRCA_l encodes a 440-amino acid protein (42.49 kDa) belonging to the β-isoforms, while KcRCA_s encodes a 474-amino acid protein (46.10 kDa) classified as the α-isoforms. Moreover, protein structure analysis revealed that both isoforms contain phosphorylation and lysine acetylation modification sites. Phylogenetic analysis indicated that KcRCA shares the closest evolutionary relationship with RCA from Cicer arietinum (chickpea) and Durio zibethinus (durian). Furthermore, RT-qPCR analysis revealed that the expression levels of KcRCA_l and KcRCA_s were significantly upregulated in K. Candel leaves under the combined stress condition. The following functional validation studies in transgenic Arabidopsis demonstrated that overexpression of the KcRCA cDNA enhances the plant’s tolerance to resist flooding and salinity stress while improving antioxidant capacity and increasing RCA and Rubisco activity, thereby maintaining photosynthetic efficiency under combined flooding and salinity stress. Our study not only provides new experimental evidence for understanding the molecular mechanisms of plant flooding and salinity stress, but also offers theoretical foundations for breeding flooding- and salinity-tolerant crops. 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

The herbicides used with crops that have been made resistant to them with transgenes are assumed to have no significant effects on these crops. Crops made resistant to glyphosate, glufosinate, dicamba, 2,4-D, mesotrione, and isoxaflutole are discussed in this paper. Most of the literature on this topic has been on glyphosate-resistant crops, as these have been the most successful of all herbicide-resistant crops. Reports of adverse effects, such as phytotoxicity symptoms, disrupted mineral nutrition, and reduced yield, caused by these herbicides on these crops are reviewed and critiqued herein. These reports are often conflicting, however, and there is no consistent evidence of any major adverse effects of these herbicides on these crops. Literature on the accumulation of residues of the intended herbicides in the parts of the plants that are used as food is also discussed. Reports of potential unintended beneficial effects, such as effects on crop pests and stimulation of crop growth and development are also critiqued. 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

Miscanthus, a perennial grass, is renowned for its remarkable tolerance to abiotic stress. Excessive levels of drought severely impair plant growth and yield. Plant nuclear factor Y (NF-Y) transcription factors (TFs) play pivotal roles in regulating responses to drought stress in species such as Arabidopsis and maize. However, their functional roles in conferring drought tolerance in Miscanthus remain largely unexplored. This study’s genome-wide analysis and gene expression profiling of Miscanthus under dehydration/osmotic stress identified a transcription factors gene, MsNF-YA4, which was significantly upregulated under dehydration/osmotic stress. MsNF-YA4 overexpression in Arabidopsis significantly enhanced drought tolerance, leading to increased transcription of stress- and antioxidant enzyme-related genes. Compared with the wild type (WT), the transgenic lines exhibited markedly higher relative water content (RWC), chlorophyll content, proline level, and antioxidant enzyme activity. Furthermore, the MsNF-YA4/MsNF-YB3/MsNF-YC2 improved the transactivation of the Miscanthus P5CS1, SOD (Cu/Zn) and CAT1 promoters in the transient system. These results offer fresh perspectives on the role of Miscanthus NF-YAs in drought tolerance and offer promising genetic resources for developing drought-tolerant crops through breeding programs. Full article

Salt stress is a major abiotic factor limiting crop productivity worldwide, as it disrupts plant growth, metabolism, and survival. In this study, we report that the genes PvPR10-2 and PvPR10-3 were significantly up-regulated in bean leaves and stems in response to combined salt and jasmonic acid (NaCl–JA) treatment. Foliar application of JA with salt induced physiological alterations, including stem growth inhibition, H₂O₂ accumulation, and activation of antioxidant enzymes. To investigate the role of PvPR10-3 in response to salt and phytohormones, we introduced this gene into Arabidopsis and found that its heterologous expression conferred salt tolerance to the transgenic lines. Interestingly, exogenous JA contributed to salt tolerance by reducing H₂O₂ levels, inducing ROS-scavenging enzymes, and promoting the accumulation of phenolic compounds and ABA. Furthermore, gene expression analysis of the transgenic lines revealed that PvPR10-3 expression under NaCl–JA stress is associated with the induction of JA-related genes like MYC2, JAZ2, JAZ11, and JAZ12, as well as SA-responsive genes, like ALD1 and TGA2, and two ABA-independent components DREB2A and ERD1, suggesting potential coordination between JA, ABA, and SA signaling in salt stress response. Additionally, key flowering regulators (FT, GI) were upregulated in transgenic lines under NaCl–JA treatment, suggesting a previously unexplored link between salt tolerance pathways and the regulation of flowering time. Taken together, our findings suggest a role of PvPR10-3 in enhancing salt stress tolerance and the involvement of exogenous JA in tolerance potentially by modulating ROS balance, hormone-associated gene expression, and protective secondary metabolites. Full article

Alfalfa (Medicago sativa L.) is a vital global forage crop. Transgenic technology promises enhanced yield and quality, but requires rigorous environmental risk assessment, particularly regarding pollen-mediated gene flow, for which standardized protocols are lacking. Based on an optimized in vitro culture medium, this study developed a method to assess alfalfa pollen viability. Using a single-factor experimental design, key assessment parameters were established at 1/4/8 h and 20/30/40 °C. A comparative analysis revealed no significant difference (p > 0.05) in pollen viability between the transgenic line SA6-8 and its non-transgenic parent “ZM-1” within this evaluation system. This result indicates that the genetic modification did not impact the pollen viability of SA6-8. By establishing this in vitro germination-based pollen viability assessment system and comparatively analyzing pollen viability between transgenic alfalfa and its non-transgenic parent under diverse environmental conditions, our approach provides crucial insights for optimizing transgenic alfalfa planting strategies and strengthening biosafety review protocols. Full article

Pre-harvest sprouting (PHS) reduces the quality and quantity of crop seeds. PHS can be imposed through the embryo or husk pathway of cereal crops. Most reported PHS seeds are imposed via the embryo pathway. Here, we generated transgenic rice plants overexpressing rice melatonin 2-hydroxylase (OsM2H), which catalyzes the hydroxylation of melatonin to 2-hydroxymelatonin (2-OHM). OsM2H overexpression (M2H-OE) showed PHS under paddy conditions. Germination assays revealed that intact seeds harvested at 26 and 36 days after heading (DAH) showed PHS, whereas dehusked seeds did not, indicating husk-imposed PHS. Overproduction of 2-OHM was observed in M2H-OE seeds compared to wild-type control. In addition, M2H-OE lines produced more hydrogen peroxide than the wild-type. 2-OHM-induced reactive oxygen species resulted in the induction of OsGA3ox2, a gibberellin (GA) biosynthesis gene, and repression of OsGA2ox3, a GA degradation gene, in caryopses at 2 DAH, but in the induction of the ABA degradation gene OsABA8ox3 in intact seeds at 26 DAH. In addition, M2H-OE seedlings were longer and showed increased levels of hydrogen peroxide and OsGA3ox2 expression versus the wild-type. This is the first report showing that 2-OHM can induce PHS via the husk pathway in rice seeds through the induction of GA biosynthetic and ABA degradation genes. Full article

The cereal cyst nematode, Heterodera avena, is responsible for substantial economic losses in the global production of wheat, barley, and other cereal crops. Extracellular enzymes, particularly those from the glycoside hydrolase 18 (GH18) family, such as chitinases secreted by Trichoderma spp., play a crucial role in nematode control. However, the genome-wide analysis of Trichoderma longibrachiatum T6 (T6) GH18 family genes in controlling of H. avenae remains unexplored. Through phylogenetic analysis and bioinformatics tools, we identified and conducted a detailed analysis of 18 GH18 genes distributed across 13 chromosomes. The analysis encompassed gene structure, evolutionary development, protein characteristics, and gene expression profiles following T6 parasitism on H. avenae, as determined by RT-qPCR. Our results indicate that 18 GH18 members in T6 were clustered into three major groups (A, B, and C), which comprise seven subgroups. Each subgroup exhibits highly conserved catalytic domains, motifs, and gene structures, while the cis-acting elements demonstrate extensive responsiveness to hormones, stress-related signals, and light. These members are significantly enriched in the chitin catabolic process, extracellular region, and chitinase activity (GO functional enrichment), and they are involved in amino sugar and nucleotide sugar metabolism (KEGG pathway enrichment). Additionally, 13 members formed an interaction network, enhancing chitin degradation efficiency through synergistic effects. Interestingly, 18 members of the GH18 family genes were expressed after T6 parasitism on H. avenae cysts. Notably, GH18-3 (Group B) and GH18-16 (Group A) were significantly upregulated, with average increases of 3.21-fold and 3.10-fold, respectively, from 12 to 96 h after parasitism while compared to the control group. Meanwhile, we found that the GH18-3 and GH18-16 proteins exhibit the highest homology with key enzymes responsible for antifungal activity in T. harzianum, demonstrating dual biocontrol potential in both antifungal activity and nematode control. Overall, these results indicate that the GH18 family has undergone functional diversification during evolution, with each member assuming specific biological roles in T6 effect on nematodes. This study provides a theoretical foundation for identifying novel nematicidal genes from T6 and cultivating highly efficient biocontrol strains through transgenic engineering, which holds significant practical implications for advancing the biocontrol of plant-parasitic nematodes (PPNs). Full article

Background/Objectives: Alfalfa is a widely cultivated high-quality forage crop, and salinity tolerance is one of the most important breeding goals. Glycine max SALT INDUCED NAC 1 (GmSIN1) was found to enhance salinity tolerance in soybean plants. The phylogenetic analysis showed there were two homologs of GmSIN1 in Medicago truncatula, MtSIN1a and MtSIN1b. This raised questions regarding the roles of MtSIN1s in alfalfa under salinity stress. Methods: From a Tnt1 mutant collection, we identified the mutants of MtSIN1a. We recorded the survival rate and plant height of mtsin1a-1 and mtsin1a-2 after 100 mM NaCl treatment. Subsequently, we generated 35S:MtSIN1a-GFP transgenic alfalfa lines via genetic transformation. Two lines with relatively high MtSIN1a expression, 35S:MtSIN1a-GFP#3 and 35S:MtSIN1a-GFP#4, were selected for gradient NaCl treatments. In addition, DAB and NBT staining were performed, and the H₂O₂ content and catalase (CAT) activity were determined. Then, we used RNA-seq analysis and RT-qPCR to study the mechanism of its tolerance. Results: This study found that after salt treatment, the survival rate and plant height of mtsin1a-1 and mtsin1a-2 were significantly lower than those of the WT. The mutants of MtSIN1a were sensitive to salinity stress. The transgenic alfalfa plants exhibited higher plant height, weaker DAB staining, stronger NBT staining, less H₂O₂ content, and enhanced CAT activity. The transgenic alfalfa constructed by transforming MtSIN1a showed enhanced salinity tolerance with elevated ROS scavenging. We identified MsSOD1 showing elevated expression levels in transcriptomic analysis. Conclusions: MtSIN1a is a positive regulator for enhancing salinity tolerance in alfalfa with activated ROS scavenging. Full article

As nutrient allocation trade-offs occur between reproductive and vegetative development in crops, optimizing their partitioning holds promise for improving agricultural productivity and quality. Herein, we characterize the phenotypic diversity of the fruitfulness trait and identify associated genes in tea plants (Camellia sinensis). Over three consecutive years, we monitored the fruitfulness of an F₁ hybrid population (n = 206) derived from crosses of ‘Emei Wenchun’ and ‘Chuanmu 217’. A marked variation was observed in the yield of individual plants, ranging from complete sterility (zero fruits) to exceptionally high fertility (1612 fruits). Using the high-resolution genetic linkage map and the fruitfulness data, we identified a stable major QTL designated as qFN5. To fine-map the underlying gene(s), artificial pollination experiments were conducted with extreme phenotype individuals (with the highest vs. lowest fruit numbers). Bulked segregant RNA sequencing (BSR-Seq) with ovules collected at two and seven days post-pollination (DPP) identified the genomic intervals that exhibit a high degree of overlap with qFN5. Analysis of expression dynamics combined with functional genomics data revealed a prominent candidate gene, CsETR2 (TGY048509), which encodes an ethylene receptor protein. When CsETR2 was overexpressed in Arabidopsis thaliana, the transgenic lines exhibited significantly decreased reproductive performance relative to the wild-type plants. Relative to the wild type, the transgenic lines exhibited a significant decline in several key traits: the number of effective panicles decreased by 72.5%, the seed setting rate dropped by 67.7%, and the silique length shortened by 38%. These findings demonstrate its role in regulating plant fruitfulness. Furthermore, yeast one-hybrid and dual-luciferase assays verified that CsMYB15 (TGY110225) directly binds to the CsETR2 promoter, thus repressing its transcription. In summary, our findings expand the understanding of genetic regulation underlying fruitfulness in tea plants and provide candidate target loci for breeding. Full article

Diseases caused by phytoparasitic nematodes are still a heavy constraint on modern farming, causing losses in crop yields as well as increased production costs due to pest management. Root-lesion nematodes (RLNs) are soil-dwelling migratory endoparasites that infect the roots of several crop species. RLNs feed and reproduce in the cortical cells of affected plant roots typically characterized by development of necrotic spots. Injuries to plant tissues result in weakened plants that become more prone to attack from opportunistic pathogens. In alfalfa (Medicago sativa L.), resistance to Pratylenchus penetrans has been linked to increased transcription of key enzymes in the biosynthesis of phenylpropanoids, important molecules for countering oxidative stress. However, the mechanisms of resistance are still unknown. The present work analyzed indicators of oxidative stress in extracts from transgenic roots of susceptible (cv. Baker) and resistant (cv. MNGRN-16) alfalfa. On extracts of susceptible alfalfa transgenic roots, levels of lipid peroxidation were more than three times higher after seven and fourteen days of growth, while activity of guaiacol peroxidase (GPX) was approximately four times higher after fourteen and twenty-one days of growth, in comparison to the resistant cultivar. This suggests that resistance response may be dependent on plant redox state. Future work will focus on metabolomic characterization of these varieties in contact with RLNs. Full article