Cucumber (Cucumis sativus L.) is one of the most widely cultivated vegetables in the world. High temperature and other stress conditions can affect the growth and development of this plant, even leading to the decreases in yield and quality. The mitogen-activated protein kinase (MAPK) family plays a crucial role in plant stress responses. However, the role of MPK4 in the stress response of cucumber remains to be reported. In this study, we cloned CsMPK4, which encoded 383 amino acid residues. The qRT-PCR results showed that the expression level of CsMPK4 was the highest in leaves and flowers, moderate in roots, and the lowest in stems and tendrils. CsMPK4 was located in the nucleus and cytoplasm, and it had a close relationship with CmMPK4 in muskmelon. The cucumber plants overexpressing CsMPK4 became stronger and shorter, with reduced length and quantity of tendrils. Moreover, the transgenic seedlings were more resistant to high temperatures, with decreased malondialdehyde (MDA) content and increased activities of peroxidase (POD) and superoxide dismutase (SOD) in young leaves. Furthermore, the protein-protein interaction between CsMPK4 and CsVQ10, a member of the valine-glutamine family, was confirmed by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. The results suggested that CsVQ10 cooperated with CsMPK4 in response to the high temperature stress in cucumber. This study laid a foundation for the further study on the stress response mechanism of CsMPK4 and the breeding of stress-resistant cucumber varieties.
Cucumis sativus/metabolism* ; Mitogen-Activated Protein Kinases/physiology* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Gene Expression Regulation, Plant ; Stress, Physiological/genetics* ; Cloning, Molecular

Mercury (Hg)-contaminated soil poses a significant threat to the environment and human health. Hg-resistant microorganisms have the ability to survive under the stress of inorganic and organic Hg and effectively reduce Hg levels and toxicity. Compared to physical and chemical remediation methods, microbial remediation technologies have garnered increasing attention in recent years due to their lower cost, remarkable efficacy, and minimal environmental impact. This paper systematically elucidates the molecular mechanisms of Hg resistance in microbes, with a focus on their potential applications in phytoremediation of Hg-contaminated soils through plant-microbe interactions. Furthermore, it highlights the critical role of microbes in enhancing the effectiveness of transgenic plants for Hg remediation, aiming to provide a theoretical foundation and scientific basis for the bioremediation of Hg-contaminated soils.
Mercury/toxicity* ; Biodegradation, Environmental ; Soil Pollutants/isolation & purification* ; Soil Microbiology ; Plants, Genetically Modified/metabolism* ; Bacteria/genetics*

The fungal bioluminescence pathway (FBP) catalyzes the oxidation of endogenous caffeic acid to produce green bioluminescence through an enzymatic cascade. Genetic engineering of FBP into plants creates autoluminescent specimens that circumvent the substrate limitations of conventional reporter systems. These transgenic plants serve dual functions as aesthetic displays and versatile biosensing platforms, enabling applications in real-time gene expression monitoring, continuous environmental surveillance, and non-invasive bioimaging, offering novel opportunities for horticultural production, environmental conservation, and bioengineering applications. This review synthesizes current advances in plant FBP engineering and explores how machine learning approaches can optimize autoluminescent phenotypes, thereby accelerating innovation in agricultural biotechnology, environmental sensing, and synthetic biology applications.
Fungi/genetics* ; Plants, Genetically Modified/metabolism* ; Genetic Engineering ; Biosensing Techniques ; Luminescent Measurements ; Caffeic Acids/metabolism* ; Luminescence

Flowering and bolting are important agronomic traits in cruciferous crops such as Brassica juncea. Timely flowering can ensure the crop organ yield and quality, as well as seed propagation. The WRKY family plays an important role in regulating plant bolting and flowering, while the function and mechanism of WRKY12 in B. juncea remain unknown. To explore its function and mechanism in bolting and flowering of B. juncea, we cloned and characterized the BjuWRKY12 gene in B. juncea and found that its expression levels were significantly higher in flowers and inflorescences than in leaves. BjuWRKY12 belonged to the Ⅱc subfamily of the WRKY family, and subcellular localization indicated that the protein was located in the nucleus. Ectopic overexpression of BjuWRKY12 in transgenic lines promoted bolting and flowering, leading to significant increases in the expression levels of flowering integrators SOC1 and FUL. Furthermore, yeast one-hybrid and dual luciferase reporter system assays confirmed that BjuWRKY12 directly bound to the promoters of BjuSOC1 and BjuFUL, undergoing protein-DNA interactions. This discovery gives new insights into the regulation network and molecular mechanisms of BjuWRKY12, laying a theoretical foundation for the breeding of high-yield and high-quality varieties of B. juncea.
Mustard Plant/metabolism* ; Flowers/growth & development* ; Plant Proteins/physiology* ; Promoter Regions, Genetic/genetics* ; Gene Expression Regulation, Plant ; Plants, Genetically Modified/genetics* ; Transcription Factors/metabolism* ; MADS Domain Proteins/metabolism*

Microalgae possess high photosynthetic efficiency, robust adaptability, and substantial biomass, serving as excellent biological resources for large-scale cultivation. Malic enzyme (ME), a ubiquitous metabolic enzyme in living organisms, catalyzes the decarboxylation of malate to produce pyruvate, CO₂, and NAD(P)H, playing a role in multiple metabolic pathways including energy metabolism, photosynthesis, respiration, and biosynthesis. In this study, we identified the Scenedesmus quadricauda malic enzyme gene (SqME) and its biological functions, aiming to provide excellent target genes for the genetic improvement of higher plants. Based on the RNA-seq data from S. quadricauda under the biofilm cultivation mode with high CO₂ and light energy transfer efficiency and small water use, a highly expressed gene (SqME) functionally annotated as ME was cloned. The physicochemical properties of the SqME-encoded protein were systematically analyzed by bioinformatics tools. The subcellular localization of SqME was determined via transient transformation in Nicotiana benthamiana leaves. The biological functions of SqME were identified via genetic transformation in Nicotiana tabacum, and the potential of SqME in the genetic improvement of higher plants was evaluated. The ORF of SqME was 1 770 bp, encoding 590 amino acid residues, and the encoded protein was located in chloroplasts. SqME was a NADP-ME, with the typical structural characteristics of ME. The ME activity in the transgenic N. tabacum plant was 1.8 folds of that in the wild-type control. Heterologous expression of SqME increased the content of chlorophyll a, chlorophyll b, and total chlorophyll by 20.9%, 26.9%, and 25.2%, respectively, compared with the control. The transgenic tobacco leaves showed an increase of 54.0% in the fluorescence parameter NPQ and a decrease of 30.1% in Fo compared with the control. Moreover, the biomass, total lipids, and soluble sugars in the transgenic tobacco leaves enhanced by 20.5%, 25.7%, and 9.5%, respectively. On the contrary, the starch and protein content in the transgenic tobacco leaves decreased by 22.4% and 12.2%, respectively. Collectively, the SqME-encoded protein exhibited a strong enzymatic activity. Heterologous expressing of SqME could significantly enhance photosynthetic protection, photosynthesis, and biomass accumulation in the host. Additionally, SqME can facilitate carbon metabolism remodeling in the host, driving more carbon flux towards lipid synthesis. Therefore, SqME can be applied in the genetic improvement of higher plants for enhancing photosynthetic carbon fixation and lipid accumulation. These findings provide scientific references for mining of functional genes from S. quadricauda and application of these genes in the genetic engineering of higher plants.
Nicotiana/genetics* ; Photosynthesis/physiology* ; Malate Dehydrogenase/biosynthesis* ; Plant Leaves/genetics* ; Scenedesmus/enzymology* ; Carbon Cycle/genetics* ; Lipid Metabolism/genetics* ; Plants, Genetically Modified/metabolism*

Stresses induced by the deficiency or excess of trace mineral elements, such as manganese (Mn), represent a common limiting factor for the production of crops like Brassica napus. To identify key genes involved in Mn allocation in B. napus and elucidate the underlying mechanisms, a member of the metal tolerance protein (MTP) family obtained in the previous screening of cDNA library of B. napus under Mn stress was selected as the research subject. Based on the sequence information and phylogenetic analysis, it was named as BnMTP10. It belongs to the Mn-cation diffusion facilitator (CDF) subfamily. Expression of BnMTP10 in yeast significantly improved the tolerance of transformants to excessive Mn and iron (Fe) and reduced the accumulation of Mn and Fe. However, the yeast transformants exhibited no significant changes in tolerance to excess cadmium, boron, aluminum, zinc, or copper. The qRT-PCR results demonstrated that the flowers of B. napus had the highest expression of BnMTP10, followed by roots and leaves. Subcellular localization studies revealed that BnMTP10 was localized in the endoplasmic reticulum (ER). Compared with wild-type plants, transgenic Arabidopsis overexpressing BnMTP10 exhibited enhanced tolerance to excessive Mn stress but showed no significant difference under Fe stress. Correspondingly, under excessive Mn stress, the Mn content in the roots of transgenic Arabidopsis increased significantly. However, under excessive Fe stress, the Fe content in transgenic Arabidopsis did not alter significantly. According to the results, we hypothesize that BnMTP10 may alleviate excessive Mn stress in plants by mediating Mn transport to the ER. This study facilitated our understanding of efficient mineral nutrients, and provided theoretical foundations and gene resources for breeding B. napus.
Brassica napus/genetics* ; Manganese/metabolism* ; Plants, Genetically Modified/genetics* ; Plant Proteins/physiology* ; Arabidopsis/metabolism* ; Gene Expression Regulation, Plant ; Phylogeny ; Cation Transport Proteins/metabolism* ; Stress, Physiological

Geminiviruses cause substantial crop yield losses worldwide. The replication initiator protein (Rep) encoded by geminiviruses is indispensable for geminiviral replication. The Rep protein encoded by beet severe curly top virus (BSCTV, genus Curtovirus, family Geminiviridae) induces VARIANT IN METHYLATION 5 (VIM5) expression in Arabidopsis leaves upon BSCTV infection. VIM5 functions as a ubiquitination-related E3 ligase to promote the proteasomal degradation of methyltransferases, resulting in reduction of methylation levels in the BSCTV C2-3 promoter. However, the specific domains of Rep responsible for VIM5 induction remain poorly characterized. Although Rep proteins from several geminiviruses act as viral suppressors of RNA silencing (VSRs), whether BSCTV Rep also possesses VSR activity remains to be illustrated. In this study, we employed a transient expression system in the 16c-GFP transgenic and the wild-type Nicotiana benthamiana plants to analyze the VSR and the VIM5-inducing activities of different truncated Rep proteins haboring distinct domains. We found that the N-terminal domain (amino acids 1-180) of Rep suppressed GFP silencing in 16c-GFP transgenic N. benthamiana leaves. The minimal N-terminal fragment (amino acids 1-104) induced VIM5 expression upon co-infiltration, while C-terminal truncations lacked VIM5-inducing activity. Our results indicate that the N-terminal domain of Rep encoded by BSCTV mediates the suppression of RNA silencing and induces VIM5 expression. Thus, our findings contribute to a better understanding of interactions between geminiviral Rep and plant hosts.
Geminiviridae/genetics* ; Nicotiana/metabolism* ; Arabidopsis/metabolism* ; RNA Interference ; Viral Proteins/metabolism* ; Arabidopsis Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Protein Domains ; Plant Diseases/virology* ; Methyltransferases/metabolism* ; Ubiquitin-Protein Ligases/metabolism* ; DNA Helicases/genetics*

The dehydration responsive element binding (DREB) transcription factors play an important role in plant growth and development and are extensively involved in plant responses to abiotic stress. The DREB family contains six subfamilies, and TINY belongs to the DREB-A4 subfamily. The Arabidopsis thaliana TINY gene, AtTINY, plays a role in regulating plant growth and responses to stress. In order to investigate the evolutionary characterization of the DREB-A4 subfamily and the biological function of the MdTINY gene in apple (Malus domestica), in this study, we used the databases GDDH13 and TAIR and online tools (Expasy and WoLF PSORT) to study the biological information of the DREB-A4 subfamily in apple. In addition, the tertiary structures of the proteins were predicted. The apple DREB-A4 subfamily contained 22 genes, all of which had a conserved AP2 domain, and subcellular localization predictions showed that DREB-A4 subfamily proteins were mainly located in the nucleus. The transgenic calli of MdTINY were obtained by the Agrobacterium-mediated transformation method, and the main biological functions of MdTINY were explored by quantitative real-time PCR (qRT-PCR) combined with anthocyanin content determination. MdTINY shared the highest amino acid sequence similarity with AtTINY. The coding region of MdTINY had a full length of 759 bp, encoding 252 amino acid residues. Analysis of the promoter elements and expression patterns indicated that MdTINY was responsive to light and multiple stress conditions. MdTINY was localized in the nucleus and had transcriptional autoactivation activity. The overexpression of MdTINY in calli inhibited normal growth and promoted anthocyanoside accumulation. These results indicated that MdTINY negatively regulated apple plant growth and promoted fruit coloring, providing a candidate gene for the breeding of apple varieties with high quality of fruit color.
Malus/metabolism* ; Plant Proteins/metabolism* ; Transcription Factors/metabolism* ; Gene Expression Regulation, Plant ; Plants, Genetically Modified/genetics* ; Stress, Physiological ; Anthocyanins/metabolism*

High salt content in soils severely hampers plant growth and crop yields. Many transcription factors in plants play important roles in responding to various stresses, but their molecular mechanisms remain unclear. WRKY transcription factors are one of the largest families of transcription factors in higher plants that are involved in and influence many aspects of plant growth and development. They play important roles in responding to salt stress. The regulation of gene expression by WRKY proteins is mainly achieved by binding to the DNA's specific cis-regulatory elements, the W-box elements (TTGACC). In recent years, there have been many studies revealing the roles and mechanisms of WRKY family members, from model plant Arabidopsis to agricultural crops. This paper reviews the latest research progress on WRKY transcription factors in response to salt stress and discusses the current challenges and future perspectives of WRKY transcription factor research.
Transcription Factors/metabolism* ; Plant Proteins/metabolism* ; Stress, Physiological/genetics* ; Salt Stress/genetics* ; Crops, Agricultural/genetics* ; Gene Expression Regulation, Plant ; Phylogeny ; Plants, Genetically Modified/genetics*

Galactinol synthase (GolS) genes play important roles in plant response to abiotic stress. In this research, the plant expression vector of soybean GmGolS2-2 gene was constructed and transformed into tobacco to study the drought tolerance of transgenic tobacco. A GmGolS2-2 gene with 975 bp coding sequence was cloned from soybean leaves by reverse transcription-polymerase chain reaction (RT-PCR). GmGolS2-2 was linked to the plant expression vector pRI101 by restriction enzyme sites Nde Ⅰ and EcoR Ⅰ, and transformed into tobacco by leaf disc method. Genomic DNA PCR and real-time PCR showed that three GmGolS2-2 transgenic tobacco plants were obtained. The growth status of GmGolS2-2 transgenic tobacco under drought stress was better than that of wild-type tobacco. After drought stress treatment, the electrolyte leakage and malondialdehyde content of transgenic tobacco were lower than those of wild-type tobacco, but the proline content and soluble sugar content were higher than those of wild-type tobacco. The results of real-time PCR showed that the heterologous expression of GmGolS2-2 increased the expression of stress-related genes NtERD10C and NtAQP1 in transgenic tobacco. The above results indicated that GmGolS2-2 improved drought resistance of transgenic tobacco.
Drought Resistance ; Tobacco/genetics* ; Soybeans/genetics* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/genetics* ; Stress, Physiological/genetics* ; Droughts ; Gene Expression Regulation, Plant