Search Results (332)

The whitefly (Bemisia tabaci) (Hemiptera: Aleyrodidae) is a small phytophagous invertebrate of herbaceous plants, shrubs, trees, wild plants, and crops of economic importance. It generates substantial economic losses due to direct damage caused by sap sucking and virus transmission. This work presents referential images of the morphology of B. tabaci and one of its main biological controllers in southern South America, thus serving as a reference for other researchers. In addition, results are presented of studies carried out to evaluate the pathogenicity of two fungal isolates (previously selected in vitro against Sclerotinia sclerotiorum and Botrytis cinerea and plant growth promoters) identified as Metarhizium taii CEP-722 and Trichoderma afroharzianum CEP-754 in immature stages of B. tabaci in tomato plants (Solanum lycopersicum). The trials were conducted under controlled conditions in controlled chambers, ensuring optimal growth conditions for B. tabaci, after morphological prospection, collection, identification, and mass rearing of adults in entomological cages. The results indicate that M. taii CEP-722 caused approximately 30% mortality in the immature stages of B. tabaci, while T. afroharzianum CEP-754 did not increase mortality under the experimental conditions. This study provides new knowledge on the potential of M. taii as a biological control agent against B. tabaci, offering a promising alternative in integrated pest management strategies. The results with T. afroharzianum suggest that further methodologies or combinations should be explored to improve its efficacy. Full article

Agrobacterium tumefaciens (A. tumefaciens), the causal agent of crown gall disease on several plant species, is responsible for substantial yield losses worldwide. The limitations of conventional pesticides in controlling this disease highlight the need for alternative antibacterial solutions. Phage biocontrol can be an option, effectively managing bacterial plant diseases, by reducing pathogen loads while driving evolutionary trade-offs, often enhancing synergy with other antibacterial strategies. In this study, we aimed to explore and develop a sustainable strategy to control A. tumefaciens, by combining Agrobacterium phage PAT1 with the natural antimicrobial peptide “Ascaphin 8” and leveraging the fitness trade-offs resulting from phage resistance. In vitro and in planta investigations showed that PAT1 in combination with Ascaphin 8 at the sublethal concentration of 3 μM could effectively eradicate A. tumefaciens in YPG broth and reduce tumor formation by 46.33% on tomato plants, unlike their individual applications, indicating that the combination was synergistic against A. tumefaciens. This synergy was attributed to the fitness trade-offs in A. tumefaciens induced by phage resistance, which led to increased sensitivity to antimicrobial peptides, slower growth rate, and an 89.96% attenuation of virulence in the PAT1-resistant mutant (AT-M1). Transmission electron microscopy analyses showed that treatment with 1 µM of Ascaphin 8 induced cytoplasmic condensation in 80% of AT-M1 cells, whereas only 16% of the wild-type CFBP 5770 cells exhibited similar alterations under identical conditions. Furthermore, proteomic analyses performed on AT-M1 and CFBP 5770 revealed that the mutant AT-M1 exhibited a loss of DNA-binding protein HupB and downregulation of SDR family oxidoreductase and superoxide dismutase. These molecular alterations are potentially associated with the reduced virulence and heightened AT-M1 sensitivity. This study investigated the fitness costs associated with phage resistance in A. tumefaciens and laid the first foundation for potential biocontrol of plant bacterial diseases, particularly A. tumefaciens infections, using phage–peptide combination. Full article

JmjC domain proteins play crucial roles in plant growth and development, regulation of epigenetic processes, flowering control, and stress defence. However, these proteins have not been systematically identified or characterised in tomato. Here, we performed a genome-wide identification of JmjC domain-containing genes (JMJ family) in tomato and identified 23 SlJMJ genes within the tomato genome. Expression analysis indicated that SlJMJ15 was responsive to drought stress, prompting us to investigate its functional role in tomato plants. We found that SlJMJ15-RNAi lines displayed a severe dwarf phenotype, whereas SlJMJ15-overexpression lines exhibited increased drought sensitivity compared to wild-type plants, indicating that SlJMJ15 negatively regulates drought tolerance in tomatoes. Further investigation suggests that SlJMJ15 may reduce drought tolerance in tomatoes by modulating the expression of key genes involved in abscisic acid signalling pathways through its demethylation activity. This study deepens our understanding of the roles of SlJMJ family genes in tomato growth and abiotic stress responses, laying the foundation for developing strategies to improve drought stress tolerance in tomatoes. Full article

Global climate change is the impact of combined abiotic and biotic stresses negatively affecting plant health and productivity. This study investigated the molecular and cellular responses of Nicotiana benthamiana L. plants to wild-type tomato bushy stunt virus (wtTBSV) infection under conditions of pre-existing heat stress. The experiments were conducted under controlled temperature regimes of 30 °C and 37 °C in combination with virus challenge. Morphological and biochemical analyses in plants under the influence of combined stress showed the alleviation of disease symptoms, reduction in virus content and reduced expression levels of viral proteins P19 and P33. Under conditions of combined stress, accumulation of hydrogen peroxide and malondialdehyde, as well as activation of the antioxidant enzyme catalase, especially in root tissues, were observed. Notably, at 37 °C, virus infection was suppressed despite high levels of oxidative stress, whereas at 30 °C, a marked decrease in the expression of host factors was observed. The results indicate that thermal stress modulates virus–host interactions and activates defense mechanisms, including antioxidant and RNA interference pathways. Therefore, temperature adaptation can be considered as a promising strategy for enhancing plant resistance to viral pathogens under climate changes. Full article

Carpel number has been recognized as a critical factor influencing fruit size, ultimately determining yield and economic efficiency. The WUSCHEL (WUS) protein is essential for maintaining stem cell homeostasis in the floral meristem. Its expression level directly influences the size of the floral meristem (FM), thereby determining the number of floral organs in Arabidopsis thaliana, Solanum lycopersicum, and Cucumis sativus. While its role remained largely unexplored in grapevine (Vitis vinifera). This study cloned the VvWUS gene from the polycarpic grape cultivar ‘Jizaomi’. Transgenic tomato lines expressing VvWUS heterologously exhibited accelerated floral transition, enhanced carpel/floral organ initiation, and had significantly higher locule numbers relative to wild type. Furthermore, direct binding of VvWUS to the VvAGAMOUS (VvAG) promoter and activation of VvAG expression were demonstrated through yeast one-hybrid (Y1H) and dual-luciferase (LUC) assays. These findings elucidated the molecular function of VvWUS in grape carpel development, providing a foundational basis for molecular breeding strategies targeting large-berry grape varieties. Full article

Mitogen-activated protein kinases 3 and 6 (MPK3/MPK6) are central to pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) in Arabidopsis, yet the involvement of long noncoding RNAs (lncRNAs, >200 nt) in these pathways is poorly understood. Here, transcriptomic analyses were performed to compare lncRNA and protein-coding gene (PCG) expression profiles in wild-type (WT) and MPK3/MPK6-deficient (MPK6SR) Arabidopsis plants. These plants were inoculated with either Pseudomonas syringae pv. tomato (Pst) DC3000, which elicits both PTI and ETI, or its type III secretion-deficient mutant, Pst DC3000 hrcC⁻, which induces only PTI. RNA sequencing (RNA-seq) analysis of 18 samples identified 1388 known and 70 novel lncRNAs, among which differentially expressed lncRNAs (DElncRNAs) involved in disease resistance were further identified. Using integrative analyses, including weighted gene co-expression network analysis (WGCNA), prediction of lncRNA cis-regulatory targets for PCGs, and validation via reverse transcription-quantitative PCR (RT-qPCR), three core lncRNA-mediated regulatory modules were identified: (i) MPK3/MPK6-dependent PTI and ETI, where lncRNAs amplify signals; (ii) MPK3/MPK6-dependent PTI, where lncRNAs fine-tune basal immunity; and (iii) MPK3/MPK6-independent PTI and ETI, where lncRNAs serve as a backup regulatory network. These modules form a multi-layered immune regulatory network via cis- and trans-regulation and further enable the identification of lncRNA-PCG pairs involved in both regulatory modes. This work enhances the understanding of the molecular mechanisms underlying plant innate immunity. Full article

As an auxin-responsive gene, Gretchen Hagen 3 (GH3) maintains hormonal homeostasis by conjugating excess auxin with amino acids in plant stress-related signaling pathways. GH3 genes have been characterized in many plant species, but the characteristics of pepper (Capsicum annuum L.) GH3 (CaGH3) gene family members in response to multiple stimulants are largely unknown. In this study, we systematically identified the CaGH3 gene family at the genome level and identified eight members on four chromosomes in pepper. CaGH3s were divided into two groups (I and III) and shared conserved motifs, domains, and gene structures. Moreover, CaGH3s had close evolutionary relationships with tomato (Solanum lycopersicum L.), and the promoters of most CaGH3 genes contained hormone and abiotic stress response elements. A protein interaction prediction analysis demonstrated that the CaGH3-3/3-6/3-7/3-8 proteins were possibly core members of the CaGH3 family interaction. In addition, qRT-PCR results showed that CaGH3 genes were differentially expressed in pepper tissues and could be induced by phytohormones (IAA, ABA, and MeJA) and abiotic stresses (salt, low temperature, and drought) with different patterns. In addition, CaGH3-5 and CaGH3-7 were cloned, and the sequences showed a high degree of conservation. Moreover, the results of subcellular localization indicated that they were located in the membrane and chloroplast. Notably, after overexpressing CaGH3-7 in tomato, RNA-seq was performed on wild-type and transgenic lines, and the differentially expressed genes were mainly enriched in response to external stimuli. This study not only lays the foundation for a comprehensive understanding of the function of the CaGH3 gene family during plant growth and stress responses but also provides potential genetic resources for pepper resistance breeding. Full article

Aphis gossypii is a significant global pest that impacts numerous agricultural crops and vegetables, causing direct damage to food plants and indirect damage through the transmission of phytopathogenic viruses, primarily begomoviruses. In Panama, particularly in the Azuero region, viral infections transmitted by this aphid can affect a substantial share of tomato crops cultivated for industrial use. A traditional alternative to synthetic pesticides involves exploring plant extracts with insecticidal properties derived from wild plants found in our tropical forests, which can be easily prepared and applied by farmers. In this context, the present research aimed to evaluate the insecticidal activity of ethanolic extracts from the stems and leaves of Sphagneticola trilobata on both nymphs and adults of A. gossypii. Mortality was assessed at 24, 48, and 72 h after applying three doses of each extract (25, 50, and 100 µg/L). A standard phytochemical analysis to determine insecticidal activity revealed that both extracts exhibited significant efficacy at the highest concentration tested; however, the leaf extract demonstrated greater effectiveness at lower concentrations. A comprehensive metabolomic study indicated that the active compounds are diterpenes derived from the pimarenyl cation. These compounds have been extensively documented for their insecticidal potential against various insect species, suggesting that ethanolic extracts from this plant could serve as viable candidates for agricultural insecticides to combat aphid infestations. Full article

The wild tomato (Solanum sisymbriifolium) is a globally distributed shrubby weed with both negative and positive impacts, including its invasive properties and the potential for pharmaceutical and traditional medicinal uses. Despite its ecological significance, the plant’s reproductive biology and pollination ecology remain poorly understood. This study aimed to investigate the floral biology, pollination ecology, and plant reproduction of the weed species. Some flower traits, such as flowering intensity, flower display size, and pollen and ovule production, peaked during spring, summer, and the monsoon, while flower longevity and stigmatic receptivity were the longest in winter. The plant species was self-compatible (ISI = 0.02), heavily depended on pollinators (IDP = 0.72), and experienced minimal pollination limitation (D = 0.10) under open-pollination conditions. Flower visitors’ traits (e.g., abundance, diversity, and richness) were higher in the spring, summer, and the monsoon, and these were lower in winter. The vital pollination service was provided by Amegilla zonata, Ceratina binghami, Lasioglossum cavernifrons, Nomia (Curvinomia) strigata, Tetragonula pagdeni, Xylocopa aestuans, Xylocopa amethystina, Xylocopa fenestrata, and Xylocopa latipes. Reproductive success, as indicated by fruit and seed set, varied seasonally, being higher during the spring–monsoon period and lower in winter. These findings support effective management of this weed species and help conserve the associated bee populations. Full article

Tomato (Solanum lycopersicum) is a globally important crop, and enhancing its fruit quality and phenotypic traits is a key objective in modern breeding. This study investigates the role of the LEAFY-COTYLEDON1-LIKE4 (L1L4), an NF-YB subunit of the nuclear factor Y (NF-Y) transcription factor, in tomato fruit development using RNA-sequencing data from zinc-finger nuclease (ZFN)-targeted disruption lines. Differential gene expression (DEG) analyses of two independent l1l4 mutant lines compared to the wild-type line revealed significant alterations in key metabolic pathways and regulatory networks that are implicated in fruit ripening. Specifically, L1L4 disruption impacted the genes and pathways related to the fruit’s color development (carotenoid and flavonoids), texture (cell wall modification), flavor (sugar and volatile organic compound metabolism), and ripening-related hormone signaling. The analyses also revealed multiple differentially expressed histones, histone modifiers, and transcription factors (ERFs, MYBs, bHLHs, WRKYs, C2H2s, NACs, GRAS, MADs, and bZIPs), indicating that L1L4 participates in a complex regulatory network. These findings provide valuable insights into the role of L1L4 in orchestrating tomato fruit development and highlight it as a potential target for genetically improving the fruit quality. Full article

The domesticated species currently available in the market have been developed through the breeding of wild relatives. Breeding strategies using wild relatives with high genetic diversity are attracting attention as an important approach for addressing climate change and ensuring sustainable food supply. However, studies examining gene expression variation in multiple wild and domesticated species are limited. Therefore, we aimed to investigate the changes in gene expression associated with domestication. We performed a meta-analysis of public gene expression data of domesticated species of rice, tomato, and soybean and their presumed ancestral species using 21 pairs for rice, 36 pairs for tomato, and 56 pairs for soybean. In wild relatives, the expression of genes involved in osmotic, drought, and wound stress tolerance was upregulated, with 18 genes included in the top 5% of DW scores. In domesticated species, upregulated expression was observed in genes related to auxin and those involved in the efflux of heavy metals and harmful substances, with 36 genes included in the top 5% of DW scores. These findings provide insights into how domestication influences changes in crop traits. Thus, our findings may contribute to rapid breeding and the development of new varieties capable of growing in harsh natural environments. Hence, a new cultivation method called “de novo domestication” has been proposed, which combines the genetic diversity of currently unused wild relatives and wild relatives with genome editing technologies that enable rapid breeding. Full article

Bacterial wilt (BW) is a globally serious soil-borne disease in a wide range of plants, caused by diverse strains of Ralstonia solanacearum. However, there are few research reports on melatonin regulating plant resistance against R. solanacearum. N-acetyltransferase SlSNAT2 is a rate-limiting enzyme in plant melatonin synthesis. This study elucidates the mechanisms of SlSNAT2 modulating tomato resistance to BW. SlSNAT2 was expressed in tomato roots, stems, and leaves and induced upon R. solanacearum inoculation. Knocking out SlSNAT2 significantly decreased the melatonin content in CRISPR/Cas9 mutant slsnat2. With R. solanacearum inoculation, the morbidity and disease index value of slsnat2 were significantly higher than those of the tomato wild-type plant Micro-Tom (MT) according to the wilt rate and severity. The chlorophyll levels, photosynthetic rates, and callus deposition quantity in slsnat2 were notably lower while the reactive oxygen species (ROS) level was considerably higher than those in the MT after inoculation. Additionally, the SlSNAT2 deficiency depressed the expression of the mitogen-activated protein kinase (MAPK) pathway genes (SlMPK1, SlMKK2), salicylic acid pathway genes (SlGluA, SlPR-1a), jasmonic acid pathway gene SlPin2, and pathogenesis-related (PR) protein genes (SlPR-STH2a, SlPR-STH2b, SlPR-STH2c, SlPR-STH2d). These results revealed SlSNAT2 enhanced the tomato resistance against R. solanacearum by orchestrating ROS homeostasis, callose deposition, MAPK signaling, hormone pathways, and PR gene transcripts. Full article

NF-Y transcriptional regulators play crucial roles in diverse biological processes in plants, primarily through the formation of NF-Y complexes that bind to specific DNA motifs. These complexes modulate the expression of downstream genes, which influence plant development and growth. In our research, the function of the NF-Y family C subunit member SlNF-YC9 gene in tomato was investigated with the CRISPR/Cas9 method. In contrast to the WT (wild type), the mutant CR-SlNF-YC9 exhibited a prominent protrusion at the fruit tip. The quantitative PCR analysis displayed that the transcription levels of genes associated with auxin transport (PIN4, PIN5, and PIN9) as well as auxin response genes (ARF7 and LAX3) were enhanced in the CR-SlNF-YC9 fruits than in the WT. Analysis of dual-luciferase reporter and EMSA assays showed that the SlNF-YC9-YB13b-YA7a trimer specifically binds the FUL2 promoter and represses its expression. In conclusion, our results suggest that SlNF-YC9 is crucial in influencing tomato fruit shape by the formation of NF-Y heterotrimeric complexes. Full article

The domestication process not only reduced the allelic diversity of tomato genotypes but also affected the genetic traits associated to microbial recruitment, their composition, and their diversity in different compartments of the plant host. Additionally, this process included the transition from natural to agricultural soils, which differ in nutrient availability, physicochemical properties, and agricultural practices. Therefore, modern cultivars may fail to recruit microbial taxa beneficial to their wild relatives, potentially losing important ecological functions. In this study, we analyzed the phylogenetic relationship and the rhizosphere microbiota of four tomato genotypes, Solanum chilense (wild species), S. lycopersicum var. cerasiforme (Cherry tomato), and the S. lycopersicum landrace ‘Poncho Negro’ and the modern cultivar ‘Cal Ace’, grown in both natural and agricultural soils. Microbial communities were identified using 16S rRNA (bacteria) and ITS2 (fungi) amplicon sequencing, allowing cross-domain taxonomic characterization. While the soil type was the main driver of overall microbial diversity, the host genotype influenced the recruitment of specific microbial taxa, which exhibited different recruitment patterns according to the genetic diversification of Solanum genotypes and soil types. Additionally, co-occurrence network analysis identified two main clusters: first, taxa did not show any preferential associations to particular genotypes or soil types, while the second cluster revealed specific microbial patterns associated to fungal taxa in natural soil and bacterial taxa in agricultural soil. Finally, the functional analysis suggested the loss of specific functions through tomato domestication independently of soil type. These findings highlight the role of the plant genotype as a fine-tuning factor in microbiome assembly, with implications for breeding strategies aimed at restoring beneficial plant–microbe interactions. Full article

Chaperonin 60 proteins plays an important role in plant growth and development as well as the response to abiotic stress. As part of the protein homeostasis system, molecular chaperones have attracted increasing attention in recent years due to their involvement in the folding and assembly of key proteins in photosynthesis. However, little is known about the function of maize chaperonin 60 protein. In the study, a gene encoding the chaperonin 60 proteins was cloned from the maize inbred line B73, and named ZmCpn60-3. The gene was 1, 818 bp in length and encoded a protein consisting of 605 amino acids. Phylogenetic analysis showed that ZmCpn60-3 had high similarity with OsCPN60-1, belonging to the β subunits of the chloroplast chaperonin 60 protein family, and it was predicted to be localized in chloroplasts. The ZmCpn60-3 was highly expressed in the stems and tassels of maize, and could be induced by exogenous plant hormones, mycotoxins, and pathogens; Overexpression of ZmCpn60-3 in Arabidopsis improved the resistance to Pst DC3000 by inducing the hypersensitive response and the expression of SA signaling-related genes, and the H₂O₂ and the SA contents of ZmCpn60-3-overexpressing Arabidopsis infected with Pst DC3000 accumulated significantly when compared to the wild-type controls. Experimental data demonstrate that flg22 treatment significantly upregulated transcriptional levels of the PR1 defense gene in ZmCpn60-3-transfected maize protoplasts. Notably, the enhanced resistance phenotype against Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) in ZmCpn60-3-overexpressing transgenic lines was specifically abolished by pretreatment with ABT, a salicylic acid (SA) biosynthetic inhibitor. Our integrated findings reveal that this chaperonin protein orchestrates plant immune responses through a dual mechanism: triggering a reactive oxygen species (ROS) burst while simultaneously activating SA-mediated signaling cascades, thereby synergistically enhancing host disease resistance. Additionally, yeast two-hybrid assay preliminary data indicated that ZmCpn60-3 might bind to ZmbHLH118 and ZmBURP7, indicating ZmCpn60-3 might be involved in plant abiotic responses. The results provided a reference for comprehensively understanding the resistance mechanism of ZmCpn60-3 in plant responses to abiotic or biotic stress. Full article