Sri Lankan cassava mosaic virus (SLCMV) is a highly destructive plant virus that poses a significant threat to cassava cultivation. It causes severe symptoms, including distinctive leaf mosaic patterns and stunted plant growth. Here, transcriptome sequencing revealed that SLCMV infection induced widespread transcriptional reprogramming, with 10,164 differentially expressed genes-6910 up-regulated and 3254 down-regulated. Notably, the down-regulated genes were primarily associated with plant chloroplast components and photosynthesis pathways. Reverse transcription-quantitative PCR analysis confirmed the suppression of key genes involved in photosystem I (PSI) and photosystem II (PSII). Further investigation revealed that SLCMV infection disrupted chloroplast ultrastructure and reduced total chlorophyll content, thereby inhibiting photosynthetic capacity in Nicotiana plants. Importantly, our findings highlighted the critical role of the SLCMV-encoded BC1 protein in repressing photosynthesis-related gene expression and attenuating overall photosynthetic activity. SLCMV-encoded movement protein BC1 down-regulates the expression of photosynthesis-related genes and disrupts chloroplast structure, ultimately leading to reduced photosynthetic activity.

Reynoutria japonica, known for its exceptional growth capacity and tolerance to multiple abiotic stresses, represents an ideal model for studying the trade-off between plant growth and stress adaptation. However, the molecular mechanisms underlying the balance between plant growth and stress resistance in R. japonica remain unclear. Increasing evidence indicates that WRKY proteins play a direct role in regulating the equilibrium between plant growth and resistance. In this study, we identified and conducted bioinformatics analysis about WRKY gene family from two haplotype chromosomes (HapA 89, HapE 82) in R. japonica. These 171 RjWRKY members distributed in three groups: group I (34), group II (115), and group III (22). RjWRKY members within the same group or subgroup typically exhibited similar conserved motifs and gene structures. Promoter sequences in the WRKY gene family contained a series of cis-acting elements related to plant growth and development, stress response, and hormone response. Based on transcriptome data, we screened 12 candidate RjWRKY genes that are associated with stem elongation and are simultaneously responsive to methyl jasmonate (MeJA, a stress-response ‘messenger’) and ultraviolet (UV) radiation. Further, we confirmed the relative expression levels of 12 RjWRKY genes during different stem-growth stages as well as under auxin (IAA) or auxin antagonist (PEO-IAA), salt, cadmium (Cd) and manganese(Mn) treatments by qRT-PCR. The 12 RjWRKY genes, responsive to both auxin signals and abiotic stress, may thus represent key regulators mediating the trade-off between plant growth and stress in this invasive plant species. In addition, overexpression of HuZ00251595.1 (a homology of AtWRKY11, designated as RjWRKY11) in A. thaliana significantly enhanced resistance to Cd. These results establish a solid foundation for further exploration into the functions of the RjWRKYs in the balance of growth and adaptation to various abiotic stresses in R. japonica.

Supplementary Table S3: RT-qPCR Primers and short hairpin RNAs (shRNAs) sequence of BHLHE40

N 6-methyladenosine (m6A) is a prevalent and functionally significant RNA modification regulating mRNA metabolism. While m6A modification in plant mRNA is well-characterized, its role in ribosomal RNA (rRNA) function has remained largely unexplored in plants. In this article, we provide a comprehensive overview of two recent findings that Arabidopsis rRNA N(6)-adenosine-methyltransferase 5 (METTL5) specifically mediates m6A deposition at position A1771 of the 18S rRNA—an event that plays a pivotal role in ribosome assembly and translation of stress-responsive genes.

Pattern-triggered immunity (PTI) is the first layer of the plant immune system, which relies on the perception of pathogen-associated molecular patterns. Recently, it has been found that double-stranded RNA (dsRNA), a hallmark of viral invasion, triggers typical PTI responses; however, the underlying signaling pathways are not yet elucidated. Here, we identify a plant-specific, leucine-rich repeat family protein, AtCERES, involved in dsRNA-triggered activation of defense-related genes, MPK3/6 phosphorylation and seedling growth inhibition. AtCERES directly binds the mitochondrial glycoprotein AtXIAN, which also positively regulates dsRNA-triggered immune responses. Upon dsRNA perception, AtXIAN and AtCERES affect the level of mitochondrial reactive oxygen species (mROS), which is independent of respiratory burst oxygenase homologs D. Importantly, the generation of mROS is required for immune responses triggered by dsRNA. Together, our results uncover the function of AtCERES and AtXIAN as components of the dsRNA-triggered immune pathway, and suggest a link between mROS and antiviral immunity in plants.

BACKGROUND:Insect vectors are responsible for transmitting the majority of plant viruses. While the interplays between insect vectors and viruses have been extensively investigated, how other organisms associated with the shared host plants of the insect and virus impact virus transmission dynamics, and the corresponding viral countermeasures, remain largely unknown. RESULTS:We explored the modulation of whitefly-mediated transmission of geminiviruses by two non-vector herbivores and the role of viral C2 proteins. The infestation of cotton bollworm induced the accumulation of jasmonic acid (JA) in plants, which in turn elicited plant repellence against whiteflies. Tomato yellow leaf curl virus (TYLCV) and its C2 inhibited JA-induced plant repellence against whiteflies. However, infestation by another non-vector insect, the green peach aphid, induced salicylic acid (SA) accumulation, thereby decreasing TYLCV infection in plants. TYLCV C2 dampens SA-induced antiviral defenses against TYLCV. The functions of TYLCV C2 in subverting both JA-induced plant repellence against the insect vector and SA-induced antiviral defenses seem conserved, as it was also observed in C2 proteins encoded by members of two other genera Becurtovirus and Topocuvirus. Mechanistically, geminiviral C2 proteins did not affect JA or SA biosynthesis but suppressed the signal transduction of both pathways. CONCLUSION:This study demonstrates that geminiviral C2 proteins suppress JA- and SA-mediated defenses induced by non-vector herbivores, thereby facilitating whitefly-mediated virus transmission. © 2026 Society of Chemical Industry.

Cysteine palmitoylation (S-palmitoylation or S-acylation) is a reversible post-translational modification dynamically controlled by opposing enzymes: palmitoyl acyltransferases (PATs) and depalmitoylases. Despite its established roles in other systems, the mechanistic details of S-acylation in plants, particularly its spatiotemporal regulation during plant-virus interactions, remain poorly understood, largely due to the lack of validated enzyme-substrate pairs. Using the geminivirus tomato yellow leaf curl Chuxiong virus (TYLCCxV) as a model, we show that the viral effector C4 undergoes S-palmitoylation at Cys-4, a modification essential for its plasma membrane anchorage and subsequent mediation of viral pathogenesis. NbPAT4, a palmitoyl acyltransferase from Nicotiana benthamiana, catalyzes C4 S-palmitoylation, promoting its membrane localization, protein stability, and viral infection. Conversely, the C4S substitution (C4C4S) abolishes S-palmitoylation, leading to cytoplasmic redistribution, protein destabilization, and impaired viral pathogenicity. We further identify NbABHD6 as a depalmitoylase that interacts with C4 and catalyzes its S-depalmitoylation, triggering C4 degradation via the 26S proteasome pathway. This study reveals a regulatory axis in plant-geminivirus interactions, identifying NbPAT4 and NbABHD6 as antagonistic enzymes that dynamically regulate the stoichiometry of C4 S-acylation. These findings support a host-pathogen enzymatic tug-of-war model in which competitive S-palmitoylation homeostasis governs viral subcellular trafficking and pathogenicity.

Crop breeding endeavors are frequently constrained by the growth-defense trade-off, and uncoupling this trade-off remains challenging due to the limited knowledge of master regulators. Geminivirus-betasatellite complexes, through the betasatellite-encoded protein βC1, suppress auxin-mediated plant growth and salicylic acid (SA)-mediated immunity. βC1 interacts with and prevents the degradation of plant IAA16 by blocking ATL52-mediated ubiquitination. IAA16 functions as a negative regulator of both auxin and SA signaling pathways. IAA16 interacts with OBP4 to promote the transcription of the SA-signaling repressor NPR3. Notably, regulation of auxin and SA signaling by IAA16, as well as viral manipulation of IAA16 stability, appears to be conserved, as they were documented in tomato plants. Together, our study of viral action on IAA16 reveals a negative regulator of both plant growth and immunity. These findings open fresh avenues for understanding viral manipulation of plant growth and immunity and suggest potential targets for crop improvement.

The rapid commercialization of Nicotiana benthamiana as a scalable biofactory for molecular farming necessitates large-scale cultivation, which in turn elevates the agronomic risk of significant yield loss due to pest outbreaks. The plant cell wall is a crucial primary structural barrier against herbivores, yet the molecular mechanisms underlying cell wall-mediated defense, particularly against piercing-sucking insects, remain poorly characterized. In this study, we demonstrate that aphid infestation of N. benthamiana triggers a broad defense response and significant cell wall thickening. Through expression profiling, we identified a Xyloglucan endotransglucosylase/hydrolase gene (NbXTH30) as a key insect-responsive gene, which plays an important role in modifying cell wall architecture. Functional characterization revealed that NbXTH30 enhances plant resistance to aphids by disrupting insect feeding behavior. Further enzymatic analysis confirmed that NbXTH30 functions as an active xyloglucan endotransglucosylase (XET), contributing to cell wall reinforcement. The conservation of this mechanism was underscored by the fact that the tomato ortholog similarly conferred resistance against piercing-sucking insects. Our findings delineate a defense mechanism, from the induction of NbXTH30 to XET-mediated cell wall thickening and ultimately enhanced insect resistance, providing both fundamental insights into plant structural immunity and a promising genetic target for breeding insect-resistant crops.

The Toll7 pathway is crucial in defending against diverse pathogenic microorganisms, including viruses. This study reveals that a plant virus (rice stripe virus, RSV) infection activates Toll7-mediated antiviral response in the insect vector Laodelphax striatellus. We identified a specific interaction between the TIR domain of Toll7 and RSV glycoprotein (Gc). Furthermore, Toll7 silencing significantly enhanced RSV replication and acquisition, suggesting its antiviral role in L. striatellus. Transcriptomic analysis indicated that Toll7 negatively regulates the PI3K-Akt-mTOR pathway, a key autophagy regulator. Toll7 knockdown upregulated the expression of PI3K, Akt and mTOR; simultaneously, autophagy-related genes (Atg3, Atg5, Atg8, Atg9, Torc1 and ULK1) were downregulated and autophagy inhibitor Sqstm1 was upregulated. Conversely, silencing PI3K, Akt or mTOR suppressed RSV replication, highlighting the essential role of this pathway in viral persistence within its vector. These findings demonstrate that Toll7-mediated inhibition of the PI3K-Akt-mTOR pathway activates autophagy, restricting RSV replication in L. striatellus. This study uncovers a conserved Toll7-dependent antiviral mechanism modulating autophagy to inhibit viral infection, offering new insights into the co-evolutionary dynamics between plant viruses and insect vectors.

Supplementary Table S1: Detailed sources and clinical information for each 22 single-cell RNA-seq sample.

The cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) is a major pest of numerous crops. Plant responses to cotton bollworm attack are generally attributed to two primary factors: physical wounding and components of insect oral secretions. Discriminating between these responses is critical for understanding plant defense and developing pest control strategies. In this study, we found that cotton bollworm infestation specifically upregulated the expression of NtNAC29 and NtNAC94, whereas mechanical wounding did not. Functional analyses revealed that silencing either gene promoted bollworm growth, whereas overexpression suppressed larval development. These results demonstrated that NtNAC29 and NtNAC94 had pivotal roles in enhancing plant resistance to bollworm. Further analyses showed that both NAC transcription factors regulated the expression of Cysteine Protease Inhibitor 8 (NtCPI8) by binding to specific sites within the NtCPI8-1 and NtCPI8-2 promoters. Consistently, NtCPI8 exhibited a similar defensive role, significantly inhibiting cotton bollworm growth as reflected by reduced larval weight gain and shorter body length. Overall, our findings suggest that tobacco plants recognize cotton bollworm attack and activate downstream defense responses, including the induction of NtNAC29 and NtNAC94. These transcription factors in turn upregulate NtCPI8 expression, thereby strengthening plant resistance against insect herbivory. Notably, this NAC-CPI regulatory module is conserved among different crop species, providing a promising target for improving crop protection against herbivorous insects.

The transmission of many plant viruses depends on arthropod vectors, which acquire viruses while feeding on infected plants and subsequently inoculate un-infected hosts. Efficient virus acquisition, particularly for persistently transmitted viruses, requires sustained vector feeding on infected plants. However, how vector infestation influences plant-virus interactions and the modulation of these impacts by viral factors remains poorly understood. Here, we show that whitefly infestation on begomovirus-infected plants activates host antiviral defenses through inducing salicylic acid (SA) accumulation. Betasatellites associated with begomoviruses, specifically the βC1 protein encoded therein, suppress these whitefly-induced defenses by interfering with SA accumulation and signaling. Mechanistically, βC1 interacts with Nicotiana benthamiana ENHANCED DISEASE SUSCEPTIBILITY 1 (NbEDS1), disrupting its interaction with NbPAD4 to reduce SA accumulation. Additionally, βC1 interferes with the association between NbEDS1 and NbTGA2, thereby attenuating NbTGA2-mediated transcription of SA-responsive genes. Our findings unravel a novel mechanism by which βC1 promotes begomovirus-whitefly compatibility, offering new insights into insect vector-mediated transmission of plant viruses.

The outbreak of vector-borne plant viruses entails both efficient in planta virus infection and productive vector-mediated transmission. Yet, the factors that concurrently regulate these two key viral traits remain understudied. Here we examine the role of viral proteins and the salicylic acid (SA) signaling pathway in modulating virus infection and vector preference to virus-infected plants. Infection of plants by the bipartite begomovirus, Sri Lankan cassava mosaic virus (SLCMV), dramatically induces the accumulation of SA, a positive regulator of antiviral defense. As countermeasures, SLCMV DNA-B and the BV1 protein encoded therein interfere with SA-induced antiviral defenses and SA signal transduction. Furthermore, whilst SA induces plant repellence to whitefly vectors, this repellence is mitigated by SLCMV DNA-B and BV1. Mechanistic explorations in N. benthamiana plants reveal that BV1 downregulates the transcription of BTB/POZ and TAZ domain-containing protein 1 ( BT1 ), a positive regulator of plant SA signal transduction, antiviral defenses and repellence against whitefly. Finally, these principles of plant-bipartite begomovirus interactions are also documented for another bipartite begomovirus. Together, our data highlight the role of virus-SA interplay in enabling competent interactions among plant hosts, bipartite begomoviruses and their whitefly vectors, and advance our understanding of the molecular mechanisms that promote the persistence of vector-borne plant viruses.

Aphids threaten many economically important crops by extracting plant sap and efficiently transmitting plant viruses. To elucidate the molecular mechanisms underlying plant-aphid interactions, we performed mRNA, circRNA, and microRNA sequencing to investigate the response of tobacco plants to infestation by the aphid Myzus persicae. Our results revealed that aphid infestation significantly upregulated 1,091 genes and downregulated 407 genes. Notably, differentially expressed genes were enriched in several key pathways, including the MAPK signaling pathway, α-linolenic acid metabolism, glutathione metabolism, and plant-pathogen interactions. Analysis of circRNA expression identified 53 circRNAs with significant changes following aphid infestation. However, neither their predicted miRNA targets nor their host genes exhibited altered expression levels, suggesting that circRNAs may play previously uncharacterized roles in plant responses to aphid attack. Approximately 400 miRNAs were predicted in each library, with nearly two-thirds identified as novel. Among them, 22 miRNAs were differentially expressed in response to aphid infestation, but only 8 were predicted to target mRNAs, indicating a selective role of miRNAs in regulating gene expression during the aphid response. In summary, our findings shed light on the transcriptional and post-transcriptional regulatory mechanisms activated in tobacco during aphid infestation. Our findings provide a basis for future studies of aphid-responsive regulatory mechanisms in plants.

Bemisia tabaci is a complex of cryptic agro-economically important pest species characterized by diverse clades, substantial genetic diversity along with strong phylogeographic associations. However, a comprehensive phylogenomic analysis across the entire complex has been lacking, we thus conducted phylogenomic analyses and explored biogeographic patterns using 680 single-copy nuclear genes (SCNs) obtained from whole-genome sequencing data of 58 globally sourced B. tabaci specimens. We constructed both concatenation and coalescent trees using 680 SCNs, which produced highly supported bootstrap values and nearly identical topologies for all major clades. When comparing these concatenation trees with those constructed using mitochondrial cytochrome oxidase I (mtCOI) and mitochondrial genome, we found conflicting phylogenetic relationships, with the later trees recovering fewer major clades. In a separate comparison between concatenation and coalescent trees, particularly those generated using IQ-TREE, they were found to delineate population relationships more effectively than RaxML. In contrast, coalescent phylogenies were proficient in elucidating geographical dispersal patterns and the reorganization of biological species. Furthermore, we provided a strict consensus tree that clearly defines relationships within most clades, laying a solid foundation for future research on the evolution and taxonomy of B. tabaci. Ancestral range estimates suggested that the ancestral region of the complex is likely situated in equatorial Africa, the Middle East, and Mediterranean regions. Subsequently, the expansion occurred into part of the Palearctic and further into the Nearctic, Neotropical, Indomalayan, and Australasian regions. These findings challenge both previous classifications and origin hypotheses, offering a notably more comprehensive understanding of the global distribution, evolutionary history, diversification, and biogeography of B. tabaci.

Phosphoserine/threonine-binding proteins from the 14-3-3 class are involved in a variety of regulatory processes in all eukaryotic cells, including yeast, protozoa and mammals. Recently, 14-3-3 proteins have been identified in the saliva of some phloem-feeding insects, but their function remains poorly understood. 14-3-3 protein, secreted by the phloem-feeding whitefly Bemisia tabaci (Bt14-3-3), is delivered into tobacco plants during feeding. Within the plant, Bt14-3-3 interacts with the tobacco abscisic acid-insensitive 5-like (ABI5) basic leucine zipper transcription factor, repressing its ability to bind cis-acting activating elements present in the promoter region of the plant defensin J1-2 (PDF1.2) gene. Downregulation of PDF1.2 expression suppresses plant defenses, leading to enhanced whitefly performance. A homologous 14-3-3 protein secreted by the phloem-feeding aphid Myzus persicae was found to similarly enhance aphid performance on tobacco plants by interfering with the ability of ABI5 to transactivate the PDF1.2 gene. These results raise the possibility that during the evolutionary 'arms-race' between plants and phloem-feeding insects, 14-3-3 proteins present in the insects' saliva might have evolved novel functions that contribute to the ability of these insects to counterbalance their host plant defenses, transforming them into a suitable habitat for feeding and reproduction.

Plant viruses cause symptoms with devastating consequences for agriculture. However, the molecular mechanisms underlying symptom development in viral infections remain largely unexplored. Here, we show that tomato yellow leaf curl virus (TYLCV) interferes with host developmental programs through a host-mimicking domain present in the viral C4 protein. This domain mediates the interaction between C4 and a family of RCC1-like domain-containing (RLD) proteins, previously shown to be required for proper plant development and environmental responses. C4 outcompetes an endogenous interactor of RLDs, hijacking RLD proteins to the plasma membrane and disrupting their function in orchestrating endomembrane trafficking and polar auxin transport. Strikingly, macroscopic symptoms do not affect viral accumulation in the plant but serve as attractants for the insect vector, presumably promoting pathogen spread in an ecological context. Our work sheds light on the molecular underpinnings and biological relevance of symptom development triggered by TYLCV in tomato. Since most plant viruses are insect-transmitted, the principles described here might have broad applicability to crop-virus interactions.