Calcium ions (Ca²⁺) serve as ubiquitous second messengers, orchestrating various physiological and developmental processes in plants and other eukaryotes. Upon immune activation, spatiotemporal changes in cytosolic Ca²⁺ concentration, referred to as calcium signatures, play a crucial role in linking pathogen recognition to specific downstream intracellular immune responses. These signatures are generated via the coordinated activity of calcium-permeable channels, including cyclic nucleotide-gated channels, glutamate receptor-like channels, hyperosmolality-gated calcium-permeable channels, annexins, two-pore channels, and resistosomes derived from nucleotide-binding leucine-rich repeat receptors, as well as by mobilization from intracellular organelles. Meanwhile, Ca²⁺ pumps and antiporters maintain cytosolic homeostasis. Calcium signals are decoded by calcium sensors, such as calmodulins and calmodulin-like proteins, calcium-dependent protein kinases, calcineurin B-like proteins, and CBL-interacting protein kinases. This decoding triggers crucial downstream immune outputs, including reactive oxygen species production, defense gene expression, hormone modulation, and programmed cell death. Pathogens deploy effectors to modulate calcium influx, sensor function, or downstream signaling, highlighting calcium signaling as a primary target in host-pathogen interactions. This review summarizes the fundamental role of calcium signaling in plant defense, focusing on recent discoveries in signal decoding and pathogen counter-strategies, and aims to provide strategies for engineering disease-resistant crops.

Insect natural enemies, encompassing predators and parasitoids, serve as vital regulators of pest populations and architects of ecosystem balance. Most studies on natural enemies have focused on understanding the mechanisms by which these insects eliminate pests after an attack. For example, in parasitoid wasps, the majority of studies have focused on how parasitoid venoms manipulate the host's immune system and development. However, it is important to recognize that natural enemies and pests often coexist in the same space prior to an attack, allowing for interactions that may occur before the attack itself. These preattack interactions have the potential to influence pests to varying degrees, yet they remain an underexplored area in current research. Although some existing studies have investigated the molecular mechanisms underlying pest responses to parasitoid detection, few have explored the practical implications of such findings for biological control practices. In this commentary, we aim to explore the key findings regarding the physiological and behavioral impacts of parasitoid wasp intimidation on hosts before parasitoid attack. We also examine the differences in host responses under diverse parasitoid stress, highlighting the complex interactions that occur before actual parasitism takes place. Finally, we discuss the insights these findings provide for developing novel pest control strategies.

Locusts and grasshoppers are worldwide agricultural pests, with their reproductive regulation serving as the critical basis for group growth and dispersal. Advances in bioinformatics and molecular biology have expanded the understanding of reproductive regulation beyond physiological responses and classical neural control. Numerous coding and noncoding genes participate in the intricate regulatory networks of reproduction. Studies on locusts and grasshoppers not only shed light on regulatory mechanisms of non-Drosophila insects but also identify potential targets for pest control. However, a comprehensive summary of reproductive regulatory mechanisms in locusts and grasshoppers remains lacking. Here, we synthesize key findings on hormones, neuropeptides and neurotransmitters, multifunctional integrative genes, epigenetic factors, and population density-dependent regulation. We strengthen the interplay between extrinsic environmental factors and intrinsic gonadal systems of locusts and grasshoppers. Finally, we propose future directions for studies on the regulation of reproduction in locusts and grasshoppers.

Plasmodesmata (PD) are unique connection structures between plant cells that play a key role in the transportation of signal molecules and metabolites. In noncell-autonomous immunity, PD function as battlegrounds against intruders, including viral, fungal and bacterial pathogens. Recent studies have demonstrated that a variety of proteins, including catalytic enzymes involved in callose metabolism, callose-binding proteins, receptor kinases, lipid-associated proteins, and tether proteins, serve as critical molecular hubs in plant defense responses by facilitating the closure of PD. Here, we present a comprehensive overview of the regulation mechanisms of PD-related proteins in the process of plant disease resistance. Moreover, we discuss the challenges currently encountered in PD regulation and highlight critical questions for future investigation. Addressing these issues will further enhance our understanding of intercellular communication in plant defense system and promote its application in agriculture.

Plant diseases cause severe yield losses annually, threatening global food security. Traditional resistance breeding faces challenges such as rapid pathogen evolution and yield-defense trade-offs. Defense heterosis—the phenomenon where F₁ hybrids derived from crosses between genetically distinct parental lines exhibit superior disease resistance compared to parents—provides a promising solution. This review summarizes recent advances in understanding defense heterosis, from its conceptual evolution to modern genomic insights. Here, we outline three classical genetic hypotheses (dominance, overdominance, and epistasis) and introduce molecular mechanisms, including differentially expressed genes, epigenetic regulation (DNA methylation, histone modifications), and salicylic acid-mediated coordination of immunity. Case studies across rice, maize, wheat, and potato demonstrate the prevalence and variability of defense heterosis. We highlight that future efforts should utilize multiomics data, genome editing, and microbiome manipulation to predict and deploy defense heterosis. This integrated perspective bridges fundamental research and agricultural applications, offering a roadmap to enhance crop resilience and food security.

The beet webworm Loxostege sticticalis (Lepidoptera: Crambidae) is a transcontinental migratory pest whose population outbreaks are driven by the coordination of migration and reproduction through the interplay of internal and external factors. This study reveals that prolonged flight in sexually immature adults induces two key post-flight responses: (1) increased feeding behavior and (2) flight muscle histolysis, characterized by ultrastructural reorganization of myofibrils and mitochondrial degeneration. These processes collectively redirect metabolic resources (lipids, glycogen, and amino acids) toward ovarian development. Concomitantly, flight accelerates juvenile hormone (JH) biosynthesis, which activates the JH receptor methoprene-tolerant (Met) and its downstream effector Krüppel-homolog 1. This signaling cascade upregulates vitellogenin expression and promotes yolk deposition. Crucially, RNA interference-mediated knockdown of Met disrupts ovarian development, suppresses fecundity, and abolishes flight-induced reproductive benefits, thereby establishing the necessity of this pathway. Together, these integrated mechanisms accelerate ovarian maturation and synchronize oviposition, effectively resolving the flight-reproduction trade-off by repurposing nutrients derived from flight muscles for vitellogenesis. Our findings elucidate key adaptive mechanisms underlying insect migration, identifying JH signaling and muscle remodeling as critical targets for disrupting life-history strategies and suppressing pest populations.

The codling moth (Cydia pomonella) is a globally significant internal-feeding pest of apple and other pome fruits, yet its cryptic larval behavior poses challenges to conventional control strategies. To identify effective feeding stimulants for manipulating larval-stage behavior, we established an integrative pipeline combining large-scale transcriptomic profiling, in silico receptor-ligand docking, and behavioral assays. Based on transcriptomes spanning 10 tissues and 21 developmental stages, we annotated 59 gustatory receptors (GRs) (CpomGRs) and 53 ionotropic receptors (CpomIRs). Candidates enriched in chemosensory tissues and larval stages were selected for structural modeling. Computational docking of 117 apple-related metabolites against selected receptors identified high-affinity interactions, particularly between sugar compounds and GRs/IRs. Behavioral feeding assays confirmed that isoquercitrin, a flavonoid glycoside, significantly enhanced larval feeding in a dose-dependent manner, with 1‰ concentration yielding effects comparable to a full sugar mixture. This study demonstrates the utility of transcriptome-guided in silico screening for discovering behaviorally active tastants and provides a foundation for developing bait-based control strategies targeting codling moth larvae. The approach outlined here offers a scalable framework for identifying chemosensory targets and feeding stimulants in other cryptic insect pests.

Residual nicosulfuron in soil can induce persistent phytotoxic effects on subsequent soybean (Glycine max L.) crops, yet the physiological trajectory from early stress to photosynthetic collapse remains unclear. Here, we established a multimodal phenotyping framework that integrates hyperspectral reflectance, ultraviolet-excited multichannel fluorescence, and chlorophyll fluorescence quenching imaging to capture stage-specific soybean responses under nicosulfuron stress. Early pigment disruption was marked by a 12.3% decrease in the chlorophyll index 3, while metabolic activation was indicated by an increase in fluorescence at 450 nm to 3.26 ± 0.16 at 100 μg/kg, compared to 2.05 ± 0.05 in the control group. These were followed by photosystem II (PSII) dysfunction, including a decline in the maximum quantum efficiency of PSII under light adaptation (Fv/Fm_Lss) from 0.71 to 0.37, a 102% increase in non-photochemical quenching under light adaptation (NPQ_Lss), and a 38% reduction in maximum fluorescence under light adaptation (Fm_Lss), reflecting photosystem disintegration. Such impairments culminated in a marked elevation of the Integrated Biomarker Response version 2. This study identifies a distinct injury-regulation-collapse pathway and phase-specific markers, while the integrated imaging approach enables earlier, non-invasive detection and dynamic monitoring, providing a mechanistic basis for risk assessment in herbicide-impacted rotation systems.

The entomopathogenic fungus Metarhizium anisopliae plays a crucial role in sustainable agriculture by controlling diverse pests, but insect innate immunity hinders its efficacy by impeding spore germination. GameXPeptide (GXP), a metabolite derived from entomopathogenic nematode symbiotic bacteria, suppresses insect immunity, yet its interaction with entomopathogenic fungi (EPF) remained unstudied. This study demonstrates that GXP enhances the efficacy of M. anisopliae against cotton aphids, as evidenced by laboratory bioassays, metabolomic profiling, and experimental investigations. Our results reveal that GXP does not have any adverse effects on the fungus. However, the combined application of GXP and M. anisopliae significantly increases the mortality rate of cotton aphids. Furthermore, our findings indicate that this synergistic interaction notably influences the metabolic processes of cotton aphids. Notably, there is a significant decrease in purine metabolism compared to that in aphids infected solely by M. anisopliae. This alteration in purine metabolism could potentially account for the observed reduction in melanization in aphids infected by the fungus in the presence of GXP. In summary, our results highlight that the combined effect of GXP and M. anisopliae enhances the virulence of the fungus against cotton aphids by modulating their metabolism and immune responses. This study is the first to demonstrate that GXP can enhance the virulence of M. anisopliae against cotton aphids. These findings provide a novel strategy for improving biopesticide efficacy in sustainable agriculture.