This review provides an in-depth examination of the intricate interactions between plant metabolites and the digestive and antioxidative enzymes in insects, highlighting their essential roles in shaping insect herbivory and adaptation strategies. Plants have evolved a diverse arsenal of secondary metabolites to defend against herbivorous insects, which, in response, have developed sophisticated adaptations to overcome these defenses and efficiently exploit plant resources. We outline the importance of digestive enzymes, such as proteases and amylases, which allow insects to break down complex plant compounds and access vital nutrients. Additionally, the review focuses on antioxidative enzymes in the insect midgut, including superoxide dismutase and catalase, which play a crucial role in mitigating oxidative stress generated during digestion and other metabolic processes. Synthesizing findings from various studies, this review also considers how environmental factors, such as heavy metal exposure and temperature changes, influence these enzymes’ activity levels. It highlights the dual function of antioxidative enzymes in detoxifying harmful plant-derived compounds while preserving cellular stability. The implications of these biochemical interactions for pest management are discussed, with an emphasis on the potential for developing biopesticides that target specific enzymatic pathways to disrupt insect feeding and growth. By elucidating the biochemical mechanisms that underlie plant-insect interactions, this review enhances our understanding of co-evolutionary dynamics and offers insights into sustainable agricultural practices that could leverage these interactions for effective pest control. Finally, the review proposes future research directions aimed at identifying novel plant metabolites with enzyme-modulating properties and exploring the ecological impacts of enzyme-targeted pest management approaches.

The present study was carried out in a pot experiment to examine the bioefficacy of three biocontrol agents, viz., Trichoderma viride, Bacillus subtilis, and Pseudomonas fluorescens, either alone or in consortium, on plant growth promotion and activation of defense responses in potato against the early blight pathogen Alternaria solani. The results demonstrate significant enhancement in growth parameters in plants bioprimed with the triple-microbe consortium compared to other treatments. In potato, the disease incidence percentage was significantly reduced in plants treated with the triple-microbe consortium compared to untreated control plants challenged with A. solani. Potato tubers treated with the consortium and challenged with pathogen showed significant activation of defense-related enzymes such as peroxidase (PO) at 96 h after pathogen inoculation (hapi) while, both polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) at 72 hapi, compared to the individual and dual microbial consortia-treated plants. The expression of antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT) and the accumulation of pathogenesis-related proteins such as chitinase and β-1,3-glucanase were observed to be highest at 72 hapi in the triple microbe consortium as compared to other treatments. HPLC analysis revealed significant induction in polyphenolic compounds in triple-consortium bioprimed plants compared to the control at 72 hapi. Histochemical analysis of hydrogen peroxide (H₂O₂) clearly showed maximum accumulation of H₂O₂ in pathogen-inoculated control plants, while the lowest was observed in triple-microbe consortium at 72 hapi. The findings of this study suggest that biopriming with a microbial consortium improved plant growth and triggered defense responses against A. solani through the induction of systemic resistance via modulation of the phenylpropanoid pathway and antioxidative network.

The current reports on phytopathogens multidrug resistance have become a significant issue for plant health and global food security. Antimicrobial peptides (AMPs) have recently gained generous attention as potential alternatives to prevent plant disease resistance because of their potent, multifarious antimicrobial activity. AMPs are low-weight protein molecules. Living organisms secrete a wide range of AMPs, with some synthesised by canonical gene expression, known as ribosomal AMPs, and non-ribosomal AMPs, synthesised by modular enzyme-generating systems. Plants produce an array of AMPs, yet they are still unknown to many infection processes of causal agents. Plant-derived AMPs have a wide range of structures and functions, and they induce an innate immune system in plants. The biologically active AMPs in plants mainly depend on direct and indirect interactions with membrane lipids. Transgenic plants have expressed several AMPs, the basis for the model of new synthetic analogues, to provide support against diseases. These peptides have shown significant ability to manage plant diseases and can provide an eco-friendly alternative to hazardous conventional methods. Here, we have a comprehensive study on AMPs to identify their role in plant pathogen stress suppression activities and their mode of action. This would surely facilitate a bottomless insight into AMPs' mode of action against pathogen infections. An improved understanding of the mechanism will facilitate the development of the next generation of antimicrobial peptides, potentially employing a multitargeted approach.

Soil is a crucial component for plant growth, as it provides water, nutrients, and mechanical support. Various factors, such as crop cultivation, microflora, nutrient addition, and water availability, significantly affect soil properties. Maintaining soil health is important, and one approach is the introduction of native organisms with multifaceted activities. The study evaluates the effects of introducing these microbes (Trichoderma asperellum strain TAIK1, Bacillus cabrialesii strain BIK3, Pseudomonas putida strain PIK1, and Pseudomonas otitidis strain POPS1) and their consortium, a combination of four bioagents, on soil health, plant growth, and the incidence of stem rot disease caused by Sclerotium oryzae in rice. Upon treatment of soil with the consortium of the four native bioagents mentioned above through seed treatment or soil application, variations/increases in the chemical properties of the soil were observed, viz., pH (8.08 to 8.28), electrical conductivity (EC) (0.72 to 0.75 d S m⁻¹), organic carbon (OC) (0.57 to 0.68 %), available soil nitrogen (SN) (155 to 315 kg/ha), soil phosphorus (SP) (7.87 to 24.91 kg/ha), soil potassium (SK) (121.29 to 249.42 kg/ha), and soil enzymes (urease (0.73 to 7.33 µg urea hydrolyzed g⁻¹ soil h⁻¹), acid and alkaline phosphatase (0.09 to 1.39 and 0.90 to 1.78 µg of p-nitrophenol released g⁻¹ soil h⁻¹), and dehydrogenase (0.14 to 16.44 mg triphenyl formazan (TPF) produced g⁻¹ soil h⁻¹)), compared to untreated soil. Treatment of seeds with the consortium of four native bioagents resulted in a significant increase in plant height (39.16%), the number of panicles (30.29%), and average grain yield (41.36%) over control plants. Under controlled conditions, the bioagent-treated plants showed a 69.37% reduction in stem rot disease. The findings of this study indicate a positive correlation between soil properties (pH, EC, OC, SN, SP, SK, and soil enzymes) and plant growth (shoot and root length, fresh and dry weight) as well as a highly negative association of soil properties with stem rot disease severity. The results suggest that using native bioagents as a management strategy can control stem rot disease and enhance crop productivity, while reducing reliance on chemical management. These findings provide valuable insights into the development of sustainable agricultural practices that maximize productivity by minimizing negative environmental impacts, which promotes soil health, plant growth, and disease management.

Rhizobacteria are vital component of soil–plant interfaces which helps in plant growth responses and disease management. Precisely, the role of biosurfactant production by rhizobacteria in biocontrol mechanisms is underscored. The current study explores the destructive effect of a biosurfactant-producing bacterium Bacillus cereus BS14 on fungal growth under in vitro experiments and showed in vivo reduction of disease severity in pulse crop Vigna mungo. In this study, B. cereus BS14 was observed as plant growth-promoting rhizobacterium (PGPR) based on abilities of production of phytohormone and HCN, phosphate solubilization and biocontrol of Macrophomina phaseolina. The purified biosurfactant from BS14 inhibited the fungal growth by arresting radially growing mycelia. Scanning electron microscope (SEM) study revealed deformities at cellular level in the mycelia of M. phaseolina. The biosurfactant of Bacillus BS14 was identified as cyclic siloxane in GC–MS spectroscopy and FT-IR spectroscopy analyses. In the pot trial studies, B. cereus BS14 proved its efficiency for the growth promotion of Vigna mungo and significantly reduced disease severity index. The present study concludes that biosurfactant of rhizobacterial origin and rhizobacteria can serve for biological control, improvement in crop production and agricultural sustainability. In future, it can be developed as biological control and biofertilizer formulations for legume crops, and commercialized for routine farming practices.