Power of seeds: exploring the growth boosting potential of endophytes

Insect pests on agricultural crops cause biotic stress, resulting in enormous yield losses. Nowadays, microbial insecticides for insect pests have been explored to overcome insect resistance and environmental hazards caused by chemical insecticides. Bacillus thuringiensis (Bt) is known as the most successful microbial insecticide globally, but its commercial application is limited due to its vulnerability to abiotic factors. To overcome these factors, the establishment of Bt as an endophyte in maize plants by seed treatment has been proposed. So, for that reason, the present study aimed to investigate the effect of seed endophytic bacteria in maize on Bt isolates and vice versa. Furthermore, the study was also carried out to assess the antibiotic resistance of these bacteria as well as their role in plant growth promotion. A total of 12 maize seed endophytic bacterial isolates were used for this study. In that, seven isolates belong to the Bacillus genus, two to the Staphylococcus genus, and one each from Paenibacillus, Pantoea, and Enterobacter. No antagonistic effect of seed endophytes was observed against Bt strains. Five isolates had the ability to solubilize phosphate and potassium, seven showed zinc solubilization, and all the isolates showed nitrogen fixation ability. Thus, these seed endophytic bacteria can be explored as potential bio-inputs for improving plant growth, and their harmonizing effect on Bt has been found to be promising for the establishment of Bt as an endophyte in maize plants

Differential Activities of Antioxidant Enzymes, Superoxide Dismutase, Peroxidase, and Catalase vis-à-vis Phosphine Resistance in Field Populations of Lesser Grain Borer (<i>Rhyzopertha dominica</i>) from India

Susceptibility to phosphine was compared in 15 populations of lesser grain borer (Rhyzopertha dominica) collected from grain storage godowns across India. A high level of resistance to phosphine was noticed in R. dominica collected from northern India compared to those collected from northeastern regions of India. The median lethal concentration values varied from 0.024 mg/L to 1.991 mg/L, with 1.63 to 82.96-fold resistance compared to laboratory susceptible checks. Antioxidant enzymes have been reported to negate the reactive oxygen species generated upon encountering the fumigant phosphine. Distinct differences in the activity of antioxidant enzymes were noticed in the field populations exposed to phosphine. Peroxidase activity varied between 1.28 and 336.8 nmol H2O2 reduced/min/mg protein. The superoxide dismutase inhibition rate was between 81.29 and 99.66%, and catalase activity varied between 6.28 and 320.13 nmol H2O2 reduced/min/mg protein. The findings of our investigation show that the activities of peroxidase and superoxide dismutase are positively linked (p 2•−, H2O2,•OH) associated with tolerance to phosphine in R. dominica.</i

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Not AvailableThrips palmi (Thysanoptera: Thripidae) is the predominant tospovirus vector in Asia-Pacific region. It transmits economically damaging groundnut bud necrosis virus (GBNV, family Tospoviridae) in a persistent propagative manner. Thrips serve as the alternate host, and virus reservoirs making tospovirus management very challenging. Insecticides and host plant resistance remain ineffective in managing thrips–tospoviruses. Recent genomic approaches have led to understanding the molecular interactions of thrips–tospoviruses and identifying novel genetic targets. However, most of the studies are limited to Frankliniella species and tomato spotted wilt virus (TSWV). Amidst the limited information available on T. palmi–tospovirus relationships, the present study is the first report of the transcriptome-wide response of T. palmi associated with GBNV infection. The differential expression analyses of the triplicate transcriptome of viruliferous vs. nonviruliferous adult T. palmi identified a total of 2,363 (1,383 upregulated and 980 downregulated) significant transcripts. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed the abundance of differentially expressed genes (DEGs) involved in innate immune response, endocytosis, cuticle development, and receptor binding and signaling that mediate the virus invasion and multiplication in the vector system. Also, the gene regulatory network (GRN) of most significant DEGs showed the genes like ABC transporter, cytochrome P450, endocuticle structural glycoprotein, gamma-aminobutyric acid (GABA) receptor, heat shock protein 70, larval and pupal cuticle proteins, nephrin, proline-rich protein, sperm-associated antigen, UHRF1-binding protein, serpin, tyrosine–protein kinase receptor, etc., were enriched with higher degrees of interactions. Further, the expression of the candidate genes in response to GBNV infection was validated in reverse transcriptase-quantitative real-time PCR (RT-qPCR). This study leads to an understanding of molecular interactions between T. palmi and GBNV and suggests potential genetic targets for generic pest control.Not Availabl