Myco-engineered selenium nanoparticles elicit resistance against tomato late blight disease by regulating differential expression of cellular, biochemical and defense responsive genes

•Tomato plants primed with SeNPs induce resistance against late blight disease.•SeNPs-primed plants showed remarkable plant growth promotion.•A significant deposition of callose, lignin and H2O2 was observed in primed plants.•Induced resistant plants triggered biochemical and defense responsive genes.•Myco-engineered SeNPs as a nano-fungicide for crop protection. With the advent of rapid evolution of oomycete pathogen lineages, the need for sustainable agriculture practices has become the need of the hour. The late blight of tomato caused by Phytopthora infestans, has recently emerged as one such devastating disease in India that led to huge crop losses. Hence, in the present work seed priming with mycogenic selenium nanoparticles (SeNPs) for elicitation of resistance against tomato late blight disease is investigated. It also aims to understand the defense responses triggered by SeNPs at cellular, biochemical and transcriptomic levels. Enhanced plant growth parameters were observed in bioactive SeNPs-primed tomato plants as compared to control plants. SeNPs-primed and pathogen inoculated plants exhibited a significant protection of 72.9 % against late blight disease. The primed plants also recorded a remarkable accumulation of lignin, callose and hydrogen peroxide that serve as the cellular defense over the control plants. Further, an elevated level of lipoxygenase (LOX), phenylalanine lyase (PAL), β-1,3-glucanase (GLU), superoxide dismutase (SOD) corroborated the biochemical defense in primed plants, which was also reflected in the corresponding transcriptome profiling of the genes encoding the enzymes. Thus, the present study represents an orchestrated correlation between resistance and defense responses incited by SeNPs against tomato late blight disease, which can be used as nano-biostimulant fungicide in protecting tomato plants.