In a groundbreaking study published in the journal *Frontiers in Plant Science* (formerly *Frontiers in Microbiology*), researchers from Kerala Agricultural University have unveiled a novel approach to combating a wide range of plant diseases using green-synthesized nanoparticles derived from beneficial bacteria. The study, led by Dr. A. Mary Sharmila from the Department of Plant Pathology at the College of Agriculture in Vellayani, Kerala, demonstrates the potential of *Bacillus amyloliquefaciens* 8SE-IF1 (Ba-8SE-IF1) to produce antimicrobial compounds that can be transformed into nanoparticles to protect tomato plants from devastating pathogens.
The research focuses on the green synthesis of nanoparticles (Gs-NPs) from water-diffusible antimicrobial metabolites (WDM) produced by Ba-8SE-IF1. These nanoparticles have shown remarkable efficacy against a variety of phytopathogens, including oomycetes, fungi, bacteria, and viruses that infect tomato plants. The study highlights the significant inhibition of mycelial growth in several pathogens, such as *Pythium aphanidermatum*, *Phytophthora nicotianae*, *Fusarium oxysporum* f. sp. *lycopersici*, and *Colletotrichum gloeosporioides*, as well as the reduction of symptoms caused by *Tomato spotted wilt virus* (TSWV) and *Tomato leaf curl New Delhi virus* (ToLCNDV).
Dr. Sharmila explained, “The water-diffusible extract (WDE) of Ba-8SE-IF1 contains a rich array of antimicrobial compounds. Our analysis identified 26 major organic compounds with antimicrobial properties, including phenols, carboxylic acids, alcohols, and aliphatic hydrocarbons. Notably, five compounds exhibited simultaneous activity against oomycetes, fungi, bacteria, and viruses.”
The study further demonstrates the green synthesis of zinc oxide nanoparticles (Gs-ZnO-NPs) from the WDM of Ba-8SE-IF1. These nanoparticles, even at low concentrations, drastically reduced the growth of various pathogens and the symptoms they cause in tomato plants. “The Gs-NPs at 100 ppm significantly reduced the incidence of bacterial wilt caused by *Ralstonia solanacearum* to less than 10%, compared to more than 60% in control plants,” Dr. Sharmila noted. “Additionally, the nanoparticles promoted plant growth, enhancing height, number of branches and leaves, leaf area, and shoot and root biomass.”
The implications of this research are far-reaching for the agricultural sector. The use of green-synthesized nanoparticles offers a sustainable and eco-friendly approach to plant disease management, reducing the reliance on chemical pesticides and fertilizers. This innovation could lead to increased crop yields and improved plant health, ultimately benefiting farmers and consumers alike.
Dr. Sharmila emphasized the broader impact of their findings: “This study opens up new avenues for the development of multifunctional biopesticides and plant growth promoters. The simultaneous control of multiple pathogens with enhanced growth traits in tomato plants is a significant advancement in the field of plant pathology.”
As the global population continues to grow, the demand for sustainable and efficient agricultural practices becomes increasingly critical. The research conducted by Dr. Sharmila and her team at Kerala Agricultural University represents a promising step forward in addressing these challenges. By harnessing the power of beneficial bacteria and green-synthesized nanoparticles, the agricultural industry can move towards a more sustainable and productive future.
This study not only highlights the potential of *Bacillus amyloliquefaciens* and its derivatives but also paves the way for further research into the use of microbial metabolites for plant disease management. As the scientific community continues to explore these avenues, the agricultural sector can look forward to innovative solutions that promote sustainable and efficient crop production.