Summary of Foliar Application of Vegetal-Derived Bioactive Compounds Stimulates the Growth of Beneficial Bacteria and Enhances Microbiome Biodiversity in Lettuce
Biostimulants Boost Lettuce Growth and Enhance Microbiome
Many studies on plant biostimulants and organic fertilizers focus on their ability to increase crop productivity and improve tolerance to abiotic stresses. However, few studies examine their effects on plant-associated microbiota, which play critical roles in plant health and development. This study aimed to evaluate three vegetal-derived products—a protein hydrolysate (PH), a copper-enriched PH (Cu-PH), and a micronutrient-enriched tropical plant extract (PE)—for their ability to promote lettuce growth and influence microbial communities.
How Biostimulants Boost Lettuce Growth
Foliar application of these three products significantly increased shoot biomass in lettuce plants. This confirms their strong biostimulant effect. Moreover, the treatments altered the composition of the epiphytic bacterial population. Culture-independent methods, including Terminal Restriction Fragment Length Polymorphism and Next Generation Sequencing, along with culture-dependent approaches, revealed that beneficial bacteria such as Pantoea, Pseudomonas, Acinetobacter, and Bacillus thrived after treatment.
Biostimulants Stimulate Beneficial Bacteria in Lettuce
Some of the bacterial strains enhanced by the biostimulants showed plant growth-promoting traits or biocontrol activity against fungal and bacterial pathogens, including Fusarium, Trichoderma, and Erwinia species. Importantly, the treatments did not increase populations of human or plant pathogenic bacteria, ensuring safety for both crops and consumers.
Synergistic Effects of Biostimulants and Microbiota on Lettuce Productivity
Overall, this study demonstrates that biostimulants boost lettuce growth not only by directly stimulating plant development but also by promoting beneficial bacteria. Signals produced by these microorganisms act synergistically with plant-derived compounds, enhancing lettuce productivity. These findings highlight a promising approach for sustainable agriculture and improved crop performance.
Publication: Frontiers in Plant Science
