Initial analysis of Lactuca sativa seedlings transcriptome under microalgae treatments

The use of new natural eco-sustainable products is becoming an interesting option in order to reduce the use of chemical fertilizers and increase crop yields. Seaweed extracts have gained major attention as plant biostimulants due to their positive effect on plant-growth as well as on improving plants’ tolerance against abiotic stresses. Among the horticulture crops, lettuce (Lactuca sativa L.) is a major fresh vegetable crop in the Mediterranean area, which often requires the use of natural biostimulants to improve both the quantity and quality of production. The aim of this work was to assess the effect of either Chlorella vulgaris or Scenedesmus quadricauda extracts on lettuce seedlings (Lactuca sativa L.) by motoring the induced transcriptomic modifications using a RNA-seq approach. The results showed that both C. vulgaris and S. quadricauda extracts positively influence the growth of lettuce seedlings. However, a higher reprogramming of the gene expression occurred in the case of C. vulgaris treatment than in the case of S. quadricauda. Considering the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway functional enrichments, the main KEGG terms are in the “Biosynthesis of secondary metabolites”, “Metabolic pathways”, “Carbon metabolism” and “Biosynthesis of amino acids” categories. This study lays the basis for understanding the mechanisms and processes triggered by the use of microalgal extracts, which can represent an easier-to-handle and cheaper method for an eco-sustainable cultivation of lettuce plants than the application of chemicals.