Transcriptome analysis reveals differentially expressed genes (DEGs) related to lettuce (Lactuca sativa) treated by TiO2/ZnO nanoparticles

The widespread use of nanomaterials raises concern over their effects and roles in plants. Many researches have proved that nanoparticles could promote the growth and development of plants, so as our previous experiments in lettuce. However, the molecular regulation mechanisms involved in the lettuce treated by nanoparticles remain largely unknown. Herein, a cDNA library of lettuce (Lactuca sativa) leaf and root in the middle growth stage (25th day after transplanting) was constructed. Approximately 10.4 GB clean reads were obtained, and a total of 36919 unigenes were formed by initial sequence splicing, with an average read length of 897 bp. 29136 unigenes (78.92%) were annotated based on at least one database. 509 genes were identified as differentially expressed genes (DEGs) in leaf treated by nanomateials, which comprised 223 up-regulated genes and 286 down-regulated genes, while 3666 genes were identified as DEGs in root, which comprised 844 up-regulated genes and 2822 down-regulated genes. Hundreds of genes potentially involved in nanoparticles were identified from these DEGs, including the genes related to photosynthetic metabolism, antioxidant enzymes, nitrogen metabolism and sucrose and starch metabolic pathways. Ultimately, a preliminary regulatory mechanism of growth and development of lettuce treated by TiO2/ZnO nanoparticles was proposed based on transcriptome analyses and published documents.