Genome-wide expression analysis of <i>LBD</i> genes in tomato (<i>Solanum lycopersicum</i> L.) under different light conditions

Lateral organ boundaries (LOB) domain (<i>LBD</i>) genes, a gene family that encodes the transcription factors (TFs) of plants, plays crucial functions in the development and growth of plants. Currently, genome-wide studies of the <i>LBD</i> family are still limited to tomato (<i>Solanum lycopersicum</i> L.), which is considered an important economic crop. In this study, we performed a genome-wide analysis of <i>LBD</i> in tomato. In total, 56 <i>LBDs</i> were found in the tomato genome. Protein alignment and phylogenetic classification showed that <i>LBDs</i> were conserved with other species. Since light emitting diodes (LEDs) light have promising applications for tomato growth. To better understand the potential function of <i>LBDs</i> in response to LED light in tomato, we conducted a genome-wide expression analysis of <i>LBD</i> genes under different light conditions. As expected, different LED lights affected the tomato growth (e.g. hypocotyl length). RNA-seq data showed that eight <i>LBDs</i> in tomato seedlings were differentially expressed under different light treatments, including white, blue, red, and far-red light, compared to the dark-grown condition. It indicates that these <i>LBDs</i> might regulate plant development in different LED light conditions. Interestingly, two <i>LBD</i> genes (<i>SlLBD1</i> and <i>SlLBD2</i>) were found to be differentially expressed in four distinct lights, which might be involved in regulating the plant architecture via a complicated TF network, which can be taken into consideration in further investigation.