Multidimensional gene regulatory landscape of motor organ pulvinus in the model legume Medicago truncatula

Nyctinastic leaf movement of Fabaceae is driven by the tiny motor organ pulvinus located at the base of leaf or leaflet. Despite the increased understanding of the essential role of ELP1 orthologs in determining organ identity, key regulatory components and molecular mechanisms underlying this movement remain largely unclear. Here, we used WT pulvinus and the equivalent tissue in elp1 mutant to carry out transcriptome and proteome experiments, and the omics data indicated that there are multiple cell biological processes altered at gene expression and protein abundance level during the pulvinus development. In addition, comparative analysis of organ specific transcriptome from different leaf tissues provided clues to illuminate the origin of pulvinus and signaling pathways of leaf movement. Furthermore, mutants of clock gene MtPRR5 confirmed its function in the leaf movement, meanwhile auxin signal played in important role in pulvinus development. By the way, molecular and histochemical results confirmed lots of cell wall and photosynthesis related genes are involved in the pulvinus development. This study provides a comprehensive insight of the nyctinastic movement, further supplies a rich dataset to facilitate the identification of novel players involved in nyctinastic movement.