Although the history of plant hormone research is less than 100 years old, the history of plant hormones spans hundreds of millions of years. In recent years, the advent of advances in genome analysis tools such as next-generation sequencers and CRISPR genome editing has led to rapid progress in phytohormone research in early-diverging land plants, including bryophytes and algae. This led to the accumulation of knowledge about the origin and evolution of phytohormones.
The functioning of plant hormones requires the matching of hormone substance production, reception, and signal transduction. Previous studies have shown that the establishment of plant hormone action during evolution is diverse for each plant hormone. In addition, it is becoming clear that ligand specificity and diversity of receptors have been acquired during evolution. The diversification of signal transduction systems has led to the diversification of actions, which has led to the establishment of elaborate mechanisms controlling plant growth and development.
