Rhizobium rhizogenes-Mediated Hairy Root Transformation Protocol for Lotus japonicus and Other Legumes

Rhizobium rhizogenes-mediated hairy root transformation has been extensively applied across various legumes, ranging from model species such as Medicago truncatula and Lotus japonicus to crop legumes like Glycine max and Phaseolus vulgaris. This technique is highly regarded for its simplicity and rapid production of transgenic roots, making it invaluable for studies on gene expression and function, root biology, symbiotic interactions, and metabolic engineering. Consequently, multiple protocols have been developed to optimize its use in legumes. In this chapter, we present a detailed protocol for hairy root transformation in the model plant Lotus japonicus, emphasizing key elements essential for success that can be adapted for use in other legumes.