Fig. 3

Functional analysis of chimeric receptors in L. japonicus can provide information on ligand-induced dimerization of LysM protein ectodomains (EDs). Indicated chimeric proteins were expressed in roots of ecotype MG-20 and Nod factor receptor gene mutants. Co-transformation of the NINp-GUS construct provided an estimate for NIN gene expression. Prior GUS staining, roots were treated with sterile water, 1 μM chitoheptaose [(GluNAc)₇] or 10 μg/mL chitin for 4 h. a Roots co-expressing LYK1^ED–NFR1^ID with LYK5^ED–NFR5^ID showed blue coloration upon treatment with chitoheptaose or chitin. b Co-expression of LYK1^ED–NFR1^ID with LYK1^ED–NFR5^ID resulted in weak blue coloration when roots were treated with chitin. c No blue coloration was observed for the combination LYK1^ED–NFR1^ID with LYK4^ED–NFR5^ID. Bars = 0.8 cm