H3-4 and infection: –Auxin production by rhizobia; ectopic auxin overproduction promotes nodulation–Auxin response (GH3, Aux/IAA, SAUR, DR5) associated to epidermal infections and cortical cell divisions/nodule primordia–A local inhibition of PAT (and PIN gene expression) is associated to rhizobial infections–The symbiotic inhibition of PAT depends on flavonoids and on cytokinins (see below)–ARF16a positively regulates infections in the root epidermis