With respect to AM fungal infection, it is interesting to note that two of the 37 Myc-related and 14 of the 50 Sym-related genes activated by nsMyc-LCOs are up-regulated in regions containing early infection structures and hyphopodia (APP, [30]) or in arbuscule-containing cells (ARB, [30], Additional file 2: Table S2), while 12 and 22 were activated in whole AM roots, respectively ([28], Additional file 2: Table S2). This evidence concerns the gene SYMPK and infection.