Subcellular localization of SlAGO proteins in BY2 protoplasts. Plasmid harboring CaMV 35S:SlAGOs-GFP tag were transformed into BY2 cell. (A) Two types of localization of SlAGO proteins. Type 1 localized to membrane of cytoplasm and nucleus; Type 2 localized to cytoplasm and nucleus. More localization of SlAGO proteins were listed in Additional file 7. (B) Different subcellular localization of AGO1B in different cells. Type 1 localized to nucleus; Type 2 localized to membrane of nucleus; Type 3 localized to cytoplasm and nucleus. (C) Different subcellular localization of AGO4D in different cells. Type 1 localized to cytoplasm and nucleus; Type 2 localized to ring structure in nucleus. (D) Subcellular localization of AGO1A and AGO1AMUT. (E) Site mutation strategy of SlAGO1A at complimentary sequences to mature SlmiR168. Red letters in AGO1AMUT sequence stand for mutation sites. Blue letters were amino acids coded in the open read frame. (F) Strategy for recombination of SlAGOs:GFP. The scale indicates 5 μm. (G) Resistance test of SlAGO1AMUT in transgenic plant. 1#, 2#, 3# were individual transgenic plants of SlAGO1AMUT; SlAGO1A was transgenic plant of SlAGO1A; WT was wild type micro-TOM.