Figure 4.20 Arabidopsis root-inhabiting bacteria are detectable on the rhizoplane. a–e, Scanning electron micrographs of bacteria-like structures. Bars, 1 mm. f–j, Detection of bacteria by fluorescence in situ hydridisation (FISH) using probes against specific bacterial groups (bacteria in green due to AlexaFluor488) on the root surface (red, root autofluorescence) by confocal laser scanning microscopy. f, Most Eubacteria detected with probe EUB338. g, negative control with reverse complementary probe of EUB338 (NONEUB). h, Betaproteobacteria detected with probe BET42a. i, Bacteroidetes detected with probe CF319a. j, Actinobacteria detected with probe HGC69a. Bars, 20 mm. (Reproduced by permission from Macmillan Publishers Ltd from D. Bulgarelli D et al., Nature 488: 91-95, 2012)